WORLD HEALTH ORGANIZATION vBc/90.2 MAUgO.2 ORGANISATION MONDIALE DE LA SANTE ENGLISHONLY @ Distr.:LIMITED
VECTORBIONOMICS IN THE EPIDEMIOLOGYAND CONTROL OF MALARIA
PARTII
THEWHO EUROPEAN REGION AND THEWHO EASTERN MEDITERRANEAN REGION
APPLTE[oiHlFJtuDrES
SECTIONltl: VECTORBIONOMICS, MALARIA EPIDEMIOLOGY ANDCONTROL BY GEOGRAPHICALAREAS
(A)THE MEDITERRANEAN BASIN
PREPAREDBY A.R.ZAHAR DISTR.: LIMITED WORLD HEALTH ORGANIZATION DISTR.: LIMITEE
ORGANISATIONMONDIALE DE LA SANTE vBc/ 90 .2 @ MAL/90.2 ENGLISHONLY
VECTORBIONOMICS
IN
THE EPIDEMIOLOGY AND CONTROL OF MALARIA
PART II
TI{E WIiO EUROPEANREGION
&
THE WIIO EASTERNMEDITERRANEAN REGION
VOLI]MEII: APPLIEDFIELD STUDIES*
SECTIONIII: vEcToRBroNoMrcs, MALARTAEPTDEMIoLOGY AND CONTROLBY GBOGMPTTICALAREAS
(A) TI1EMEDITERRANEAN BASIN
PREPARED BY A.R. ZAITAR FORMERWHO ENTOMOLOGIST
* Literature search ceased at the end of December 1989
This document is not issued to the generalpublic, and Ce documentn'est pas destind d Otredistribu6 au grandpublic all rights are reservedby the World Health Organization et tous les droits y affdrentssont r6servispar l'Organisation (WHO). The document may not be reviewed, abstracted, mondiale de la Sant6 (OMS). ll ne peut Ctre commentd, quoted, reproduced or translated, in part or in whole. rdsumd,citi, reproduitou traduit,partiellement ou en totalitd, without the prior written permissionof WHO. No part sansune autorisationprdalable icrite de l'OMS.Aucune partie of this document may be stored in a retrieval system or ne doit Otrechargde dans un systdmede recherchedocumen- transmitted in any form or by any means - electronic, taire ou diffus6esous quelque forme ou par quelquemoyen mechanicalor other without the prior written permission que ce soit dlectronique,m6canique, ou autre - sansune of WHO. autorisationprdalable dcrite de l'OMS.
The viewsexpressed in documentsby namedauthors are solely Les opinionsexprim6es dans les documentspar des auteurs the responsibilityof thoseauthors. citdsnommdment n'engagent que lesditsauteurs. vBc/90.2 MAL/90.2 Page 2
VOLIJMEII APPLIEDFIELD STUDIES(conrd)
SECTIONIII: VECTORBIONOMICS MALARIA EPIDEMIOLOGYAND CONTROLBY GEOGMPHICALAREAS
(A) THE }TEDITERRANEANBASIN
DETAILED TABLE OF CONTENTS
Page
INTRODUCTION (+
ADDI T IONA]. ACKNOWLEDGEI'IENTS 6 Subsection (i): VECTORBIONOMICS r0
1. The An. naculipennis complex J.U
1.1 Vector inportance 10 L.2 Breedlng hablrar 10 1.3 Swarning and natlng 19 I.4 Dispersal 19 1.5 Local spatlal and seasonal distribulion 20 1.6 Resting behavlour & 1.7 Bitlng behaviour 35 1.8 Sanpling of nosqultos in flight 41 1.9 Host feeding patrerns 47 1.10 Longevity 49 1.11 Natural infection 51 1.12 Vector resistance to lnsectlcides 54
2. An. superpictus and An. sergentil 57
2.1 Vector lmportance >t 2.2 Breeding habirat 58 2.3 Swaming and naclng 64 2.4 Dispersal 64 2.5 Local spatial and seasonal dlstributlon o) 2.6 Resting behaviour e 2.7 Biting behaviour 74 2.8 Sanpling of nosqulros iu flight 2.9 Host feeding patterns 2.10 Longevity 79 2.11 Natural infection t9 2.12 Vector resistance to insectlcldes 80
3. An. pharoensis 81
3.1 Vector importance 8l 3.2 Breeding habitat 81 3.3 Swarning and nat.ing 83 3.4 Dispersal 83 3.5 LocaL spatial and seasonaL distrlbutlon 84 3.6 Resting behaviour & 3.7 Biting behaviour 85 3.8 Sanpling of nosquiros in fllght 89 3.9 Host feeding parterns 90 3.10 Longevity 92 3.11 Natural infection 94 3.12 Vector reslstance to lnsectlcides 95 vBc/90.2 r4Ar./90.2 Page 3
Page
Secondary and suspected vectors 95
.+.I An. hyrcanus group 95 4.2 An. claviger s.1. 97 4.3 An. hispaniola 101 4.4 An. drthall ro2 4.5 An. multicolor LO2
Subsectlon (ii): EPIDEMIOLOGYAND CONIROL0F MALARIA r05
1. Epideniological studies and control operations 105 2. Resistance of P. falciparun to chloroqulne in the Mediterranean Basin 163 3. llalaria and its concrol ln water resources and other development projecEs 164 4. Alternative nethods of control 190 5. Connunity participation 196
CONCLUSIONS:SECTION III(A) 198
SELECTEDREFERENCES 205
ANNEX1: SELECTEDREFERENCES ON ,MALARIAQUAI{TITATIVE EPIDBI"IIOLOGY 224
ANNEX2: ABBREVIATIONS 226 vBc/90.2 r[AL/90.2 Page 4
INTRODUCTION
ThC SeTiES of PART II of VECTORBIONOMICS IN THE EPIDEMIOLOGYAND CONTROLOF MALARIA
Docurnent VBC/88.5-MAP/88.2 (issued in November 1988): VOLUMEI: VECTORLABORATORY STUDIES
Docunent VBC/90.1-}{AL/90.1 (issued in April 1990): VOLUMEII: APPLIEDFIELD STUDIES
SECTIONI: AN OVERVIEWOF THE RECENTMALARIA SITUATION AND CURRENTPROBLEMS SECTIONII: VECTORDISTRIBUTION
Docunent VBC/90.2-ML/90.2 (the present document issued in May 1990)
SECTIONIrI.. VECToRBIoNOMTCS, MALARIA EPIDEMIOLOGY Al.lD CoNTRoL BY GEOGMPHICALAREAS (see Fig. 1)
(A) THE MEDITERRANEANBASIN
Docunent VBC/90.3-l{ALl90. 3 (in prepararion)
SECTIONIII: VECToRBIONOMICS, MALARIA EPIDEMIOLoGY AND CoNTRoL BY GEOGMPHICALAREAS (see Fig. I)
(B) ASIA WESTOF INDIA
The same set of principles and the system shown in the PREFACEof VOL. I (pp. 6-10) have been observed when compillng inforrnation in VOL. II, wlth some nodi.ficat.ions.
It should be enphasized that when new infonnation is not available, resort is nade to old knowledge to provide a background on the basis of which nener studies can be planned. Furthennore, depending on the availability of published or unpublished reports, the type and depth of infornation conplled uay vary from country to country.
Where aPProPriate, it has been necessary to refer to the knowledge conpiled in the ..THE SETies of PART I I.JHOAFRICAN REGIONAND THE SOUTTIERNWIIO EASTERN }IEDITERRANEAN REGION". The serles of documents of this part has been llsted in ANNEXI in VOL. I.
As mentioned in the PREFACEOF VOL. I, results of the recent precipitin tests for the period 1971-1978 are quoted frou the data annexed to the review of Garrett-Jones, Boreham & Pant (1980)r. Regarding vector resist.ance to j.nsecticides, records are quoted from the lists conpiled in the reports of the WHOExpert Conmittees of Vector Biology and control respectively, (wHo, 1980 - TRs. No. 655, and l,Illo, 1986 - TRS: No. 737). More recent infornatlon is added from reports of susceptibillty tests cornnunicated to WHO/VBC by field invectigators i.n several countries durlng Lg}4-LggB2
Infornation on the recent nalaria si.tuation by country are obtained roainly fron WHO publications and data communicated to WHO/MAPby the WHORegional Offices (E}IR0 and EURO).J Additionally, country profiles constructed in a document entitled "Regional Malaria Information" by Dr G.A. Farid, WHORegional I'lalarla Adviser, E!1R0, are used for inforoation on countries of that Region.q Records of chloroquine resistance in P. falciparurn in the Regions under review as mapped by WHOare reproduced. Inmunological studies of malaria are beyond the scope of this conpilatlon, but seroepidemiological surveys as part of nalaria epideniological studies are suumarized.
1. Perroissj-on to quote these data was granted by the late Dr C. Pant and the Commonwealth Institute of Entouology (Dr J.M.B. Harley) in April 1983. 2. A conputer printout of these reports was provi.ded through the cooPeration of Mr G. Shidrawi, VBC/VCT. 3. Copies of these data were provided through the cooperation of Mr J. Henpel, l"lAP/El,tE. 4. Pernission to use information contained in this docunent was granted by the Regional Director, WHO/EMRO,Alexandria. vBcl90.2 t4aL/90.2 Page 5
Due to language problens, i! has not been possible to summarize adequately infornation published j-n Russian in the USSR. However, it was useful to find articles writt.en in English by certain Soviet workers in the proceedings of a seminar entitled "International Scientific Project on Ecologically Safe Methods for Congrol of l"lalaria and its Vectors" published in l4oscow(1980) - lCotiected lecrures, Parrs 2 e:;.1 From rhese publications, certain articles have been sunmarized or a brief orientatlon Eo their contents has been made in the present issue.
At the end of this docunent, selected references are listed. Since the ain of this series is to assist newly assigned nalaria workers to trace lhe source of infornation on their oldn or adjacent countries of sinilar conditions, the references are arranged by country in alphabetical order. At the top of the list, references dealing wlth subjects of general nature or coverlng several countries are placed first.
As nentioned in the PREFACEof VOL. I, it is inpossible to define adequately the mathenatical terms used by some authors ln a reasonable space. Orientation to the relevant literature to be consult.ed is shown in ANNEX1 in this document.
Someabbreviations have been used in this docunent, the glossary appears in ANNEX2.
It is necessary to reiterate that literature search was made through screening the abstracts published in the Tropical Disease Bulletin (TDB) of the Bureau of Hygiene and Tropical Medicine, London, [IK, and the Review of Applied Entooology (RAn), Series B, of the Conmonwealth Instltute of Entornology, London, Ut<. Tne efforti-nade by these institutions are fully acknowledged and greatly appreciated.
It should be explained that the preparation of this document was at the final stages in December 1989 before the disestablishnent of the Division of Vector Biology and Control (VBC) and the Malaria Actlon Progranrne (MAP). Therefore, it has been decided to retain ln the text the designation of the o1d unlts of VBC and MAP to whLch the WHOofficers who contrlbuted to this document were formerly asslgned. However, the names of these 0fficers are arranged in the Additional Acknowledgenents accordlng to their posts in the units of the new set up: Divislon of Control of Tropical Diseases (CTD).
1. Copies have been provided through the cooperation of Dr R.L. Kouznetsov, }IAP/PAT. vBc/90.2 r4AL/90.2 Page 6
ADDITIONALACKNOWLEDGEMEN]:S
In addition to the Acknowledgenents shonn in V0L. I (cocunenr VBC/88.5 - l,lAP/88.2) grateful thanks are expressed to the following colleagues in various institutions and WHO for their valuable contribution to the present and precedi.ng issues, and to authors and copyright authorities for granting permi.ssi.onto reproduce illustracions and/or data from published papers:
Prof. Eroeritus G. Davidson, former Director of the Department of Entonology, London School of Tropical Medicine & Hygiene, for his conti.nued interest in the series and for his explanation of aspects relaced to vector resistance to insect.icides and speci.es complexes.
!1r N. Eshghy, c/o School of Public Health & Institute of Publlc Health Research, University of Teheran, for providing explanations of the behaviour of certain vectors in lran, as well as maPSof and notes on the distribution of vectors of nalari.a and the malaria situation in certain areas of the country.
Dr N.G. GtaEz, former Direclor of VBC, for hls continued interest and for providing advice on relevant papers of certaln topics and on malaria in water-resources projects, from his computer-stored literature.
Dr I.A.H. Isnail, former I{H0 Entonologist, VBC, for providing coples of oaps of anopheline distribution while working ln VBC.
Prof. H. Kasap, Head of the Department of Medical Biology, Faculty of Medecine, University of Chukurova, Adana, Turkey, for providing reprints and sunrnaries of published studies or Papers (in press) on Dalaria vector bionomics in Turkey.
The efforts of Mrs Marianne King, forner WHOTechnical Officer, VBC, in indexing literature, editlng and correcting the present text are gratefully acknowledged and fully appreciated.
Dr A. Marchi, Istituto di Biologia Generale, Universiti di Cagliari, Sardinia, Ita1y, for providing a reprint of studies on the seasonal distributlon and relative abundance of nosqui.los ln the Cagliari area.
Dr D. Muir, forner WHOEntonologlst, MAP, for his explanation of probleos encountered in nalaria control ln certaln countries and for providing copies of his assi.gnroentreports.
Dr F. Oddo, former WHOllalariologisL, for exp.laining the problen of imported rnalaria in relation to receptivity and vulnerability of nalaria in Italy, and for translating parts of several papers rdritt,en in ltalian as shown in the text. r'lr C.D. Ransdale, forner WHOlechnical Officer, for providing an advance copy of the ianuscript of his paper on "Anopheles Mosquitoes and Inported }lalaria in Libya", and for ;ranting pernission to reproduce a oap of Libya and for exchanging views and redrawing t.he oap of Libya and the nap of seasonal populatlon Dovement in Turkey.
Prof. A. Sabatini, Laboratorio di Parassitologia, IsEltuto Superiore di Saniti; and Prof. M. Coluzzi, Istj.tuto di Parassitologia, Universiti "La Sapienza", Roma, for providing an abstract in advance of their publication on An. superplctus in ltaly.
Dr M.W. Service, Departnent of Medical Entonology, Liverpool School of Tropical Medicine for his interest in the whole series to be included ln his publicatlons.
Dr A. Soith, former WHOEntonologist, for providing a copy of his Chapter with Dr I.D. Carter in "International Transportation of Mosquitos of Public Health lmportance"
Dr G. Vassiliou, Benaki Phytopathological Institute, Kiphissla-Athens, Greece, for providing a reprint of the paper on the toxic effects of insecticide air-spray on nosqulto-fish in Greece. vBc/90.2 r.rAL/90.2 Page 7
To authors and/copyright authorities (as shown in the text), thanks are expressed as follows:
Dr J.D. Allen, Promotions Controller, for C.A.B. International, Oxon, UK, for pernission to use certain abstracts froo the RAE.
Prof. P. Anbroise-Thomas, Serviee de Parasltologie, Centre Hospitalier Regional et Universitaire de Grenoble, France.
Dr S. Belazzoug, Redacteur en Chef, Instit.ut PasEeur drAlg6rie.
Dr E.H. Benzerroug, Division du paludisme et des naladies parasitaires, Institut Nationa- de Sant,6 Publique, Alger./Or f. Rodhain, Unit6 drEcologie des SystEnes Vectoriale, for Institut Pasteur, Paris, France. ALso thanks are due to Dr Benzerroug for granting permlssion to use information contai.ned 1n the report of the lvlinlstry of Public Health, Algeria to the R6union Intermaghr6bine de Coordination des Activit6s Antipaludiques. Alger, 4-6 d6cenbte L973.
Dr Carolyn A. Brown, Editor,/Assistant DirecEor, Bureau of Hygiene and Tropical Medicine, London, U.K., for pernission to reproduce certain abstracts fron the TDB.
The late Prof. L.J. Bruce-Chwatt, for glving permission to use infornation from his various publications.
Prof. A. Chadli, former Dlrector of the Pasteur lnstitute of Tunisia/Prof. Ag.K. Dellagl, Institut Pasteur, Tunis.
Dr S. El-Said, Principal Investigator, Research & Training Center on Vectors of Diseases, Aln SharnsUniversity, Abbasia, Cairo, Egypt/Dr Ronald A. Ward Editor Journal of the American Mosquito Control Associatlon, Washington, USA. l'1r N. Eshghy/Tropical Geographical Medlcine, Ansterdam, the Netherlands.
Dr l'1.A. Farid, former WHOllalariologlst/Ms l,tarEha Strassberger, Rlghts and Permissions, Acadeoic Press, Orlando, Florida, USA.
Dr A. Gebreel, Regional Mviser for Coordinat.ion, IrlHO,EIlRO/Annals of Tropical Medicine and Parasitology, Llverpool School of Tropical Medicine, UK.
Prof. A. Lavagnino, Istituto Drlgiene "Gi.useppeDrAlessandro", Universlti di Palermo, Sicily, Iraly.
Dr E. Onori, forner WHOl4alariologist, Via de1 Gueba 9, Rome, Italy.
The late Dr C.Pant/Dr J.M.B. Ilarley, the Connonwealth Institute of Entooology, London, UK.
Mr C.D. Ransdale, foruer WHOTechnical Officer/Dr John R. Baker, Editor, Transactions of Ehe Royal Society of Troplcal t"ledicine & Hygiene/Prof. D.G. Bradley, Editor, Journal of Tropical l'ledicine & Hygiene.
Dr M.W. Servlce/BlackweLl Scientific Publications Linlted.
Prof. Laura Valentino, Universita di Palermo, Istituto drlgiene "Guiseppe DtAlessandro", Sicily, Italy. wHo/EMRo,Alexandria
Thanks are expressed to Dr 14.H. Wahdan, Director of Disease Prevention and Control, for granting pernission on behalf of the Regional Dlrector to use inforoation cootained in unpubli.shed reports of WHOAdvi.sers and Consultants as showa in the reference li.st. Thanks are also extended to Dr G.A. Farld, Regional Malaria Adviser for providing copies of these rePorts. vBc/90.2 rlAL/90.2 Page 8
WHO/EURO,Copenhagen
Thanks are expressed to Dr B. Bytchenko, Regional Officer for ConrnunicableDiseases, for granting pernission on behalf of the Regional DirecEor to use information contained in unpublished reports of WHoAdvisers and Consultants as shown in the reference list.
WH0, Geneva
Division of Control of Tropical Dlseases (CTD)
The wri.ter is grateful to Dr N.A. Najera, Director of CTD, for his continued interest and most useful di.scussions regarding the effects of environmental changes on malaria, and for providing the latest infornation on inported nalarl,a and literature on malarla in water-resources projects.
Grateful thanks are expressed to colleagues in certain units of the Division for their valuable contribution to the present work as follows:
Directorts Office
Dr N. Rishikesh, Entonologist, for providing infornation on certain techniques currently being developed.
Inf ormatlon Documentation
l'1r J. Hempel, Technlcal Officer, for providing coples of data on inported nalaria and on the malaria situatlon 1n countries undertaking antinalaria activities as communicated by the WHORegional Offices (EMRO& EURO)as well as relevanr tables and maps as shown in the text.
Mrs P. Duchesne, Assistant (Library) by providing coples of assi.gnment reports of WHO Advisers/Consultants and certain publlcations.
Operational Research (OPR)
Dr L. l'lolineauxr Chief OPR, for his briefing on discussions in the recent Deeting of International Travel Medicine.
Ms F. Lebtahi, Technical Officer, for explalning the eeological conditions in the Saharan oases of Algeria in relation to the risk of lntroduction of the An. ganbiae coroplex.
Dr J.A. Rozendaal, AssociaEe, for advlsing on proposed inpregnated-nets trials in the present geographical area.
Training (TDT)
Dr P.F. Beales, Chief TDT, for providing copies of the hrorking papers of the 19th Expert Conmittee on Malaria, Novenber 1989.
Dr R. Kouznetsov, I"tedical Officer, for his cooperation in explaining the situation of inported ualaria in relation to the receptivity and vulnerability of nalarj.a in the USSR, for providing copies of the proceedings ruentioneci in the INTR0DUCTION,and for translating parts of several papers written in Russian as shown in the text.
I'1r G. Shidranj.r Entomologlst, for providing cooputer printouts of the results of computerized reports of susceptibllity tests cotrmunicated to WtlOduring 1984-1988, and for useful discussions on aspects related to vector resistance to insecticides.
Malaria Control (MAL)
Dr E.B. Doberstyn, Chief MAL, for arranging the revision of the present doculents. Dr P. Herath, Entomologist, for constructively revising SECTIONSI, II & III(A) of the Present docuuen!s. vtsc/90.2 IIAL/90.2 Page 9
Filariasis Control (FIL)
Dr R. Le Berre, Chief FIL, for his help in translating parts of a paper on testing blood donors for nalaria in France as shown in the text.
Dr A.B. Knudsen, Entonologist, for providing a draft report on impregnated bed-net t ri.a1s.
Division of Environrnental Health (EHE)
The writer is graEeful to Dr R. Slooff, former Director VBC, for his continued interest and most helpful suggestions as work progressed including Ehe demarcation of the present. geographical area on a ulap, and for commenting on certain points in the present text.
Thanks are expressed co Mr R. Boss, Scientist, for providing certain report.s related to malaria in water-resources projects.
WHOLIBRARY
Thanks are extended to the library staff (notably Mr B. Eionda) for securing copies of publications and books on tenporary loan that are not available in the WHOLibrary.
GRAPHICS
Thanks are expressed to the staff of this servi.ce for their efforts in producing several maps shown in the present text.
DUPLICATING& BINDING
Thanks are due to this servj.ce for expeditiously processing the various documents of this series with utnost accuracy. vBc/90.2 t4AL/90.2 Pagel0
SECTION III: VECTORBIONOMICS AND MALARIA EPIDEMIOLoGYAND coNTRoL BY GEOGMPHICALAREA
(A) THE }'IEDITERMNEANBASIN (Fie.1)
Thi.s area 1s bounded on the north by a group of countries of Mediterranean Europe: from west to east: Spain, France, Italy, Yugoslavia, Albani.a, Romania, Bulgaria, the USStt close to the tslack Sea, Greece and Turkey (with Mafta added to this group); and ln the south by countries of the North African coastr' frorn west to east: llorocco, Algeria, Tunisj.a, Libya, and Egypt; and in the east by: Syria, Lebanon, Israell and Jordan with Cyprus added to this last group.
Subsection (i); VECTORBIONOMICS
The nain vectors of the l{editerranean Basin dealt with here are: membersof the 4n. ntculiPeqnis conplex, An. supefpictusr A{r. sergentli, and 4,n. pharoensis. Of the secondaryandsuspectedvectorsreferencewiffbenacGtotneenl-IFroup,theAn. gl?"iegl CToYg:.An. hispanlola, An. drthali and An. nulticolor.--ThE-5o&-of Senever &- Andarelli (1956) represents a valuable sotrrce of-EEEi.E-E6ffiIge of the Eaxonouy, distribution and biology of the anophelines of North Africa and the I'lediterranean Basin, fron which certain information will be recapltulated when newer infornation ls not available. Slnilarly, in the absence of newer studies on certain aspects of vector biononlcs, infornation will be briefly cited fron the book of Horsfall (f955) which well docunented the old knowledge as studied by various workers during the l920rs-1940ts. For certain vectors, speclfic lnfornation will be conplled fron the review of Zahar (1974) and Service (1986) as necessary.
A useful review has been presented 1n English by Arteniev (1980). This will be used as a main source of inforuation on vector biononics in the USSR,although it deals with whole republics and terrltories of the USSRand not necessarily the Black Sea area. l. The Anopheles naculipennts conplex
I.l Vector iBportance
All menbers of the An. maculipennis complex are potential vectors in conlinental Europe. As shown under SECTIONII in document VBC/90.1-I,!AL/90.L, An. sacharovi is an important vector i.n Turkey and Syria, and has recently reappeared j.n Israel and still exj.sts in Jordan and is regarded in both countrles as an important potential vector. An. labranchiae has been regarded as the maln vector of malaria in }lorocco, Algerla and Tunisla and is now responslble for nalaria transmission in soalJ. persisten! foci ln Morocco.
1.2 Breeding habitar
It ls useful flrst to recapltulate in the followiug the basic knowledge of the breedi.ng habitat of nenbers of the @culipennis- conplex from Senevet & Andarelll and subsequently add the available neweffiE6lEil
- maculiPennis s.s. (=gpf"rt".)s Its typical breedlng habitat is in cold waters occurri.ng 1n upland regions, but thls specles was also encountered in areas close to sea leve1 associated with messeae in running rraters. It was also recorded in rdartDrraters as for exanple, cerrain aGFErroundlng Naples, Italy.
- nesseae: It ls rarely found ln waters contalning nore than 1.5 g NaCl/l. It prefers shadedffing places. It ls generally assoclated wlth typicus and melanoon.
- melanoon: lt breeds ln freshnater and rlce fields (north of ltaly). It also breeds ln narG-iil- shramps(oriental coasE of Spain). l. It should be noted t.hat some infornation sumoarized here deals with investigations carri.ed out ln areas and localltles of the Occupied Territories. vBc/90.2 t(AL/90.2 Page 11
z l f J -aYz* s z *H
qj ll. vtsc/90.2 r4AL/90.2 Page 12
- subalPinus: It breeds in fresh water or slightly sallne as in sunlit swampsand ponds wlth vegetation, but avoids snall shaded breeding places. It also breeds 1n rtvers and streams as well as rice fields. ln the spring it prefers the stagnant \raters overgronn with horizontal vegetatlon. In sunmer, its eggs, as in che case of typicus and messeae, are easily identifiable, whi.le in the sprlng and auttrmn they are less recogni.zable (black in colour).
- labranchiae: The breeding places are very variable: swanps and rivers overgroltrr trith vegetation, holes, canals, xlarshes, basins etc. In general, it prefers sunlit breeding Places.
- at.roparvus: It breeds in brackish or freshwaters and prefers well-lit breeding places (Portugal and Spain).
- sacharovl: It breeds in all snal1 rrat,er collections containi.ng aquatic vegetatlon.
Service (1986) gave a general description of the breeding habitat of certain members of the An. naculipennis conplex as follows: An. atroparvus breeds ln sunlit, exposed pools and ditches with either fresh or brackish water, as rdell as rice fields. An. labranchlae breeds in brackish waters in coastal marshes, fresh waters of rlce fields, marshes and edges of grassy streams and dicches; it prefers sunlight. An. sacharovi breeds in fresh or bracklsh rraters of coastal or inland marshes, pools, ponds, especially those with vegetation; lt prefers sunllt habltat.
In France, Cousserans, Salieres & Tesson (L974) recorded for the first tlne An. uraculipennls s.s. (= typlcus) 1n the ltontpelli.er area and described its breedingEbitat in the Lez river at the northeast of the town. The rlver was extrenely slolr moving as a result of the very dry sunmer of 1973. The lower reaches of the stream were overgrorro with dense vegetatlon coupoeed of Potamogeton natans wlth patches of Scrlpus lacustris. The analysls of lrater of the river differed fron that of the natural breeding places of An. subalpinus which were frequently encountered in the tt6rault and Les Bouche-du-Rh6ne. The analysis showed: pH 7.8; Cl 71 ng/l; organic naterial (in ng Oz/L): of aninal origln, 1.3 and vegetable orlgln, 7.5. In thls biotope, naculi.pennis s.s. was associated wlth and predonlnated over eubalpinus. The presence of macuLipennis s.s. ln this Mediterranean sub-region ls a slgnlflcant flndlng fron an ecological standpoint, taking into account that the classical biotope of this species was described as cold nater in higher reglons (clting Senevet & Andarelli, 1956) [It should be noted that Senevet & Andarelli at the same tine indi.cated that naculipennis s.s. was encountered in runnlng wat,ers at sea level but less frequently, and also in warm tsaEers. l
Also Ln France, Pichot 6 Deruaz (1981) presented the results of identificatlon of the An. naculipennis complex collected ln the Lyon region. The presence of messeae ltas s.s. rras recorded for the first time. Ttre !ffi-ce of aCroparvus lras suspected and should be checked by further studles, and careful vigilance on anopheline fauna should be irnpleoented because of the risk of nalaria transoission froo gametocyte carriers. On the larval ecology, the authors found t,hat nacglllglg s.1. was widespread and abundantly present a! Donbe ln surveys nade during L9m Tine larvae were collected froo pernanent breeding places, principally around ponds, along rivers and slramps. The large-sized breedlng places were sun-llt and overgrolrn wlth vegetation such as: Sparganiup ep., Phragoites coomunis, @!g and Juncus sp. Development of the irnnsgusa stages occurred between the end of l{arch and October. The larvae were associated with An. claviger and Culex spp. The water of t.he breeding places was clear, colourlesst generally neutral (nean pH 6.95) and waru (nean ternperature 20.460 C). During L977-L978, surveys nade in Bas-Dauphin6 and Cr6mieu island showed that larvae of maculipennis s.1. were breeding in slmilar situations.
In ltaly, Bettini et al., (f978) drew attention to the potential inplications of extension of rice cultivation 1n the central part of the country [see SECTIONI, under 1.2.1, (1) in document VBC/90.I-DtAL/90.11. Somenore details of the surveys carried out bytheseauthorsareg1venhere.InthePast'49@hadbeentheoost1nportant malaria vector ln the coastal plains and the inland hiUs of central lta1y. In 1947, DDT house spraylng was applled ln the malarious areas of Tuscany and North Latlun of I'lareoa Reglon, resultlng ln interruption of nalarla transoisslon. At San Donato (Grosselo, Tuscany), a locality preVlously known to be highly malarious, few adults of labranchiae vBc/90.2 t"taL/90.2 Page 13 were found afEer spraying, Ehe last specinens were collected in 1958, thus the speci'es appeared to have been eradicated from the }4arenmaregion, except for one locality in the extreme south (citing CoLuzzi & Finizio, 1966). Regular searches for adults of Ehe An. nacul-ipennis couplex carried out in Grosseto province sholted only a constan! presence of melanoon in rice fields about 3 kn fron the sea, and low densities of messeae (citing GJ-orL et al., 1970) and atroparvus (citing Coluzzi. & Finizio, 1966). Riee had never been cultivated in San Donato locality or j.ts surroundings until 1975 when it was grown experimentally in a small area. Tn L977, rice was groh,n in 65 hectares around the locallty wichout the permission of authorities. An entomological survey was carried out in August 1977 in paddy fields and was extended later to Ehe surrounding rice-growing areas. Adults of nacullpennis s.l. were abundantly found in aninal shelters close to paddy fields. In the fields, a large proportion of the larvae collected showed norphological characters corresponding to those of labranchiae. The larval density was as high as ro-so larvae/dip. Based on the egg character;;%vipositions raised from fenales of oaculipennis s.1. collected fron stables in San Donato during August-Seplember were identitiea as toffows: 40.5% labranchiae, 55.32 nelanoon, 3.42 messeae, 0.82 naculipennis s.s. Fron 690 oviposffiiF6i the areiFro.rnding sinEGto, 31.52 vere identified as labranchlae. The percentage of farms positive for labranchlae was lower in thesurrounain[@5Z)thaninSanDonato1tself(82.8%).Thefocioflabranchiae covered about 30 knz. Before nalaria eradi.cation, rice cultivatlon rJas accepted as a means of land reclamation on account of the alleged preference of non-vector species for freshwater. in contrast to the adaDtabilitv of vector sDecies. labranchiae and sacharovi to brackisfr warer (cirlng Hackert ,'1944 ani Panpana, 197+4). eiEinE--ffl:]f(I934fafr?l- Pampana (L944), the ltater ln rlce flel.ds during the first years of cultivation would maintain a sufficient salt concentration, thus beconlng suitable for the vectors. However, four water samples collected randomly fron paddy fields at San Donato showed very low chloride concentation values (46, 40, 41 and 78 g/t), thus confinning that labranchiae breeds in fresh lrater as well as bracklsh water (citing Pampana, L944). The present findings illustrate how uncautlous farning policy can lead to rapid increase in vector density, to levels hlgher than those observed before DDT spraying, wlth the risk of re-establishnent of nalaria transmlssion in Ehe presence of inported cases.
In Sardlnia, l"larchi & Itlunsternann (1987) reported the results of a 5-year survey conducted to deternine the changes in mosquito fauna 35 years after Ehe malaria eradication caupaign. As a result of the anitaosquito canpaign known as: Ente Regionale per La Lotta Anti-Anofellca in Sardegna (ERLAAS) that nas carried out during L947-L95O, nalaria was effectively eradicated fron the whole lsland. The canpaign rras directed a1mostexclusive1yagainsttheprinc1Palvector,@'byapp1yingDDThouse spraying and land reclamat,ion. Slnce the long-tern effects of the canpaign on the oosquito fauna have scarcely been lnvestigated previously, the authors carried out the survey during f980-f985 to fill ln this gap in knowledge. In recent years an increasing nunber of inported malarla casea have been reported ln Sardinia. Insecticide Pressure, although on a very reduced scale, has been roaintained in a number of the more widespread anopheline foci, and extended to include several major oosquito pests. tiich the expanding urbanlzatlon and changes in farning practices, profound alteration of the natural habitats have occurred, especially along the coast. The basts of conparlson of the mosquilo fauna was the thorough study of the Sardinian Cullcidae by Aitken (1954). Data of nosquito species of six genera: Culex, 3!5!g, Culiseta, Orthopodornyia, Coquillettidla, and Anopheles rrere presented. The species composition was siroilar to that recorded during the years of the eradicati.on carnpalgn, except for the genus Anopheles. 0f the eight Anopheles species previously recorded, only four were identified in collections of 1159 larvae from 85 posltive sites. An. labranchiae was the most frequencly encountered anopheline, but rePresentedon1yr2zffiffio1lectionsofmosquitos.Comparisonwithprevious records indicated a progressive lncrease in sites positive for this species over the Past 35 years. Larvae of labranchiae were always found in freshwater. Anopheleq hisPaniola nas not encouncered, although it traa apparent,ly replaced labranchiae soon afEer the eradication canpaign (citing Altken c Tiapido, 196r). unffiEanchiae were comnon in the sites. where the replacement phenonlnon had been observed.
D'Alessandro, Bruno-Sniraglia & Lavagnino (1.971) when presenting their studles on the biology of An. labranchiae suumarized the history of malarj.a eradlcation in Sicily and recapitulated the breeding habitat of thls species as Ebe principal vector of roa.l-ariain the island. Large scale DDT house spraying whlch began Lt L947 was gradually reduced froo 1960 onwards lrith the exception of linlted areas. Ten years have elapsed since the last vBc/90.2 NtAL/90.2 Page 14
indigenous nalaria case was recorded, and different forms of vigilance activities have been mai.ntained i.n the fornerly endenic zones. An. labranchiae existed at sea 1eve1 as well as at higher altitudes; the highest alrirud;6AinE-Im;-in l'lonre Soro, l'lessina. Its larvae can be found in river poo1s, brooks, marshes, puddles and spring-rdaEer. Cool, sunlit, slow noving fresh wat.er are preferred. A moderate salinity of the water is tolerated.
In their Presentation of a cytogenetic study for comparing An. sacharovi populations existing in Italy and Turkey, Petrarca et al. (1980) [see VOLUMEI, under L.L.z, p. 33] described the breeding habltat of this species. The Itallan An. sacharovi fornerly a vect.or of nalaria was drastically reduced through residual troiffiEffig-or through Ehe effect of pollutlon i.n t.he littoral swaops which had been a typical breeding habitat of this species. An. sacharovi still exj.sts ln Puglia on the Mriatica and probably in Sardinia, u,tt a66TG?f,- a high density. In contrast, the Turkish An. sacharovi which is an inportant vector causlng severe roalaria epidemics breeds especialJ.y j.n freshwater inland and extends its existence co areas of over 500 n altitude (see more details below under Turkey).
In Yugoslavia, LepeS & VitanoviC (L962) following a malaria epldenic that occurred in 1959 in Stojakovo village, Bogdanci nunicipality, southeast llacedonia, carri.ed out an entomologlcal investigation in thls area during 1960. In additlon to recording several membersof.the An. naculipennls complex (maculipennj.s s.s., atroparvus, messeae and subalpinus), the authors dlscovered the presence of sacharovi in four settlements close to the Greek border. As sacharovl had never been reported previously fron |4acedonia, they suspected thar it nust-TlGlirie-igrated across the border froo Greece. Differences in the ProPortlons of sacharovi found in various settlenents nas attrlbuted to the degree of ttater salinity of the breedlng places; high sallntty being necessary for the developnent of the inmature stages of this species. At Bogorodica village for example, the nater salinity j.n one of the breeding places (a pond of about 1.5 ha), reached 74 mg/L, aad, sacharovi accounted tor 69i( of the anophellne larval population, while at Palurci village ilere the Irater salinity was 15-18 ng/i (the normal percentage of saLinity in freshwater) sacharovi larvae consti.tuted, oaLy 2.6"A,
In Ronania, Duport et aI. (L974) when presenting their studies on the inpact of insecticidal spraylng on the anopheline vectors of malaria sumnarized infornation on the breeding habltat of the four previously recognized vectors as follows:
- atroparvus: As lts larvae prefer bracklsh wat,er, it predoninates in the inland as well as the Iittoral zones. - oesseae: As its larvae thrive in freshwater, it is found in the plains breeding sometimes ln snall collections of water, but abundantly in ponds, lakes as well as ln hilly areas where lt breeds in slow-running well-aerated freshwater streans.
- sacharovi; This ltediterranean specles is encountered i.n a very liuited zone forning a band of 10-15 km along the littoral part of the Black Sea. In the past, this species had been responslble for explosi.ve malaria epideDics in the easlern part of Constanta and Tulcea districts. It is now considered a vector of oinor inportance because of its very linited dlstribution. The drastic reduction of sacharovi populations and even its disappearancefronRomanian1ittora1hasapparen@tedfroor..desalinization.'and drainage operations carried ouE in several lakes as nell as from the appllcation of residual lnsecticldes.
Bilbie et al. (1983) during thelr investlgation on the response of potential nalaria vectors to insecticides in previously oalarious areas in the Danube plain and Dobrudja, Romania during 1981-1983, observed nosqui.to fauna ln rice plantations. ln Grldlstea rice plantation, no or few nosquito larvae were observed in lday-June due partly to the aPPllcatlon of insecticldes during the first phases of rice developnent, and partly to the intermitlent irrigation scheme (i.e., temporary flooding during 24 hours and followed by water drainage during 3-5 days). Under these conditions, Culicidae larvae were found at a reduced density (0.5 larvae/dip, using a dipper of 8.5 cn dlameter), with anopheline larvae constituting 9O7. In July-September, when the rice plots were pernanently flooded, the larval denslties renained low 0.8-1 larva/dip) wlth che anophelines constitutlng 957!. The irrigation canals are sloped and have sErong water velocity due Eo punping, hence not vBc/90.2 vlAL/90.2 Page 15 suitable for larval developnent. On the contrary, drainage canals which discharge the r^rater fron rice p1ots, are broad and not sloping, thus having slow water current and are often overgrown with energent and submerged vegetation. Therefore, lhey provide a favourable habitat for larval developnent. At the end of June, a mean density of 1.7 larvae/dip was found in these canals wlth the anophelines consuituting 76i( and the culicines 24%. In July-August, the density increased Eo 5.3 larvae/dip with the anophelines consti.tuting 99"A. During the same period species identification based on the chaiacgers of the eggs which were raised frorn anopheline fenales collected fron shelters at trdo nearby villages showed that 862 nere messeae and 142 naculiPennis s.s. In another irrigated area (Schira), while lhe mean denslffiT 0.2-l.t tarvae/aip in llay-June, it increased to 4.2 larvae/dlp in July-August of which 482 were larvae of anophellnes. The speciesconpositionwas:78Znesseae,[email protected].
In the USSR,Arteniev (1980) included in hi.s presentation on the main malaria vectors of the Soviet Union, notes on the breeding habitat of menbers of the An. maculipennis complex as follows:
- maculipennis s.s.: breeds 1n sEreams or beds of uountain rivers. Larval developnent occurs at temperatures between l0 and 35o C, with the optinuD being 25-300 C. At Eemperatures below 7.5o C or above 35o C, larvae becone torpid. Larvae rnay gradually get frozen in ice and can tolerate lowering of lenperature Eo -l0o C for several hours. Prolonged exposure to ice or an increase of tenperature to trore than 45o C kills the larvael Breiding occurs ln bodies of water rich in oxygen. Polluted naters particularly t.hose with high nltrogen congent are avoided. The naxi.mumsalinity tolerated by Ehe larvae is 97!. Larvae can tolerate naters lacking salts better than do other species of the conplex. When calclum salts are present ln the water, larval breeding lroproves considerably. The presence of aquati.c vegetation is also favourable although larval breeding can successfully occur in waters devoid of vegetation provided that the water is pure. Larvae have been frequently encountered in shallotd water of slate-covered beds of mounlain rivers coopletely devoid of algae and other vegetatlon.
- melanoon and subalpinus: Arteniev (loc.clt.) renarked that Soviet entomologists rarely drew dlstincEio; between these two forms, and lhus Ehe ecological and biological observations revLened by hin are equally appllcable to both subspecles. [Evidence has now been provided that subalpinus ls a good species discinct from nelanoon - see Bullini & CoLuzz! (1982) and Cianchi et al. (1987) in VOLUIlEI, under 1.1.2' pp. 36 & 38 respectively]. The larvae breed ln stagnan8 freshwater bodj-es rich in aquatic vegetation. The chemlcal conposltlon of the water is sinllar to that of naculipennis s.s., but the tno species are oore salt-tolerant, and at the satre time they can readily survive ln salt-free lraters. Tempera.ture requlrements are sinilar to those of macullpennj.s.
- atroparvus: Larvae develop in standing waters, often brackish and usually containinS, aquatic vegetatton. They can tolerate salinities up to L4%, but the best develoPment occurs in sllghtly bracklsh vater having a salinity ranging between 3 and 102. Larvae of [email protected] toferant to waters deficient ln calciuu salts. The tenperature requiremenEs are sinilar to those of maculipennis s.s.
- pesseae: Larvae develop in standing non-saline waters overgroldn Itith vegecation in the plaj-ns. The temperature requirements are sinilar to those of nacull3glg s.s.; larvae become rorpid at 50 c ana' 40o c. The optinun temperature ii6ffiE and 30o C. larvae of messeae are sensitive to rtater sallnity and cannot develop in waler lrith a salinlty above 5-67, L.e., they are less tolerant to salinity than maculipenniq s.s. The optimun salinity Ls I-27. The larvae of ry cannot develop in polluted waters.
- bekleoishevl: Previously thls species was taken as macullPennis s.s. existing ln lowlanl-and trigtrland areas of Russla and Slberia. Based on cytogenetic studles of the polytene chromosones and egg norphology, the species was described and named beklenishevi. Ecologically, it is close to ry' but the tlto sPecies are @tyiso1ated.[SeeStegnil&Ibbanovi(1978)inVoLtJ}4EI,underL.L.2, pp. 28-291. The infornation on the ecology of macullpennis s.s. in the north of the USSR actually relates to beklernishevi. vbc/90.2 t4ALl90.2 Page 16
- sacharovi: In Central Asla, larvae of thls species can develop nornally ln bodies of waCer where the tenperature rises to 38- 40o C in daytine. lts breeding habitats are quite variable.' puddles, dilches with standing water, canals, boggy areas, coastal marshes of ponds and lakes etc. tllgh salinity ls well tolerated by the larvae of sacharovi than any other neober of the An. rnaculipennis conplex; its larvae can develop ln waEers having salinities up to 20"4. Di.stilled water cannot be tolerated. tligh NaCl contenEs are needed, even if calciun and nagnesiun salts are presen!.
In western Georgi.a, Sichinava, Stegnii & Sipovich (f983) studied the distributi.on and the biology of An. naculipennis s.s. and An. subalplnus. The immature stages of maculipennls s.s. developed in nater reservoirs with sandy or stony bottoms, while those of subalpinus developed in biotopes with peat or clay beds.
In Turkey, Postigllone, Tabanll & Ramsdale (1973) polnted ouL that in view of identlfication dlfficulties, it was not possible to deflne exactly the ecological requlrernent,s ln the larval habitat of lndividual uembers of the An. naculipennis complex. The recorded habltats of the three members of the conplex ttrat o-ffi..Efl naculipennis s.s., subalplnus and sacharovi, lnclude brackish and freshwater in sltamps, excavations, open reservolrs, lrrigation and drainage canals, roadside ditches, and rice fields. Horizontal or energent vegetati.on ls invariably present. High densities of all three specles occur at sea level and regular breeding can be seen up to an altltude of 2300ninthecaseofnaculipenniss.s.,[email protected] @'a1thoughasingJ'erecord1ndicatedthatsacharov1wasfouudatana1titudeof 1t20 D G'itlng Gokberk, 1961). However, thls speciil?-66en unable to establish ltself at this altitude. Identlficatlon of eggs collected fron breedlng places ln Turkey has shown that al.though each species can occur ln pure cultures, tlro or even all three species utilize the same habitat ln certain areas. Thue, all three species were found breeding in flooded rice flelds ln the l'lerlc valley, Edirne province on Ehe Greek border. In contrast' subalplnus and sacharovi were extreuely rare ln the rice-growing area of Biga, Canakkale province, south of the I'larmara sea, where oacullpennis s.s. nas abundantly Present. On the other hand, nacullpennis s.s. was vlrtually absent fron the shores of lakes Eber and Aksehir, Afyon and l(onya provinces on the cenlral Anatolian plateau, where high densltles of subalpinus and sacharovi occurred. In this area, subal.plnus was dominant in some places, while sacharovl was dominant lu others. The degree of donlnance of sacharovl oay often depend oiffiLllnlty, but salinity is not necessarily the deterni.nlng factor, slnce it was the douinant specles Ehroughout the year in oany freshwater inland and coastal habltats. Nothing ls known about the factors deternining the relative abundance of naculipennis s.s. and subalpinus. Although naculipennis s.s. is known to be a hlghland speciesr lt na6 the dorninant speci-es at sea level.
In llorocco, Guy (1963) in his account of the epidenlology of malari.a in the country incorporated notes on the biology of the vectors. The classical breeding habitats of the main vector An. labranchiae were descrlbed as sun-lit ponds overgrown with vegetatlon as wel1asr1ce-FIffi1argedensityoflarvaeI'asencounEered.
In Algerla, the only available descriptl.on of the breedlng habltat of An. labranchiae cones fron a long study (1932-1956) ln the region of Alger reported by Colllgnon (1959). ThehabitatofAn.-1abranchiae([email protected])wasc1assified inco: the traurtilffilGG and the trauitat of ttre nountalns .s in the following: ",ura.i"ed
-The habitat of the plain; In general, the typical habitat is a depression isolated or linked wlth a lraEer course. The water which is retained for a sufficient tlme is characterlzed by being fresh, clear, shallow, and slightly exposed to the action of the wind and variatlon ln its depth. The type of aquatic vegetation whether floatlng or emergent plants depends on the depth of the water. lJhile Ranunculus and !g99g9g9.!g are labranchiae"o''oo,e'[email protected];;vaeof avold sites close to crucifer plants, and they are often absent in waters havlng floatlng Lemna. It seems that this is not due to the presence of the plant ltself but to the pollution of water which deters the ovlposlcing fenales. llaters shaded by a dense growth of emergent vegetatlon such as -TJ3$ or aquatic grasses are less favourable to the larvae.
- The habitat of the Eountain: In the hil1y reglons, whlch drain lnto the plains, rratcr courses with eravel and pebbles offer another type of breeding habitat for wc/90.2 IIAL/90.2 Page L7 labranchiae. This habltat contalns llttle vegetation, except for some filanentous algae. l,arvae can also be found in residual pools or the bllnd ends of streams whenever water stagnates and has a suitable temperature for developroent. The larvae avoid the algae sites. Their density is much less than that found in the breeding places of the plain. tsreeding places of the mountalnous reglon are usually situated close to human agglouerations.
The presence of labranchiae ln the habltats of the plains and the mountains indicates the wide distribution of the species ln the Alger region fron the sea to 8ou Saada.
No newer infornation in the breeding habitat of Iabranchiae in Algeria could be tracect.
In Tunisia, Juminer (1959) in his notes on the anophelines of the country described the breeding habitat of labranchiae as being brackish or actually sal-ine nater withouc any trace of vegetation. tlo-iGi:EJo-rnation couLd be traced.
In Libya, records of anophellne fauna were reviewed by Macdonald (1982). An. lebranchlae was recorded from Tauorga and it seems that Trlpolltania is lts eastern linit. It breeds in fresh and bracklsh nater of rivers and narshes, especially where there is some shade.
In Cyprus, before the Anopheles (nalaria) eradication canpaign that was launched in 1946, An. sacharovi and superpictus lrere regarded as the oain vectors of nalarla. Under the eradicatlon operations, gig@9g! was eradlcated but superplctus persisted at a very low denslty. It should be recalled that ualaria eradicatlou ln Cyprus lras officially certlfied in october 1967 [see Docuoent VBC/90.I-MAL/9O.L - SECTIONI, Table 1 under 1.11. Zulueta (L974) ln an unpublished report to WHO)pointed out that desplte che Proxiuity of the Turkish coastal areas to Cyprus (less than 80 kn) the relntroduction of sacharovi into Cyprus through ehlps seens unlikely because the forner breeding places of this species have been radlcally changed by land reclamatlon and agricultural developoent. Thus, it seeus difflcult for sacharovi. to re-establlsh igself on the island, but the potentlal danger, nevertheless, n.ts-6@ ln uind. From uore recent lnfornatlon conpiled by Shldrawl (1983) no sacharovi has been found in entomological surveys up to 1982 sioce 1ts last record in 1952.
In Jordan, t,he only meuber of the An. nacullpennie cooplex is An. sacharovi. Farid (f954) ln hls article on the effect of DDT house epraying on EaLarla tranemission i.n the Jordan Valley, lncluded notes on the bionoulcs of the malon vectors. An. sacharovi was recordedin1arge1rlm|g1ginprem1sesl.nthenorthernpartoftheJord!i.@itwas found to breed ln resldual pools along the rlver and perennial streams, as well as in a few sprlngs located in the foothills. Its prevalence in the valley decreased towards the south.
In Israel, the only member of the An. macul-Lpenni.s complex is An. sacharovi. In the past, Saliternik (1957) presented hls conprehensive observations on this species as an lnportant vector of nalarla in the country. Durlng L938-L942, the ecology of the aquatlc stages of sacharovi was studLed in 38 different breeding places. The breeding occurred in valleys cooprising water-filled pits, along river banks, neglected fish ponds, wide canals, blind ends of streams chat are almost stagnant or with a very slow current sunlit or covered by horizontal vegetation. In hilly areas, breeding was occasionally found ln rain puddles. Larvae nere generally distributed anong floating horizontal vegetation. Optlnun condltions for breeding of sacharovi were shom to be:
- teater depth generally over 30 cn; - current absent or very lreak; - pH ranges frou 7 to 8.8; - leDperature beteeen 10 and 360 C wlth the optimun belng 2L-25o C; - uater exposed to sunlight; - sallnity not hlgher than 0.72; - vegetation of the followlng types: (a) wlth roots, floating vegetation: Potaeogeton and Ranunculus. (b) rootless, floating vegetalioo: llyriophyllun aud @p$fg. (c) floatlng, fllanentous algae.
No breedlng lras found ln waters with dense cover of Lemna mlnor, !:_J@., -!ilgg@. caerrrla. Nuohar luteutr and Jussiaea repens. vBc/90.2 rlAL/90.2 Page 18
In his review of the historical dlstribution and blonooics of nalaria vectors in Israel, Saliternik (L974) sumari.zed the breeding habltat of sacharovi as belng stagnant or slowly moving waters of swamps, ponds, pools and rivers, c6ffi61 sone specific horizontal aquatlc vegetation. Breeding and adult densities of sacharovi decreased gradua11yandthespec1esdisappearedconp1etelyduri.ngr9o0-r97ffiactorsthat influenced the elinination of this most dangerous vector nere:
(a) drainage of all inportant swampsln the country; (b) wide areas of stagnan! naEer collectlons have dried up because their level sank through extensive punping of underground water; (c) unsuitable conditlons for breeding in streambeds were crealed by sewage pollution; (d) sacharovi population being an endophllic species was greatly affected and reduced by wicie-scale DDT house spraying.
Saliternik concluded that sacharovi- has aloost been eradicated and has no vectorial inportance in Israel.
Ben-Dov (1971) reported the reappearance of An. sacharovi as it was identified in sanples collected during routi.ne surveys of potential breeding places carried out by antinalaria inspectors of Tiberias district. This reglon iras not under Israeli adninlstration prior to June 1976, and no infornation lras available on anopheline breeding before then. Of 91 larval samples collected fron this area and other localitles, three lncluded larvae of sacharovi: tsutelha valley, Rauot (spring), Rauot (swanp), and a spring near the entrance o?-Iffi?aan varrey into the sea of Galiree.
t'ollowing the above report, Pener {i l(ltron (I985a) started to monitor An. sacharovi populations in rsraer froo 1970 to 1984. Based on rhe idenriflcarton of riGEi6lltea routinely by the antloalarla inspectors and infornatlon collected by the authors on the breedlng habltat and ecologlcal condltlons, sacharovl larvae continued to increase fron 1971 when they were found at three sltesr nnFFgS when they were found 20 rines i.n one year. The increase was parElcularly narked between f978-1979 and 1984. Durlng thls period sacharovi density increased by 6-fold to become the second uoat commonAnopheles "pectes@)found1nnorthernIsrae1.MostofEhebreedingsitesof .sacharovi (7S.9Dwere focated at the nargins of streams and springs. The ienaining breeding sites were nearly all i.n standing nater habltats, such as stramps, fish ponds and seePages.
In Leban91, An. sacharovi - ls the only nenber of the An. naculipennls complex present. Granlccia (f953) in his presentatlon of the malaria situatlon :.n atfterent regions of Lebanon, included notes on the blononics of the maj.n vectors. The breeding places of sacharovi were described as belng sunlit stagnant lrater collections in swamps or senl-stagnant at narshy banks of rivers or along the large irrigation canals. The breeding wat.ers of this species in Lebanon were always fresh, unlike its habitat ln certain countries of Europe where lt breeds 1n brackish waters.
In Syria' Abdel-l{alek (1958) reported the results of a survey of anopheline mosqui.tos in the northern part of the country, whlch was carried out during l'larch 1953 - Deceuber 1954. Starting from lloms, the survey was extended to the northwest covering the governorate of llama, Aleppo, and Lattakla up to the Turkish border in the north. The survey was also extended to the northeast coverlng the governorates of Euphrates and Gezira uP to the border of Iraq in the eas!, and the Turklsh border in the north. An. sacharovi was found to be che nost predominant anopheli.ne species. Larvae were usually encountered in stagnant waters of marshes exposed to the sun for most of the day. These breeding places had nats of floatlng and fllanentous altae. Such breeding places Itere commonin the area around Homs towD. From these places larvae of sacharovl were associated with those of superpLctus during Aprll-Septenber 1954. An. sacharovi was also found breeding in seoi-stagnant rraters along banks of oarshy riversaiEEiiFlikes. These breedJ-ng sites ltere overgrown with a great mixture of aquatic vegetation, emergent herbaceous plants such as grass and reeds wlth patches of floating vegetat.ion. Such breeding places were connon around Homs lake where larvae of sacharovi were found alone or in association with those of hyrcanus and superplctus. UnderEffiE conditions Larvae of sacharovl were also encountered in assoclatlon nith those of superpictus in swamps on the Medlterranean coast near the mouth of Nahr-es-Sinn about 30 kn froo Lattakia. This type of breedlng habltat was also seen ln the Ghab whtch was regarded as the largest vBc/90.2 t4N./90.2 Page 19
inland sldampforned by the Orontes river. Larvae of sacharovi were also found in neSl.ected irrigation canals ln che vast area surveyed. Such a breeding place was encountered in nany villages i,n Dirik, Qanichlieh, Hasakeh, Deir-el-Zor areas ln the northeast where sacharovi larvae rrere associated with those of superpicEus. lt was only in two villages i@rbousche in Hasakeh, and Souar in Deir-el:Zoil@phrates) areas that larvae of sacharovi were associated with those of superpictus and pulcherrinus. The same type ot ur@fl"ces was also observed in r"rry ifJf@l"tong the Orontes river in lloos and Hana governorates. Rice fields provided a favourable breeding habitat for sacharovi 1n the Aleppo area and along the Hons-Tripoll road. Water in all breeding Effitts of sacharovi encountered was fresh. No newer infornation could be traced fron Syria.
1.3 Swarning and nating
I'lost of the knowledge on swarming and nating of the An. naculipennis conplex cones fron the early observations carried out during the 1920rs-1940ts. These have been revlewed 1n the book of Horsfall (1955) and should be read in the original. On the nating behaviour, it can be briefly stat.ed that as also surnmarizedby Senevet & Andarelli, 1956) nacullpennls s.s. and messeae are eurygaEous nhi.Le atroparvus is st.enogamous.
Recent lnfornation on sltarning and mating of An. nacullpennis conplex that could be traced is very lluited. Arteniev (1980) in the USSRstates that oales of atroparvus fol'low the fenales everywhere to the extent that thelr proportion in a colT&Tto-fr-nay reach 602. Copulatlon may occur indoors, and for thls reason thls speeies can be cultured in the laboratory, although thi.s ls nore difflcult to achieve compared with atroparvus.
Kasap & Kasap (1983) explalned that sacharovi is dlfficult to colonize in the laboratory, partly due to the behavlo,tr 6fff,fri1es which swarrn before nating; f1eld observati.ons in Turkey showed that nales rf,ere seen swarming above lrater or above any other object which is 1.5-2 rn htgh. [See attenpts to colonize sacharovi ln t,he laboraeory in VOL. I, under 2.1.2, pp. 64-661
1.4 bispersal
Horsfall (1955) also reviewed the old observations reported by early norkers during t,he 1920rs-1940ts on the dispersal of An. uacullpennis complex, particularly atroparvus and naculipennis in the Netherlands, for which the book should be consulted. Ltiih regard to labranchiae, Senevet & Andarelli (1956) gave lEs range of flight as 2-5 kn depending on the place and the assoclated conditions such as the presence of a light breeze, the exlstence of trees etc.
In Algeria, Collignon (1959) working in the Alger region observed that the location of the resting sites of labranchiae depends prlnarlly on their dlstance and altitude in relatlon to the ureedlffiE6 The dlspersal range of this species is usually linlred and concentrated around the breeding source. The restlng sites situated at a dlstance of less than 100 n frou each other in straight perpendicular l1nes fron the breeding sites usualJ-y harbour decreaslng densl.ties of labranchiae as the distance from the breeding source lncreases. !1ost frequented restii!-G-s are those situated wlthin 400 n, and the least frequented are those occurrlng at 800 rD or Dore frou the breeding place. lleight is rePugnant to labranchiae as lt becaoe more scarce in higher storeys of bulldings. lloreover, houses of populations of north Algeria situated on hills are less frequented by labranchiae, and remain free of autochthonous malarla. This actually benefited the original inhabitants of the mountains who came to settle in ll6cidja, after thet drainage of the llittoral] plalns allowed chen to settle lndefinltely.
In Israel, Sal.lternlk (1957) revlewed the early observations on the dispersal of sacharovl. Durlng the spring and suomer the resting places and feedlng sites of sacharovi are not very far fron the breedlng places. In June J.924, about 2000 wild-caught adults of sacharovl were marked ulth nethylene blue and released in ihe Shonron plain, (citing Shaplro & Saliternik, 1930). After three days marked oosquitos uere found in houses in Hedera, a village situated at 2.5 km fron the release polnt. In general the najority of mosquitos appear in the village closest to the breedlng places, and in such vlllages they are concent,rat.ed in the houses cloEest to the breeding sites. If the breeding places are far frou the blood source, the dispersal flight can exceed the nor:nal range, reaching 3.5 km fron the breeding places. Ln such cases, the number of male and young female vBc/90.2 NtlJ-/90.2 Page 20
Dosquitos is proporti.onally reduced as the distance froro the breeding place increases. In the late autumn when the naln purpose of the dispersal. flights is ro seek suitable sheltered resting places for hibernation, the distance of dispersal flights may be much Sreater. In Hu11eh valley, large nunbers of sacharovl entering hibernation were found to cover distances reaching six tines their norniffiE flight i"nge, (clting Reitler & Saliternikt L929). In this particular area, numbers of sacharovi were found in Rosh Pina, a village situated at 14 kn froro the nearest breeding pfiF llany lnfected females were included in those nigrating populations (citing Kligler & Iler, 1931). Dispersal flighrs were found to occur in two waves; the first in October conprlsing approximateLy 352 males, and second at the beginning of Noverobercontainiog L51l males, and the latter flight reached greater distances. By the beginning of Decenber the males disappeared and the fenales were found fertil.ized, buE their ovaries were underdeveloped, and large fat bodies were formed. If sone of these mosquitos are infective, they may lransuit nalaria in villages that had been free of sacharovi and the disease. The nurnbers of mosguitos in late autumn dispersal. flights iililair.cE proportion to the distance from the breeding sites. It was suggested that t.he proporlion of fenales with fat body co be found in the autumn in any given plaee could be used as an indicator of the distaoce betneen the breeoing source and the resting place where they were found, (citing Klig1er & l'ler, f930).
In Syria, Sollnan (f96fa) studied the dispersal of sacharovi fron its breeding places in the Rouge valley ln the cencral nestern part of SyrfiffiilO ko frorn Aleppo. t.jithi.n the valley and its west end, several natural sprlngs were flowing lnto marshy areas. The developnent of a new lrrlgatlon project lrlthin the area Led to diainage of u-ost of the marshes, and enabled the cultlvation of part of the area. It was expected that when the Project is conpletedr the whole valley wlll be brought under cultivation and t,he vast breeding places suitable for anophelines, parti.cularly sacharovl would no longer exist. During routlne entoBologlcal surveys, it was declded to fnvestfgate the natural distrlbutlon pattern of sacharovl in relatton to the distance of different villages fron its breeding sttes. rn Effitre selected vlllages, four roorns and four stables nere searched by hand caPture in the early mornings. The results nere based on the nean of three aurveys carried out in each vIllage. The observations were carried out in June 1958 when the density of sacharovl lras still high (Lhe peak was in l"lay). The results showed that: sacharovi tre@te-i-Ti1lages closer to the breealng sites at a hlgher densiry rhan ttre dtsGffiages, provided that hosts are availabre. virlages situated ar 0.5-1 kn yielded L2O'L73 females of sacharovl/nan-hour, while villages situared at 2-3 kn frorn the same breedlng source, yietaEi-7li-Enales/nan-hour. Catches nade at two vlllages situated at 4.5 and 7 km respectively gave l-2 females/nan-hour, but qone was caught in a village situated at 1l km fron the breeding site. It was concluded that algthouE,h sacharovi can disPerse uP to 7 ko, its highest concentratlon is wtthin one kn fron the breeding site.
1.5 Local spatial and seasonal distribution
In Spain, An. labranchiae used to be an important vector in the southeastern part of the country. Blazquez & Zulueta (f980) explained that unlike atroparvus which has a widespread distrlbution ln Spain and Portugal, labranchlae was found only in an area of aPProxinately 1000 knz ln the provinces of Alicante and Murcia. It was the only oeuber of the An. naculipennis complex present in this area except in lts southern part in the vicinlty of Cartagena, and in the north near Elche, where i.t was associated with atroparvus. The annual lncidence of oalaria in 1944 in the labranchiae area was 28 tines greaterthan1ntherestofthenalariousareaofSpain.ThIffihat1abranchiaehad been an ioportant vector in Spaln. DDT and HCHspraying applied in L947 haEfiG-ediate effect on t.he prevalence of nalaria and labranchiae, and by 1949 its larvae could be found in rice fields of San Fulgenclo, in the centre of its distribution area. Entonological investigatlons were carried out by Blazquez & Zulueta (loc.cit.) covering this locality and other parts of the labranchiae area during Septernber 1973, July 1978 and I'tray-June I979. The investigatloiffiGl-39 localities of which 12 were examined rwlce and three limes. The nunber of houses, stables, cow-sheds, pigsties and other structures searched (in 132 nan/hours) vas 220, and the number of larval sites searched was 45 involving about 20 dips per breeding place exaulned. None of these surveys, nor the trapping carried out during one night by nan-bait capcure and light traps, yielded a single specinen of labranchiae. There was also a complete absence of atroparvus in places where it had been Present Previously ln assoclation with labranchiae.-Jh-;;f anopheline found rsas Anopheles alg,eriensis captured in anfuoal shelters and by a llght trap. These results led the authors to conclude that labranchiae has disappeared froo the ooly area it occupied in Soain. thus reducins consider6'6$-the receptivity to roalaria. The extensive searches made vBc/90.2 MAL/90.2 Page 21 during three separate years substantiate the clain that labranchiae has disappeared from Spain and fron the Iberian Peninsula as a whole. This nust have been due to the cornbined effect of residual house spraying, and the application of agricultural pesticides on a large scale. The discontinuation of rice cultivation in 1952, and iroproved drainage as well as changes ln agricullura1 practices, must have also contributed to the disappearance of labranchlae. The fact remains that atroparvus is sti11 found i.n most parts of its forner area of dlstribution in Sapin and Portugal seems to indicated that, unlike labranchiae, atropry is a specles of long standing and well adapted to the conditions of the Iberian Peninsula.
In Francer sone records were reported on the distribution of membersof the An. naculipennis complex. Rioux & Ruffi6 (1957) uslng larval chaetotaxy discovered the presence of subalpinus in Bas-Languedoc. Rioux, Sicart & Ruffi6 (1958) applying the cytotaxononic nethod of Frizzi (1953)r recorded the following species in the south of France:
- subalpinus: in the Toulouse region (Grenade-sur-Garonne). - atroparvus: soulhwest of loulouse. - maculipennis s.s.; in the same area as above.
Later, Sicart, Rioux & Ruffi€ (1958) gave a full account of the cytogenetic identification of Ehe Ehree species in t,he Toulouse region, applied on larval sanples coll'ected fron southwest of Toulouse and Goure Ducail at Grenade-sur-Garonne. Previously the authors identified naculipennis s.s. and rpesseae froro this area, based on the character of egg ornanentation, but it was realized that messeae does not exist in che Toulouse region where it was probably replaced by subatpiila-species whlch has a distribution range extending appreciably beyond thtMedi.terranean subreglon. I! was also pointed out that there is alnost total resemblance betrreen the eggs of messeae and subalPinus. The presence of atroparvus could help to clarify the questEi?the responslble vector that had been lnvolved ln the historical epidenics of rnalaria in the llaut-Languedoc.
As shown under 1.2 above, cousserans, saliErs & Tesson (L974) recorded nSculipennis s.s. io the ltontpelller area in addition to the already present subalpinus; the identification was based on the characters of the eggs, which were obtalned fron adults collected fron shelters near the breeding sites.
SaliErs et al. (1978) identified the members of the An. naculipenni,s complex occurring j.n the area of Languedoc-Roussillon coastline during four sunner seasons. The cytogenetlc nethod could not be applled as this would need profound experience with the chromosomal arrangeEents of each species. Resort was, therefore, made to diagnosis based on the character of the antepalmate hair on segDent IV and V in 4th inst,ar larvae with the statistical analysis of dat,a. The characEer of the egg was also considered. Three species were recognized.'maculipennis s.s. (found only once in the region under study - see above), subalpinus (very abundant, the ornamengation of its eggs exhibited uarked polynorphisn), and atroparvus found only in the fourth season of observatlons.
Reference has already been made !o the study of Plchot & Deruaz (198I) (see under 1.2 above)[email protected].,andconfirnedthepresenceof messeae in the Lyon region.
Suzzoni-Blatger & Sevin (1981) studied statistically the chaetotaxy of the larvae of egcglipennis s.s., aEroparvus, subalpi.nus and messeaewhich have been recorded in the Toulouse region. It was found that the characters of the larval popuJ.ation of atroparvus were not signiflcantly different from those of the same species existing in Montpellier, France and Portugal but they greatly differed fron those of atroparvus of Genoany and England. lJhile the nacullpennis population lras not signific!ffiFerent frou that of llontpellier, it was significantly different fron that of Albany. The authors concluded that the larval chaetotaxy ls a poor character for differentiating between membersof the An. naculipennis complex, particularly when macu.Lipennis s.s., atroparvus and oesseae coexlst.
1.. See VOLUI.{EI, under 1.I.2, p.24. vtsc/90.2 tlAL/ 90.2 Page 22
rn rta1y, as has been shown under sEcrroN r, L.2.r (i) in documentvBc/90.1-MAL/90.L, Coluzzi (1980) showed that recent entomological surveys dernonstrated the absence of che main vectors An. labranchiae and An. sacharovi in certain areas. This has been attributed to environnental changes s.rch as ffiGffi:r o-t swampy areas, pollution of waters by industrial wastes, and contaminatlon of breeding places wlth herbicides or agricultural Pesticides. In sone areas the Anopheles populacions were even replaced by anthropophilic populations of C\ pipiens. However, Anopheles populations are stil1 present in all areas not affected by such environnental changes. ttigh densities of labranchiae have been reportedfromsomesectorsinLazioinViterboprovince,Toscaniffitoprovj'nce,as well as Calabria, Sicily and Sardinia.
From a survey carried out in Latlna provlnce, Italy, during 1965-1968, Sacci, Scirrochi & SteLla (1969) found that out of 13 Anopheles species previously recorded, only five were encountered, vi'z:. nagulipennls s.s., rEIEid clavi.ger_, petragnanl and Plunbeus, al1 of which have a 1orl degree of anthropoptrily.--Tt-Eenfrl2ffi nain malaria vectors have been eradlcated fron all the province. of L26 213 adult mosquitos collected during the survey period, only 847 were anophelines, and the reoaining were roostJ.y cx- piplens which is increaslng every year due to water pollution.
Further, Majori et al. (1970) studied the residual anopheline fauna in the Grosseto province, Italy. DDT house spraylng which had been apptied for nany years was finally di.scontinued in 1966, not only because of the interruptlon-Instead, of nalarla transmission, but also in view of the appearance of vector resistance. oi.l larviciding was applied and proved to be effective not only on anophelines but also on culicines. During che j.969, larviciding carnpaign of a survey was carried out in t,he coastal areas of the province where malaria vectors had been present previously. The following species were recorded: clavlger, alge.ri?ns1s and nacullpennis s.1., wlth melanoon and rlqsseae separated onthebasisofeggoorpho1ogy.Thelictttrattt'emainvectffisacharovi Itere not encountered durlng this survey in their characterlstic breeding places indicates that their densities must have been greatly reduced, or the two speci.es have been eradicated fron the province. The authors observed a marked increase in melanoon density associat.ed with rice whlch was being grorrn on an experinental basis in ttrffiastat areas of the province. If successful, rice cultivation will be extended, and the risk of labranc]riae and sag!@ returning to the area was underlined. The authors also scressed ffi ne;aTor per-iodical nouitoring of anopheline density, and at the same rime app]ying oil larviciding which has glven satisfactory control of residual anopheline fauna and other exophilic species. In fact, rlce cultivation was lntroduced and extended in San Donato ln the same province starting fron 1975 and labranchiae became abundant breeding in r1cefteldsasrePortedbyBetc1n1eta1.(r978)-ffi.2above.
In Sardinia, also shown above under 1.2, Marchi 6 llunstermann (1987) indicated chat there has been a progressive lncrease in the breeding sites positive for An. labranchiae over the past 35 years.
In SiclJ.y, as already mentioned under 1.2, DrAlessandro, Bruno Sniraglia & Lavagnlno (1971) studied the biology of An. labranchiae. Although the specles exists at sea level, large numbers were found at atffif,$fiFthan 200 n. The studies rdere carried out in central and western parts of Sicity, since repeated searches shoned the absence of anophelines i.n the eastern part of the island. The studies ained at deterni.ning the seasonaL distributlon and the physlological age of labranchiae populatlon. Anophelines were collected in domestic shelEers (houses, stables etc.), and extradonestic sites (caves, bridges, hollow trees and animal burrows). The specineus were brought alive to the laboratory where Ehey were processed for identification of the species, exanination of the spernatheca, and deternination of the physiologieal age by Polovodovats technique (in Detlnova, L962). In Sicily, the rrarn dry season lasts six months, frou l4ay to October. During this period the temperature varies betlreen 20 and 35o C. Winter lasts about four Eonths, from Decenber to l4arch, when the tenperature is about l-0o C and rarely falls below 0o C. Under these conditions the period of seasonal prevalence of labranchiae is April-september, and lts hibernation perlod is october-!{arch. Accordinglilffirts ltere presented for the two contrasEing peri.ods as shown in the following:
(a) Perlod of winter rest: Results of dissectlon of samples of labranchiae females collected fron all types of shelters at several localities during the period vtsc/90.2 t4aL/90.2 Page 23
October 1966-l,tarch 1967, are presented ln Table 11, and data of Eonoactivity recorded in sanples-of the same species classified accordi.ng to the type of shelter are presented in Table 21.
The observallons showed that nales of labranchiae disappeared in Novenber, and 9OZ of. a rotal of 686 feoales dissected r"re ir,GGlff As shown in Table 1, the nunber of fenales nith fat body, particularly the non-gonoactive, gradually increased reachlng a maxi.munin December-January, which are the oonths with shortest day-light. Fron Table 2' it seens that hibernating females of labranchiae preferred to rest in nalural or ext.radonestic shelcers. The data also provided evidence Ehat hibernation was incornplete since the following categories of females lJere encountered:
- non-gonoactive females with fat body which could represen! truly hibernating fenales; - non-gonoactive females with little or no fat body, some of which had bLood in their guES; - gonoactive fetrales with fat bodY - gonoactive fernales without fat body: - parous females existed ln winter (October-l.tarch) although their proportion did not exceed 22.3"1 (L53/686). I*lost of the 153 fenales nere l-parous and only a few were 2-parous. In Novenber, tbere were only three parous feuales deternlned as 2-parous, of which one had a snall amount of fat body. In February, of 29 fenales dlssected there were 27 deternined as l-parous, of whieh eight had fat body and only two as 2-parous whlch did not have fat body. It appears that the parous fenales behaved physiologically just as the nulliparous in that thelr hibernatlon is incomplete, i.e., it is possible that some fenales can break their diapause and become gonoaclive, but their survival seeos to be curtailed.
(b) Period of seasonal prevalence:
- when the larvae of labranchiae made its first appearance in Aprll 1967, no adult fenales courd be found rnEffiearched; - the first abundant catches of adult fenales were obtained in the second half of l,lay. A high density was recorded in a stable situated at about 50 n fron the breeding places in the river Tato, and this represented the typical ecological habitat of labranchiae in Siclly: - almost all the females were inseuinatedl - the density peak appeared in August; - i-n suoner females of labranchiae prefer to rest in donestic shelters.
In their conclusions, the authors pointed out that labranchiae is still present in sone linited areas of Sicily, where the habicat has not been alEered, and continues to rest j-ndoors and outdoors. However, it is anticlpated that in the near fuEure, rdith the environnental changes arising from construction of dams and land reclamation under way, as well as the increase of hlgh-yield crops and che progressive reduction of the human population due to migratlon, the density of Iabranchiae population will further decrease.
[This contrasts with the situatlon of the sane species in Sardinia-see above].
Cephali & Lavagnino (1978) who reviewed research studies on anophelines remarked that labranchiae in the island exhibits incomplete hibernatlon. Its fenales aPPear with fat 56fltartingfronoctober.Theyarecapab1eoflayingeggseveninco1dmonthswhenthe temperature is Low.
ln Yugoslavia, several entouological surveys have been carried out in different areas since 1974 until recently, as part of arbovlrus nosquito studies, and also to deternine the distribution and relative abundance of the potentlal nalarla vectors nainly in former malaria endemic areas, in view of the increasing nutrber of iroported cases. The results of these surveys rrere progresslvely published principally by Dr Z. AdanoviC of the Institute of lledical Research, Belgrade. In these surveys mosqultos were collected alive excLusi.vely froro indoor resting shelt.ers ln hunan dwellings and animal houses. Some or nearly al1 nenbers of the An. macullpennls complex have been recorded depending on the
1. Reproduced by pernlssion of Prof. A. Lavagnino from the paper of DtAl.essandro, Bruno Smir:'rlia & Lavaenino (1971). vtsc/90.2 PtaL/90.2 Page 24
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Table 2. Observations made on female A. L. Labranchiae found in donestic or natural shelters.
Domesti.c shelters
NulU.parous Parous I"lonch Nunber Number fenales Gonoactive Non-gonoactlve fenales Gonoactive Non-gonoactive
October 37 3 J4 22 I9 J
November 8 4 4 6 1 5
Decernber 55 I 54 3 3
January 25 22 3 5 I 4
February
}larch 5 5 L4 r3 I
TotaI r30 J) 95 50 34 16
Natural shelters
October 33 L7 16 32 24 8
Novenber 31 11 20 L2 4 8
December 83 2 8l 2 2
January 2LL 24 187 27 5 22
February 43 34 9 29 4 25
March 2 2 1 I
Total 493 90 313 103 39 64 vBc/90.2 't[AL/90.2 Page 26
area; thelr identification nas based on che characters of the eggs which were ralsed froo the adult fenales collected. Anopheles specles other than the nenbers of che An. naculi.pennis complex were: glgElg.gg (considered as a potential vector),_clavl8st EFEanFET,rnue,rs, and algEiiensis in some areas. The general features that can be drawn from these surveys are surnnarized as follows:
- atroparvus predoninates in areas of alkallne and saline soils due to relati'vely high concenffiEl6iEJ-f dissolved salts ln stagnant and slowly flowlng waters, as in Potisje of the Pannoian plain, south Barla and west Badka.
- Desseae nas Ebe roost predominant anopheline species in the alluvial plains of the great ffis of the Danube and Sava and the lower reaches of Vel-lka llorava river 1n Serbla. It was rare in the hilly area of Pocerlna with a notable exception as it was abundantly present at one village, VukoSiC. Although it seems that uesseae breeds characteristically in great inland valleys wlth large oarshes and swamps, an extensive swanp wlth a narginal belt of dense submergent, floating and emergent vegetaElon was seen near VukoBiC. The proxloity of a typical breeding site could explain the abundance of nesseag adults at this hllIy vlllage. On the other hand, the populatlon denslty of messeae was very low 1n South Serbla and Macedonla compared with that found ln the Ibdands of the great rivers of the Danube and Sava. Along the rivers Vardar and Crna Reka, there had been large snanps whlch were drained after World War II, and a large area of fertlle soil has been reclalned for agriculture. The elinination of many sltamPsnay be one of the posslble factors lnfluencing the decrease in abundance of lpesseae in the lowland of South Serbla and l4acedonia.
- atroparvus and gry lrere extremely rare 1n the lowlands of llacedoni.a where hot and dry cliuace seeo to be the llnltlng factors for the two species.
- oacullpennls s.s. nas most abundant in Procerina, Serbla, southeast Serbla and east !4acedonia.
- sacharovi was recorded restlng indoors much nore frequently than any other meober of the An. oacullpennis cooplex at sites close to the area of saIlne and alkaline soils in east l.lacedonla. lt was al.so collected indoors associated wlth subalpinus at Zoganjsko Blato i.n Montenegro where narshy plalns of brackish water exlsted.
- shlle subalpinus was recorded in flve areas, melanoon was identified (only one fenale) for ctre first tioe fron south Serbia. nepeaElng-and extending the search for this species uas suggested.
- labranchlae rras encountered only in one area: Ravni Kotarl in northern Dalnatia whichhasat1editerraneanclimate,wheresubalpinus,@andsuperPicEuswereaIgo recorded.
- che following specles of the An. maculipennis complex are consi.dered important potenEial vectors in Yugoslavia; maculipennis s.s., 9.!i.gjry, E9S, labranchlae and sacharovi.
For the distrlbutlon of superpictus see under 2. below.
For detailed lnfomatlon on the distrlbutlon and the relaEive abundance of anopheline species in dlfferent areas of Yugoslavia, interested readers should consult the following papers: AdanoviC (1975 a,b & c); ManovLC (L977' 1978, L979a & b, 1980, 1981' 1982' 1983a& b, 1984,1985,1986); AdanoviC& PauLus(1983,1984,1986); Paulus & AdanoviC (1e83).
Early observations ln Yugoslavla by Guelnino (195f) provided useful infornatlon on the hibernation and the assoclatlng physiological changes in certain species of the An. nacullpennis (hltherto cousidered varleties) viz: typicus (=-gaculipennis s.s.)r resseae and atroparvus. The observatlons were conducted at a vlllage where messgae ffiuted 632 of the anopheline population, and another vlllage where typlcus fonned 9lZ. As atroparvus represented only 2.2 and L.L1! of the anophellne population in the two villages respectrvety, the physlologtcal study of this species during hibernation could not be co1ducted. Durlng suoDer, the three species congregate in stables havlng simllar attraction to the host and to favourable physical conditlons. Wlth the approach of the vBc/90.2 t'tAL/90.2 Page 27 winter, while typicus and atroparvus remain in warm stables where domestic animals are kept, and where they rest throughout the winter, W changes its habitat and flies to a cold shelter. The hibernation of messeae in cold shelters is the nost pronounced eco1ogica1featurewhichdistinguishesitfrong1g;!gggand.e@-andisdueto physiological adaptatlon of oesseae for spending the nlnt'er at a low temperature. The first preparation of messeae for hibernation is this change of the resting habltat which occurs at the end of liffior the beginnlng of Septenber. Despite the fact that messeae abandons warm stables ln favour of a cold shelter, it continues to feed up to the niddle of November. The bloodneals are dlgested slowly, as shown by the unchanged appearance of the blood withln the alinentary canal for a period of many days. This species continues to oviposit untll the end of Septenber when oviposicion cones to an end, al.though the nean outdoor temperature ls 15.50 C. Follicular developnent, howeverr continues after the cessation of oviposition and does not subside until the end of October. Females caught during this period appeared to have active ovaries, though the eggs \rere not. completely forned. Although the follicular actlvity appeared to be proceeding, the follicles theroselves ltere apparently at a stage of inclpient involution. The fornation of adipose tissues in the abdoninal cavity of messeae begins early, at the titre when oviposition is being discontinued, although ovarian activity has not conpletely subsided, as was denonstrated by findlng follicles at different stages of developmen!. With further fornation of fat body, a parallel involutive process takes place within the follicle, until the ovaries flnally lose their resemblauce to active gonads. Froo the beginning of November unEil the end of February messeae ls to be found in a state of conplete hibernatiog i.e.r lt remains passivf,@not react to light, and cannot be roused, even by touchr fron lts wi.nter lethargy. Fron the beginning of March, the hibernation cooes to an end, when messeae nigrates in large numbers fron its cold quart.ers to stables where animals are kept. At that tine, the stored fat has nearly di.sappeared, and the females begin to feed on blood, and the ovaries become reactivated. The first oviposition of feuales of nesseae which were brought to the laboratory occurred on 17 !4arch, when the mean outdoor teDperature was 10.70 C. Whlle messeae hlbernates in a state of lethargy, typlcus maintains a certain degree of actlvitfilis-was shown by its perlodical feedlng on bLood and its actlve aensory reactions. The differences in physiology and behaviour of messeae and typicus during hibernatlon was attrlbuted to nicroclinatic factors, Particularly the temperature of their habitat. While Eesseae prepares for hlbernat.ion ln Sept,ember, typicus does so at the beglnning of October; lts physl,ological adaptation for hlbernatlon differs somewhat fron that of nesseae. The blood feeding of typicus continues during Novenber-Decenber, but ceases conpt@Tn January. The nunber oF6Gil'-fea females decreases proportionally with the fall ln the outdoor temperature. Thus, the feeding activity of typlcus is directly lnfluenced by the mlcrocllnatic condltion of its habitat' Particularly the temperature. Besldes which the process of digestion of the blood is very slow; fresh blood in the ventricules dld not change ln colour for 8-10 days or even longer. In typicus ovipositlon ceases when the mean outdoor tenperature ls 11.50 C, and ovarian-ZE-elopment is conpletely suspended at 5-7o c. The reproductive functions cease conpletely by the end of October; the last oviposition nas seen in the laboratory on 14 October. The winter temperature ln the stables where typi.cus rests ls higher by 5-6o C or more than the outdoor teaperature, depending on ttre-EtiiEure of the st.able and the number of cattle within. Thus, the cessation of ovulatlon and the arrest of the follicular developuent occur in the two species nerely aE different times, but the teDpelature conditions are approxlnately the sane. The process of foroation of adipose tissue which in messeae is conpleted during the prehibernation period, is prolonged j.n t.ypicus until the coldest days. By perlodical feeding on blood, -!)EiS_ replenishes its reserves of fat which have becone exhausted by its Eore active netabolism; an activity caused by the hlgher temperature within the stables. It ls known that the netabolisn of the insect is dependent upon the internal temperature whj.ch is proportional to the tenPerature of t.he environment. Duri.ng Novenber-DecerDber, the temperaiure in many stables is about 10-150 C, a level which 1s above the liults necessary for the mosquito nutritional actlvlties. The nunber of typicus wlth adlpose rissue progressively increases throughout the inltial period of the wifi3ffi!- to January, at the end of December about 8Z of the mosqultos could be seen wlthout a reserve of fat. In January when the tenPerature wlthin the scables falls below the linits necessary for nosquito feeding activities, typicus passes from a state of seni-hibernatlon to complete hlbernation, and i.ts decreased need for energy is supplied by endogenous caloric oaterial froo the adipose tissue. The outdoor temperature begLns to rise progressively until it reaches 60 C in the second half of February. By that tine t.he stored fat in typicus, whlch is less than In rpesseae, is almost exhausted; bloodneals are, therefore, reE6ffied and folllcular activiEl-6@ns vBc/90.2 t'[AL/90.2 Page 28
afresh. 0viposltion starts at the beginning of l"larch, when the mean outdoor t.emperature is 7.50 C.
In Romania, as uentioned under 1.2 above Duport. et al. (L974) showed that the potential vect.ors of nalaria are: atroparvus, W, naculipennis s.s., and sacharovi. They explained that in 1961, the rffifi6,tsilpr"yingEs-discontinued in a56iiE-EZE of the endenic area lhat enlered the consolldation phase of the nalaria eradicati.on Prograrnrne. The absence of indigenous nalaria cases led to discontinuation of the spraying fron 1965 in the whole country. The year 1961 rnarked the appearance of dieldrin resistance 1n the anophelines and fton L964-1965 rooderate DDT resistance was recorded in members of the An. nacullpennis conplex. During the 4-5 years that elapsed after the cessation of spfrffifrfiilEptreline density increased but not in a regular manner; the collective systetr in agriculture and in donestic animal raising changed the concenlracion sites of nosquitos, thus represenLed the technique of zooprophylaxis. In 1973, anophelines were rarely seen in hunan dwel1lngs, unlike the situation that existed before the introduction of house spraying. This does not represent a nodiflcation in mosquito behaviour, but it is a consequence of inproved living conditions of villagers. They generally undertake control of nosquitos by indlvidual application of insecElcides, and prevent,ion of nosquito entry into their houses. The change in anopheline species conposition was observed at Enisala locality, Tulcea district due to the dininution of sacharovi populat.ion denslty. For example, the proportion of thls species dropped fron 96.82 in 1961 to 2.3 Lt L962, to zero ln 1963. This was not an isoJ.ated phenornenon,as this species has not been encountered on the Ronanian llttoral startlng fron 1963-1964.
Bilbie et al. (1978) carrled out an investlgation to update the knowledge of potential vectors in the previously endemic areas of the Danube plain and Dobrudja, since the nunber of malaria inported cases ln Romania has been lncreasing and could lead to rei.ntroduction of oalaria transmission. The investlgatlon was carried out during L976-L977 coveri-ng 48 localities in seven districts. The choice of the localltles was based on the presence of a hign incidence of rnalaria and the predominance of its vectors before the introduction of malaria eradication. The investigation conprised recordlng soclal and environmental conditions, locatlon of the breeding sltes, indoor restLng collection, determlnation of species conposi.tion and carrylng out insecEicide susceptibillty tests. Eggs were raised from adulc females caught alive for identification of nembers of the An:_naculipennis_ conplex. The results showed a general decrease ln the denslty of theTonDer vectors. This was attributed to soclal and environmental changes, of which reference was oade:
(a) residual house spraying carried out during the nalaria eradj.catlon canpaign (1949-1960) resulted in a general reduction of the endophilic specles nocably sacharovi and atroparvus;
(b) almost complete elimination of many breeding sites due to extensj.on of agriculture and improvement of nater Danagenent;
(c) the disappearance of some feeding sources due to the numerical decrease of draft animals as a result of nechanized agriculture;
(e) the high nortallty anong nosqultos due to the use of insecticides particularly organophosphorus conpounds in agriculture and ln individual farms.
The quantitative reduction ln ahopheli.ne fauna Ied to changes in species composition of the forner four najor vectors: sacharovi, atroparvus, W and maculipennj.s s.s. The essential changes have been: the disappearance of sacharovi, the considerable reduction in atroparvus densj.ty, and the prevalence of messeae. The situation of these former vectors was shown as follows:
- sacharovi had been the Dajor vector of malaria iD restricted areas along the Black sea sh6ffis presence in this area of Rooanla was regarded as the extreme north adaptatlon linits of the lledlterranean climate. It was responsible for severe epidenic ltaves ln Constanta and Tulcea districts where the prevalence of malaria was often as high as 1002. The species has been under continuous nonitoring until its disappearance was recorded in 1963 (citing Duport et al., L974 - as shown above). The present investigation carried out during L976-L977 confirned the absence of sacharovl from several localities and areas it previously occupied. vtsc/90.2 r'tAL/90.2 Page 29
- atroparvus in the past had been an inportant vector of nalaria through its presence in rnost of the localities of the endemic areas. It used to be quite widespread in the country and its breeding occurred in sites with hlgh rdater salinity, buE its biononics and vectorial efficiency varied fron one region to another. Now, it has decreased in numbers in nany localities. 0f 32 locallties investigated, in only six did atroparvus constitute over 502 of the anophelines collected. Conparative observations in 20 localities where infornation on the anopheline species coopositlon 20 years previ.ously was available showed that the proportion of atroparvus decreased in 13 localities. In certain areas this reduction was quite oarked, but in others it was less clear.
- pesseae has now become the predooinant species in the whole area investigated. In 26 out of. 32 locali.ties exanlned this species constituted over 507 of the anoPbelines collected and in 15 localities 1t even exceeded 802. Previous data showed that this species was much less widespread. In 17 out of 20 localities examined, messeae showed a roarked numeri.cal i.ncrease. The previous house spraying of the malaria .EEGlot canpaign affected the anthropophilic indoor resting sacharovl and atroparvus Particularly in Dobrudja, but had lit.tle effect on ry by virtue of its exophi.lic tendencies allowing it to escape the action of the insecticide.
- macullpennls s.s. is the fourth forner vector occurring especially in hilly areas. Its role in nalarla transmission 1n the past ltas considered of low order of nagnitude. Its prevalence now has not been changed except In some localities where its proportion decreased.
In conclusion, the authors considered that with the present situatlon of the former vectors, the chances for reintroductlon of nalaria in the Danube plain and Dobrudja has been considerably reduced. This has been particularly due to the disappearance of sacharovi and to the quantitatlve reduction of aeroparvus. llowever, the prevalence of the iatterspeciesincertain1oca1it1es,andthepffi?veryh1ghdensitiesofry in some areas should be kept ln mind, although the latter specles in the past had a very 1ow sporozoite rate (0.07i().
In Bulgaria, Dintchev et al. (1960, L962) lndicated that fron early studies the following members of the An. maculipennis complex rrere recorded in the counEry: maculipennls s.s. (=gypl*_), and sacharovi. Other anopheline species encounEered were: superplctus, -W!.ii., .!gS (pseudopictus), claviger and marteri. Of all these species, only naculipennis s.s. and superplctus were playing an inportant role ln malaria transmissi.on. Ic was not posslble to deternine the role of the other species. The species composition of anopheline fauna on the Bulgarian littoral of the Danube had noE been exactly detemined before 1956. Following the convention to undertake malaria eradicaEion on both sides of the Danube, the authors carried out systemati.c surveys covering 28 localities on the Bulgarian side of the Danube during 1956-1958. Species of the An. naculipennis conplex were found to consist of; gglg $3.L"A), lypicus (32.L%), nelanoon (f.82), and atroparvus (O.3Xi - this was a collection from a stable at a single locality). It was observed that messeae clearly predoninated in the eastern half of the study area, while in localities sfffil- 18-20 ku fron the Danube bank populations of typicus exclusively existed. In conclusion, the authors anticipated that the progressive drying and cultivation of land in the Danube plain, whlch started in i944, would lead to changes ln the breeding conditions of anophelines, and consequently the eradicatlon of malaria fron the Bulgarlan Danube littoral in a fev years.
In the USSR, informat.ion on the distributlon and vectori.al importance of nenbers of the An. naculipennis complex was presented by Arteni.ev (f980) as follows:
- maculipennis s.s.: Before eradicatlon of malaria in the USSR,maculipennls s.s. nas the urajor vector of nalaria in Georgia, Armeniar Eountainous areas of Azerbaijan and Dagescan, and in certain localities of the northern Caueasus. At present, nacullpennis s.s. acts as a potential vector. Its vectorlal efficiency is probably lower than that of sacharovi, superpiccus and .EfSEig.
- melanoon: Thls species is found only in hunid areas in the plains which have warm ltinters. Formerly, i.t nas a malaria vector ln some areas of Lenkoran lovland, Abkhazia, and l(abards. Its vectorial efflciency rras less than Ehat of ]@-and sacharovi. vBc/90.2 t4AL/90.2 Page 30
- messeae: Thls specles is wldely distributed in the USSR. In the east, lt reaches the noffi-tern Manchurla and Blagoveshchensk. The southern boundarles pass through Central l(azakhstan, the lower reaches of the Enba river, and the foothill areas of northern Caucasus. Feoales of nesseae hlbernate ln cold shelters far away froo thelr hosts. Hlbernation of messeae ts conptete and the fenales never take bloodmeals in wi.nter. In the lloscow ..gi"", dlapauslng (prehlbernatlng) feuales are first observed ln July, and by nld-September they constltute a najorlty of the anophellne populatlon. In the spring, fenales of nesseae migrate out of shelters of different tyPes at different tLmes and occaslonally nfgratioo lray last 1-2 rlonths. Near Moscoltr the migration froo shelters nay vary ln dlfferent years fron nid-Aprll to uid-l{ay, usually occurring at a nean dally teuperature of 4-8o C. In suomer, messeae fernales begin to fly aud feed when the temperacure rlses to 70 C; the upper finft of ttre actlvlty is at 25-300 C. At 25o C, thelr blting frequency is high, but at 30o C ls nil; the uPPer Iinit for the life of the adults is 35o C. The optinal temperature in resting places in suomer is Lg-2to C. This is a hygrophillc specles, and it begins to avoid dry resting places when the air hultldlty ls below 652. Water losses i. ry occur roore rapidly than in any other anopheline species, and Chls appears to be the uaj.n factor Preventing 1ts southward spread. An. messeae rras the species whlch stlmulated the aPPearance of the term "anophellsn without nalarla". The high densltles of thls species in northern Europe and Siberia were not coDpatlble wlth the absence or lou lncldence of nalarla; the xoain cause of this phenomenonbeing the low temperature. In the latitude of Vologda, it ltas estinated thac 1n oae out of three or four years the tenperature is sufficlently high to allow the coopletj.on of one sporogonlc cycle. In the latltude of }loscow, a cold_su-.gf occurs once every three or foirr yEars wh-ennalarla transolsslon becoues inposslble. Thust adverse temperature condltlons solely make messeae an lnefflcient vector. However, the susceptibillty of pesaeae to malaria parasttes, lts density, degree of contact wlth nan and survival rates are all sufflclent characterlstics that would allow ualarla transmisslon to occur. Thls had been repeatedly wltnessed ln the past, when large outbreaks of nalaria occurred ln che nlddle belt of Russla or Slberla ln certaln years.
- atroparvus: The northern boundarles of this AtlaDtlc speci.es ls roughly a stralght line fion Lallnlngrad in the west to Astrakhan ln the east. Thls species ls particularly abundant ln the southeru lJkraine and northern Caucaeus. It also extends southltardly to Alder and Gudernes, and ls coonon in the Crlnea. Unllke W, atropoarvus hibernates in relati.veJ.y waro quarters in areas of ulld wlnters. Durlng hlbernatloa, the temPerature usually varles fron 3 to 90 C, and only occaslonally falls to zero. lllbernating feroales exhaus! thelr fat reserve rapldly and are obllged to take bloodoeals from man or animals during ninter, but the ovaries do not develop, as the bloodneal ls used for fonnation of fat.AstenPeraturer1ses,[email protected] atroparvus tends to be more prolonged than in messeae under the same cooditions. ln the past, bttlng of atroparvus durlng hibernatlon ltas consldered at tiues as of great epldeniological tnportance, since it favoured the fornatlon of foci of transnisslon withln houses. l'la1arla cases rrere seen where the proportion of infected specimens among hibernattng feuales nas as high as 2O-3O2. However, early heating of the rooms, though favoured the cessaEion of hlbernation, it caused the death of dlapausing fenales and thereby ellulnatlon of uicrofocl. Because of lts distrlbutlon in regions of tenperate cllnate, atroparvus had not been an active vector ln Ehe past. Nevertheless, it had been respons1bffibIena1ariafoc1incertainareasoftheUkra1ne,theCrineaand Dorthern Caucasus durlng the last century.
- sacharovi: This is the oo6t southerly and Ehe mos! thernophilic species of the An. r.",rliiffiForplex ln the uSsR. It ls the donlnant specles in ttre plains of Transcaucasus and Dageslan, and is abundantly present ln northern areas of Turkoenia and Tadjikistan, and lt atso o"cnrs in lbzakhstan. It penetrales lnto northern lqzakhstan up to 460 N. There had been nugerous records of this species in the Past in southern areas of Turknenla, Uzbekistan and Tadjlklstan, but these are no longer valld. If this species had been present in the hotter r-gions, it probably dlsappeared after the instltution of nalaria control oeasures. The CenEraI Aslan and Transcaucasian forms of sacharovl differ appreciably in their ecological requirements, and there has been evidence reported by V.N. Stegnil that the arrangernents of the polytene chromosomesof the two sPecies are dlfferent.l Ob.rionsly, ertenlev presenced his notes before the flnal deslgnatlon of the
1. The cwo fbrns have now been separated; the naroe An. nartlnius has been reinstaEed as t,he valj-d name for the taxon existing ln Central Asla, and the nane An. sacharovi has beeo - relained for the Transcaucasian laxon aee Stegnil (f976), White (1978) and Stegnii (1982) in Dp. 27. 29 and 31 respectively in VOLUMEl, under 1.1.2. wc/90.2 MAL/90.2 Page 31
two taxa as independent specles. As he expected this designaEion to materialize, he reviewed the bionornics of sacharovi in the USSRon the basis of lwo separate forms: the Centra1As1an(nov=ggtil"''dtheTranscaucasian(now=sacharovi).Therefore'the sunmary of his review shown below should be interpreted according to the new designation of two independent taxa. In Central Asia, where wlnEers are relatively cold, hibernation follows the same pattern as that of nesseae, i.e., the females rest in cold shelters and do not feed. In Azerbaijan, the hibernating habit is slnilar to that of atroparvus, hence the possibility of man to contract Che infection during erinter should not be excluded. In both Central Asia and Transcaucasus, hibernation usually ends in February, bu! females entering hlbernation appear earlier in Central Asia, usually in Septenber. In Trnascaucasus, where the clinate is nild, hibernation begins I-L L/2 months later. Norrnally, the forn of Central Asia has 5-6 generations, while that of Transcaucasus has 6-7 generalions. In Azerbaljan, the seasonal prevalence varies from one area to another. Where teoporary pools predominate and dry up by oid sunner, the density peak oecurs j.n June, after which the density decllnes progressively reaching near zero by the end of the summer. In areas having nunerous perrnanent breeding places and hot c1imat.e, the density remains very high throughout the sunmer and the first half of the autuon. Very large oumbers of diapausing fenales cone Eo hibernate ln houses. A third seasonal density peak Day still be seen usually in cool areas of the foothills rdhere many sui.table breedlng sites occur. Altbough enoruous numbers of anophelines are seen at the beginning of hibernation, very few of them survive the ninter. An. sacharovi is considered the nost dangerous nalarla vector in the USSR, with Transcaucasian forn showing a nuch higher vectorial efficlency than the Central Asian forn. The ualn reasons are.' the hish temPerature extendiirg the season of anophellne act,ivity and consequently the trlnsnission season is prolonged; the persistence of a high anopheline densitles fron year to year; and the endophillc hablt that results ln a high degree of contact with nan. Al1 these characleristics are uuch less nanlfested in the Central Asian populations.
In Greece, Hadjinicolaou & tsetzios (1973a) whlle presenting the results of their investigation on An. sacharovi ln Thernopylae village ln Lania plaln provided sone inforrnation on the anopheline fauna of this area. Lamia p1ain, whlch is situated at 190-250 km northwest of Athens, was fornerly an area wlth a high degree of nalaria endenicity. The vector species were maculipennis s.s. and sacharovi of the An. naculiPennis comPlex, as well as superpictus, but sacharovl was considered Ehe nost inPortant vector. Other Anopheles species consi.dered as non-vectors were: @., claviger, algeriensis, pluubeus and qg!. The Lania plain was subjected to intensive DDT house spraylng fron 1946 to 1959, after which perlod no residual lnsecticide has been applied for nalaria control. Prlor to DDT spraying, sacharovi was the most predominant species ln the lower part of Lania plaln, while oaculipeiriris s.s. and ggg:pig were rePresented by proportions ot 4-L7Z and 1-82 of the total vector species collected respectlvely. During 1968-1970, catches showed that the most predominant specles was sacharovi standing as the potentLal vector of nalarla in Greece. After World War II, a lot of drainage work has been done in the Laoia plaln, particularly ln freshwater marshy areas, and thousands of hectares have been reclained for agricul-ture. This resulted in the vlrtual dlsappearance of naculipennis fron the area. In addltion, a strean that flowed fron the hills, through the plain, to the sea has been dlverted for irrlgation, and [email protected].
In Turkey, some informatlon was provided by Postiglione, Tabanli & Ransdale (1973) on the distrlbution of members of the -fronAn._-gaculipeglg. coroplex related to the breeding babitat, as shown under 1.2 above. fdt6er infonnation provided by the saroe authors, maculipennis s.s. is the most widely distrlbuted in Turkey; its area extends fron the west coast to the eastern highlands. An. subalpinus has been recorded tron the Black Sea coast, European Turkey, the l'larnara Region and the central Anatolian plateau. Both nacul.ipennis s.s. and subalplnus nere present in hlgb densities ln the formerly nalarious plains of Biga, Cannakale provi.nce as well as in certain areas in northern Turkey. However, their role in maLarla transnission in mauy places was obscured by the simultaneoug presence of sacharovi or superpictus or boch. r{n. sacharovi is undoubtedly t'heoajorvectorofna1arf!iE-Gkeyfrffireaofaistffitendsfronthe rrestern and southern coastaL plains and valleys, to the hot southeastern provinces bordering Syria and lraq. It also extends to the central plateau, but lt is absent fron the eastern and northeastern highlands, and fron the greater part of the Black Sea area. It is the donlnant species ln al1 areas which are still malarious or where oalaria resurgence has occurred. A1l three specj.es of the An. uaculipennls cooplex hlbernate as vBc/90.2 rrAL/90.2 Page 32
adults ln Turkey. In general, humandwelllngs are sufflclently heated durlng winter, thus they are too hot and dry for nosquito survival. In contrast, stables and other aninal shelters are cold when they are eEpty during the day, but at night after the anj.mals enter thenr they become warn and sufficiently hunid to pernit mosquitos to feed and survive throughoutthewinter.ontheotherhand,@fena1eswerefound1ncornplete hibernation under subzero temperat.ure conditions in natural shelters. Colleccion of mosqultos fron day-tine resting shelters and by baited-net traps Ln Turkey, indlcated that fenales energing fron hlbernation were short-ltved, and relat.ively few feoales survived untll the appearance of the adults of the flrst sunner generation. Adults are invarlably scarce during April-Ilay, and the build-up of denslties varies between places rather than between species. The regions of greaiest nalari.a receptlvlty are those with irrigated cult,lvatlon where the extent of breeding depends on agrlcultural. practices. In these areasr hi.gh adult densities are not observed until JuIy, wlth peaks usually appearlng in August and early Septenber.
Ransda]e & Haas (1978) provided further lnformati.on oo the hibernatlon of nernbers of the An. maculipennis complex (including sacharovi) as well as superplctus in Turkey. Diapauslng (prehibernatlng) fenales probably start to appear in August or early Septeuber. Thus, the auturln populations are composed of two groups: older, non-diapausing females' whose larval development nas conpleted during the sunoer, and younger, diapausing fenales uhich will eventually give rlse to the surmer generations of the following year. Diapausing fenales nay take one or nore bloodneals after eoergence, but appear as the season becones progresslvely cooler. Most females pass the wlnter in stables, where the cool, humld envlronment ls more favourable to thelr survlval than the deslccating condltions ln human dwellings, and where continued feedlng on anlmals leads to depletlon of any sporozoltes that may have been forned. Though the posslbility exists, ninter transuission has never been recorded in Turkey, hence of llttle epideniological significance. Reactlvatlon of nosqultos during the sprlng occurs at tenperatures below the threshold of the ualarla parasites, or under condltlons ln whlch the sporogonic cycle is greatly prolonged. Therefore, it is inprobable that newly reactlvated nosqulto are able to t,ransmlt malaria ln the spring, though they oay acqui.re an lnfection at that time, and some can survlve to a potentially dangerous age as was establlshed in the USSR(citing Deti.nova, L962). However, reactlvatlon occurs during the unstable conditlons of the sprlngr which are characterized by intenaittent warm, cold and storny perlods. Observatlons 1n Turkey lndlcated that nost nosquitos have a rather short reactlvated life, wlth very few surviving long enough to become infecttve.
(1982) Clarke in an unpublished report to !lHO) gave more specific lnforoation on lhe seasonal dlstrlbutlon of sacharovl in pukurovar plains, sout.h of Mana. During the ttinter 1n the low-1y1ng arei of Cukurova, sacharovl does not enrer rrue "i?GGE hibernation. Internlttent feedlng does not lead to oi6lEffivelopnent and the females remain ln gonotrophlc dissociation throughout the co-Lder Donths. The first male specimens of sacharovi whlch indicate the energence of the flrst adult generation were collected on 25,m9March1980,l981andti82resPect1ve1y.Twopeaksofsacharoviwere observed. The flrst occurred ln l,lay-June following a oarked lncrease in density in early Aprll, then the density rose again forning the second peak ln Septeuber-October. Thereafter, a decline lras observed until the loner wlnter densities were reached by December. Two peaks of nalaria casea occurred approxlnately one nonth after sacharovi peaks.Thelowdens1tiesobservedinAugustwerenotduetona1ariavector"ffitto the effect of the aerial Lnsectlclde applicatlon on cotton plantations from uld-July to oid-Septenber. Cotton crops represented, SLll of crop cultlvation in the lower Seyhan irrigatlon scheue in 1981.
tQsap (f987) sunmarlzed the results of hls observaELons on the effect of photoperlod on the developoent of sacharovl i.n controlled lnsectary and field condltions in Turkey. Both laboratory experlffiI- fietd observations showed that long days increased the bitlng rates of sacharovl females, and shortened the developmental perlod of the irnnature stages and the length of the first gonotrophlc cyc.le, hence a rapld population increase under condltions of long days. In the fteld, oviposltion ceased when the phoeoperlod became shorter than l0 hours and the temperature was less than 18o C, but this dld not occur in the laboratory at 8 hours photoperiod, because the tenperature was maintained at 25 + 20 C. I! was concluded that decreasing temperature coupled wi.th decreasing day length appeared to be important factors ln lnltlbting hlbernalion of the adult females.
1. Written also Chukurova. vBc/90.2 I|AL/90.2 Page 33
Recently, Mlniof,lu, Kasap & IGsap (1958) studied the relationship between the seasonal density of sacharovi and the malari.a lncldence in Chukurova area. The observaEions were carried out during the breeding season of sacharovi, i.e., February to November. The densicy of sacharovi started to increase from February reaching a peak in l"lay, followed by another peak in Septenber. A second peak was observed in July, but was not as high as the other two peaks. Malarla cases lncreased at least one or two nonths after the seasooal peaks of the sacharovi. populatlon.
In l'lorocco, Guy (1959a) wrote a comprehensive memoire on the taxonony of lloroccan anophelines with notes on their blology and dist.rlbutlon. Further, Guy (1959b) presented the avallable infornation on the distrlbution of anopheline species existinB in the country and their relation to nalarla transmlssion. An. labranchlae, the ubiquitous nalaria vector in North Africa, was found to be widely distributed in the Mediterranean and Atlantic coastal areas in I'lorocco. Its inland distrlbution extends fron Rif to l4oyen Atlas. lts southern linit is demarcated by the northern slopes of the Haut Atlas, buE it was recorded further south ln some oases such as Fouo-Zguid and Tagounit (clting Gaud, f953). It is essentially a species of the rnaritine plains as it forms 952 of the anopheline populatlon on the Atlantic littoral extending from Tanger to l{azagan Isouth of Casablancal. Two observatlons illustrate the close relationship between malaria [email protected]'as!heconsiderab1eincreaseinspIeenindices fron l'lay to October which coincided with the great frequency of the population of this species. Secondly, examinatlon of the nap of the endenic zones of malaria laid dorn by Dr J. Gaud in 1952 showed that there was a zone 1o the reeion of llabat-lleknEs-Fez. where the spleen iodlces were well ovet 257, and this was the piinclpal zone of labranchiae.
Guy & Holsteln (1968) reported Ehe results of further studi.es on the anopheline fauna of the llaghreb. l{lth regard to laPranchiae, its southern linlc was in the Eiskra region ln east Algeria, sllghtly above 35(J N latltude. Careful entomological searches provided evidence that labranchiae was present ln Ferkane and Ain Md1la 1o the departDent of Annaba,sri'ghtI'mn1atitude.Nevertheless,1tI'asfoundin}toroccos1ightly south of 31o N latltude Ln Osarzazate provlnce. Its presence in Algeria was connected with autochthonous cases of nalarla grouped Ln uuch denser foci than those usually seen in arid zones where this specles does not exlst. Some observations stinulated the authors to investlgate the condttlons of hibernation of labranchiae as the uajor vector of malaria j-n North Afrlca. Durtng the fourth quarter of f96fr5Eervat1ons carried out on the AtlanEic and lledlterranean llttorals, showed that the populatlon of labranchlae conslsted of two fractlons: one fractlon was forned by fenales passing through partial hlbernation as evldeneed by the presence of fat body, fresh blood and cessatlon of ovarlan development' and the other was forned of gonoactlve females. In the Larache region, south of Tanger on the Atlantic coast, t.he proportlon of females having fat body and the ovarles in ChrlstoPhers' stages I and II, lncreased fron 102 to 5OZ as the distance froro the ocean to the lnterior lncreased, whlIe the proportion around Ehe l'ledlterranean coast was only 3-72. Out of 434 fenales of labranchiae dissected during the last quarter of 1965, 43.92 ltere gonoactlve. Durtng tne ?F!ffi"r of 1966, December 1966 and the first guarter 1967, saropl.es of labranchlae fenales collected frorn the sane Larache region were dlssected. The proportion of females wlth fat body did not exceed 7% of 142 dissected in t'larch J.966, and there rras a high proportion of fenales with ovarian stages III-V in the whole period of observatlon. During the rsinter ot I967-L968, all the fenales collected were gonoactlve and none had fat body, despite the fact that winter nas very severe. It waa, therefore, presuned that some factors other than those of the teDperalure and huoldlty may induce true hlbernation. To deteroine the epideulological irupllcations of the presence of actlve populatlons of labranchiae on the Moroccan littoral during the who1eyear'aninfantblood5urveyn'."flst"'"ti""11ycon Benmansour, Laaziri & Ilouki (L972) suunarized the records of anophelines in llorocco and discussed the geographlcal, cliuatological, economlcal and operatlonal factors influencing specles dlstributlon. They also pointed to observations carried out by Holstein1n1966'1ndicat1ngth"t@isthepr1nc1pa1vectorofna1ariain llorocco. Its spatlal and seasonal distrlbution, longevity, degree of contact with rnan are characterlstlcs wblch en8ure uaintenance of malarla transmission. vBc/90.2 'tlAL/ 90.2 Page 34 In AJ.geria, HoJ-stein et al. (f970) further listed and roappedthe distribution of anopheline species with special reference to the fauna of the Sahara. This inforoatj.on was needed for extension of the nalaria eradication programmeEo the south of Algeria. The enlomological studies that lrere initiated by the Sergent brothers at the beginning of the century (Sergent & Parrot, l96f) were pursued up to recent years by adding new infornation on anopheline dlstri.bution in the country. Infornation gi.ven here concerns only labranchiae, while species other than those of the An. macu.l.ipennis conplex are shown under paragraphs 2 and, 4 beJ.os. The distribution of labranchi.ae was shonn ln 1968 to be intheextrenesouthofAnnabadePartmentinEhepre-ffie.ThePresenEsurveys showed that larvae were found south of Laghouat, thus extendlng its existence beyond the precipitatlon curve of 200 lnm per annun. Reference was made to two prevj.ous records of labranchiae in the Hoggar region of the Sahara at Silet and Abalessa. These have been doubted since they were based on slngle feuale specinens obtained by night capture. The authors considered that these specimens uust have been iroported through passive transporlation by a truck or in tents of the noroadscoming fron the north. Rarnsdale& Zulueta (1983) who studied the inpllcations of construction of a trans-Saharan highway [see subsection (ii) 2 below], underlined that labranchiae ls the most inportant nalari.a vector in the western Mediterranean and is stiGliGule for foci of P. vivax near the Algerian coast. They agreed with Holstei.n et al. (1970) that the nostGffily llnlt of labranclr.e ls Lagtuai on lhe southern slope of the Atlas, and that the presence of specine"" thit species previously recorded at Silet and Abalessa "f must have been due to passlve transportation. To confirm this, they searched for the possi.ble existence of a relict population in Hoggar, but lrere unable to find adult specinens or suitable larval breeding sites. ln Libya, labranchiae was recorded fron Tripolitania which seeo6 to be its easternmost linit of distributlon ln North Africa (see under I.2 above), as indicated by l,tacdonald (1982). In Tunisia, long before the nalarla eradication programme was established, Juolner (1959) showed that labranchiae is widely distributed in all northern coastal areas, and extends also to ttreJffiETwo lines: one passing from Tabarka to Nefzaoua, and the other extendlng fron Mahdia to Nefzaoua passlng through l(airouan and Sbeltla. In his assignment report, Wernsdorfer (f973) lndicated that based on the pre-eradication survey which was carried out ln 1957, labranchiae has been considered as the prlncipal veccor ln the northern and central regions of Tunj.sia, whi.Ie sergenti acts as the main vector in the southern region. In Israel, Saliternlk (L957) reviewed t,he historlcal observati.ons on the seasonal distrlbution of sacharovi whlch are useful to recapltulate in vlew of the recent reappearance of tiffiies (see under 1.2 above). ott hibernation, the behaviour of sacharovi was sinilar to that observed in Turkey. Due to nild winters in Israel, no true ET6-ernation ltas found among loca1 anopheline populations. At the beginning of nlnt.er (0ctober or Novernber), nales of sacharovt dlsappear and ferfilized fenales begin to store fat and enter a state of seol-hibernation. According to Mer (1931) hibernation begins in October at a temperature which is usually higher than that of the spring when their activity conmences. The fenales which eventually enter into hibernation do noC energe from pupae with stored fat body, but accumulate it prlor to hibernation. The tendency to accumulate fat body occurs lrhen pupa develop at loer autumnal temperatures. The length of time that the fat body renains ln the fernale depends upon the winter temperatures. If the Idinler is nilder t,han usual, the female nay obtain soue bloodmeals during hibernation, develop its eggs earlier and even occasionally oviposlt during the ninter. On seasonal prevalence, data lrere presented to show the nonthly lemperature and the percentage of sacharovl of the total annual catch. At tenperatures of L2.4, 13.2 and 15.20 C tn January, February and l4arch respeclively, the percentages showed that sacharovi nay reappear in large numbers a tronth earlier than usualr buE 1f the winter was cold with heavy rains, the reappearance of sacharovi nay be delayed by one utonth. The data also showed that sacharovi has two peaks: April-July and October-December, lrlth a falling density Uetw&-n .luty and Septenber. An increase in the numbers of adults was observed in areas where breedlng continues throughout the surnmer. Changes in the physical condltlons of loca11zed breeding sites roay permit continued breeding, thereby the denslty of sacharovi adults increases during July-Septenber. vBc/90.2 trAL/90.2 Page 35 Pener & Kitron (1985a & b) reported on the reappearance of sacharovi in Israel (see also under 1.2 above). An. sacharovi which used to be one of the most iDportant vectors of mal.aria in Israel, wafrffi-d iron 1960 to 1969. It was subsequently rediscovered in the Golan helghts by Ben-Dov (1971 - see under 1.2 above). It is now found in Hu11a valley and along the west coast of the Sea of Galilee. In 1983, it was found 30 tines consit.uting 74"/ of the total nunber of Larvae collecled. AIso in 1983, it was found, for the first time since the 1950ts, in the Halfa adroinistrative region. On Ehe exEent of sacharovi distribution, lhe authors showed that it also exists in the Jordan valley and eastLrards. In the Tiberias region, superpictus and sergentii have always been Presen!' until sacharovi joined them, as shown by surveys made in 1981-1983. Regarding the seasonal distribution, the seasonal changes in prevalence of anopheline species seems to be related rnore to changes 1n their tota.l [relative] frequencies than to actual changes in their seasonal pattern. One possible exception may be sacharovi, which in Che past had two peaks: one from April to June, and one in October-December with a decrease in sumoer (see above). These two peaks were assoclated with two peaks of nalaria cases in early summer (June) and late autuun (Novenber). Based on lhe relat.ive frequency of sacharovi larvae anong all anopheline species, the nonthly distri.bution of its larvae in recent years (I974-L984) shows a clear peak in lhrch. Subsequently, the frequency becomes low fron April to July, and then rises in August for the late sullner peak, and remalns relatively high until November (no data are available for the wlnter season, Decenber-February). llore observations are needed to determine accurately the seasonal pattern of sacharovi. This would show whether this change will persist, and whether it is part of Ehe adaptation of this species to the reinvasion of its former habitats, which have since become rouch nodified through agricultural and urban developroent. In Lebanon, Graniccia (f953) lndicated that in coastal regions, sacharovi predoninates at the beginning of the sunrrer, but gradually is partly replaced by superplctus, then fol.l.owed by hyrcanus and rarely sergentil. In villages of hil1y regions, superpictus (and rarely sacharovi) is followed by claviger tn the autunn and the beginning of the winter, particuLarly ln villages wlth an abundance of wells (cisterns) where it can complete iEs development all year round. In Syria, Abdel-l'lalek (1958) showed the spatial distribution of sacharovi as indicated froro larval surveys conducted fron }tarch 1953 to December1954 (see under 1.2 above). On the seasonal prevalence, the density of sacharovi adults increased gradual.ly fron l'lay onwards reachi.ng a peak in October. tThi-s co"trasts with sacharovi in Israel where it was shown t.hat its density declines late in the sunrner - see above]. Abdel-|lalek further showed that fron November until February, sacharqlli fernales were found inside human habitation and stables in a state of hibernation. 1.6 Resting behaviour & 1.7 Biting behaviour Infornation on che resting and biting behaviour of members of the A3-:_nagglignnig conplex in the Mediterranean basln is available from a lfunited number of count.ries. It is useful to recapitulaLe the early knowledge on the two aspects from the book of Senevet & Andarelll (f956) as a basi.c background. - maculipennis s.s.; This species 1s easily deviated to aninals. Despite being zoophilic, it may, nevertheless, bite man and Eransmi! malaria accidentally. - uesseae: It is a vector of oalarla in certain regions, but in general, it should not be considered as an important vector because it is also zoophilic. It rests in aninal shelters that have few air currents, e.9., cattle sheds, horse stables and pig shelters. - oelanoon: It is a zoophilic species; it plays a minor role in ualaria transmission. In theffiltivation area in the Valence region, Italy, it used to exist in abundance, but there was no ualaria, unlike the situation in [foroerly] rice growi.ng areas in Portugal where atroparvus rJas the most predomlnant vector. -subalpi.nus:IEsro1einoa1ariatransmi'ssionis1essthanthatof.ry.or labranchiae; it rests in aninal shelters and less frequently in human habitati.on. - labranchiae: Its prlnclpal host is Ean, but lE can devlate to anioals when man ls unavailabLe. It is an important vector of ualarla in the }tediterranean basin. lt is strictlv endoohilic. but it exhibits exophilic tendencles under certain condltions. vBc/90.2 r4AL/90.2 Page 36 - atroParvus: It is a domestic species wit.h undistinguished zoophillc tendencies. While it was not considered a vector of malaria in Italy, it was the nain vector in Portugal, Spain and north of the Alps. - sacharovi.' It voluntarily bites man and rests ln human habitation, but i.t can reaait@Timals. In Sicily, Italy, Cefafui, Oddo & Sacci (196f)1 carried out studles on the bionomics of the labranchlae population during 1959-1960 and early 1961 in the Roccamenaarea, Pal.rtol6Gfwhere DDT house spraying was discontinued for three years. Anong these studies were observations on the resting behaviour of this species by direct collections of samples from donestic and extradomestic (natural) shelters (caves, crevices and the under sides of snall brldges), and by rnark/release/recapture experiments as shown in the followtng: - Observations on the dlstribution and the physlological state of Iabranchiae in donestic and extradouestic shelters for whlch the followlng data were presenEed: Table 3(a) Data of collections made in 1959 & 1960 Physiological state Z Site of coLlection Total collected Unfed With fresh blood & females ltith nature ovaries conbined Donestic 4446 28.l 7r.8 Extradomestlc r303 59.9 40 Table 3(b) Data of collectlons uade ln Septeober 1959 Site of collection Total collected Physiological state Z Unfed Wlth fresh blood With nature ovarles Domestic 256 44.8 30.4 24.6 Extradonestlc r48 52.3 L7.8 29.8 The above data clearly show that a high proportion of unfed fenales was recorded in natural shelters. Newly energed fenales seem to prefer to rest as a first step near the breeding sit.es. The data of Table 3(a) also shows that the proportion of fed * gravid females in natural shelters was 40% versus 72"1 In donestic shelters. The gravid females found restlng in natural shelters probably lras composed of the following fractions: (a) those couing to rest in outdoor shelters after feeding on blood until the gonotrophic cycle is conpleted; (b) and those which coupleted the gonotrophic cycle in dornestic shelters and left theo before the oviposltlon time was due. Assuning that t.he duratlon of the gonotrophic cycle in sunmer is 48 hours, theoretically there should be an equal proportion of fed and gravid females, if no moveoent. occurs. As shonn in Table 3(b), the proportion of fenales with fresh blood was greater than that of the gravid in donestic shelters, bu! the sttuation was the opposite in the extradooestic shelters. This supports the suspicion that a proportion of females leaves the donestlc shelters before the conpletion of t.he goootrophic cycle, but the data rrere not sufficient to draw firn conclusLons. The outstanding probleo is to know whether the fenales whlch conpleted the entire gonotrophic cycle in natural shelters had fed outside or obtained their bloodoeal indoors aud left afler feedf.ng. Precipicin tests were run on bloodneal soears of labranchiae females collected resting in donestic and natural shelters. ot. 436 smears tr66l6iEE shelters 9.92 were positive for man, 8Q.92 fot bovid, 4.47 for other donestlc aninals, and 4.82 undeternined. Of 54 smears from natural shelters, 3.72 were posltlve for man, 64.8"1for bovid, LL.2"/.for other donesti.c animals, and 20.32 undeternlned. The hlgh percentage of bovid-positive smears nas not considered 1. The authorst surnmary has been expanded by translating parts of the lext through the ktnd coooeration of Dr F. Oddo. forner LIHOMalariolocist. vBc/90.2 r[AL/90,2 Page 37 significant fron the standpoint of feeding preference, as it only reflects the situation in the study area where cattle represented the most abundant host available for Anopheles. The smears which were posi-tive for man carDefrom houses or mixed dwellings' while the two nan-posj.tive srnears from natural shelters caoe from a cave. These observations indicate that labranchiae feoales rest in the same shelter in which they had fed, as in the case of doroeffiEiErs, and also lhose capLured in natural shelters must have fed on cattle outside durlng suumer, i.e., exophagic. -Mark/release/recapture experlmenLs: Since labranchiae ls a difficult species to colonize in the laboratory because of lts eurygamy, the release exPeriments ldere made with wild-caught fenales with two different strains: nethylene blue for those collected fron donestic shelters, and eosin for those collected from natural shelters. Laboratory observations on slained mosquitos showed that they survived well and their colours remained for a sufficient tioe. The distribution of narked labranchiae fenales in the two types of shelters and the recapture rate6 are shown in Table 4.r Table 4. Results of mark/release/recapture experiments of labranchiae fenales Released Recaptured Source Colour Total 7 Unfed Recapture Colour Unrnarked Total SlEe Blue "/. recap Red Z recap rate rate Domestic Blue 2205 22.6 Dooestic 20 0.9 9 L.24 934 963 Natural Red 722 34.4 Natural 13 0.5E 6 0.83 345 364 Total 2927 Total 33 L.49 l5 2.07 L270 L327 recaP. rate = recaPture rate Although the recapture rates were Iow, the experluents rendered useful indications of the resting behaviour of labranchiae ln relatl.on to domestic and natural shelters. The fenales that originated tffiE-o-estic shelters (narked blue) lrere recaptured ln both donestlc and naEural shelters. Llkewise, the females that originated from natural shelters (narked red) nere recapEured in both donestic and natural shelters. This indicates t.hat the fenales of labranchlae are lndifferent with regard to selection of a certaintypeofsheIter.tretffi7therest1ngshelterisprobab1yinfluencedby exlernal factors, i.e., the avallabillty and proxlnity of one type of shelter or another. The data also show that the recapEure rate was higher in nosquitos that originated fron natural shelters (oarked red). Thls was probably due to the presence of a high ProPortion of younger mosquitos which virtually lived longer. This nay be supported by the fact that the natural shelters were 1n close proxiroity of the breeding siEes, and a larger proportion originally caught fron natural shelters vrere unfed. It was concluded that the experirlent provided evldence of facultatlve exophily in labranchiae in Siclly, in the sense of Senior-White (L9Sq2 and Gillies (1956)2. This behaviour is exhibited by the population as a whole and lt is likely that the assutrption of the existence of tlto distinct population variants: one is endophilic and the other exophilic can be ruled out. The authors furt,her considered the assunpEion that the facultative exophily is due to selection pressure of DDT as inprobable. It is trore plausible to assume that the sPecies has behaved like this since its origin and its behaviour has not been losE despite its long association with oan and domestic aninals. Fron a practical standpointr the irnport,ance of the outdoor resting behaviour of labranchlae lles in the fact that it protected this species from being eradicated by DDT spraying. tlence, labranchiae will be able to invade the domestic environment again, after the disconLi.nuation of mosquito control by insectlcides. 1. Pernission to reproduce Tables 3a & b and Table 4 was granEed by Dr F. Oddo and Pqrassltologia fron the artlcle of Cefali, Oddo & Sacci (1961). 2. See ANNEXI in PARTI, document VBC/85.1 - MAP/85.I, pp. 2L7'2I9. vBc/90.2 NAL/90.2 Page 38 In the USSR,Arteoiev (1980) described naculipennis s.s. as endophilic and resting ln human dwelllngs and stables. It feeds on nan Soth indoors and outdoors. The proportlon of fenales with hunan bloodneals depends on the nunber of cattle 1n a gi.ven farn. An. melanoon ls an exophillc or semi-exophilic specles preferrlng to rest on vegetation, Einr<,ilffials or other huoid outside shelters. In Lankoran lowland, it was recorded from human dwelllngs, but only in snall nunbers. It feeds on lnan indoors and outdoors, but has narked preference for cattle. An. messeae ls an endophillc species to a considerable extent as it was found fn Effiil6-ers in stables, barnl and cellars as ltell as i.n human dwellings. It usually feeds on cattler although feeding on man 1s not unconnon. An. atroparvus is an endophillc speci.es whlch feeds both indoors and outdoors. It prefers toE;a on bovj.ds, but readlly feeds on nan. An. sacharovi in Transcaucasus is endophi1icasithasnotbeenobservedrestinginnacure,ffiCentralAsianforn (= An. nartinius) exhibits a certain degree of exophily. It feeds on Dan but would also feed on cattle when available. In Turkey, Postiglione, Tabanli & Ransdale (f973) descrlbed the resting behavlour of naculiPenniss.s.,[email protected].[lousesorstab1es,orboth'areoften unoccupled, but whether occupied or not, the darker stables offer nore attractlve resting sites than do houses, and usually harbour large denslties. An. sacharovi i.s most common in houses but, like the other two species ls nuch more abund;t in sta5les. Exlt-traps fitced to unsprayed prenlses captured feaales of all three species in various physlological conditions. This conflrned early observatlons in Greece prlor to house spraylng Chat the fenales exhibit a uarked tendency to leave their lndoor shelters durlng the nlght, irrespectlve of the degree of thelr ovarlan developnent. E: On the biting behavlour, the authors poiuted Eo observations elsewhere indlcatlng that sacharovl differs narkedly fron naculipennls s.s. and subalpinus in its degree of anthropophlly. PreciPitin tests run on bloodneal smeara of sacharovi collected fron dlfferent areas of lts dist,rlbutton showed that this species-[Z-s degree of "-frealer anthropophlly (clting Eruce-Chwatt, Garett-Jones 6 l{eitz, L966). Baited-net trapg operated in unsprayed and sprayed villages, as well as analysis of bloodmeal smears of sacharovl collected fron different biotopes in Turkey confirned this feeding preference. The actual anount of feeding on rnan whlch takes place in Turkey clepends on the local conditions that Day provide protecElon for people froo nosguito b1tes. Numerous donestlc animals are stalled in each village at night, and in surmer they are usually dispersed outslde amongst houses. In cooler regions, people sleep indoors throughout lhe year, often on an upper storey, but in other reglons they sleep outside in sunner, on the flat roofs of their houses, or on upper storey balconles, or at ground level, thus the relative availablllty to nosquitos is not constant. Bed-nets are almost universally used. However, all people, whether sleeplng Lndoors or outdoors, are most vulnerable to nosquito bites during the evenlng before they retire, and when they are sitti.ng in the open in their villages. Durlng harvest, villagers often sleep in the fields, shere the sane protection is not offered as that of the preseace of concentratlons of anlnals in v1llages. Even when they return to their vlllages to sleep, they start working in the flelds at dawl aud continue untll dusk, and they often rest in the fields during the heat of the day. Observatlons ln different parts of Turkey showed that people sleeping in the fields were heavlly attacked by sacharovi, and to a much lesser extent by uacul1penniss.s.,andthatinasheltereds1tuat1on'@wasaPers18tentbiter during the day. The lnportant crops in Turkey are cotton, rice and sunflower, and these are harvested during late August and Septenber. By this tlme, mosqulto populations have already reached or paseed their peak denslties and contalned an lncreaslng proportion of older, more epldeniologically dangerous females. Thue in most rural areas, the period when people are oost exposed to mosqulto bltes coincldes with the perlod when the probabillty of recelving an infective bit,e is highest. vBc/90.2 !lAL/90.2 Page 39 In I'lorocco, Guy (1963) described labranchiae as an endophilic nosquito as it is found abundantly in the roorning in human traElEffiiF?nd aninal shelters. Afso in Morocco Sacci & Guy (1960) using irritability tests in the laboratory and conducting field observalions demonstrated that labranchiae evaded DDT sprayed surfaces. The lrritability of labranchiae was nuctrG6Fl-ronounced than the natural moveuent observed j.n untreated corFol b-atches of the sane species. Despite chls pronounced irrltability of labranchiae to DDT, no inferences could be nade as to the lnplications of these findlngs to the anitmalaria canpaign. As these results were of a prelininary nature, it was suggested that nore profound studies should be conducted wlth the following alms: - to elaborace the development of a more accurate Dethod for measuring the irritability of uosquitos on a st.andardized basis; - to detennine the levels at whlch the DDT irritability would exert an influence on malaria transnission; - to deteroine whether the irritability is a result of selection pressure or whether i.t pre-exists i.n nornal populations. No information is available to indicate that such studies have been undertaken. However, indirect evi.dence that nelther irritability to DDT nor the natural facultative exophily of labranchiae had any operatlonal lnplications, comes from the fact that the malaria eradicatlon programmein countries of North Afrlca successfully conpleted the attack phase and advanced to the naintenance phase. There is no evidence that the few residual foci of transmission are due to refractory behaviour of labranchiae. In Algeria, Collignon (f959) in his studies on the biology of the anophelines in the Alger regionr observed the restlng behaviour of labranchiae in many locallties in the northern part of the country. This species is aliE|-iEGcted to places where man or domestic anlnals abound. In general, premlses excluslvely occupled by aninals are much more attractive than those utllized by nan. Stables constitute a oain restlng shelter for thls species, a6 they contaln hunid dark corners protected fron air currents. The Presence of l-abranchiae in lndoor resting shelters during day-fine is not an obligatory constant blological character. The urge for feeding nay at times drive the fenales t,o feed on hosts available in nature. The turnover of the labranchiae population at night causes a conslderable nunber of fenales to wander in nature, eventually leading to exophlly. Observatlons ltere made at a slce where a snall reed shed situated between a breeding place and dwellings. The site was located under trees where sone bovids were stalled. The site escaped the attentlon of personnel undertaking an inagocidal programne applied at that tine. The nunber of labranchiae feoales caughc was sinilar to that obtained fron the same site one year previously. It was, therefore, deduced that the J.arge number of fenales Ehat persist in nature do not cone ln contact nith treated Pretrisesr or that the najoriEy of these are distantly sit,uated in nature, thus escaping the actlon of the insecticide. In sun'nary, the character of endophily or partial exophily of labranchiae females seens to depend on the exterior conditions whether favourable or unfavourable for their turnover. The fenales resor! to lruman habitatlons and their accessible prenises when these satisfy cheir need for feeding and resting. No newer lnforoation could be traced on the resting and biting behaviour of labranchiae in its area of dlstribution in I'iorth Africa. In lsrael, Saliternik (1957) referred to early observations i.n the Huleh swamparea, whereby the greatest concentralion of sacharovi eras locat.ed in houses and bedouin lencs during l"lay-July. However, the hablts ;ffiffunan population nay influence the localized density of nosquitos. For exanple, the frequent folding and traosporting of the tenls during sunmer, and the smoke from fires durlng the cool nights of the aututrn were aoong the factors that reduced the number of nosquitos in the tents (citing l(ligler & I'ler (1932). On the resting sltes, sacharovi prefers to cling to the horizontal surfaces that do not transuit the heat well, such as the underside of beds, wooden shelves and tables, while a ferc rest on walls and spider webs. On very hot, dry days sacharovi was solnetlnes found on the lower portions of the wall.s near Ehe floors. In suomer, sacharovi wasoostlyconcentrated1nstablesandbarns,whi1einwinterit\'asfound1natF atore roorDs and cellars. In the open bedouin tent.s, sacharovi fenales were easily found in the early norning hours before the winds began to disturb Ehen. vtsc/90.2 y.AL/90.2 Page 40 In Syria, Abdel-llalek (1958) observed sacharovi resting in humandwelllngs, stables and other aninal shelters. Its adults werG,tg-ht whiLe restlng on ceilings or roofs. Spider webs hanging frono roofs in nixed dwelllngs (nan and animals) and stables in viJ.lages were the preferred resting sites. Adults of sacharovl were usually associated wlth adults of superplctus in its resting sites. FenalffiGcharovi Irere never caught outside resting shelters. lluir (1982) (unpublished report to WHO)while oq a mission to Syria to part.iciPate in techni.cal discusslons on a posslble change of oalathion used by the malaria control programme, collected data of house-resting densities and the blood digestion stages of sacharovl recorded by the prograrnme fron sprayed and unsprayed villages in the llama area. Dm,rrg Aiy-August 1980, the density of sacharovi in the unsprayed village Idas in the range of.32.5-43.4lroom, while in the r"Iiffi-n sprayed village, it was t-2.4/room. The fed (F); half-gravid (HG).'gravid ratio (G)) in the unsprayed village rras L.44:Q.77:L during July-August. Assuning that the duration of the gonotrophic cycle during that perlod was 2.5-3 days, this ratio gives a prellminary indi.cation that sacharovi in the llama area is endophllic. In the sprayed vlllage, there rras a large deficit in the gravid proportlon; the F:HG:G ratio was 62:7;1, as would be expected fron the effect of nalathion to which sacharovi was still susceptlble. Further, Sadek (1984) (unpublished report to WHO), while conducting observatlons in Syria co assess the effectlveness of perrnethrin house spraylng, recorded the blood digestion stages of sacharovi sanpled by pyrethrum spray collection (PSC) and by exit-trap collectlon (ETC) ln spra;-ye"'-andunsprayed vlllages in the Quneltra area, south-west of Damascus durlng Septenber-October 1983. The density of sacharovi in the unsprayed village was 41.8-7L.6/roon durlng September, and the F:G ratlo was 0.86-I.04.'I, giving a preliuinary indlcation that sacharovi in Quneitra area is also endophilic. During the same peri.od, the denslty r" ffip-r.yed village was 0.7 and 6.7/roon 8 and 22 days after pernethrin spraylng and F:G ratio was 3:0 and 4.8!1 respectively. The sanple of October ln the unsprayed village unexpectedly showed F:G ratio of 1.56:l with a density of 24.4/toom versus 1.5:1 with a density of 6.8/roon in the sprayed village. No explanation was offered as to the hlgh F:G ratlo in the unsprayed village whether some special circunstances lnfluenced the exodus of a proportion of fenales before conpleting the gonotrophic cycle. The nunber of fenales obtalned fron exit trap collecti.on was too snall to allow inferences to be made as windy and cold conditions prevailed during the latter part of the obeervations. onthebit1ngandrestingbehaviourof@someinfonnationisavai1ab1efrom observations made i.n Syrla prevlously during DDT spraying in 1968 and recently in an area under pentrethrin spraying in 1985. Zahar (L974) (clting unpubllshed data by Onori & Zaiar, 1968) polnted out that confirnation of the presence of DDT resistance in sacharovi in the Ghab area, Syria nas obtained during July-August 1968, and at the same tlme entonological/parasitologlcal observations were carrled out t'o deternine the operational inpllcations of DDT resistance. At the tine of susceptibllity testing, sprayed surfaces showed exlensive disturbance from replasterlng and whitewashing. Females of sacharovi were collected frorn dlsturbed and apparently sprayed prenises in fair densitles and at different stages of the gonoErophic cycle, mostly on unsprayable surfaces, though a few were collected fron sprayed walLs. The number of indigenous malarta cases lncreased progressively after the first DDT spraying round of 1968. Exit windoir traP observations showed that sacharovi leaves the house nainly in the unfed and gravid states. The mean rrap mortauffiFfu-l8Z indlcating little effect of DDT spraying, the mean biting density per rnan per night was 8 indoors by dtrect balt capture and 15 by baited net,s outdoors. I"Iostofthepeople1ntheGhabareas1eepoutdoorsinsunmerand@entershouses duringtheear1yhoursofthemorningafterfeedingoutdoors.Th.,s,@Eeemstobe largely endophllic in the Ghab area. Zahat (loc.cit.) further pointed to the area occuring at the junction of the Khabur and Tigris rlvers on the borders of lraq, Syria and Turkey where swanPy areas provide sacharovi with sultable breedtng places. The biting of people sleeping outside during sunoer. and the suspected outdoor resting of sacharovi were thought to be responsible for the persisEence of malaria transoission ln this ecologically horoogeneousborder area despite DDT spraying (citing Zulueta, unpublished rePorE to htiO, L967). Larval suscepttbillty tesCs carried out in October 1965 at Derik in El llasseke province showed chat sacharovl was 8ti1l susceptible Eo DDT. vBc/90.2 \'LAL/90.2 Page 41 Recently, Eshghy (1936) while working in Syria nade observations in the same border area of northeast Syria under pernethrin spraylng covering six villages durlng 29 Septenber-2 October 1985. In each village, 10-12 roous Itere searched for adults with negative results. Bait caplure on four men conducted at one village for three hours comoencing at sunset ylelded only two superpictus. Surveys of breeding places at three [email protected] cul.tivation in some areas near breeffifpl-aces, t[Einhabitancs sleep oucdoors froo June to Septenber. l'lost of the biting occurs outdoors during the transmission season and leads to persistence of transuission ln this border area. Eshghy further explained Ehat it cannot be stated with certainty whether a proportion of the populations of these vectors enters the sprayed prenises, or seeks resting shelters outdoors, lhus evading contact wit,h the sprayed prenises. 1.8 Sanpli.ng nosquitos in flight Very linited infornation is available from the geographical. area under revi.ew. In Morocco, Ballly-Choumara (L973a) reported the results of a snall scale trial for assessing the efficlency of the CDClight trap (of Sudia & Chanberlaln, 1962) as a mosquito sanpling tool ln comparlson with conventlonal sanpling nethods. The trial was carried out at Larache-Sheishat (in the North Atlancic plalns with sub-humld cllnate) where An. labranchiae predoninated. The houses selected had a ceiling of well-constructed t'arau6?ffitheroof.Thehouseswerere1a!1ve1yc1osed!'ithoutgapsbetIdeen the walls and roofs, but many gaps existed at the level of-the doors and wiidbw shutters. The aninal shelters were situated close to houses, and their constructi.on IJas poor. They were forned of chree nalls jolned by a roof, all made of reeds. They were used as a shelter of newly born or slck anlmals, but most of the llvestock are kept in the oPen around houses surrounded by thorny enclosures. The trlal was conducted over three nights (13, 14 and 15 Llay 1968) shortly after the sprlng explosion of nosgulto populations. A CDC llght trap whlch nas operated with 4.5 volts torch batterles was placed ln a bed-room, another trap in the nearest anlmal shelter, and a thlrd trap ln the open outside. Another set of CDC traps was nodified by provldlng each with 12 volts battery and an ultraviolet (UV) fight source. These nodified traps were placed in the same sites, but afler a few days following the operation of the normal traps. Eac,h morning the bags of the light traps nere emptied, and the resldual fauna (= uosquitos remainlng in the sane room as the trap) was collected by hand capture. Besldes whlch, hand capture lras made towards 1700 h ln three rooms and three stables havlng the same condltions as those of the light traps. For comparison, direct nan-bait capture and man-baited nets were utilized. Each nethod of capture was perforned in the 6ame site for three consecutlve days wlth the exception of the UV trap which was operated for two days. The material collected was identified as !o specles including cuLicine mosgultos. Feoales of labranchiae were classlfied according to the blood digestion siages, and the parous rate lras deteroined on the fracti.on of the sample eligible for dissecEion by the technique of the ovarian tracheoles of Detinova (1962). Bloodneal amears for precipitin testing lrere prepared from a certain number of fenales of labranchiae thar were collected by the light traps. The conclusions drawn fron rhis rriar ffiTlows: - The CDClight traps gave a good yield of Culicidae present in a locallty in northern Morocco. - The CDClight trap operated by torch batterles yielded a large number of labranchiae when placed in a fairly closed roon. - CDC/UVJ.lght trap operated by 12 volts battery collected hlgher numbers of labranchiae since it has a more powerful suction, but its uechanlsm was cumbersooe, bulkyt ;ffi-?ragiie-, liable to break down frequently. - The najority of fenales sanpled by the light traps was unfed, nearly sinilar to the sanple collected by nan-bait capture. - The species conposition of the fauna of a roon without llght trap that was sanpled in the afternoon (1700 h) was analogous to that of the residual fauna saupled in the morning after the operation of the light trap; only labranchj.ae was the species present, with its engorged females fornlng 957"It the bed-rooms and 932 in the anirnal shelters" vBc/90.2 MAL/90.2 Page 42 - The proportion of engorged fenal.es in the residual fauna collected in the morning after the operation of the light traps was sinllar to that obcained fron rooms without Eraps. - Although the proportion of engorged females collected by the light traps was smaIl, it rendered useful lnfornation on the origin of bloodneals. The results of preclpitin tests run on bloodneals of labranchiae collected by the light trap rras nearly sinllar to thoseoftheres1dualfaunaFogettrerthesamp1esshowedthata1owproportionhadfed on man (L-2"/") and a very large proportion (89-93%) had fed on bovids. In the sanples derived fron the bed-rooms where no light lraps teere operated, the bovids remalned the mos! frequent hosc (66"1), but the proporElon that had fed on man rdasnuch higher (257!) than in sanples of the residual fauna or the light traps. It seems that the high zoophily of labranchiae caught by the traps in bed-roorns would support the assumption that the presence of the CDClight trap artificially augments the entry of the fenales that had fed outside on aninals. - The Parous rates in samples of labranchiae collected by CDCor UV indoors whether in human or animal shelters were not sigffi@aifferent (882 and l00Z respeccively) indicating that the samples were taken from a homogenous population. These rates also did not differ significantly fron those recorded in sanples collected by oLher nethods (nan-balt caPture, residual fauna in human and aninal shelters. In contrasE, the parous rates of fenales sanpled by CDCand UV light traps placed outside were much higher than those recorded 1n sanples of man-bait capture (respecti.veLy 9L7! and 96i( versus 74% trom man-bait capture). As a final conclusion, the author recomrnendedehe use of light traps for sanpli.ng labranchiae populatlons in l.lorocco as an efflcient compleoent to tlre conventional sanpling nethods. Light traPs nay also be useful for sanpling this species in other countries of the Medlterranean Basln. It was also suggested that assessing the efficiency of the llght traPs to sample populations of other anophelines under sinilar conditions should be trled. Bailly-Chourara (1973b) further reported the results of a nore comprehensive trlal 1n I"lorocco involving eighc saopling methods. These nethods nere: (f) Hand capture tn hunan dwelllngs and anlmal shelters. When the nos<1ulto density was low (1-20 females per roon), the collector spent on an average five rainutes per room. (2) llan-bait capture: This capture extended fron sunset to sunri.se enploying 4 collector-baits indoors and a similar number outdoors- (3) !4an-balted nets; One man slept under a bed-net, the lower edge of which was partially elevated, and engorged roosquitos were collecced in the morning. This nethod was applied only outdoors, and essentially tested in the stations of labranchiae. (4) cDC llght trap.' This was as descrlbed above, one trap was suspended fron the ceiling of a bed-room where sone people sLept and another trap was placed i.n an animal shelter, and a third placed outdoors between houses. (5) CDC/UVlight trap: As mentioned above, a CDCtrap was nodified to provi.de u.Ltraviol.et light. This trap lras occasionally used in dwelllngs, stables, but often outside houses. (6) Sheet trap: This nethod consisted of collection of nosquitos with an aspirator fron a white screen oade of a cloth sheet suspended vertically and illuninated by reflection of a 200 natts opague bulb. This nethod necessltatect the presence of a collector penlanently, unllke the CDCllght trap. It was always used outside, betneen the breeding places and the village. (7) Collection from outside resting shelters: Thls was done in certain localities by sweeping vegetation wlth a net. Also hand capture was made in one locality where a culvert existed near breedlng places. It was also done in large earthennare pots servi.ng public bachs. At one locality, the only outside restlng places rrere those among rocks at the sides of a rlver. vBc/90.2 rlAL/90.2 Page 43 (8) Ivlalaise trap: ISee description in the l'l.anual of Practlcal Entono].ogy in l"lalaria (i.iHo,1975).rl Several villages were selecE.ed as capEure stations representing different geographical,/ecological reglons of Morocco. Most observalions were carrj.ed out once nonthly over a period of. L-2 years, except in remote stalions where the observations had to be carried out on consecutive days. The selection of the stations in the rural zone of I"lorocco was based on the anopheline fauna, the presence of permanent breeding places, and proxinity of nalaria foci. The various regions, t.heir bloclinatic substrata and the selected stations were as follows: Region Bioclinatic substratum Selected stations Rif Occidental, Medit- l'ledi t erranean, t exoperate T6touan, Merja (=swanp) of Soir eranean coasE cli.nate, sub-huoid in river: Thi.s area situated near Gibr- winter altar straic which is exposed to strong wi,nds that often reduced mos- quito yields. l,lerja had rich densi- tles of labranchiae & 2 Aedes spP. North Atlantic plains as above Larache,l4erja Sheishat; The predoni- nant species were labranchiae and Culex theileri. North Atlantic plains seni-arid Sidl Yahia of Rharb,I4erja Poka: Culicines abundant; labranchiae maxl- mumdensity at beginning of spring. Despite low density in sumser, malaria endenicity high. Interior nediun plains Arid with temperate winter l'larrakechr Souk des Oudaias : Predoninant species were: lslggglll and hispaniola and was one of che rare stations of Anopheles zienmani; labranchiae density was lower than i" ttt" sEaEions, but station represented"b""e active malaria focus. Oriental l'lorocco Seni-arid with tenperate Berkane,l"lerja Boubker: *j4!!jl and lrlnter labranchlae predoninated; region had small residual foci of malaria. Interior souch Saharlan with tenperate FouroZguidrMrioiua river: a sub- winter desertic region where drthali and rnulticolor lredonina tedT The results of the different capture nethods were dlscussed with the data tabulaced and graphically presented for each species (anophelines and culicines) and station. For labranchiae, a summary of the results follows: - Larache station: lland capture gave a Dean of 67 fernales/room in human dwellings and 27/anLmal shelter. Man-bait-capture indoors gave a nean biting rate of 3Llmat/night and a maximumof L16/nan/night. The normal CDClight trap placed in a bed-roou yielded 5- and l-0-fo1d higher numbers of feuales than man-bait capture under the same conditions. The UV trap operated over three nlghts during the peri.od of hlgh density caught 2O-fold oore females than man-bait capture. Under the condition of poor conslruction of animal shelters, the CDCand UV light traps respectlvely yielded 7-fold and 3-fold less females than 1n bed-rooms, despite the zoophily of labranchiae as evidenced by the results of precipitin tests. l,lan-bait-capt,ure outdoors gave a nean biting rate of 24 and a maximumof 101 bites/nan/night, whlle nan-baited nets outdoors gave 2-fold less bites,/nan/night. The CDCand UV light traps placed outdoors gave comparable yields to that of oan-bait caplure 1. "Manual on Practi.cal tlntonology in Malaria". Prepared by the WtlO Division of llalaria and other Parasitlc Diseases. PART II, I.lorld health Organlzation, Geneva, L975 (pp. 36-39). vBc/ 90.2 r[AL/90.2 Page 44 outdoors under the same conditions, but yielded l0-fold less mosquitos than the indoor traps. The yield of the sheet lrap nas poor and the l'lalaise trap was negative. It was concluded Ehat the CDCand UV traps attract.ed rouch higher numbers of labranchiae fenales; thei.r good performance, however, was seen only in well closed indoor shelcers. - Sidi Yahla and l,larrakech statlons: In these two locallEies, ![g!!g existed under a more dry atnosphere which is less favourable for its survi.val. Its density was lolr, but it was still playing a good role in malaria transmlssion. The trend of the yield by different capture nethods was similar to that observed a! Larache; the best performance was obtaj.ned by the CDCand UV light traps in human habitation. - Berkane station: This station provided resulls which were not concordant with t.he above mentioned stations. In this area of oriental l"lorocco, the stables being well constructed, gave a density of nore than 1000 labranchiae fenales/stable by hand capture. Nevertheless, the light traps placed in these stabies 6?ve a ouch .Lower yield (naxinun L2/ttap/night) sinilar to those placed ln bed-rooros of adSacent houses. An altempt was oade to explain this inconsistency. Doubts about the functioning of the light traps were ruled out, since the sane traps in stables caugbt a large number of sergentj.i (naxinum 152/trap/night), despite the fact that lts density in the stables was nuch lower than that of labranchiae. It was assuned that labranchlae during the visit to the sEation 1n nia:SEpGEFwas possibly in a state@Ef66rnatlon, hence not susceptible to attraction to light, while serdentil ltas at lts maxlmumautuanal activlty. Collection of a sanple of labranchiae females by hand capture from a stable shorred that. 902 were bloodfed and 102 were gravids. Upon dissection, fresh blood was found but no traces of fat body were observed. The parous rate was about 632. Apart froo the deficit in the gravld proporti.on, there was no evidence favourlng the cornmencementof prehibernation. This was the only instance where the light traps gave a poor yield desplte the presence of a high density of labranchiae tn the stable, a case which remains lnexplicable. - T6touan station: This statlon is situated in a touristic region which has been regularly treated wlth DDT house spraying in addition to the use of space-sprays which were applied during the perlod of observations. Very hlgh bltlng rates of labranchlae were recorded reachlng a maxlmuo of 112 bites/nan/nlght indoors and 89 bltes/rnan/night outdoors which were sinllar to the record of Larache. In contrast, haud capture yielded very lov densities ln hunan habltation and ln anl.oal shelters (less than 2 feaales/roon) indlcating the effectlveness of the lnsecticide used. On the other hand, the yields of CDCand UV light traps in human dwellings nas very low, respect,ively 3.8 and I feuale/trap/night, compared with those of Larache. IE is clear that the liE,ht traps !'ere not capturing a1l the nosquitos lthich entered to feed as evidenced by man-bait capture. In this partlcular case, it was assumed that despite the presence of the insecticide, the fenales sti1l could enter the rooms and bite the sleepers, but they go out rapidly wit.houE being caught, as it seens that the attractlon of the light trap nas less powerful than the effect of the insecticide excitorepellency. The processlng of Daterial collected by different nethods rendered the following infornation: (a) The sex ratio: The results nere given for all species encountered in general but detailed data were tabulated snowing the sex ratio of each species recorded by each nethod of capture. Although the sex ratlo is generally close to 1.'1 at emergence, most of the records show a narked departure fron thls ratlo. The sex ratio was found to be much influenced by the site of capture. In the indoor restlng shelters, the proportion of males varied fron 0 to L41l (labranchiae 3-4/"), whlle in the outdoor resting shelter, the ProportLon of nales varled fron 20 to 5Q"/.(labranchiae 402). There rras no appreciable difference betrreen the indoor and outdoor resting shelters. The sheet trap attracted more nale than CDClight traps placed outdoors, but the nethod which gave the highest percentage of nales was hand capture tn the outslde rest,lng shelters. vBc/ 90.2 irAL/90.2 Page 45 (b) The blood dLgestion stages: Ttre hlghest proportion of unfed fenales was virrually observed by nan-bait capture. Uand capture indoors gave an inverse proportion to those recorded by the light trap, as there rras an excess of fed females resling indoors. The data for labranchiae were as fol.lows: 7"UF 1!E %9 Indoor restlng (hunan shelter) 20 56 24 Indoor resting (anirnal shelter) 7 63 30 CDC (hunan shelter) 8l 13 6 CDC(aninal shelter) 78 IO L2 CDC/UV(aninal shelter) 88 5 1 Hand capture in outslde resting sheLters gave nore balanced proportions of blood digestion stages for anophelines than culi"clnes which showed an excess of unfed females. Wit.h labranchiae the proportions of UF, F and G were respectively 39, 2L and 407". With CDCand UV light traps placed outside, the proportions of unfed females of labranchiae were high, 96 and 822 respectively. The sheet trap also gave a high proport,ion of unfed, 882. (c) Parous rate: The decernination of the parous rate lras oade on the proportion of the unfed females collected by nan-bait capEure and CDC1lght traps indoors and outdoors, all of which gave comparabLe parous rates ranging fron 82 to 952 for labranchiae, with the exception of sanples collected at Sidi Yahia tsoka statlon where oan-balt capture gave a Parous rate of 642 which was slgnificantly different froa 84% recorded in a sample of CDC light t,raps indoors. For indicating the advantages and disadvantages of the different sanpling methods, the author adopted the classiflcatlon of the oethods proposed by Service & Soorman (1965) as follows: (1) t'lethods wlth no attractlon: - Hand capture in human habitatton and animal shelters: This classical technique is slople and rapld to perfontr partlcularly with endophlllc species such as labranchiae. The yleld ls usually hlgh in aninal shelters, lf these are nell conslructea i?ffililase of human habitatlons. For evaluatlon of this technique, a pyrethrin solutlon in kerosene was sprayed followlng hand capture in suall oud houses. It was realized that hand capture collected 47% of. the anopheltne populatlons restlng ln these houses. Thls percenlage was even reduced in a large Saharan house wlth high inaccessible ceilings. Another inconvenience of hand capture is that aome lnhabitants refuse to adnit Ehe collectors to search their rooms. - Collection fron outside resting shelters.' Collection by a sweeping net fron vegeE,aElon is usually utilized in hunid, sub-humid and seni-arid zones, while hand capture lrith an aspirator ls used in arid and Saharan reglons. These techniques are tiue consuming and usually give a poor yield. Nevertheless, they provlde unbiased inforroation on lhe exophilic fraction of the population. - Malaise trap; This technique did not give satisfactory results in the present trlal. In addltlon, it takes a long tine to assemble and Dount its parts, with frequent breakage during stroog wlnds. (2) !4ethods utillzing bait atEracllon: - llan-bait capture: This is an indispensable technique for collecting species of nedical importance, and obtalnlng infornation on the titre and site of their aggresivity. Its disadvantages lie in the exhausting night work and the problen of findlng tenporary workers at high cost. Furthernore, in North Afrlca, inhabitants object to the presence of strangers ln thelr houses all night and this creates a much rnore dlfficult. situation than with day-tlne work. - Man-balted nets; This technique is less exhaustlng because the subject can sleep all nlght, but the yield ls far inferlor to that of direct man-bait capture conducted concurrently nearby. vbc/90.2 ttAL/90.2 Page 46 (3) I"lerhodsutillzing light attraction; - CDClight crap: This trap collected all the anthropophilic nosquito species in larger nunbers than man-bait capture. Its yield is optinum rdhen utilized in closed places. The trap also collects exophllic species which enter houses for a short period to feed. The najority of the fenales collected by this trap rdere unfedr but there was also a certaln proportion of fed mosqui.tos caught. This proportion allowed the deternination of the origin of bloodneals (see the initial observatlons by the tight Lraps above). The naterial collected by the lighc trap was usually in good condition; the collection of predators such as ants Itas rare in l"lorocco. The roortali.ty in the collecting bag increased as the densities of nosquicos lncreased, and it sras also influenced by the anounc of voltage and the arldity of the air. ln the arid and Saharan zones, it is necessary to ensure that the collecting bag is kept hunid if live mosquitos are required. With regard to handlinS, the light traps are robust, easy to assemble, and Eheir cost are reasonable. I"loreover, the inhabitants welcone che installation of the light traps in their houses; tn fact the fanily chief who refused the work of nan-bait capture, accepted and he hirnself installed the light-trap in his roorn until lt was collected in the morni-ng by the operator. - CDC/UV: This trap collected nore mosquitos of species that are of uajor interest in Morocco than the nonnal CDCtrap, but the nortality in the collectlng bag was highr possibly because this trap attracts hlgh densitles enEerlng the room where it is placed. However, as indlcated above, this trap is difficult to repair and transport with a 12 volts battery which also needs to be recharged frequently. Moreover, the llght of t,hi.s t.raP is so intense that it troubles the inhabitants and dlsturbs their sleep. - Sheet traP: This trap pernitted the collectlon of all cultcine and anophellne mosquito specles encountered in t.he present study. It was utilized nostly in itinerant misslons for faunistlc studies slnce it collected a large number of nale mosquitos. In her conclusions, the author relterated that the normal CDCLight trap represents a useful tool for sanpllng all anthropophilic species of nosqultos in l"lorocco. Despite the Presence of certain quantitative and qualitative differences, the sanple of Culicidae nas very close to that collected by nan-bait capture. The use of the CDCtrap in Morocco should peruit the deternlnation of the seasonal prevalence of anthropophilic mosquito species, reducing the need for oore frequent nan-bait capture. However, it would be useful to coopare the results of the two technlques fron time to tioe. The results of sergentii and other anophelines collected during this trlal are shonn under paragraph 2 below. In Syria, Sadek (1984) durlng his assignnent to assess the effectiveness of perrnethrin house spraying (see 1.6/I.7 above) trled to assess the CDCl1ght trap as an addirional tool for collecting the local nalaria vectors, especially sacharovi, to be utilized in longltudlnal studles. Four CDCllght traps were used, but no lnfornation nas given as to the sites and the procedures of operating these traps. It seeus that they were only placed indoors. The traps gave unsatisfactory results in both pernethrin treated and untreated villages. In the treated village, the density of sacharovi before spraying was 3.5 fenales/trap/night. After spraying, the fenale density fEl to l sacharovi and,2 superpictus/trap/nlght. In the untreated viJ.lage, the density was 2 sacharovi/trap/night, but dropped to zero at the end of Septeober due to the onset of cool weather. On the other hand, che light trap gave a good yield of cullcine nosquitos before and after spraying. Frou these observations, Sadek concluded that the llght traps are not suitable for sanpling sacharovi ln Syria compared with other sanpling rnethods. IExperience sith llght traps varl.ed greatly. Although the light-traps gave variable results with the An. ganbiae gonplex'tt and {qr. funestus in tdest Afrlcar, they perforned sarisfacrority inEffia2. seeosE-f,-e variabirity of tocit condirions and the design of the experinental procedures are aoong the factors influencing the success or failure of the light traps as saropli.ng tools. Although there is alnost an ag,reement chat l. See PART I, document VBC/85.f I|AP/85..L, SECTION III(A) LIL,STAFRICA (under 1.8), pp.82-88. 2. See PART I, docuoent VBC/85.3 MAP/85.3, SECTION III(D) EAST AFRICA (under 1.8), pp.68-71. vBcl90.2 r4AL/90.2 Page 47 the light traps cannot replace the epldeniologically relevant technique of man-bait capture, they can be useful tools for sanpling anopheline fauna lncluding exophilic species that are rarely found resting in houses, and for collecting samples for dissectionsJ. 1.9 Host feedlng patterns Results of some precipitin tests carried ou! on bloodneal snears of labranchiae as Part of studies on its biting and restlng behaviour in Sicily, ltaly, and in conjunction wit,h sanpling by llght lraps in Morocco, have already been given above (see 1.6'L.7 and 1.8). In Greece, Hadjlnicolaou & Betzios (f973a) for their investigatj.on on the feeding behaviour of sacharovi at Thernopylae, Lamis plain, collected bloodneal smears of fenaLes of this in human dwellings, animal shelters and artificial pit-shelters"p.ciE!-EGfresting during 1968. The results showed thas 61.52 of. 260 smears fron human dwellings that gave a positive reaction, were positive for oan. This high proPortlon was recorded at that village when the man:anlnal ratio was 1.'9 or L;7.2 during the peak of the surmer season. This result was comparable to that recorded during L932-L934 by Barber ti Rice (f935) when 6J.32 of 3980 positlve smears of sacharovi resting j.o houses, were posi.tive for Dan. This was taken to lndlcate that sacharovi in Greece has remained anthropophilic,12 years after the cessation of DoT house-liilli!. However, a further sanple of smears collected and analyzed during 1970, gave 38.52 posit,ive for man. Some explanalion for thls reduction 1n the human blood i.ndex was offered in a further paper as shown below. Garrett-Jones & Borehan (L973) analyzed the data of preclpitln tests carried out on sanples of bloodneal smearls of sacharovl collected by lladjinicolaou & Betzios from Thernopy1aedur1ng1970andrgzrFrtnavieI'todeternin1ngtt,.preva1enceofuixedfeeds. Exhaustive preclpltin testing (designed to detect nixed oeals) of 1025 bloodneals fron chree different blotopes.' hunan dwelllngs, Ewo anlmal sheds and two pit-shelters revealed that 91 or 8.92 of 1021 posltlve snears contained blood froo two serologically distinct hosts. In a routine survey nade in 197I, when testlng was not exhausti.ve, mixed meals were detected in only 2 or 0.LZ of 1798 positive suears tested. In the 1970 collection, no mixed neals were found ln plt-shelters, suggesting that a mosqulto interrupted while feeding outside tends to move to an indoor biotope to conplete its meal. The proportion of Eosquitos sith oultlple neals, i.e., those conpleting their feeding on the same host specles, could not be detected by the precipitln tesc. The frequencies of these "cryptic" nultiple meals could be conputed for three nain blotopes studied. Further, the authors remarked that the data of 1970 showed that the most inportant hosts of sacharovi in cattle sheds were sheep (or goats) and Equldae, vhereas in the saople fron human dwellings, the blood of oan and pig rras the most prevalent. It, was explained that most houses in Thernopylae are fitted wlth windorr screens against mosquitos, hence it was difficult co collect large numbers of specluens. In fact, the rnajority of blood-fed females fron this biotope came froo a slngle room in which the screens were in poor conditlon and which overlookeci a yard where pigs were kept. For this reasoa, the sanple from houses ltas probably not representati.ve ln that it contained a lower proportion of huroan land possibly nore mixed neals) than night have been expected in typical houses of the village. The nost recent consoli.dated data of precipltln testing lras tabulated by Garrett-Jones, Boreham & Pant (1980) for the perlod L97L-L978. Fron these data, the results of tests on the An. nacullpennls complex froo the Mediterranean Basin are shown in Table 5. Fron this table, it ls clear that a6 can be expected, samples of the An. naculipennis eonplex derived frorn O biotope, i.e., with non-human hosts gave no or very low Positive reaction for nan. In contrast, samples derived from human dwellings whether in unsprayed or ex-DDT areas, gave ooderately higher human blood lndexes (HBl), the exception being the records of nacullpennis s.1. froo Yugoslavla Ln L974 and 1977. Only a single sanple of Iabranchlae fron H biotope came frou a DDT sprayed area ln I'torocco, which gave as Lov as 2% Ean-poffie sDears, while the remaining smears were positive for anioals (79% f.or bovids and L91t for ocher anluals). No infornat,ion is avallable on the ecological conditions associated with this biotope that nay have influenced this pronounced zoophily. However, chis indicates an epldeniologlcally favourable trend, but the sanple size was too snall to allow drawing a generalized conclusion. vBc/90 .2 vtAL/90.2 Page 48 @ U) tr E OrJ OrJ 0) ! OA (f) rl c|0F- (') 0) @ .s d) !n F- !.r F o\ .rt ||OJ !v O \OO\OO.$O rn(7).rf \?6t.3'oo- .frn O c-l o tt) ol v rn (Y) (7) .Fl c{ C.t V) F oo o(d U lr 0) >E IF tsl + .r{ ol t' b.{ .'1'l o. .rr I FI lJ t, ol (dl Otr d0 tr I .|.J o oo H lr orld @ rnq\oQtv)@ \or+lO c{ .$@O@\O Oo\ r\ r\ io Ec! .rt o.ldl-CrlF-\O !nOrn .f, \o.+--O -- (7) (,lr -r--9 i\ (\l Nfi6r Fo{ !n - lr I .r{ t. .o l+r (iF- o> .A OF- 2+ Eor +, lr cr)F o (,)o I F{ (!F- ..{ o q, o\ o Eq) €EF ! QU @o o qc acn .ro tr }J TJ !^,TAFAFAE^E v*v*vrv+A+uv*v I+{ FQ (,'o Ld H3 O 'r{ U)o cr.tr !o .|.J d(,,>t thtr ,od o$ (!>tr !H ! di o l. tro v) r!(oU) c, >ot u (!r (U o .dE o o.o >tJ uan '.r E rglJ E E E E EE E E OU) (, E.-{ i trO z ?= zzi= zz? z =EFE? ?= F F (! oo o! x x x Q XQ X X lrE u, ah o(l)0Jo)q)(uajit x t H U){J E OrJ tl r! r: troo O.J ts (,)x lrO I oqif{ ucl ll tr X lr t, 0) O .ri oe -c!o 3Be 6 U)o() o! tt) 1. l0 Longevity The nosc detalled and intensive work on this aspect rdas carried out in the USSR coverlng che potentj-al vectors of Ehe An. naculipennis complex for which the monograph of Detinova (1962) should be consulted. Apart fron Ehat, there is no inforrnation availabfe on age-grading of field populations of the An. nacullpennis complex in the Medilerranean Basin except the work done in Sicily, It.a1y, during the 1960rs-1970's. Cefahi, Oddo & Sacci (f961) during their studles on the behaviour of labranchiae in RoccamenaareaofS1ci1y,Pa1ermoprovince(seeunder1.6-1.7above)app].ffil-ova's technique (see Detinova, 1962) for deterrnining the physiological age of Ehe populations of thls speci.es sanpled fron houses and natural shelEers. A suomary of the data is shown in Table 6.r Table 6. Deternination of the physiological age of lab:anchiae ln Sicily, 1960-1961. Period Sice of capture No. dissected Nulliparous Parous 22.09.60- Houses 101 19* 57* L7r, 6* 2 28.11 . 60 18.8 56.4 16.8 5.9 2 26.09.60- Natural shelters 33 8* 18610 01. 05. 61 o/ 24.2 54.6 L8.2 3 0 Tocal houses & natural shelters r34 27 75 23 7 2 20.I 56 L7.2 5.2 1.5 *A snall number of females nere non-gonoactive and contained fat body during Septenber-Novemoer. It is clear that labranchi.ae in the study area had a short physiological age, with the najority of the tenatffiat-ling-within the nulllparous and priniparous groups, and only a few fenales could complete the 4th gonot,rophic cycle. The dominance of physiologically young nosqultos was explained as probably having been due to the persistence of actj.ve DDT deposits in many indoor shelters Ehree years after t.he last spray creating an lmpac! on vector density and age. As shown above, the dissections nade in the autunn showed the presence of a proport.ion of labranchiae fenales wlth well developed fat body and inactive ovaries. This provlded an eiirpfot ttte variability of behaviour of labranchiae under different ecological conditions existing in the sane region. The study area of Roccamena is at 500 n altitude above sea-level. This phenomenon of diapause was less pronounced in coastal areas, where the ovarian deveJ.opnent slowed down but did not becone conpletely arrested (citing Dlariani & Cefald, 1954). Also in Sicily, Valentino & Bruno Sniraglia (L9OS12carried out a detailed study of the physiologlcal age of labranchiae during 1964 in two dlfferent areas. Periodic collections were Dade from January to December L964 in various localities of Trapani province in which the annual DDT spraying was starred in L947 and ended in 1964. For compari.son, collections of the same species were made in sooe localities in Palerno provl,nce in whlch DDT spraying was also started in 1947 but dlscontinued in 1961. The dissection foll.owed Ehe Eechnique of Polovodova (in Detioova, L962) for deternination of the detailed physiotogical age of labranchiae populations. Detailed data of uonthly 1. By pernission of Dr F. Oddo and Parassitologia fron the paper of Cefalt, Oddo & Sacci (1961). 2. The authorsr suonaries of this paper and the paper of Cefali, Oddo & Sacci (1961) were expanded through the klnd cooperation of Dr F. Oddo. vBc/ 90.2 t[AL/90.2 Page 50 dissections roadein 1964 were tabulated, but it is sufficient here to give the consolidated totals for the whole year as shown in Table 7.r Table 7. Deterninarion of the physiological age of Iabranchiae ln Sicily, 1964. Area No. exani.ned Inseninated Z Nulliparous Z ParousZ --i z5 Trapani province 488 77.46 51.43 39.55 9.O2 0 0 DDT:1947-64 Palermo province 811 95.31 34.L5 46.L219.03 3.5 0.5 DtT:1947 -60 These data clearly indicate that in the area still under DDT spraying only 9.O27"of the labranchiae population conpleted the 2nd gonotrophic cycle, and none had reached the 3rd gonotroPhic cycle, whereas in the area where DDT spraying was discontinued in 1960, there was a proPorcioo of the fenales that could conplete four gonotrophic cycles. However, the longevity was not as great. as that of labranchiae exlsting in areas that have never been sprayed. These observat.lons agreed wiEf,Gffi Cefali, oddo & Saecd (1961) in rhac rhe residual effect of DDT nay shorten the mean age of the labranchiae population even as long as four years after the last spraying. This also conflrns the unchanged susceptibility of labranchiae to DDT in Siclly. Exami.natlon of the spentrathecae showed that in the area ;ffia;? DDT spraylng abLut 22.52 of the females nere not inseminated, whereas in the area where DDT was discontlnued, only 4.72 of. the fenalea were not inseminated. This uay have been caused by different factors, amongst which ls the greater susceptibility of labranchiae nales to DDT. Further work in Sicily on the physlological age of labranchlae was carried out by DrAlessandro, Bruno Sni.raglia & Lavagnlno (1971) .s parfrf-th.ir studies on the bionooics of this specj.es 10 years after DDT spraying nas discont,lnued (see I.5 above). The results of dissections nade during the seasonal prevalence of labranchiae are shown in Table 82. Table 8 . Observations nade on adult females of labranchiae collected in [email protected]. llonth Nqqler Nulllparous Parous females L2345 I4ay 46 46 27 L9 June 270 26L 139 96314- July 230 226 9t 9039631 Angust 605 602 2L6 211 101 57 15 5 Septenber 488 482 t9r 22459131- Total f 639 f 617 664 640 230 80 19 6 "A 98.7 40.5 39 L4 4.9 L.2 0.4 From these data, it ls clear that during the favourable season nearly al-l the femal.es of labranchiae were inseminated. At the beglnning of the season the population was largely forued of newly energed feroales of the sunmer generations (58.7%), and a propartion of fenales which conpleted one gonotrophic cycle (4L.3'/"). As the season progressed, the parity of the populatlon increased and more aged indlviduals appeared. The naxlnum physiolobical age of flve gonotrophic cycles was observed in JuIy and August. [This shows that labranchiae populations can reach a potentlally dangerous age from an epideniologlcal. standpoint during surmer months when it can transrnit P_.vl'vax, if suitable lnported cases 1. Reproduced by peroisslon of Prof. L. Valentlno froro the paper of Val.entino and Bruno Sniraglia (1965), but permlssj-on fron Rlvlsta di I'talarlologla could not be obtained as this Journal has been discontinued. 2. Tables 8 and t have been reproduced by penolssion of Prof. A. Lavagnino, fron the paper of DrAlessandro. Bruno Sniraella li Lavagnino (197I). wc/90.2 r'tALl90.2 Page 51 of gamet,ocyte carriers becomeavailable]. The results of age-grading Iabranchlae populations in winter are shown under 1.5 above. Observations were rnadeon the duration of the second phase of the gonotrophic cycle, i.e., the tine taken for blood digestlon and maturatlon of lhe ovary (Detinova, 1962)I in labranchiae under natural condltions. Engorged fenales were kept 1n a cattle stable at Fellanonica untj.1 the ovaries matured. The results are shown in Table 9 (see footnote 2 on previous Page). It can be seen that during July-August lhe eggs of labranchiae needed 5-6 days to mature. A11 fenales which had not oviposited were found to contain eggs at Christophersr stage V. The period required for maturation of the ovaries did not vary much in nulliparous and parous feroales. In Turkey, Kasap ec al. (L9gO)2 deternined the physiological age of sacharovi during its seasonal prevalence and it.s hibernation. The study was conducted in Menekgevillage, at about 10 kn fron Qukurova University. Collectlon of sacharovi was nade at fortnightly intervals and conli.nued for one year. Females were clasffi-scording to the blood digestion stages (UF, F, G) and the presence of fat body was recorded. Frou April to August, gravld females constituled 60.2 + LL.8"Aof t.he collection, and fron October to February, unfed fenales constituted 47.{+ 20.82 of the collection, and those which had fat body constltuted 24.8 + L7.22 of the col1-ection. Dlssectlons showed that fernales which laid once (l-parous) wire recorded during April-June, and those which laid twlce (2- parous) were found during July-Septenber. From December to March, only inseninated nulliparous females were encountered, and fron Noveober to January the populatlon was characterized' by an lncreaslng nunber of females with fat body. ihis was descrlbed as being a condition of gonotrophic dissociation characterized by cessation of ovarian development despi.te continued feeding on blood. The gonoactlve period of sacharovi occurred durlng April-October. By placlng caged fenales of sacharovl undeffiffiTed natural conditions in Menekge village, the life span of this species was estluated as 20 days on an average. This pLriod was consldered to be long enough for p. vivax to conplete its sporogonic cycle in sacharovi. [Perhaps the full text of this paper when publlshed nay give sone explanation regarding the absence of sacharovi females older than 2-parous, and may also provide infornation on the duration otEftiiorrophic cycle during the favourabre season]. 1.11 Natural lnfection 01d records of infectlon rates in the An. naculipennis conplex by Boyd (1949-VOL. I) (1955) and Horsfall for which these books EtroufE-5e conffitea. It is useful , however, to recall soue of these records of sporozoite rates in certaln membersof this couplex. In Bulgaria, Drensky & Collins (1934) noted that it was comnon knowledge among private Practitioners and malaria staff in Petritch area to flnd malaria cases anong winter-borne infancs who presented acut.e attacks in Aprll-May. AddltionalJ.y, there nere cases arnong adults who had aPParently never had an acute attack of ualaria but presented acute synptons in the sprlng. In the latter case, however, the possibility of latent infections aequired during the previous autumn could not be excluded. Reports of other authors in Italy and the Netherlands that indicated the presence of lnfected anophelines among hibernating nosquitos' especially those resting in houses, were clted. Reference was also nade to other rePorts indicating that in l{acedonia oocysts nere found in hibernat.ing nosquitos. In the hope that additional light night be throrn on the possibility of new infections to be acquired 1n the sPring, the authors carrled out a series of dlssections of the mosE important vectors in Bulgaria: oaculipennis [s.1.] and superplctus, during February-Apri- I 933. _;@s62)definedthedurationofthegonotrophiccycleasthesumof!he following three phases: (a) the search for a host and inflictlng a bite; (b) Ehe digestion of the bloodneal and maturation of the ovaries; and (c) the search for a suitable breedlng slte and oviposlting. 2. An English summaryof this paper (ln press) was provided through the kind cooperation of Prof. H. Kasap (personal corn-unica!1on, January 1990). vBc/90.2 nAL/90.2 Page 52 H OJ q5Lng N ord +J +J a Oo.n lu.)i-d O.- A ."{!, ol >oo ql o.q ! '21 a dc.l lnlrnr'1ris ooa N t:l o+J s do d'-i xl El{i I.-drl--N(\l d ?t'Yl &O dl o P{ o o> sf rttttl l 4J ._t ..{ 0,) ocn o o t! tr., llll(\c\ g o o{+r o f{ -.{ U) l{ +J >d o O O AN Ntll(\rn o oo +Jl.| .A oo FA (!lntFl(l|dl o'r oo d C\ +JE o! | o AA 4A qFt o ..,t F.r o OFI -{'. il(t)€(v)< Etr -5(d o o o.c d oh fr{U Zfu o (0+J o lro O-{ €Fl !r! fn\odrnolo\ \o tr! EC sfaids o(' ao (\l o+J r+1 oo Z a o l+t F{ O+J o +) +JO tr6 lr oo ula?n ,{v >+J U! \o\o\otn|.r)rn +, doo roo t{c aEo lJ *.1 O '.{ o Lnrntnlrtu.)0 +JO o\otoo\@o o .dE F{ o|! .-t dp c! o5 7, -t +, oooo|n0 ..{ rn\o\oF\0@ dtr F{ l{ l.l t! oo +) OE qr. HX O@Ol@Oi Ei o, 5ttt f')(\6tN(v)rl 9E ad t{ E8 o EC doroNsto ri O*{ (\l (\l C.l (\l (\l .a €{E r! Fr d(\rnH3 d i N d .J o PI aa ol h4 vBc/90.2 'ttAL/ 90.2 Page 53 The results are sunmarlzed below (data of superpictus are given here for coroparlson): maculipennis s.1. superpj.ctus llo. aisGlfiiEst Z sporozoite Z No. dissected oocyst "l spotozoLte Z Februarv 208 1.9 )vu 0 |iarch 307 1.9 r07 0.9 0 April 94 1.0 1.0 39 2.5 0 Total- 609 1.8 205 0.98 0 It is clear that the infected specinens of rnaculipennis s.1. were almost exclusively with sporozoltes, while in the infected superpicius only oocysts were found. This was the reverse of the condition observed at the end of the previous sunmer, when maculipennis showed a much larger proportion of oocyst-positive specimens, while in superpictus only sporozoite-positive females were seen. I! was interesting to note that-Tle occr,rrrence of P. .fal-ciParuro infection coincided with a hi.gh sporozoite rate in superpictus in late surDDer and autumn, while the occurrence of P. vivax corresponded with a irigh sporozoite rate in macuLiPennis s.1. in the early spring. Precipitin tests carried out on bloodneals of females caught during March-Apri1 showed that an appreciably hlgher proportion of nan-fed maculipennis s.1. existed than at other periods of the year. It was concluded that there is a real possibility that new malaria lnfecclons tray occur as a result of lnfected hibernating anophelines, and thls nay explain the epldernic rlse of nalaria in the spring which rras so characteristic of the disease in the Petrj.tch area of Bulgaria. In Greece, Barber 6 Rice (1935) carried out a st,udy of nalaria lnfection rates 1n sacharovi.. naculipennis (nesseae _-- and typicus) and superpictus during April ]932-Decenber 1vJ4' as these species ltere the vectors of P. vivax, P. falciparun and P. nalarlae. i'losquito collections \dere made from a region representing alJ- northern Greece except for some localities ln whlch donestic anfuoals were less abundant. Nearly all villages were withln 50 ko of Cava1a city, but at the beginning of 1933 the srudy area rras extended to lnclude some nelt villages, of which several highly endemic villages were situated near the Nestos River. A sunmary of the resuJ-ts of sporozolte rate deternination nade nonthly (excluding I'larch) over the 3-year study period folLows: sacharovi macu.Lipennis superpictus No. sporozoite Z No. sporozoite Z No. sporozoite Z L932 8997 L.22 3777 0.13 5352 1. 48 1933 9r40 1.45 7558 0.06 4834 0.6 L934 4063 1.08 3378 0.03 L837 o.44 Dissections made in the winler months of 1933 gave high sporozoite races in sacharovi: 2.62 Ln January (189 dissected) and 1.7% in February (178 dissecred), bur none i;--- nacuLipennis, and only 0.61( in superplctus (728 dissected) in February. Fron these datar it appeared that sacharovi was the chief vector of nalaria in the study area during the three years. rnffioffiite rate of oaculipenni.s (nesseae and typicus) was very low, and epiderniologicar evldence indicarffiE-Ef,troft ggpergictus in malaria transnission vras unimportant, at least in fhe l-ast two years. The sporozoite raEes of atl species declined during the past three years, and this decline was associated with dininishing parasite rates ln the huoan populat.ion. A decrease in rainfall, affecting the density of sacharovi in particular, seemed to have been responsible for the fall in the Parasit.e and ganetocyt.e rates in the hr:man population. In Turkey, Kasap et al. (198I) started Ln 1977 a progranme of research on mosqui.tos and malari.a in Qukurova where malarla was wj.despread. In this area, the mosquitos which are like1y to t,ransmlt P. vivax malaria werei sacharovi, superplctus (see under 2.11 below) and hyrcanus (see underE-6i1ow). A sanple 6-t zoo r..ares of sactrarovi. was collecred fron sorne villages in Kigla district (Adana) and dissected in tneE6iffiry. Four of these (2i() vere oocyst- and sporozolte-positive. Kasap et al. (1988) further studied experimentally the sporogonic developoent of P. vlvax in sacharovi origi.natlng fron the Adana area. ot 792 fenales of sacharovi, 7zzffia a 5ffiear- fron t9 p. vivax patients. oocysts were obser.'eiGiEys 2 to 16 and rhe sporozoites in tEG,IFary glands on days 8 to 34 after the infected bloodneal. Starting fron day 8 post infeccion, lhe sPorozoite rate gradually increased reaching 757" and 1002 on day 20 and 26 vtsc/90.2 rlAL/90.2 Page 54 resPectively. The nean sporozoite density per salivary gland ranged fron 500 to 1000 during days 8 to 34. The authors concluded that in addition to the nan biting rate and the loogevity of sacharovi, its susceptibiHty to P. vivax makes it an efficient vector for vivax nalaria. It nay be due to such characteffiof sacharovi that even in periods of low density, ualaria transuission continued in villages oF@a region in south Anatolia. I"loreover, the nagnitude of malaria cases in this reglon seems to correlate positively with the denslty of sacharovi. Thus, thls species still remains the most lmportant vector of nalaria, besides which superpictus and other suspected vectors such as maculipennis s.s. and hyrcanus nay play a role. In Israel, Saliternik (L974) recalled several old records of sporozoite rates in sacharovi obtained by various authors nostly in winter nonths as follows: 4.27 (95 dissected) during December,cltlng Reitler & Saliternik (f929); 1.1-5.4"A (2400 dissected) durlng January-Decenber, citing Kligler (1930); 0.47. (525 di.ssected) during October-Decenber, citing Lunsden & Yoffe (1950). 1.12 Vector resistance to insectici.des As nentioned in the INTRoDUCTIoN,lhe recent staEus of veclor resislance !o i.nsecticides is extracted fron the tabulated data of the last two reports of the t+rHoExpert Conmitt.ee (WHO,1980 - TRS. No. 655, and WH0, 1986 - TRS. No. 737). Data for nembers of the An. naculipennis conplex are shown here ln Table 14. Table 10. Insecticide resistance in the An. paculipennis conplex Species DDT Dieldrin/HCH 0Plcarbanate 0thers atroparvus Portugal, BulgariarRomanl.a -Portugal : fenthion, chlor- RomaniarSpain, Spain phoxln/carbauate ussR,uK -Romania: carbamate -Spain :nalathion, f enitro- thion, f enthion, chlorphoxiu/ carbamate labranchlae Algeria, lloro- Algeria rl'lorocco Italy:oalathion cco, Tunisia maculipenni.s Greece, Greece, Turkey -Greece.' f enl t ro thion / carbanate Romania, Turkey, -Ronania:fenitrothion,fenthion/ - USSR carbamate -?urkey: fenit rothion, jodfenphos / carbama!e melanoon Turkey messeae Bulgaria, Bulgaria, Romania -Romania;oalathion, f ent hion Rouania, USSR -USSR:carbanate -Bulgaria sacharovi BulgariarGreece, GreecerLebanon ; f eni t rothion/carbanate LebanonrSyria SyriarTurkey Turkey, USSR -Greece : f enit rothion/ carbamate -Lebanon:fenitrothion - -Syria : fenitrotnion/carbanate -Turkey;nalathion r feni t.ro- Turrey: thion r fenthionr jodfenphos, pyre- chlorpyrifos,chlorphoxim, chroids phoxin, parat hion/carbamate -USSR:carbamate In the list of species and countries where insecticide resistance has had epidemiological or economic inpact and,/or necessitated a change in control operaEions (WHO, 1986 - TRS. No. 737), DDT resistant sacharovi in Syria, Turkey and the USSR was included. vBc/90.2 tlaL/90.2 Page 55 In the sane report the available findings on resistance nechanisms in anophelines and culicines were sumnarized. Ttre data pertainlng to members of the Ao. r""gfilg.i" complex are shown here in Table 11. In a recent communication by Lavagnino (1983), labranchiae in Sicily, Ital.y was shown to be conpletely susceptlble to DDTand nalathion as lndicated from susceptibility tests carried out annually during L964-I97I. Between L972-L977, labranchiae was so scarce that a only a linited nunber of susceptibility tests could be nade. This was tentaEively attributed to the increasing use of pesticides in agriculture, whlch could not be controlled and eval.uated. During 1979-1980, the denslty of labranchiae considerably increased in uany areas of Sicily. Tests were carried out during the sumner of 1981 and 1982 in Palerno, Trapani and Agrigento areas. T'he tests showed trarked reduction in nortalities on 2% DDT (fron 902 previously to 40 or ever. 207 in Palerno), and on 0.52 nalathion (fron 60 to 20 or even zero in Palerno and Agrigento). Although labranchiae in Sicily was stil1 killed by the discrininating dosages, i.e., no survi"val of adults wlth one hous exposure to 47" DDT, 52 nalathion, L7. fenitrothlon and 0.12 propoxur, there was evidence that this nosqulto, whlch has shown constant susceptlbility to DDT and oalathion during the past 20 years, was exhiblting a stight decrease in susceptibility, as indicated from exposures to the lower dosages of the two lnsecticldes. This was interpreted as "vigour tolerance" ralher than resistance. Frou the report.s of field susceptibillty tests conrnunicated to WHOduring 1984-1988, records indicating the presence of resistance (R) or requlrlng verificatlon (V)1 are shown 1n Table 12.(See foornotes of Table 12 for explanation of R and V). The detalls of tests carried out on sacharovl wlth dlfferent insecticides in Syria during 1985 were llsted 1n an unpublishea-retort to WHOby Eshghy (1986). The tests of pernethrin lndicatlng the need for verlficatlon and subsequently reslstance in 1985 were shown as follows: Locality Date Spraying Pernethrin ZMortallty* Indication (& Provinee) history concentrz (Nunber exposed) ( rounds ) t h 2h Sheikh-Hadid, DDT(10), (Hana) DL(6), Mal(8), 6-9 Jul. Peno(5). ' o.25 89.r( 211)v 2l Aug. o.25 - 88.9(45) Tal-Keishour- DDT(10), Sourek DL(6), (AJ-eppo) Mal(8), 22-23 Sept Pern( 5). 81.s( 92)v 24 Sept tt,.l *No mortality in the control was observed. DL = dieldrin, Mal = malathion, Pem = peraethrin. The exposures of two hours rrere meant to be verificatlon tests which tentativeLy confirned the presence of peroethrin resistance. The exten! of this resistance in areas under pernethrln spraylng in Syria has to be delinlted. Final confinoatlon, however, should be obtained by sending egg batches of survivors of future tests to a recognized laboratory where facilities for rearing and selectlon are avallable. If confirned, conprehensive entomological/parasitological observations sbould be conducted to deteroine the operational inplications of penlethrin resistance ln lts area of distrlbution in Syria. vBc/90.2 t4aL/90.2 Page 56 d.^.L (! trr- .'{O(!! o li .F{ .'t 5 Ot ! X !!oo o l! CJ (!!J A l|lJ or o o r+{ !>\ O .r{ t! (i t G t O Etr A | | | I oE oo trx (! O lrd li >ooo &0, > '.{ H lal Or r+{ uo6 F9 E ctl!o L) o o at lta .r{ 0, o 0, O"{ ah L, Jzl{ 0rr! o tr.tt lrEo, Ji .Athll (!0. 0ro >\ 5lr {J Ft PrJ rJ(u Ou o o trlrO ooo -c\ ; l! Gl .-J TJ 3'o u, . o (! tro o0 U .'{ll r, r! U) r.r l.d . r0 -) att (! Q@LlO\O x,c d o! | ! o Fro Ftr >| O utl t!5tro\>l rJo (! ! .dl (DAE..",a ..{ e O. F. I tl (,)Otro..F1 9l 1.tr OOI-{9 O.i t..'{ c) F{ crlJ Hl E o. qro a rl x to U EO Sli\OO. ul N o(a(u oo(a rJ . r! . orJ gl rr(!(a H-1|! 'O |,q,6t|,.t El hp ru O hlr tqrdSOr, ! crt I I >'U: ,!J .l .o O Or't]Ulri,lJ.t, rJ.|{ t(!oru u.d c, q, x cl o(/)x ogQ@ 9 U .n I ll sr.! (u Table 12. Sunnary of susceptibility tests on i.n the An. naculipennis conplex in the Mediterranean Basin comrnunicated to WHOduri.ng 1984-1988 Species Country Insecticide Reslstance Areas and Year Renarks sEatuslr2 labranchiae Tunisia DDT Bizerte (1 985-1986 ) Species sti11 suscepEible to Dalathion sacharovi Syria DDT R ,Hana( 1985 ) pernethrin K Aleppo ,'Hana( 1985) pernethrin v Aleppo;Hana(1985); Deraa( 1 984-1 985) , Quneitra( 1984-1986) bronophos Aleppo , Deraa, Hama, Used for winter Qunelt ra ( 1 985) fogging pirlniphos- Deraa( 1984) trethy1 bendiocarb v Ilana, Quneitra ( 1985) proPoxur v Ilana,Quneitra(1985) fenitrothlon v (1.985) Quneltra :--sacharovi i.s sE.1rI susceptible to nalathion & piriniphos-uethyl in several areas in Syria 1' R = Resistance ls present nhen uortallty ls less than g0Z on the diagnostlc concentratlons 2' Y = verlfication is- requlred when the nortallty on the discrimlnating dosage i.s between 80-982, accordlng.-t9 the crlterla proposed by Davidson & Zahar (Lg73) and adopred by rhe Expert cornmittee (wHo, 1986-TRS. - No. 737, pp. 49-50) verlflcation lesrs are arso explained. 2. An. sergentii and An. superpictus The two species are dealt with here whether they occur slngly or in assoclation. 2.1 Vector iuportance rn continental Europe vhere nalaria has been eradicated, superpictus 1s anong the potential vectors in certai'n areas where it exLsts as .in rtal-y, yugoslavia, Bulgaria and the ussR' rt also acts as a potentlal vector 1n cyprus, where it has persisted after the Anopheles (nalaria) eradlcatlon caopaign. rt is assoc:iated wlth sergentii and both act as potential vectors ln Jordan and rsrael where nalari.a transnissi.on has been Turkey and syrla, erininated. rn superpictus is an lnportant vector next to sacharovi.. An' sergentii has been known to be associated wi.th oases malaria as in the south of Morocco and the sahara of Algerla. rt used to exlst in south runlsia untiL it disappeared following insecticidal-aerial-spraying but reappeared Later creating problens of malaria transmisslon ln several focl (see LnaEr 2.5 beiow). rt perslsts in"Liiy. a potenr.ial vector in the southern oases. In Egypt, lt acts as a maln vector of malaria"" ln the oases of the western desert and in Falyun governorate where it is assoclated with pharoensis. exceptlonal An record-of,sergentii which represented its northernmost the Mediterranean gas1ffi;mon linit of distribution in Bulgaria, but no-into.r"troo r"" p.."iaed on the locallry of this record nor on the involvement of this species in nararia transnission. A second record fron the northern part of the Mediterraol.r, Basin caoe from pantelrerla island, sicily, rtaly, lrhere it was associated wlth a few nalarla indlgenous cases (see under below). 2.5 vBc/ 90.2 vtAL/90.2 Page 58 2.2 Breeding habitar Servj.ce (1986) described the breeding places of superpictus as torrents of shallow water over rocky strearDs, pools j.n rivers, muddy hilJ. streams in which vegetation nay be presenc - the larvae prefers sunlight. He also described the breeding places of sergentii as rice fields, burrow pits, ditches, seepages, slow flowing streams - sunlit or partially shaded. In the USSR,Arteniev (1980) described the breeding places of superpictus as shallow water bodies in roountain streams with gravel beds. The water in these is rich in calciun sa1ts, and the vegetation consists of filanentous algae. The waLer in the breeding sltes is scanding or slow-moving. In the daytime, the water tenperature usually rises !o 35-380 C, and opEi.mutrbreeding temperature is about 30o C. At this temperature, che who.Ledevelopmental period t.akes no nore than 11 days, as compared with 24 d,ays at 19-200 C. The larvae of superpictus nay breed in other types of erater bodies including rice fields provlded that the calcium contents are high. The breeding requirements of superpictus are the presence or waro water preferably flowlng streams with high contents of calciun salts. These conditions deternine the landscape and geographical distribution of this species. The best conditions for superpictus are found ln Central Asian mountains where summers are hot and dry, and the rivers becone largeJ.y dry. In the Caucasus, rdith a damp clinace, rains are frequent in sutturter,and che tenperature is re]atively low: the density of superpictus is low, while the highest density is shown by naculipennis s.s. In Central Asia, superpiclus can be found in the nountai.ns up to 2300 n altitude. In Turkey, Postlgllone, Tabanli & Ransdale (1973) found that the breeding places of superpictus in Turkey do not differ from those of other parts of its distribution range, which i.nclude unshaded gravel margins of seepages of ditches and streams, residual pools in drying strean beds and other pools fed by seepages. The most sultable sites are pools forned at the edges of streans, where the flow is restrlcted but the nater is scill connected with the uain stream. With its preference to hill strean, -9gpg5g!3!€ density increases as the flow dinlnishes extending the anount of pooling. In dry years the density Peak tends to appear earl-ier. On the other hand, a snalL rise in the streao 1evel caused by rains in the nountain catchrDent area can control. super,piglus output through the flushing ouE of the breeding places. Consequent.ly, the densiEEs of t.his species tend to fluct.uate with the local patterns of rainfall. Regarding sergentii, Senevet & Andare]ll (1956) surnnarized the available infornation on its breeding habitat ln the I'lediterranean Basj.n. The breeding habitats of this species are very variable: rice fields, irrigacion canals with weak current and ponds with dense vegetation. In the oases of the Sahara the following breeding places were encountered j.n Algeria: ltater cress beds (Adrar), puddles with clear sunlit nater nlthout vegetation (Djanet), Pools of stagnant rdater congested with veget,ation (Beni 0unif), and canals blocked with Potanogeton (Aharar). ln northern Algeria, .ry.!i.i_ was found breeding in the bl1nd overgrown with grassy vegetatlo" ana green algae. At Bou Saada, its larvae ".taffisEreamsvere co],lected in a stream, and in a snall sunlit reservol.r covered with filamentous algae. The larvae were collected ln lrater containing 2.23 g NaCl/l. The pH of the water varied between 5 and 9, and the temperature range was 10-200 C. In Libya, Macdonald (1982) noted t.hat sergentii which is the nost inportant vector in desert oases, usually breeds in shaded or unshaded slow-moving clean water such as seepages, springs, and irrigation canals, but it was also recorded from clean, still water in burrow pits. In Egypt, Gad (1956) reviewed the records of nosqulto species in the oases of the western desert adjacent to Libya, and included notes on the identification of oaterial collected during the nalaria control project in certain oases. An. sergentii rdas found in Siwa, Dakhla and Kharga oases breeding at the weedy edges of slowly running waters arising frou we11s and springs. Its larvae were also found in canals of rice fields and seepages, but rarely in wells. The seasonal prevalence of sergentii was the autunn and early trinter. Few adults of superpictus were reported froro Siwa by Salen (1933), but Gad (loc.cit.) indicated that exanination of uany thousands of larvae and a Further, a series of studies were carried out to determlne the physical and chenical characteristics of breeciing places of anopheJ.inespecies occurring in different parts of wc/90.2 t4AL/90.2 Page 59 EgyPt. The first of the series dealt with the types and characteristics of the breedlng places as rePorted by Gad et al. (1982). The study nas starred 1n June 1978 and ternlnated in Decenbet 1979, The following areas were covered: 3 governorates in the Nl1e Delta nanely Kafr E1-Sheikh (15 localities), Danletta (10 localities), and Sharqiya (19 localiEles); Suez Canal zone (13 localitles) and Faiyum governorate (23 localiries). The study was extended to the oases nanely; Siwa (6 1ocalltles - surveyed 3 tines), Bahariya (4 localitles, 3 times), the New Valley (23 tocatirles in El-kharga ana birnta oases' surveyed twice), and Farafra (one locality visited once). For larval sampling, an enamel ladle having 10 cn 1n diaueter was used in snal.L breeding places, and a net dipper of 15 cn dianeter was used in larger places. The density index was calculated on the basis of the number of larvae/10 dips. An. sergentii was found breeding in Faiyun and all oases of the western desert. The ureeaiif!ffiEe characrerized by having clear stagnant or slow novi.ng water, and essentially contain vegetation. Water depth varied fron shallow water to 10 n in deplth as in wells. The differenc types of breeding places of sergentii encount.ered were: (a) agricultural drai.ns and irrigatlon channels which lead the water from we11s or (in sPrings oases). These were found to have c1ean, strallow and slow noving rdater - larvae were nainly concentrated at the grassy edges. (b) surface and seePage waters arlsing frou wells or lrrigation channers and usually covered with thick growth of vegetation or reeds; the water wis usually fresh, but nodeiate salinity nas sonetioes encountered. (c) rice fields were consldered one of tLre principal types of breeding places of sergentii, particurarly those havlng srnall or moderately growlng plants. (d) snall water collections such as burrow pits. (e) wells and springs of all sizes wlth varying depths and havlng vegetation on water surface or at the sides. The 1arval density varied in different areas and according to the type of breeding place: - In Faiyum, the density ranged froro 0.13 larvae/l0 dips ln surface water or pools to 0.67 ln the nost preferred sltes of suall water collections. - In Siwa oasis, the density ranged fron I larva/lO dlps in seepages to 2.23 in springs and we1ls, being the Dost preferred sites. - In Bahariya oasis, the density ranged fron 1.L7 J.arvae/IO dips in sprlngs and r.rells to 4.44 in the oost preferred sites, being sEagnant poo,ls, drai.ns and irrigation channels. In rice fields, the density vas 2.42. - In the New Valley, the denslty ranged fron 0.94 Larvae/l0 dips to 6.09 i.n the nos! preferred sites, being drains and irrigation channels. The density in rice fields was 1.44. Thus 1t seems that, in general, the most favourable breeding sites for sergentii were drains and irrigation channels, with one exception recorded in Siwa oasis where Ehe density nas generally low (0.4/10 dips). Rice fields yielded moderate density. The second study concerned wlth the deteroination of the chenical characterlstics of breeding waters of different Egyptian anopheli.nes as reported by El Sald et al. (19S2). During larval surveys conducted in the governorates of the Nlle Delta, Canal zone, Faiyuo and the oases of the western desert, during L978- 1980 the pH and salinlty of waters of giif:T?t!_!lq"".of.breedlng places nere deternined. For seigenrii, the resulrs froo Faiyun ano arl oases of the western desert showed a pH value ranffi!-Gi'5.5 to 9 with a mean value of 7.01+ 0.07. wtthin this range larvae nere Dost frequently eocountered (7g.Li( of. the total obs&vations) and nost abundantly in water havlng a pH value of 7 (gg. 27.of rotal observations). wlth regard to water sallnity, the results frou the sane areas showed a range of 0.05-4-25 g CL/I or 0.005-0.4.252 with a mean value of 1.07r{.2O g CI/L or 11+0.022. water with 1ow sallnity (less than r g cI/I or o.:,.l) to be the nosr suTtable for 1arval breeding.- witni" "pp.Er"a ttt"-.uo"";.;;; of salinlty, the highest frequency of vBc/90,2 MAL/90.2 Page 60 larva1 occurrence was encountered (57.8"1 of total observations), and the highest percentag€ of larvae was recorded (69.47 of. total larvae collected). The lowest frequency (1.832) anc the lowest percentage of larvae collected (0.33"1) were recorded in a salinity of 4 g CL/L (0.4"4). It is interesting to note thar during the surveys the authors encountered lvo larvae identified as superplctus: one larva was found in a collection fron a rice field in Baharlya oasis (ff fa;fiffiEEty) where rhe pH of rhe warer \ras 7 and rhe saliniry was O.75 g CL/L. The other larva was collected frorn drainage rrater in a srnall channel in the New Val1ey (Bulaq locality) where the pH of trater was 8.5 and the salinity was 1.4 g C1/I. [An. superpictus i.s not a commonanopheline in Egypt. It was first recorded by Kirkpatricl. (1925), but later Halawani & Shawarby (1957) indicated that few specimens of this specles were collected fron Siwa oasis and Sinai - see nore detalls below]. The third study was reported on by El Said & Kenawy (1982) dealing with the relationship between the pH and salinity of breeding waters and the larval density of four commonanopheline species occurring in che same area of the previous studies. The data that have already been obtained were statistically analyzed using the least squares nethod. For sergentii analysis of data of the four study areas: Faiyun, Siwa oasts, Bahariya oasis, and the New Valley showed that there is a llnear relatlonship between larval denslty and both pH and salinity. Thls relationship rras represented by the equatior z = 7.66 + 0.02x - 1.39Y where.' z is the larval density, x is the pH value and Y j.s the salinity value. This indicated that: - the denslty slightly increased as the pH increased towards alkalinity (slightly positive relation, + 0.02); - there nas a negative relatlon (- 1.39) between larval density and salinity, 1.e,, th( density decreased as salinlty lncreased. A further analysis of the data collected during larval surveys in the Nile Delta and other areas of Egypt was made by El Said, Kenawy & Gad (f983) to deternine the species association of anophelines and cullclnes Ln the same type of breeding place. Analysis of data of four areas: Faiyum, Siwa oasLs, Bahariya oases, and the New Valley showed that sergentii I'as encountered alone in 47.92 of the total posltlve collections of mosquito larvae. It was associated with 10 cullclne species and four Anopheles species: pharoensis algeriensis, multicolor and superpictus. It was assoclated with pharoensis and multicolor in dralns, surface and seepage waters, and pools, but only with pharoensis in irrigation channels and rice flelds. Its assoclation with algeriensis nas recorded only in drains. In a rice field in Bahariya oasis, a single larva of superpictus (see above) was recorded together with larvae of sergentli. The other larval specimen of superpictus (see above) was found in associatlon with cullcLne larvae ln seepage nacer in the New Valley. Gad & Sallt (1972) reported the results of a mosquito survey carried out in the Red Sei area of Egypt. An. sergentii which is a desert species was collected for the first tine b the second author fron l,Jadi El-Anbag ln the Red Sea area in L962. Its larvae were found ll abundance in slow noving naters of spring pools which had rocks and reeds at the edges. Its fenales rJere found in houses and tents. This area nas resurveyed in 1969 and larvae o sergentii were found again in abundance, and two fenales and one nale were collected fron rooul. Tbe authors renarked that although sergentii was recorded from Falyun, about 80 ke fron llinia governorate, and fron Wadi El-Anbag about 150 kn froo Quena governorate, this specles has not so far been able to establish itself anyrrhere in the Nile Valley. Noting the above mentioned flndings, Gad, El Said & Hassan (1984) decided to carry ouE ecologlcal studies on .ggg!.!i. in the Red Sea governorate. Larvae and pupae of this species were collected from a breedlng place ln the above nentioned 1oca1ity, Wadi El-Aoba whlch is situated at about 8 ko west of the nearest group of houses in E1-Qoseir town, on the periphery of El-Qoseir-Quena road. The breeding site was about 10 kn east of the Red Sea coast. No other sources of natural surface Irater existed in this area. Potable water was transported to the locality weekly by ship or truck frorn Safaga which is located at 86 kn fron El-Qoseir. The inhabltants store freshwater in tanks on the roofs or in barrel in front of houses. Larvae of sergentit at different stages of development ltere obtained during March-July 1983 fron a large water collection forned by a freshwater spring. The water froo the spring passed through inpermeable rocks and was found to conlain lort salinity (27O-55Oae CLll) and had a pH of 7.5. The spring flowed lnto a large rocky vBc/90.2 !,lAL/90.2 Page 61 basin-like depression forning a poo1. The pool contalned slow ooving water which was clear and shallow near the source, but stagnated within 50 n. Thick growth of vegetation such as water weeds, grasses and algae were encountered in this breeding place, and larvae of sergentii were present underneath vegetation and algal filanents near the edges of the breeding place. The clluate in this area is subtroplcal, arid with warm surnrlers (17-340 C) and relatively nild winters (14-230 C) with occaslonal rainfall in oounlains in winter. Precipltatlon throughout the year ls less than 50 nn. An. sergentii was common during late autumn, winter and sprlng when the lrater temperature rai[dTffi-l5 and 20o C in daytirne. Larval density reached a mininum during summer. Recently, a rnore extensi.ve nosqutto survey in the Red Sea governorate was reported by Gad et al. (1987). Ihe survey was carried out in the western coastal area of che Red Sea, besides which three locallties situated in the mountainous area of the eastern desert were surveyed. Each locality was vi.slted at least once in every season throughout 1981-1983. Most of the uosquito specioens nere collected as larvae or pupae, but in a few i.nstances adult females were captured wh11e attenpting to feed on a human host. The only place where sergentii was encountered as larvae associated Lrlth culicines was the breeding place at El-Aobag during the ninter and spring season, where nore detailed observations on this species were conducted as nentioned above. In Sinai, several mosquito surveys have been c.arried out ln the past as well as more recently and a nunber of anophellne and culicine speci.es have been recorded. Early records by Kirkpatrick (1925) showed the presence of sergentii at Ain Musa breedlng in a slow moving grassy strean forned by the overflow of one of the springs, whlle $!.erg!cl!us- was present at lbssaina, breedlng ln a fast-flowing suall drain, ln which the salinlty was about 0.52. Salero (1938) collected larvae of sergentll ln good numbers from Ain lGdeis in July 1935, but ln August-Septenber 1937 the larvae of thls specles nas very scanty and thelr place was taken by superplctus and turkhudi. Fron Aln Gedelrat near Kosselna, the same author collected larvae of superplctus in stagnant water collectlons fron the spring near a narroer fast channel. It ls useftrl to note that the same author descrlbed a new specles hitherto naned Anopheles aegyptl nov. sp. [narned later Anopheles rhodesiensis rupi.colus Lewls]; the eggs of this species were found in a srnall collection of freshwater in Wadi Taba. Abdel-Malek (1956) found both superplctus and *rgenlii. breeding ln association in a slow flowlng strean fed fron Ain Gedeirat, havlng thlck growth of floating algae. Gad & Darwlsh (1957) recorded sergentii breeding in streams fed fron a spring at E1-Tor in 1951 but when the sane breedingllaces were visited ln 1955, they were found to be free of nosquito larvae. Gad et al. (1964) reported on a nalaria (entonological/parasitological) survey carried out in Sinal during August-septernber 1952. In the southern region of Sinai, sergentii was found breeding at El-Deesa srranp which was situated at a distance of 4 ko frorn El-Tor locality very close to the seashore. This place was surveyed prevlously in 1951 when no sergentii1arvaewereencountered,but@andaf.'@werePresent,andagain in 195t when only nulticolor larvae were recorded. Adults of sergentii (43 feoales and onena1e)wereco11ffiihousesatE1-Iladi,a1ocalitysitGteaat)'knfronE1.Deesa breedlng place. An. nulticolor was lhe associating specles in El-Deesa swamp, and its adults were also collected from houses at El-tladl locality. Other sergentii breeding places were found near El-Tor in the vicinlty of Haunan Musa springs. These springs were shallow and moved in twisted narrolt channels in which vegetation and algae were abundan!. 0f three springs examlned, only one was positive for sergentil larvae. A third locallty where sergentil was found breeding was Wadi Felran oasis. In thls snal1 oasis, many anopheli.ne specles including sergentii were found breedlng ln a snal1 spring. The oasis is sltuated at about 50 kr fron St Katherine Convent and was usually used as a rest house by vlsitors travelllng to the Convent. In the northern reglon of Slnair sergentii was founa breeding only ln Ain Gedeirat, near Kossaima ln an unlnhablted area ltlth no houses nearby. Its larvae were abundantly present in the shady part of a sPring which flows for about 6 ku in a hll1y region wlgh nany caves at the sides. These caves were high up and inaccessible' therefore could not be inspected. In a deserted hut near the sprlng an unfed neltly energec feroale of sergentli was collected. tflth regard to.ggpgg!g!g1 in Sinai, the auEhors ci'ted the records of Xirtcpatrlck (1925) from Kossaiua, Salem (f938) and Abdel-Malek (1956) fron hence it was considered that the distribution of superpictus was localized, ir S:^FO"t.at, wc/90.2 t4AL/90.2 Page 62 During a faunistic survey of the inland water sources of Sinai carrled out during 1968-1970, mosquito specles encountered were recorded and reported on by l'largalit E Tahori (1973). Ihe authors sumnarized the previous records of mosquito species recorded in Sinai (see above) and added the records obtained fron this survey. An. sergentii was found nainly on the western and eastern slopes of the southern rnountain range and also ln the coastal area. Its larvae were collected in waters having a wide chlorine range, from 23 ule/I at Bir Arbeein to 4700 ng/1 at tladi Sudar. An._sergentii- was found breedlng in associationwithseveralcu1icinespecies,andseve"@c1es:d'tha1i(5tines), (3 -E!!E!glg tines), uulticolor (twice), superpictus (once), rhodesiensis rupicolas (3 tioes), and turkhudi (twice). An. sergentil was suspected of being ttre najor veitor of nalaria in southern Sinal. An. superpictus was found in lJadi Isla at altitudes up to 800 ro. It was nuch less abundant than sergentii . An. superplctus was found breeding in association with two culLcine species, and five Anopheles species: hispanlola (once), mulEicolor (once) sergentii. (once), rhodesiensis rupicolus (once), and turkhudi (once). An. superpictus was one of the suspected nalarla vectors i.n Sinai. The results of parasitological surveys carried out in Sinai by these authors and previously by Gad et. al. (L964) are shown below under Subsection (il) EPIDEMIOLOGYAND COMIROLOF MALARIA (para I). In Jordan, Farid (1954) 7n hls artlcle on the fallure of DDT house spraying to lnterruPt rnalaria transmission in the Jordan Va1ley, polnted out that superpictus and sergentii were considered the naln vectors of nalaria. Both species were found to breed extenslvely in the vast breeding places along the banks of the Jordan river and its trlbutaries. In many lnstances both specles were found in association ln the same breeding p1ace. Shallow nater, running slowly over pebbly or roeky beds with scattered snal1 vegetatlon and exposed to the sun, offered the best breeding conditlons for both species. An. sergentll was also found breedlng along the grassy edges of snall streans and springs. In one instance, sergenti.i larvae were collected frou an exposed well 5 u i.n diaroeter and about 30 n deep, contalnlng some floating dead weeds. Both species lrere recorded in every village ln the Jordan Valley. Surveys of DDT-sprayed prenlses for adult nosquitos showed that superplctus and sergentii dlsappeared fron the lndoor restlng shelters, but larval catches tndlcated that considerable breedlng contlnued Ln nearby breedlng places. In Israel, Sallternik (1955) made a detailed review of the biononics of sergentii and response to DDT spraying using a special trap and ln comparison with .superpictus and sgcharovl. Observatlons on the optlnal breeding sites showed that sergentii ras breeding alone Ln L24 places and Ln assoclatlon wlth superpictus and sacharovl in 39 places. The most favourable breedlng conditlons for sergentii nere; - shallow ltaters fonned along strean beds and shallow puddles cut off fron the main stream havtng a water depth below 15 cro; gentle flow over gravel bottoos; and shaded canals lrith vertical banks. - optlnal rrater tenperature between 23 and 28o C. - pH fron 7 to 7.55. - because of the snall volume of water freguently utilized as a breeding place by sergentli, and as the auount of evaporatlon was large, saliniEy was as high as 0.6-0.77.. - owlng to the tenporary nature of the breeding places of sergentii, a fixed or typical flora was lacking. In unshaded places and ln lhe presence of Cladophora and other filanentous algae, sergentii was found breeding in assoclation with superpictus, and if Myriophyllun or Ceratophylluo flora nere present, lt was assoclated with sacharovi. Barkai & Saliternik (1968) studied the breeding of anopheline oosqui.tos in Israel during 1963-1965 at the last stages of the ualaria eradicatlon progranme. The breeding places were classified lnto four types each of which was considered a different biotope. Type A: sprlngs, leakages of irrigation systems and seepages; and Type B: natural streaos, wadls and irrigation channels were favoured by ry!.1i. and superpictus. Type A usually have clear, semi-stagnant water, and vegetation, if present, is usually low. lYpe B are breeding places which have running water and often bordered by vertlcal vegeta!ion. vBc/90.2 MAL/90.2 Page 63 Sallternik (1967) updated his review of the bionomics of sergentii addi.ng nore infornation fron observations carrled out in Israel during 1961-1965. An. sergentii was found to breed throughout the year, with a oaximum in October-November (55.57") and a nininum in January-March (I.7"A), mostly in seepages and leakages. With one exceptlon - the Dead Sea - breeding of sergentii was also observed during winter Eonths. Someexplanations of this phenouenonwere offered as follows; (a) Rain (only about 55 nn annually) during winter nonths of Decenber-February, tends to accunulate in numerous snall pools and reduce the chloride contents existing 1n these snal1 water col.lections. (b) Unlike other places in the country, the low rain did not nash alday the larvae fron their breeding places. (c) Water temperature in wj.nter is about 24o C, which is the optlmum breeding temperature for sergentii. Intense breeding of sergentii was also found near'settlenents that were regularly sprayed with DDT for many years, because of the exophilic behaviour of this species. Despite intenslve breeding, adults of sergentii could hardly be found in sprayed houses and stables. They could only be found ln large numbers in a few caves. - see nore details under 2.6/2.7 below. In his review of the distrlbutlon and bionomics of nalaria vectors in Israel, Saliternik (I974) surnmarizedand updated the inforroation on sergentii and superpictus. Bot.h species are oost abundant and distributed all over the country. They have the same breeding places: streams, wadls, canals, seepages and leakages. An. superpictus prefers sunlight with floating algae, and even breeds ln rapidly noving waters, while sergentii tends to breed in uore shallow, partially shaded, semi-stagnant lrater accumulations, especially under pebbles, and 1n seepages. Breedlng of both specles nas controlled by alternating streaD flow direction, perlodical drylng up of the stream beds, introduction of Ganbusia affinis into streams, drainage wor:k, DDT house spraying and larviciding operations. At present, the densltles of both species have greatly declined for the following reasons: (a) almost all natural streams have been polluted by sewage, thus rendered unsuitable for breeding anophelines. (b) almost all breeding now takes place in small artiflclal ltater accumulations with Iinlted water surfaces, which dry up periodically. Recently, Pener & Kitron (1985b) analyzed the frequency of anopheline species collected as larvae durlng 1974-f983 in northern Israel. An. superpictus and sergentii which were often found in association, together constituted 50% of all anopheline larvae collected in Dost years. The relative frequencies of the two species showed significant negative correlation, (r = -0.668,< P 0.05). In Lebanon, Gramiccia (1953) as nentioned above descrlbed the breeding habitat of najor and suspected vectors in the country. An. superpictus was found to favour running water among pebbles, banks of rlvers, irrigation canals with vertical vegetatlon and irrigatlon basins. An. sergentii in its linited dlstribution in Lebanon, preferred snalI water courses covered with vegetatlon and snanpy patches at the sides of ri.vers. In Syria, Abdel- Malek (1958) found that superplclqs ranks next to sacharovi in the northern part of the country. I"arvae of superpictus nere collected fron slow moving sun-1it mountain streans having clear lrater running over pebbles with or without green algae, neglected irrigation canals with energent and horizontal vegetation, rice fields and open parts of swamps, Larvae were also encountered in snall rtater collections such as hoof-prlnts. Larvae of superpictus were assoclated w.ith claviger in a shaLlow sun-Iit pit situated on a hill and having green algae. In several villages in Derik, Kanichlieh, Hasseche, Delr-e1-Zor, Tell-Abiad and Aln-el-Arab in the northeastern part of Syria, superpictus larvae were found elther alone or in associati.on wlth sacharovi larvae. In 6i:y two v:i:1ages ln llasseche and Deir-el-Zor, superpictus larvae nere ?d-nd breedlng in association with larvae of sacharovl and pulcherrlmus. wc/90.2 t[AL/90.2 Page 64 2.3 Swarming and nating Farid (1956) indlcated that his attenpt in 1939 to breed sergentii 1n captivity in Egypt failed, even when the dinenslons of the cage reached 3 x 2 x 2rn. Swarns of sergentii were observed in Dakhla oasis in che rdestern desert of Egypt during 1944, which were forned at dusk as well as before sunrlse over mounds of earth 10-20 rn high. Nuptial flights of this species appeared to extend for some kiloneters. Sone laboratory observations rdere made on adults of sergentli raised from larvae of this species collected during surveys of the Red Sea governorace, Egypt by Gad, El Said & Hassan (1984 - see under 2.2 above). Adult progeny were kept in cages and supplled with 102 sucrose, and human blood was offered on which the fenales fed readiJ.y to repletion under dark and light conditions. No swarning was observed. Three and four days after the bloodneal, nore than 500 eggs were laid, of which 150 hatched. Several females oviposlted unfertilized eggs. Trials to establish a colony failed. These observations led the authors to assume that sergentii populations in the Red Sea area may consist of stenogaoous and eurygamous subpopulations. In contrast, populatlons of sergentii fron Faiyun governorate and Siwa oasis in the western desert proved to be eyryganous which necessitated applylng artificial natlng techniques in order - to raise a laboratory colony [see Beler et al. (1986) 1n VOL. I, under 2.L.4, p.67. The only successful attenpt to raise a self-perpetuatlng colony of sergentil was made by Prof. G. Davidson from egg batches of this species sent from Jordan in 1967, as cited by Zahar, L974. ) No field observations on swarming and nating of superpictus could be traced. 2.4 Dlspersal In Egypt, Abdel-llalek & Abdel-Aal (1966) carried out a nark/release/recapture exPerlnent during Septeuber-October 1965 ln Siwa oasls of the lrestern desert to investigate the dispersal of sergentli. Larvae of the 3rd and early 4th instars of ggggllli were collected frgn two sp;ings in Siwa, and bred ln radloactlve solutions. Tno radioisotopes were used: rzP and J)S, and recaptured uosqultos lrere recognlzed by autoradlography. The lsotope present ln each recaptured specitren was ldentified^|y visual discrlnination betlteen high an{-lo!r energy beta particles ln the X-ray flln: JZP producing diffuse fogging, wh1le J)S gave a well-deflned lnage. Routine capture stations lrere established wlthln a clrcle of 2 kn radlus. Releases were nade elther fron the centre or near the periphery of the experimental area, so that recaptures were possible up to a distance of 3.75 kn ln one dlrection. Out of 4260 labelled sergentii released, 37 were recaptured giving a recapture rate of 0.872. fire results showed that the nales dlspersed up to 3.4 kD, and the feuales up to 2.5 kn fron the points of release. In Israel, Sallternik (L974) lndlcated that the flight range of both S.lPictus and sergentll does not exceed 2-3 kn in sumner, but ln the autunn adults of 99gg.'11!!lrere founa at a dlstance of 6.5 km fron thelr breeding place in the Dead Sea area, citing Shapiro, Sallterntk & Belfernan (1944). [These auEhors narking rnosquitos with gold dust (a bronze preparatlon finely powdered) recovered one marked sergentli fenale at a distance of about 4.2 ko frorn the place of release in Novembet, 1942.1 In Lebanon, Garrett-Jones (L957) carried out observalions in two hill villages to investlgate the nigratory flight activitles of superpictus and sergentii. lhe two villages were Dedd6 and Delr B111e, both ln l(oura country, not far fron the Lebanese town of Tripoli. Dedd6 is sltuated at an altltude of 300 m and Deir 8i11e at 800 n. Very careful larval searches ln the available traters were made around both villages to a distance of 1 1/2 kn in the case of Deir 8111e and 3 kn ln the case of Dedd6. This was repeated on several occasions, particularly ln late summer when anoPheline mosquitos were caught from houses. At that time, no actual or potentlal surface breeding place was found wtthin these distances. In early surmer, each vlllage conEalned a surface pond which later dried outl repeated searches falled to reveal anophellne larvae ln these ponds. During 1953, while the entomological surveys were in progress, some "wells" (these were described as not being true wells but were underground raiowater reservoirs, excavated into llmestone rock and usually llned lrith cement) rsere experimentally treated with DDT, IiCH and other lnsecticides, and groups of village houses Itere sprayed to ascertaln the absence of any house-restlng clavlger. The anophellnes captured were all fron unlreated premlses. At Dedd6, superplffiT not found ln houses between January and Septenber, but eight fenales were coffiilffbuildings in October and further specloens ltere found during wc/90.2 tlAL/90.2 Page 65 Novenber-Decenber 1953. At Deir Bille, several fenales of superpictus were found in a stable in March, but none was encountered in the following three oonths. In July, the species reappeared and becamemore frequent in October. No males were collected from either village. The author excluded the possibility that superpictus visited the trdo villages to feed, because men and cattle were available uuch closer to the local breeding places of this species. It would seem, though, that these observations indicate nigratory flights. Regarding sergentii, its seasonal prevalence in Lebanon was from late July to Novenber on1y. At other seasons no adults were ever collecEed, and larvae could not be detected even aft.er very thorough searches in the breeding places. In October, two females were taken in houses in Dedd6 in association with superpictus females referred to above. The author considered that sergentli females ousL have covered a distance of noE less than 3 kn in search, not of adult hibernation quarters, but of a fresh breeding place. 2.5 Local spatial and seasonal distribution In continental Europe where nalaria has been erad:icated, superpj.clus in countries where iE exists remains as a potenLial vector. In IEa1y, a cytogenetic investigation was carrled out by Sabatini, Coluzzi & Boccoli.ni (f989 - 1n press) on sanples of superpictus collected,fron the southern part of the country. An abstract of this study reads as follows:.1 "Polyt.ene chromosome studies nere carrled out on various population sanples of An. suPerpictus fron different locallties in Southern ltaly. l'lore than 7 000 fenale specimens, nostly obtained fron daytiue collections of indoor restlng nosquiloes, were successfully scored for nurse cell polytene chromosomes. Nlght biting samples were also examined in some localities. Only one chromosomal polynorphisu, due to a paracentrtc inversion involving the central third of the 2L arm, was recorded in all sanples. In all localitles, the inverted 2La arrangement showed renarkably stable frequencles although the populations examj.ned were i.solated fron each other and at least some of then have presunably been subJect to bottle neck in recenE years because of insecticide treatments or ecological changes affectlng the availabllity of breeding places. Departures fron the liardy-Weinberg exPectations, indicating an excess of heterokaryotype!;, nere noted and crltically analysed by conparing sauples obtained simultaneously in the same locality fron different con sheds, fron different sect,ions of the same cow shed and froo nlght and day catches in the saue cow shed. The phenonenon was not found uniforrnly dlstributed anong indoor restlng samples: slgnificant departures from the llardy-Weinberg expectations rrere observed in some cow sheds but not in others situated nearby or even adjacent to them. These results did not support the hypothesis that the excess of heterokaryotypes was due to their greater longevlty or to differential oortality in the preloagi.nal stages. It. ls suggested that different karyotypes may react differently to nicroclinatic specific condltions, since Ehe tiardy-Weinberg disequilibriun was most,Iy observed in samples frou resting sites t.hat were nore 1it and subject to lrider cllmaEic variation. " As shonn in documenr VBC/90.1-ltAL/90.1 - under SECTIONTL, 2.1.3, gg5gl[! was recorded for t,he first tioe in a snal.l focus on the island of Pantelleria, Sicily by DfAlessandro & Sacci (1967) durlng an epidenlological investigation carried out during October 1967 on two indigenous malaria cases. The larvae showed sone differences in the abdonlnal tergal plates and the pignentation of the head from those observed in larvae of sergentii from other geographical areas. Btrt careful exaninallon of all other characters and the adult characteristics confirned the identification of sergentii. The strain of Pantelleria, therefore, provi.des interesting naterial for further studies on the variability of sergentli. This species has never existed in the Italian territory and this conflrrned record fron Pantelleria represents the northerilDost linit of its distribution, with the exception of a single historical record fron Bulgaria (as Denti.oned under 2.1 above), where Dintchev et al. (L962) llsted sergentii and superpictus anong the Bulgarian anopheJ"ine fauna studied since 1907 in addltion to meobers of the Ao. rgligglg cooplex (see]'.5above)butnodetai1softhedisrributionofthetwospec@y Dinetchev et al. (loc.cit.). These authors gave the results of their survey carried out during 1956-1958 in the Bulgarian littoral of the Danube where the species conposition of members of the An. naculipennig cooplex was shown, besides whlch hyrcanus, pseudopictus and claviger were r6@6iffii1ention was made to either sergentffiffipeffi 1. The abstract was provided in advance through the kind cooperation of Dr A. Sabatini (personal communication, November 1989). vBc/90.2 MAL/9A.2 Page 66 In Yugoslavla, superpictus as one of the potentlal vectors of malaria in additlon to nenbers of the en. r"c"fip.nnis- coroplex was recorded from indoor-resting collecEions in several areas: so"thea"t Serffi (AdarnoviC, 1979b); Neretva Delta (Adanovld, 1983a); the plain of Skadar lake, Montenegro (AdanovlC, L984); and Ravni Kotari (AdarooviC, 1985). In the USSR, as shown by Artenlev (1980) superpictus i.s commonin the mountainous areas of Central Asia and it also occurs ln the Caucasus, and occasi.onally on the southern coast of the Crinea. In Central Asia, it is found up to 2300 rn altitude in the nountalns. 0n its seasonaL dlstribution, superpictus hibernates in the adult stage. Massive disperslon of pre-hlbernatlng (diapausing) fenales usually occurs in October. They hibernate in stables sheltering anlmal hosts and they feed on blood al1 winter except durlng very cold weather. Hibernating fenales nove out of the winler shelters in March or April. In the sprlng and the first half of surnmer,the density of superpictus is low, because wacer bodies suitable for breeding are scarce at that time, with river beds being filled with etater flowing fron the nountains, and shallow water in gravel-covered river beds is alnost non-existent. As the water level Ln rlvers recedes in uid-sunmer, the river beds get drier and numerous breeding places suitable for -gggp.i"!u" are formed. The density of thls species then begins to increase progresslvely to reach a maximumin October. Unfavourable years for superpictus are those in which the water level in mountain rlvers becomes sufficiently hlgh with surnmerrains to destroy all suitable breeding places of this species. Also unfavourable years are those which are dry when the water level ln river beds decreases sharply and breeding places of superplctus dry up. It is only in those years when the water 1n mountaln rivers renalns at a uoderate 1evel, that the density of superpictus attalns its maxlmum. Thus, the denslty of this specles is subject to great fluctuatlons from year to year dependlng on the meteorological conditions. This ln turn causes varLation ln the epldeolological signlflcance of superpictus causing narked vartationinthe1ntens1tyofna1ariatransmi8s1on.@-isoneofthe potentia1na1ar1avectorsintheUSSRandisthernost-dii@henounta1nousand foothi11areastnCentralAsia.Itcanberead11y1nfectedbyP.v1vaxand!-@'. Its epideniologtcal importance being subject to fluctuations in lts density in dlfferent years, has contributed to the appearance of sudden and large outbreaks of nalaria in areas previously consldered free froo the dlsease. In Turkey, superplctus ts widely distributed occurring in areas ac sea level to over 1700 n altitude. As shown by Postlgllone, Tabanll & Raosdale (1973), superpictus is an ioportant vector in Turkey ranking next to sacharovl. Because of their different breeding habltats, the two specles do not have ldentl@raphical or seasonal distrlbutions, but wherever they occur in one area they supplemenE each other. As superpictus exhlblts zoophilic tendencies, its vectorial loportance varles according to local condltions, and it also exists in many nonaalarious areas. However, lt was responsible for aaintaining nalarla transmlssion for many years ln certal.n llediterranean and Egean coastal regionst desplte regular DDT house spraying. Bec.auseof density fluctuations due to variable breedlng condittons, lts vectorlal lmportance varies between years. It hibernates ln the adult stage sheltering in houses or in outdoor shelters. In Morocco, Guy & Holsteln (1968) indlcated that -gs:Eg!.ll exists in the whole country practically except in the mountainous regions situated above f500-1600 n altitude. This specles whlch had been considered predominant in the llarrakesh region, is in fact widely dlstributed, sometlmes existing in abundance as ln the south of Casablanca Ln the Atlantic zone and extending to the foothills of Rlf ln a region under the Mediterranean lnfluence. Thus, the descrlption of sergentiL as a pre-Saharan species is no longer valld even though its orlginal foci in Morocco were found in the Sahara. On the contrary, it exists outside the desert ln conpetltion wlth labranchiae, although the ecologlcal conditions are not optlnal for its survival. Hence, the role of sergentli in nalaria lransmlssion ln the extreme range of its dlstrlbutlon ls probably much reduced. Previously, Guy (1963) pointed out that the role of sergentii in southern Morocco is sinilar to the role of labranchiae in the northern part, but lt was difficult to deternlne the exact role of sergeiffi-it was associated wlth labranchlae ln the aouthr or with d|tha11asasusPeffiorina1inltedareasouthof-Fhe-t1as.Theseasonal prevalence of sergentil ls nore delayed than that of labranchiae, slnce the former does not appear in appreiiable densities untll June or nostly July attaining its maxlmumdensity in Septeuber-Noveuber. This phenomenoncould explain why nalaria t.ransuisslon ln Tafllalet rras Bore retarded than in the rest of the councry. Maps were presented lDonth by nonth vBc/90.2 r4AL/90.2 Page 67 showing the extent of distribution of sergentii in Morocco in assocj.ation wj.th either labranchiae or hispaniola or with both. The foci of sergentii situated north or south of tir. tta"t-atfas ippeirea to be present continuously fron July to November. In fact, the Haut-Atlas seems to represent a strong geographical barrier that probably prevents the interchange between the north and south populations of sergentil. This was confinned by the results of precipitin tests (see under 2.9 be1-ow)and by the exclusive presence of dtthali south of thls nountain chain, a species which has the sane biological characteristics as those of sergentli. In Algeria, Senevet, Andarelli & Rehn (1960) referred to the distributlon of sergentii shown by Senevet & Andarelli (1956) as belng the southern terrltory (Sahara): MrchounEche (AurEs) and Bou Saada (Haut Plateaux). In October 1959, the authors discovered tlto new close poinrs where they collected larvae of -gergen!.ii_ both of which were in the Oran region to the borders of l{orocco: one point wiJlIIiIGd at a latitude of 3508'near Honaine, which is situated 30 kD southwes! of Beni Saf; the other was situated at 2.5 kn southeast of the former. Holstein et a1. (1970) in their presentation of lists and a nap of the distribut.ion of the anophellne species in Algerla, added the records which they collected fron Hoggar and Tassill areas in the south of the Algerian Sahara duri.ng 1958-1969. The distribution of sergentli was found to be oore extensive than they thought. Many new localities for thls specfes lrere discovered. It was the predoulnant species in Tasslli in June and in October-November, while ln the renaining areas of the Sahara, princlpally in Hoggar, it nanifested itself as a species of the autuun, with the exception of sone stations where it appeared ln Aprll-June. In the northlrest, sergentil ln Tinlnoun, El Golea and 8enl-Ounlf, is an autumnal specles, the presence of which is rarely detectable for nore than two months. In these regions, the water of the breedlng places was nostly saline; freshwater breeding sites were rare. In the pre-Saharan regions, whl}e sergentil rras present abundantly ln Biskra [in the northeast], it seens that lt has dlsappeared fron Ghardala-Ouargla-Touggourt-El Oued zone as regular searches ln the last few years in this zone falled to denonstrate lts presence. To t,he north of thls zone, it was ln the Tebessa region (Annaba wilaya) that ggg!.1! lras encountered ln 1969. In 1970, lts presence was confirned northnest of AurEs wilaya at the level of Constantine, and the species appeared in the l'ledlterranean area partly ln Bedjaia (west of Constantlne) and partly in Kolea (west of Alger). Zulueta & Rarosdale (f975) reported on an entornological/parasitologlcal survey for malarla carried out ln the Saharan reglon of Algeria. llost observations etere nade in the Hoggar zone (Tananrasset in Tamanrasset wllaya) and Tassili zone (Djanetr Ouargla wiJ-aya). These zones have provlded llttle infornatlon in the past few years, although they had been subjected to several epideniologlcal studies for nalaria in the Past. Larval searches revealed the presence of sergentli associated with dtthall ln irrlgation canals at Abalessa, or alone in sprii!il-i-3anet, and in well3-Fdeles. In the last two locallties, irrigation canals nere negatlve for all anopheline larvae due to the Presence ofGanbus1a.InGhardaia,[email protected] adult mosquitos ln 30 houses in six localities ltere negative despite the Presence of larvae in the breeding places even in localities which were positlve for larvae of sergentii (Abalessa and Djanet) as shown above. Likewlse, direct nan-bait caPlure outdoors cunducted iroo 1730 to 1900 h was negatlve except for a few cullcine nosquilos in tlto localities. In Ih6rir, sergentil larvae nere found in lrrigation canals, sprlngs and streams, and at:.-nigtr-?ilffa-pture on a donkey ylelded 48 sergentil, but unfortunately observations could not be pursued in thls locallty. The authors deduced thaE the absence of anophelines attacking oan after sunset nay lndicate poor Dan/vector contact. Some remarks were made on blood the identlty of sergentll as sholrn by the sane authors below. Exanination of 863 smears sanpled fion-EIlEe-groups including six infants at Silet, Abalessa, Djanet and IhErir were all negatlve for malarla parasites. Ransdale (1977) ln October-November 1977 continued to lnvestlgate the water Points along the line of the nelr trans-saharan highway for recordlng the local anopheline species and assessing the risks of inportatlon and establishnent of the African vectorst An. ganbiae s.s. and An. arable{rsls. He collected sone nelt records of the dlstribution of FeE-t-ii, loutttcotor.EniolA-And drthali, and conflrned earlier records of anophellne aiEfl5utlon ln gtre oasCiof the Algerian Sahara. A oap nas presented showing the available records of the anophellne species distributlon along the national routes: wc/90.2 r4AL/90.2 Page 68 Ghardala-Ain Guezzan, and Ouargla-Djanet. D.rrlng a further mission Ransdale (1978) pursued the assessment of the risks of perslstence of nalarla transmisslon ln the Algerian oases through 1ocal or inported vectors and with a view to advlsing on the appropriate preventive or correctlve measures. Many oases appeared to offer favourable conditlons for breeding of An. ganbiae s.s. and/or An. arabiensis, but no actual foci of the trro vectors were encountered. 0n the other hand, sergentll was found to be nore widely distributed than previously thought. A research project rras suggested to ascertain the identity of the forns of thls species existing in the Saharan oases (see below). A nap was presented showing the latest records of anophellne distribution in the Hoggar region. Ransdale & Zulueta (f983) in their study of the inplleatlons of the trans-saharan highway conpiled the available records of the anophellne specles in the northern and southern oases of Algeria, addlng nelrer findlngs that were recorded subseguent to the napped data of Holgteln et al. (1970). These records are shown here in Tables 13(a)^ and (b)r, while Fig. 2r shows the location of various oases and the principal roads. These records clearly show that sergentll is nore widespread in tbe southern oases, The authors pointed out that there are tno forns of this specles (citing l"lattingly & Knight, 1956 and Gillies & de Mell1on, 1968): one is Anopheles sergentil sergentii which occurs in the Asian part of the species dlstributlon range, as well as in Africa north of the Sahara and in sone Saharan oases; the other forn is Anopheles sergentli nacmahoni which occurs ln East and West African savannas and penetrates into the Saharan oases. Separation of the two forns on norphological characters depends on dellcate differences, often dlfflcult to interpret (cltlng Rloux & Jumlner, 1963), particularly ln Algerla as some intergrading seeEs to occur. Regardlng the vectorlal lnportance, the two forms dlffer strlkingly: sergentli sergentil has been recognized aa an finportant malaria vector, whereas sergentii macnahonL has never been found bltlng nan and ls of no vectorlal loportance. This narked Frerrcepo1ntstothePresenceofmorethansPec1ficseparation,desp1tetheapparent intergradlng. It ls posslble that sergentil and macmahonl are norphologically slnilar buc biologically dlstinct specles; the separation of the tno uay be dlfficult because of overlapplng dlagnostlc characters. Alternatlvely, sergentil s.1. uay include a conplex of tlto or more species not separable by applying the existing norphological criteria. Chauvet, Hassanl & Izrl (1985) also discussed the inplications of the trans-Saharan highway on the nalarla situation 1n the Maghreb and the Algerian oases of the Sahara. The Saharan species: sergentll and oultlcolor are regarded as lnefficient vectors for transmlssion of tropical P. falcj.paruu. Nevertheless, it must be kept in nind that in the Past severe epldenlcs of falciparun Dalarla occurred as in the case of Djanet and lhErir oases in Tassill NrAjjer where these two species exist. Road t.ransportation wtll pernit the colonization of new bodies of water and the Saharan oases by che two local vectors: sergentil and nulticolor whlch are well adapted to the environment. The sane suggest.ion shown above regarding the need for differentiation betrdeen the two forns of gg5!! has been stressed. The epidenlological consequences of the trans-Saharan highway including the importation of nalarla and exotlc vectors fron Afrlca south of the Sahara as discussed by all the above authors are shown under Subsection (ii)r2 below. In Tunlsla, Wernsdorfer (1973) ln h1s assignment report indicated that in the southern region, partlcularly M6d6nlne and Gab€s governorates the nalaria incidence was apparently reduced at the beglnning of the 1960rs, as a result of the control canpaign against the desert locust, creating great lnsectlcldal pressure on the 1ocal vector, sergentii, to the extent that it was elininated fron the najorlty of the zones or remalned at a minimun density in others. This created a false inpresslon in the nlnds of health authorlties thinki.ng that aalaria was eliuinated fron south of Tunisia. This impression was dissipated when an analysls of che malarla sltuatlon in Gafsa showed that this regLon was not touched by the anti-locust canpaign except at lts periphery, leaving the bulk of the sergentii population unaffected. Consequently, nalarla transnission continued in naoy foci with higb transmission potential ln others. Towards the end of the 1960ts, sergentii began to spread and increase its local denslty 1n the south. In 1969, an lnportant Dalarta focus was observed at Talalet, M6d6n1negovernorate, and in 1970-1971 very active focl were detected ln two localltles ln Gafsa governorate: Foufi/Meloussi and Faidh. Followlng the ffieproaucea-by pernlsslon of Mr C.D. Raosdale and the Journal of Troplcal l'ledicine and Hyglene fron the artlcle of Ransdale & Zulueta (1983). vBc/90.2 t4AL/90.2 Page 69 application of intensive control neasures in the foci and their surroundings, the malaria incldence decreased in L972. Nevertheless, there was one focus with 10 cases of P. falciparun that remained in an oasis outside the protected region. In Libya, very little information is available on the biononics of malaria vectors. Before the nalaria eradicati.on programrnelras started in 1960, Goodwin & Paltrinleri (1959) briefly descrlbed the nalaria sltuation in Llbya. Regarding the vectors, they considered sergentii and nulticolor as the vectors of oalaria ln the oases of Llbyar' the latter was lncrininated on epideoiological grounds (see under 4.5 below). I.lhile nultlcolor is widespread, -9gggg!.!1_ has a oore restrictive distributlon. In certaln oases of Tripolitania, the western province of Libya, hi.spaniola and -1gglglus were found, but only in noving waters. In the coastal areas, coustani and superpictus were the only vectors of non-oasis malaria 1n Libya. Goodwin (1961) conpiled a list of anopheline Table 13 (a). Anophelines recorded fron the northern oases of Algeria. Nonicm elc3 algcaLrsit dtlrali hiqaniolo lbrarchiu alttolot trrgcrl;ii s.l. Aia Scfn + A.iou + + l:gouet + + + Bi*n +. ? + + + Negrioc + + + El Oucd + Touggourt + Ourrgle + Gb.d.ir + T;'lfztro 1l 1l + El Gotce + Ecai Ounif + + + Bccb.r + ? + I(eadse + TerUt + BcDi Abbe! + + + Tiaimua + + + Mrat + + Aoulef + to Sd.h ? cNcvly rccordcdsimc regicr of Hollcia rr aL (1970). cRccordedby Bcoebadii& krrouy (1969). Table 13 (b). Anophellnes recorded fron the southern oases of Algerla. Soutbcra thodcsbtrcis tlqrPet tc"tza'a q3e3 Ahafi hispaaiola labtanchiac nlticolot tttPtcohu btousvsi s.l. Aref ? +a Ia Angucl +e + Tir + + Tclbcncoct + Abalcssa +c + + ? Silct +c ? Hirafol +c +c +a ldclcs +o +4 Trzroul + + Tahifct + A6td + + + + lo [roulaouco + + + + Talaenrassct t + + Arns.l + + + +. + Tagranbeit +. +o +o Am.ir Dianct ? + Ars.ldo + + lbcri + Ihcrir + +t + Ab.r.t + AaefcA aNcgly recordcdrimc rcvicr of Holstci! a dr. (1970) wc/90.2 r4aL/90.2 Page 70 F7g. 2. l,laps of Algeria and (detail) the Hoggar showing the principal paved (unbroken lines) and unpaved (dotted lines) roads, internatlonal country borders (hyphenated lines) together with orean Donthly rainfall (vertical bars) and temPerature (1lne) from selected stations (US Departnent of Conmerce 1967). J-OJ-DJ- ::i; A A so[Jt8nln fot m\ / rsem olllltr- tlll(,r,, .11,i,* Algirrt t goult El Golcr 36.4aN 33. 46.N 3(r sAN '*i / \ ,a,l*'' toof/ \\/ / \{zo sfv \ zso. r3rsn. 10 o*r#!*o ncgprnc! .-.i.il'.i..-.r1 tAtil.r tr, \ m ,f;r.q*ir ----',t'...- AtR ; :Ahti'! MouNrAlNs \ rrufc! !'r:,.\ r!. la: \ ..' MAU |I i '. ::^__--- 2310m g;.,J;,,:'*ilL.'...... o*,-..\*J ...'",';"/ N,rrD.y -/a(QimiNkorri I vBc/90.2 ytAL/90.2 Page 71 and culicine species recorded in Libya before 1957, and added the species he and Ehe nalaria staff recorded during 1957-1960. A nap showed the distribution of certain anophe1inespeciesandcu1icineco11ec!ionsitesinthethreeregionsofLi.bya:@, sergentii, superpictus and hispaniola. The nap showed that in Fezzan rnulticolor was widely distributed and selgenqi! was more restricted. Fewer records of nulticolor were shown i.n [email protected]:crecordsof sergentii were shown in Trlpolltanla, none was found in Cyrenaica. After the conpletion of the attack phase of the nalaria eradication programmein Libya, malaria outbreaks occurred in certaln localities of Fezzan provi.nce during L964-L965, which necessitated the reinstitution of DDT house spraying on a focal basis. From a brief survey during July 1966 covering certaln localities of Fezzan, Zahar (1966) conpared the distribution of the anopheline species encountered with that recorded during the pre-eradicat,ion survey of 1958-1959. In lladi El Mjal, sergentii and multicolor were encountered as adults and larvae, sinilar to the records of 1959, but in Gatroun oulticolor was the only anopheline found as previously recorded ln Decenber 1958. Epiaen:.ot6@lJfl the forner valley was subjected to a malaria outbreak in 1964, while the latter, accordi.ng to the avai.lable inforrnatlon escaped, even though constltuting a border area exposed to an influx of innigrants fron southern counEries, namely Niger and Chad. Ihis raised a question as to whether sergentli was solely responsible for the nalaria outbreaks or it was joined by nulticolor. Unfortunately, there were no enEonologlcal investigations during the outbreaks, at least on the anophellne specles hitherto present. In the sprayed area of Wadi El Adjal sergentii and nulticolor were found ln appreciable nuobers ln unsprayed prenlses, but only a few specloens lrere obtalned fron sprayed premises. The possibility of outdoor resting of sergentii was not explored, but lt was assuued that ln such a hostile environoent of hot and arid conditions in sunmer, the chances of finding suitable outdoor niches were remote. Thus, outdoor searches during the favourable season nere reco.mended. Inareaswhichhavenotbeensprayedforsevera1years,@appeared1nfair1yhigh density, and the pattern of the blood dlgestion stages provided an indication of its endophilic tendency at least at the tlne of the survey in July. In Wadi Chati, previous records fron Brak showed the presence of multlcolor only. The linlted search nade during July 1966 at l{ahrouga sprlng 25 kn fror BEilGf,Gi' that sergentli nas present as well. A wider survey during the favourable season nas suggested to delinlt the extent of sergentii in this valley. No nalaria cases lrere reported fron this valley durlng L964-L965 or even after the inplenentation of actlve case detection. Thls nay have been due to the fact that this valley rdas not exposed to luroigratlon as nas the case ln the other areas. There was a single record of superplctus fron Tanhana, Wadi E1 Adjal ln 1966. The July survey ln this 1oca1ityrevea1edthepresenceofsergent1iasadu1tand1a!va'and@asadult. It appeared that the identification of superpictus was based on a badly preserved single speci.nen. However, Shalaby (L972) who nade a nosquito survey in Fezzan province during 1967-1968, reported that he found larvae of superpictus ln Sebha and Gudouaduring the cold season, November-Decenber 1968. He collected a few eggs encounlered in the same breeding place of the former locality. By rearing these eggs to the adult stage, lhree survivors were obtained which he identified as two males and one fernale superpictus. He cited previous records of superpictus ln Fezzan province nauely Ghidini (1935) who recorded this species frorn Borg lizezzem, El Ghatroun and Tejerhi, and Vermell (1953) who recorded it fron Seredeles. [Mr C. Ransdale (personal conrmunicatlon, 1989) indicated that Verueil (f953) made no reference to superpictus in Fezzan and considered that lts partlcular larval ecology nust Dake it very rare indeed. Ransdale who nade several visits to the oases of Llbya and Algerla doubts the presence of superplctus in that reglon]. In a recent revien of the anopheline fauna of Llbya, Ransdale (1989 - in press)l included records of species encountered during his advisory visits. A sketch nap has been presented showing the different localltles of Libya which is reproduced here as Fig. 32. Of the anophellnes recorded prevlously in Fezzan, Anopheles rufipes broussesl, sergentii and nul-ticolor remain to be present as indlgenous species in this region. While fui. rufiiF6ffi-gesi appears to be restricted to the oases of Wadi Tanezuft, sergentF-i and roulticolor have a uuch wider distribution. These tlro species, for epideniological reasons, 1. A o?The manuscrlpt that has been subnltted for publicatlon was klndly provlded by Llr C.D."opy Ramsdale. 2. Reproduced by pennisslon of Mr C.D. Ransdale fron the manuscript of his paper in Mosqulto Systenatlcs (1989 - ln press). The nap was redrawn by Mr Ransdale to Dake it nore clear (personal cornnunicatlon, 1989).. wc/90.2 t4aL/90.2 Page 72 have been monltored over a perlod of some 15 years, durlng which thelr di.stribution has become increasi.ngly clrcumscribed. In 1983, neither sergentii nor mullicolor could be found in any of the oases of Wadi Etba and Wadi E1 eaiar, wnere ttreffiruerry had extsted. The two specles, however, sEtl1 exlst in Wadl Chatl, Hon-l,Ieddenand Dleduin-Zella group of oases, and ser€gntii is still a colnmonnosqulto ln Wadi Tanezuft. There are chree old records of superplctus from Eezzan whlch could not be substantiated and may have been due to nlsldentification of aberrant fonos of Anopheles cinereus. This specles is con-on in thecont1guousoasesofsouthernA1ger1aaMr'esterndesert. In Egypt' Kirkpatrick (1925) indicated that sergentll was not found in the Delta or Nile Valley desplte a very special search. He first recorded lt at Ain Musa, Sinai (see under 2.2 above) and later at Fayed on the nestern shore of the Great Bltter Lake, and also in Faiyum and Kharga oasis. The only record of sergentii fron the Nile Delta nas at the desert fringe as reported by Farid (1940). In August 1939, a malaria epideuic broke our 1n two soa1l villages on the forner Royal Estate of Inshas, Sharqia province near the eastern edge of the De1ta. Searches for anophelines revealed the presence of sergentil larvae breedlng in a large drain and in seepage water around it at the two villages. Adults of sergentii were collected fron houses of the two vlllages and fron cattle and goat sheds. In the two villages, pharoensls, the oaln veclor of nalaria in the Delta, was conparatively rare at the tine of the epidenic. The parasi.te rate ln the human population ranged between 29.22 and 70.4i( d.uting August and Noveuber, wlth P. falciparun predoninaring and P. vlvax constitutinganuchsma1lerProport1on.Dissecti@fena1eigave-- sporozoite tate of 2.77". The seasonal prevalence of the Egyptian anophellnes was studied by Et Said et al. (1983) through longitudinal larval sanpling. Larvae were collected by a net dipper measuring 15 co in dianeter for large breeding places, and a ladle of 10 cm dianeter for soaller ones. Larval sanpllng nas pursued fron June 1978 to May L979 at fortnightly lntervals, oaklng a total of 100 dlps per capture statl.on. For sergentli, the observatlons were linlted to Falyun governorate. Breedlng of thls specles occurred throughout the year reachlng a DaxlDum in February and a mlnlnun in Novenber. Prevlously, Halawani & Shawarby (1957) indicated that sergentll breeds during Septenber-May, 1.e., the cooler period of the year, and breeding decllnes after May. As mentioned above, suPerplctus was only found ln negllgible nuobers in one of the oases in Egypt and has no epidemlological sigalflcance. In Jordan, Farld (f956) showed that sergentil occurs in all the valleys that cut both plateaux east and west of the Jordan river and ttre Dead Sea, as well as in the Yarmuk-Jordan rlft. It breeds all year round, but attalns its maxiuuo larval density between SePtenber and Novenber. No hibernation nas observed in sergentii, as it overwinters as larvae or as adults. In Israel, Pener & Kitron (1985b) showed that both superpictus and sergentii are most :ottldlollln the Jordan Valley, lncludlng Hula and the Sea of Galilee areas. While .iuperpictus was the lDost cornnon breeder in July-August, .9g53gg.ii- had a siullar pattern but reached a peak later 1n Septeuber-November. Sallternik (L974) lndlcated that whlle guperpictus hlbernates as an adult, sergentli does not enter dlapause in winEer, but its larvae develop s1ow1y. The development tine fron oviposition to the adult stage was nine days in suEmer but was extended to three uonths during winter. In Lebanon, Graniccia (1953) lndicated that sergentil is very rare and if in certain regions the associating principal vectors are controlled, it cannot stand alone as a veccor, unllke the situatlon In Jordan. In contrast, superpictus according to Shidrawi (1959) is widely dlstributed all over Lebanon at altitudes ranging from sea level up to 1500 n altltude, unllke sacharovl which ls confined to the plains. Both superpictus and sacharovi are regarded as the najor vectors of nalarla ln Lebanon. In Syria, the dlstributlon of sr13g1.lg!E was descrlbed by Abdel-Ma1ek (1958) fron his surveys In 1953-1954 (see under Z.2aUoGfIOn the seasonat distributlon, rhis aurhor showed that superplctus slnilar to sacharovi increases its denslty fron May to reach a peak ln October, after which perlod, the density decllnes until March. In wlnter, lts females are found ln human habitatlon and stables ln a state of hlbernation. The surveys of Abdel-Malek were concentrated in the northern part of Syrla where cllnatlc condltlons vBc/90.2 MAL/90.2 Page 73 Fig. 3. Sketchroapof Libya with enlarged represenrarion of Eezzao province. I4EDITERRANEAIT 4+ *-ims-- c4E o-t 258 ilr'" ^^*oF tftuu"" ,".^Jqb' . b. i ff u"aoitt t+.-"'a.tl or'l ,.r*n**:4?^E tr"fr! nK*ur:6"" ' j tt ,:., :l OI -(r ;),'.'. ,\>- 1n (n' ^Y> ,,. ti'6o L* vBc/ 90.2 ttAL/90.2 Page 74 induced true hibernation, but this does not seen to be applicable to other parts of the country. Solinan (f961b) conducted observatlons on superpictus during December1957-May 1958 in two distantly situated localities having conEii.l@imatic conditions in winter; Kasrieh (about 30 kn northwest of Hons) in the central part of Syria, and Mehgar (about 60 kn southwest of Deraa) in the southern part of the country. Measurementof tenperature and relative hunidity during Novenber-Aprl1 gave a mean of 7.5-L2.7o C, with 58-82"1RH at Kasri.eh, and 10.8-23.90 C, with 69-882 RH at Mehgar. During this period, while 1arva1 searches were completely negatlve at Kasrieh, all larval. lnstars of superpictus were Presen! at Mehgar during winter months at a density of 24 Larvae/I0 dips ln Decenber L957 and 16 and l1/Iips 1n January and February 1958 respectlvely. Adult searches in houses ai Kasrieh yielded as nany as 36 superpictus fenales/nan-hour in each of January and February, 11 in Llarch, and 5 in April, all of whlch had fat body. In conlrast, the density of suPerPictus at Mehgar ranged fron 5 to 9 fenales/man-hour during Decenber-l{arch. all of which were bLoodfed. These observations clearly demonstrated that superpictus undergoes fu1l hibernation under conditions of a cold winter as in lGsrieh, while it renaj,ns active durlng nild winter conditions as in Mehgar. 2.6 Resting behaviour & 2.7 Biting behaviour In the USSR,Arteniev (1980) described superpictus as a thermophilic species and one that can resist dryness; hence, it is obviously endophillc. It has been found in abundance resting ln bui.ldings, particularly human dwelllngs and stables. Thls species is photophophic and invariably selects dark corners for restlng. It feeds on both nan and animals and prefers aggregations of hosts rather than indivlduals, and large-sized hosts to smaller ones. It feeds at dusk or during the nlght both indoors and outdoors. In can cover long distances ln search of food. It is usually concentrated in human settlements, and it ls very active and ooblle when feeding. InTurkey'Postig1ione'Taban1i&Ransda1e(1973)[email protected] the day in bulldlngs rnalnly stables, occupied or not. Nevertheless, it exhibited partial exophily ln both sprayed and unsprayed areas. It utillzes various types of outdoor restint shelters such as holes, crevlces under banks or overhanglng cllffs, rock cavities, caves, and nest holes. Exlt traps operated ln unsprayed prenlses showed a large exodus of suPerPlctus fenales in all blood dlgestion stages. Wlth exit traps operated ln sprayed premises, mortallty was hlgh anong females that nade exodus lnto the traps indicating that suPerPictus females continued to enter buildings after spraylng and were great.ly affected by DDT. However, because of its exophlllc tendencles, DDT spraylng alone was i.nsufficient to lnterruPt nalaria Eransmlssion in areas of southern Turkey where superpictus was the sole vector. Collection of aosqultos attacking hunan bait showea tnat ri11 feed on nan wherever he is located whether in open counrry or in vtttag{-EidEwilling"rp@_ to enter houses to feed. Because anlnals are dispersed in the open in Turkish villages, suPerpictus feeds on man when its density is very high. However, certain groups of people, such as workers engaged in wood cuttlng and constructlon, as well as those working in farns or military camPs and gypsies, who are not protected by the cl.ose proxinlty of aninal herds, are much Dore susceptible to superpictus attacks as they constitute the main source of blood. Ransdale & Ilaas (1978) further added that during traditional seasonal population movements Isee Subsection (ii),1 below], fanilies with their flocks spend the sunmer in tents sinilar to nomads lnvariably caoping near naterpoints. In such situations, superpLctus was able to naintain malaria transmission in southwestern Turkey in areas where sacharovi. was absent. In I'lorocco, Guy (1963) observed that when the night temperature inside houses exceeded 35o C, people slept outdoors. Careful searches showed that sergentii was biting people ouldoors, but tended to rest Lndoors on tops of roofs where the tenperature was quit.e low. Thr", -ry.!ii. was considered exophaglc but endophllic ln lts restlng habit.. It was relatively nore endophagic/endophilic when large nunbers of aninals were sheltered ln stables inslde the villages. This is why residual house spraying should be extended t'o cover. the walls and covered ceillngs of stables on a total coverage basis as in the lnhabited roons. Regarding the anthropophlly of sergentil, preclpitin Eests run on bloodneal, smears taken fron fernales collected in August 1961 at Zagora, Ouarazate province showed that 20.82 vtere positlve for oan. ltris confirmed the ablllty of sergentii to act as a vector south of the Atlas, unlike the sltuatlon in dlfferent local-ltles north of this chaln where only a slngle bloodneal snear out of 485 showed a posltlve reactlon for man. vBc/90.2 r[AL/90.2 Page 75 No specific observallons could be traced on the resting and biting behaviour of sergentli in Algeria or Tuni.sia. In Libya, Goodwin& Paltrinieri (1959) referred to the exophilic behavlour of sergentii observed in certain countries, but in Libya i.t was found resting lndoors in daytine. In Egypt, infornation on the biting and resting behaviour of sergentii together with p\aroensir; was obtained frorn Falyun governorate by EI Said et al. (1986) as shown under 3.6/3.7 below. In Jordan, Farid (1956) descrj-bed sergentli as an indiscrininate biter attacking nan and aninals both indoors and outdoors. It was collected during every hour of the night froro the bare legs of bedouins sleeping ln the open near their fields. The indoor-resting places were mostly found in shadecland dark corners in rooms or stables, as well as in fissures, holes or niches in wallri. In areas with caves and fissures in the neighbouring hi1ls, sergentii could be obtainecl in good numbers from these sites. In some instances, it was found in dark spaces underneath rocks, or ln holes among these roeks. Fernales of sergentii seldon entered bell-typer tents used as a trap as tried in Egypt, and although ETreyrrere found aEtacking bedoui.ns sleeplng ln their crude halr tents, they seldon remained inside after biting. They usuall)' avold light by changing their resting places during daytine in search for dark cornersi, such as folds of dark clothing, enpty earthernrtare pottery jars, pigeon-holes, flssures or holes in walls. They were very rarely found ln dense foliage, avoidlng places wi[h high hunidity. To conclude, 9gg.!1L was described as a highly excitable nosquito, and erny change in light intensity, or temperature and hunldity irritates it and causes lt to seek an appropriate resting site. Observations lrere made on sergentii in DDT sprayed premises in the Jordan Valley. Mults of this species showed marked avoldance of sprayed surfaces. Ttrus, the absence of sergentii adults fron DDT sprayed premises does not' necessarlly reflect the effectlveness of house spraylng. No follow-up observations by window traps ftxed to DDT-sprayed preuises could be nade to obtain accurate lnforuatlon as to the nunber of adults of this species which enter land leave] the sprayed prenises, hencer it is not knorrn whether they renaln for a sufficient ti.me on sprayed walls to recelve l.ethal doses of DDT. In fact, Farld (1954) in hls report on the inabillty of DDT house sprerying to interrupt malaria transmission in the Jordan Valley, concluded that the topogra.phy of the area lrlth lts weathered lioestone hllls flanklng the valley, with its sub-'troplcal clinate, together with the habits of the nomadic populatlon, can have a bearlng on the oalaria problen by favouring local nalaria vectors such as .W.!ii_, and probably sq.rpfcc*., enabling then to blte in the open and to find daytine-resting places in accesslt,le caves and flssures in the nearby hills and so evade contact with DDT sprayed premlses. Thus, a hlgh rate of nalarla transoLssion was oalntalned in the Jordan Valley, desplte the DDT house spraying carried out in Ehree successive years. Therefore, Farid advocated that in such areas, antilarval measures should resuoe their inportant role in the fight against these malaria vectors. In Israel, Sallternik (f955) recapi.tulated previous observations which indicated that sergentil was caught biting man an.d donestlc anlnals throughout the night and occasj.onally during the early evening, both indoors and outdoors. It was regarded as an avid biter during the autumn, and was considered both anthropophilic and zoophilic. Fron detailed observatlons on resting habits 1n both unsprayed and DDT sprayed areas, it was concluded that: (a) sergentii was practically eliuinated fron sprayed houses: (b) sergentii tended to seek unsprayed surfacesl (c) sna1l numbers of this species were found in open fields. Saliternik (L967) carried out additional field investigations on the biononics of sergentll durlng f961-1965 aining at enhancing vector control measures for malaria eradication 1n Israel. The main quest.ions to be answered were: why sergentii concentrated in caves; why there was a hlgh populatlon density in the Dead Sea area also in winter; and why residual house spraylng failed to interrupt Dalaria transoission. Neot Klkar farm was selected for field observatlons. It is a snall lsolated farn at the southern polnt of the Dead Sea, at 400 n below sea level. The area provldes the trost ideal conditions for sergentil: hot and dry cllnate; nunerous suitable breeding places; sources for blood, i.e., man, aniuals. lloreover, the area ls the only place Ln the country where caves and crevices in lloestone hills provide natural restlng places for sergentil. A11 buildings in Neot Kikar were sprayed at least twice annually wlth a 5"1 DDT emulsion at a dosage of 2 g/az, and all animals rrere sprayed regularly every 2-3 weeks with lZ Hexalan (a fornulatlon of HCtl). In a hill situated at 3 kn north of Neot Kikar, a crevlce was selected. Only occaslonal cattle were found ln the vlclnlty. The crevlce tras 80 cn high at the entrance vBC/90.2 I4/.l'/90.2 Page 76 and several netres deep. After the rear end was cemented the depth was 1.5 x0. Slnce sergentii hide between stones and pebbles, often change Eheir resting places because of changes in teroperature, humidity, light lntensity and draft conditlons in the surroundings, collection of nosquitos Itith an aspirator could not be made. Instead, the pyrethrum spray sheet nethod was utilized covering the entrance also with a second sheet. Collectlons were made once nonthly, and froro July 1961 to Noveuber 1963 a cotal of 223Qadults of sergentii wereco11ected.Recordsoftenperacureandrelativehun1ditywereobtaj.nedfrom_nsideand outside the cave. Adults of sergentii sere found throughout the year and there were large fluctuations in its population. During the period of collection, the mean monthly tenperature lnside the crevLce lras equal to the rneanmonthly tenperature outside in the shade, whereas the RH inside was higher in March-October and loner in Novenber-February than the nean uonthly RH outside. These microclimatic conditlons allowed the developnent of the sporogonic cycle in sergentli females throughout the year. It was concluded that the difference in hunidity lnside and outside is the deternining factor for regulation of populatlon densities of sergentii. Durlng winter months, sergentli was dispersed also in various superficial holes and flssures of the lirnestone rocks, protected fron the light and wind. Data were also collected on the effect of the presence of aninals in the vicinity of the rnosquito populatlon inside the cave. The nale population of sergentii was always high (up to 852). The presence of cattle at nlght ln the vlcinlty lncEE&-6e feroale population i.n general, and those wlth fresh blood in particular. The numbers of those with fresh blood were considerably reduced when cattle were recently sprayed (1-2 weeks previously) with Hexalan. Further observatlons llere uade on the behaviour of sergentii in sprayed and partially sprayed rooms. As sunnarized by Saliternlk, these observations showed: (a) In the Pastr many sergentii adults used to be found inslde human dwellings and in anlmal sheds before DDT spraylng lras started ln 1945. At present, they are rarely found inside dwellings, even in the Belt-Shan area, where intensive breedlng stlll continues and DDT spraying r{as discontlnued for the past six years. (b) Sone sergentii fenales feed on nan in DDT sprayed rooms, but leave innediately after biting. The irrltabillty of DDT to sergentil was well narked, as the fenales were observed to enter DDT sprayed rooms, bite oan and then disappear. In one case, all mosquitos released (94 fenales) lnside a closed enpty roon with cwo walls sprayed wlth DDT (one nonth prevlously), received a lethal dose during the nlght, although only eight were seen resting on DDT sprayed surfaces during the first hour after release. (c) An. sergentll fenales were found to be exophagic and endophaglc, biting both nan and aoinals, but wlth a nore zoophilic tendency. Their concentratlon and fluctuation depend on the availability of blood sources. Precipitin tests made on 88 bloodneal smears of -ry.!11_ col-lected fron a cave near Neot-Klkar farm, not sprayed with DDT, were all negatlve for uan. (d) No physiological resistance was detected in larvae of sergentii to DDTor HCH/dleldrin [Later HCH/dleldrln reslstance nas recorded ln sergentli in Jordan]. (e) In conclusion, the failure In incerruption of malarla transmisslon in the inltial years of DDT spraying in Israel and Jordan was probably due to the exophilic habit of sergentii. However, no indigenous malaria cases have been reported in Israel since 1964, despite the continued intense breedlng of sergentll. The possible explanatlons are: xoalarla gaoetocyte carrlers are absent in the breedlng areas of sergentii; and indoor DDT spraying for many years narkedly reduced the contact betneen sergentii and roan. Saliternik (L974) sunmed up the avallable lnfornatlon on superpictus and sergentii in Israel. The behaviour of the two species rsas slollar: both feed and rest indoors and outdoors as the fenales bite nan and animals and use the sane hidlng and sheltering places, including caves and fissures. In Lebanon, Shidrawl (1959) described the behaviour of superpictus as being different frou that of sacharovi. An. superplctus was found to enter houses in the evening shortly after sunset,-?i?-:,eaves ffiFE-awn never rest lndoors durlng daytlne, although it was sooetimes found ln stables. It was found resting in caves, tree holes, rock crevices and other natural shelters. Iherefore, the control of thls specles by DDT residual house spraying was dtfficult, even though no DDT resLstance was detected. llowever, a noticeable degree of reduction in its density rdas observed. vBc/90.2 tlAL/90.2 Page 77 In Syria, Abdel-Malek (1958) found that superplctus uses the same resting slees as sacharovi, including human habltations, aniual shelters and stables where they rest in dark spider webs, behind clothes and utensj.ls hanging on walls, underside tables or "".-ffi;inside large earthenwa;e potteries used by the inhabltants for storing cereals. In addltlon, superplc.tus was caught restlng outdoors away from human habitatlon; lts adults wereca.,ihF-berl953i''"a.'.sinRastannorthofHoms,together.w1th.c}av1g9r. Also rocky caves around Hamawere found to be favourable resting sites for adults of superpictus. 2.8 Sarnpling of nosquitos in flight In Morocco, a cornparatlve study of different sanpllng techniques was carried out by failly-Cho,p"." (f973t) (see under 1.8 above). The two non-Saharan scaEions at which sergentii was present were Marrakesh and Berkane, the caPtures were made during Septenber 1968. The nan-bltlng rate of sergentii lndoors nas as low as 1/bite/nan/night in the two localities. Llkewisl, the ind66-esting density was low ranging between 1.6 and 3.5 fenales/roon. A higher nan biting rate was recorded ouldoors at Berkane reaching 4.2/nan/t1ght on an average. The norrnal CDCllght trap in human habitatlon gave a Poor yield r.rrging between 1.6-3.5 fenales/trap/nighi, but a rnuch higher yield was obtained fron the traps placed ln stables reaching a maxlmumof 50 and \2l/trap/nlght at !(arrakesh and Berkane respectively. The llght traps placed outdoors gave a maxlmumyield of 2l/trap/rrigirt onty at Marrake-h, but-none ltas caught at Berkane in a slngle night. The p.oporiioo-of unfed feuales of sergentil varied considerably according to the nethod and site of capture. Whlle the noriffind W traps placed in human habltatlon and aninal shelters rlspectlvely gave conparable results (752 unfed), the nornal CDCtrap placed in animal shelters gave a much lower proportlon (332) as there ltas an excess of fed females (607"). The two types of traps placed outdoors gave 502 and 482 unfed fenales respectively while hand capture- ln outsid; shelters gave 362. The parous rate of sergentli recorded at liarrakesh ln collections of CDC traps lndoors vas 692 but the nunber of females dissected from man-balt capture lndoors rras too snall to be consldered (9). The parous rates recorded ln sanples of nan-bait capture and CDCtraps outdoors ltere not stgnificantly different, 657. (3I dissected) and 43"1(37 dlssected) respectlvely. These results oay indicate that the CDCtrap can be a useful tool for collecting sergentii for dissections in condltlons sinllar to those of Morocco, but oore trlals are needed in other areas of its distributlon. In Israel, Sallternlk (1967) used llght traps for saupling of sergentli. Using the New Jersey llght trap, 115 sergentli were collected ln 1955 fron one locality in the Jordan valley and 102 were collected in 1956 fron another locallty in Beit-Shan valley. Uslng the CDCninlature llght trap wlth dry lce durlng L964-L965 at Neot Kikar farn, significant numbers of sergentil could be collected, and che relatlve denslty increased fron July to October wirh the peak belng pronounced in October. 2.9 Host feedlng patterns In Turkey, Postiglione, Tabanli & Ransdale (1973) showed that precipltin tests and coEparatlve balted net trapping confirned that superpictus exhibits zoophilic tendencies as previously lndicated by Llvadas & Sphangos (f940) and fron tests conplled by Bruce-Chwatt, Garrett-Jones & I{eltz (1966). The observatlons ln Turkey showed that cattle, sheep, goat and donkeys nere more altractive to superpictus than man. Fron the results of preclpltin tests coopiled by Bruce-Chwatt, Garrett-Jones & Weitz (loc.cit.) coverlng the period July 1959-Ju1y 1964 for superpictus and sergentil ln countries of the l{edlterranean Basln are shown ln TableTF- 1. Data reproduced by pernission of Prof. L.J. Bruce-Chwatt fron the paper of Bruce-Chwatt, Garrett-Jones&tJe1tz(1966)1ntheBu].let1nofWor1d@. vBc/ 90.2 t4aL/90.2 Page 78 Table 14. Results of preclpitin tests of bloodneal soears of sergentii and superpictus in the MediEerranean Basin, L959-I964.r, No. smears "l *ve fot Country Species Spray status Resting biotope giving +ve prinate blood reaction Jordan sergentii N 0 16 ( 1),t* Morocco " N H 826 0 439 0.7 Greece superpictus N 0 363 0 DDT 0 220 0 Turkey ? H 6 111 't't 0 20 Jordan N 0 93 4.2 Syria N H 49 24.4 0 190 * See abbreviations in foolnote of Table 9. ** SanPle too small to be considered for perceotagel nunber of positive snears in parentheses. These results, however, may have been ouldated through changes 1n the ecological conditions lnvolving the man:aninal ratio. I'lore recent results of precipiti.n tests consolldate9 by Garrett-Jones, Borehan & Pant (1980) did not show data for superpicEus frorn any geographical area. For sergentli, only a single record was given fron Errl.:ffi-1971 , where 4511of 53 bloodneal smears cottectea from human dwelllngs were posltive for man. In l'lorocco' Guy (1963) (see under 2.5 above) lndlcat.ed that ln precipitin tests carrled out on bloodneal smears of sergentli collected from houses at zagora, ouatzazate provj,nce in August 1961, 20.82 were posLtive for uan, whereas only one smear was positive for rnan out of 435 srnears collected fron different localitles north of the Atlas. This nas taken to lndicate the vectorial role of sergentli south of the At1as, unllke the north. In Egypt, a series of studies of host-feeding patterns of anopheline species has been carried out in recent years. Kenawy et al. (1986) reported the resul-ts of precipirin Eescs on bloodmeals of sergengL and nultlcolor collected fron Siwa and Gara oases in the western desert. Gara is a sEEII-asls,-Enffie tine of the study domestlc ani.mals were donkeys, 8oats, sheeP, one buffalo and oany chickens, with animal sheds included i.n houses. Siwa is a large oasis and the same type of anloals existed plus cattle, horses, caroels, dogs, caEs and geese with animal sheds separated from houses. Moequitos resting lnside houses and animal sheds were samPled by space spraylng using the lndex sheet nethod (see description ul99r 3.5 below). Engorged fenales were.placed in 1.5 ul plastic vi.als and frozen at -70o C until tested. Bloodneals were ideutified by the rodifi"d preclpirin tesr (descrlbed by Tenpelis & Lofy,1963). As can be expected, the highest proporrion of nan-Positive bloodneals of sergentii caue from houses, 48ll (54 tested), wh1le 132 of the bloodmeals froo animal sheds were positive for man (209 tested). At El Gara, the proPortions of oan-positive bloodmeals of sergentii fron houses and animal sheds were 862 (21 tested) and 77"(L26 tested) respectlvef.--TE-a roral of. 435 bloodneals of sergenrii collected fron both Siwa and El Gara, 22% vere positive for uan. Only 62 bloodneEls-if- multlcolor nere tested (7 fron houses at E1 Gara and 39 frou anlnal sheds in Siwa and E] Gara) of which I4Z vere positlve for man. !1ost bloodneals of the trro species showing non-human origin were identifled as sheep/goat and horse/donkey. The proportion of bloodneals of sergentii fron both Siwa and E1 Gara givlng positive reaction for bovid was very low (12). This was explaiued as probably being due to the low relati.ve abundance of bovine hosts in tbe two oases. Reference was made to the only precipitin testing carried out prevlously on selCgnlii in Slwa by Barber & Rice (f937) recording a high proportion of bovici-positive bioffi [Fron the original publlcation of tsarber & Rice (loc.clt.), of 47 bloodneals sergencii collected fron village houses or bedouin tents, only 3 (6.4"1) nere positive for nan. Of the remainlng bloodrneals, 28 were posltive for cow, 13 for sheep and 3 for horse. Fron another village, all 36 bloodoeals of sergentli collected fron stables lrere positive for cow, bu! very few people llved in this village at the tj-ne of collectlon. ] Further studies on host feeding patterns of sergentil ln Egypt are included with those of pharoensls in Faiyun governorate under 3.9 below. vBc/90.2 MAL{90.2 ?age 79 2.I0 Longevity The only lnfornation that could be traced concerns sergentli in comparison wi.th two other species. This was part of the study of the anopheLines of the Maghreb by Guy & HolsEein (1968) to deternine the vectorial role of three Anopheles specles; hispaniola, sergentil and -g-g!g1_. The authors enphasized that dissectlon of the salivary glands ls the conventionaL nethod for incriroination of a specles as a vector of malaria, but the statistlcal probability to find a sporozolte-positlve aoong species of Africa north of the Sahara in whlch the sporozoite rate rarely exceeds 0.2-0.32 nakes the reliability of the dissection nethod doubcful. Therefore, the authors resorted to deEermination of the physiologlcal age by Polovodovats technique as a means for establlshing the vectorlal possibilitles of these species. During I966-L967, dlssection of the ovaries nas perforned on sanples of hispaniola fron different regions in Morocco, sergentil frou foci of nalaria transnission, and clavlger frorn oountai.nous regions in Algeria and Morocco. The results are conpiled here ln Table 15.r Table 15. Deterninations of physiological age of three anopheline species in Maghreb, L966-L967. Total Z Z Parous Species dissected Nulliparous 1 2 345678 hisoaniola 1226 oo.) 20.2 L2.6 0.48 0.22 0 0 0 0 setgentii 423 4s.3 17.0 18.9 2.r 9.3 3.0 2.L 2.3 0 claviger 140 62.L 13.6 r0 5.7 7.9 0.7 0 0 0 The duratlon of the gonotrophlc cycle ln hlspanlola is unknown, but it could be estinated as belng more than three days under the cliuatlc conditlons of Moroccoi the first cycle probably takes four days and the subsequent cycles three days rnaxinun. The authors pointiag to the results of dissections, consldered none of the hispaniola fenales can llve sufficienEly long for the sporogony cycle to be conpleted. Thus, hispaniola in the l.laghreb cannot act as a natural vector for hunan nalarla. The data of sergentii presents a different plcture fron that of hlspanlola. AssunLng that the duration of the gonotrophlc cycle in.sergentil ls the same, 7.4"1 of the fenales of sergentll (5-parous * 6-parous * 7-parous) can supPort the developnent of the sporogonic cycle. With claviger otJ-y Q.7Z of. its fenales (5-parous) cao allow tbe development of the sporogonic cycle. This poses a question as to the role of clavlger as a potentlal vector; the corroborating epidenlologlcal evldence indicates that in malarious localities claviger is found late ln the season causing autumnal transmission when labranchlae uanifests itself only for a short period.Theauthorsunder11nedthatthepreseiffiarepre1iroinaryanda!'aitfurther complenentary st.udies lnvolving adequate sanple sizes. However, these inltlal results could serve as a guide for the entotrological component of the epideniological studles in the oalarla eradlcatlon canpalgns in North Africa. Further data on age-grading of sergentli together with pharoensis were obtained i.n Egypt as shown under 3.10 below. No infornatl.on on age-conposition of superpLctus populations could be traced in the Present geographical area. In the USSR,Detinova (1962) cited some studles carried out on age-grading of superpictus populations in Stalinabad, but no details were given. 2.LL Natural infection Old records of oocyst and sporozoite rates of superpictus and sergentii are listed by Boyd (1949) clting the respeccive references. Of these hiscorical records, some data related !o superplctus have already been included under the An. naculipennis conplex above (see 1.Il). 1. Conplled by penuissi.on of Dr S. Bellazoug, Editor, Archives of Institut Pasteur d'Alg6r1e, fron the paper of Guy & Holstein (1968) - pernlssion of Dr Guy or Dr Holstein could not be sought as their present addresses could not be traced. vBc/90.2 r4aL/90.2 Page 80 RecenEly, Kasap et a1. (1987) in Turkey succeeded in infecting experinentally a strain of.sliP9fPictus fron Adana with a local strain of P. vivax. Laboratory conditions under which the experiment was done (24o C and 802 nti) -ere tnought to sinuiat,e natural conditions in the malaria endeni.c area of southeastern Anatolia. Thus, the experiments indicated that suggglg ls an efficient laboratory vecror, and should not be ignored in futureentono1offiZ.Ies.Thero1eofsuperpictLsinTuikeyisbeingobscuredbythat of sacharovi, wherever the tldo species exist. The authors, therefore, reconmendedthat additional fleld and laboratory studies should be conducted to provide a better understanding of the respectlve role of the two vectors in Turkey (see infornation on sacharovi under 1.11 above). Farid (1954) recorded one sporozoite-positive 1n a sanple of 7O sergentii collected from a cave at Gurum village in DDT sprayed area in rhe Jordan Vattefrn tSS2. Farld (1956) recalled his findings (Farid, 1940) of 2.7"A sporozoite rare i.n sergegl1 during an epidenic of malarla that broke out in two villages in Sharkyia prov-ince in the Nile Delta, Egypt j.n 1939 (see under 2.5 above). Saliternik (L974) in Israel also recalled sone old data of sporozoite rates that had been recorded in the Past.' citing several references.'Kllgler (1930) recording a sporozoite rate of 1.52.in supelpictgs (no. di.ssecte_dnot given), and 0.52 in sergenril (195dissecced)duringJanuffDGbe_r;Lunsden&Yoffe(rgso)-iecordingsporffites ot O-2%in suPerPictus (539 dlssected) and 0.32 in sergenrii (744 dissecred) during October-December. A new record of sporozoite rate of sergentii was obtalned fron fleld studies conducted by El Said et al . (1986) in Faiyun govei.toil-{ugypt, where pharoensis was simultaneously found wirh gland infecrion (see 3.lI below) Recently, Shehat.aet a1. (1989) attenpt.ed ro detect p. falciparun and p. vivax sporozoites in sergentil and other anophelines collecred-G;-]ETasis aiT@n governorate' Egypt, during 1983-1984r by applying the technlques of the innunoradj-onetric assay (IRMA) of Zavala et al. (1982)r and enzyme linked iomungsorbenr assay (ELISA) of Burkot, Willians & Schneider (1984a)r and Writz et al. (f9g5)1. Mosquiros were collected fron lndoor day-tine resting shelters and by man- and aniroal-baited traps outdoors. tlosquitos were slored at -70o C untll assays were perforned during october-Novenber 1986. A total of 573 mosqultos were collected fron Siwa oaJls and Faiyun governorate (the two areas are known to be active foci of malaria in Egypt): 463 iffii*''i:tt*:#*:":,::'*ffi#;'.#o::":?":l;T.::::t;:;;;;."lI one fron Faiyun governorate out of 74 test,ed (L.35i(). Most of the rnosquitos tested rdere collected restlng indoors. No P. vlvax sporozoites were detected. All sanples of nulticolor and pharoensis were ffiiii, but the sample size was too snall to lead to valid conc.lusions. The authors consldered their findings as representing the first incrlnination of selg!.fi- as the responsible vector of nalaria in Slwa oasis, and at the same tlme conflrn-Fifn-dings of El Said et al. (f9S6) in Faiyuo and Farid (1940) in Sharkyia province (see above). llowever, the sporozoltes of derected by 'lese !. lglciparun assays in this investigation were not necessarily present inside ttre salivary glands f the tesled specimens, because the extract of the whole lnosquito (head, thorax anJ abdonen) was used. This can glve rise to an inflated sporozoite rate leading to erroneous epideniological interpretatlons. For this reason, the authors regarded their fi.ndings as identifying sergentii as a potential rnalaria vector ln Siwa oasis and !'aiyun go.r"rrroi"t". [This tern Potentlal should not apply to Faiyun where El Said ec a1. (1936) provided evidence indicating definite incrlmination of sergentii from classical gland dissection, unless there have been doubts that the sporozoites found in the glands vere not of huuan originl. 2.L2 Vector resistance to insecticides The recent status of resistance of sergentii and superpictus to insecticides is extracted fron the tabulated data ln the last two rep-itE -f ttre WtlOExpert Coumittee of Insecticide Resislance (WHO,1980 - TRS. No. 655, and WHO,1986 - TRS. No. 737) as shown in Table 16. 1. See VOL. I, document VBC/88.5-MAP/88.2, under 2.9, pp. f71-181. vBc/90,2 MAL/90.2 Page 81 Table 16. Insecticide resistance ln An. sergentii and An. superpictus in the t'lediterranean Basin. Species DDT Dieldrln/HCH OPlcarbamate Others sergentii Egyptl Jordan Jordan: teoephos superpictus Afghanis tan, USSR No genetical or biochenical studies have so far been carried out on DDT resistance 1n the tl^ro species. There is a record in TRS No. 737 showing temephos resistance in ssrgentii in Jordan, butrecenttestscarr1edoutinJordanshowedthatbothsergent11an@g.'sare susceptible to temephos. Isee under Subsection (il), I below]. In the list of specles and countries where insecticide resistance has had epldemiological or econonic impaet and/or necessltated a change in-control operations (in TRS. No. 737, L986) DDT reslstant sergentli in Egypt was included.I More recent reports conmunicated to WttOduring 1984-1983 did not include t,ests for sergentll ln the present geographical area. Only a slngle test nas reported in L985 froo Syria indicating that superplctus lras susceptible to pernethrin in the Aleppo area. An. pharoensis 11 Vector importance In its wide range of distrlbution, pharoensls acts as a principal vector of rnalarla only in the Delta and Nile Valley tn Egypt (see StrCttONII, under 2.L.4 and Fig. 4 in docunent VBC/90.1-MAL/90.1). It was only ln the southern coastal plalns of Israel that a snall outbreak of oalarla occurred 1n nalaria-free settlenents nhere pharoensis was detected and thought to have flown fron Egypt through long-distance roigratory fllghts (see 3.4 below). 3.2 Breeding habltat In Egypt, Gad et al. (1982) who studied the characteristics of breedlng habitac of anopheline species in different parts of the country, described the breeding places of Pharoensis as belng clear, stagnant and shallon waters especially those having a thick growth of vegetation. Shade ls essentlal, and this ls provided by plants growing in both breeding naters and at the edges of the breedlng p1acel no record was obtalned for breeding of pharoensis 1n sltes exposed to dlrect sunlight. The types of breeding places encounEered were.' - dralns and irrigation channels havlng stagnant rrater as commonly seen ln rice fields; - surface rtater collectisons includlng seepages, pools and burrow-pits characterized by havlng vertical vegetation; - rice plantations especially those situated near human dwellings and having snall or noderately growing plants. In plots !.1th high plants, larvae nere concentrated nainly at the edges of the field; - other cultlvations rnainly those havlng sites with thick growth of "Samnar" (used for naking nats). Rice flelds are the most favourable breeding places for pharoensls; the mean larval denslty in these flelds ranged between 3.38 and 7.02 larvae/lO dlps in the Nile Delta, Canal Zone, Faiyum and the New VaIIey. ffifrasbeenmadetodefinetheexactarea1nEgyptfronwhichDDTres1stance1n sergentil was recorded. vBc/90.2 t4AL/90.2 Page 82 In Faiyun governorate, Soliman, Rifaat & Ibrahln (1967) found pharoensis larvae breeding in pools overgrown with grasses, edges of lakes, swanps, ffii6-Ef-uurrow-pi.ts as well rlce as fields with noderately growing plants. In sumner, the teoperature of the breeding waters ranged fron 21.1 to 36.60 c, and larvae avoided sltes exposed Eo direct sunlight. The larvae were found xnostl-yaoong clunps of reeds and grasses situated at the edge the of breeding places. Breeding wat.ers contained I.65 ng/I Jodiun chloride, and the pH was about 7.5. Larvae were abundant during June-December, but their numbers subsequently decreased fron January to reach a nini.muo in February-March. As mentioned under 2.2 above, El Said et al. (1932) determlned the chenical characteristics of breeding \{aters of anopheline species occurring In Egypt. The data of five anopheline species includlng pharoensis were presented. Based on thls, it was concluded that: sergentii, - . Pha{ognsis, suPerpig.tgs, algeriensls and tenebrosus are freshwater (the breeders range of saliniry level for pEiioenFwas o-ffilct/1, or 0.005-5.02); - nulticolor is an indiscrlnlnate breeder, found ln fresh and brackish water (salinicy range ;ffi25 g cL/I or o.o2-2.I25j!). Previously KirkPatrick (1925) found that 89.8"1 of pharoensis larval samples were collected from waters havlng less than 0.2'l saLE and tEi?GiETng sanples were obrained fron rater havlng 0.21-1.5"1 saLt. The data for roulticolor glven [y the same author were.. \8:?'zofthesaop1eswerefronr'[email protected],zfron0.2L-3.o"Asalt,and 8'47" ftom 3.1 to 6.02 salt, 1.e., uultlcolor can tolerate uuch hlgher sallnity than that recorded by E1 Said er al. (1982) The study of the relationshlp between the pH and salinlty of the breedlng waters and the larva1 density of Egyptlan anophellnes by Lr sara c renawy (1982) showed thar rhe larval denslty of sergentll increases as the alkalinlty increases, but it showed an lnverse relatlonshlp with sallnlty (see 2.2 above). tit. larval density of pharoensis was found hlgher to be in breedlng places whlch have a high plt value and llwer ffiff wrtn nulticolor there -!tas a negative relationship between larval density and pH va1ue. 1'his species can breed in waters wlth high sallnlty that cannot be tolerated by other Egypclan anophellnes. In the study of El Said, Kenawy & Gad (19S3) on specLes assoclatlon of Egyptian anophelines i-n breeding_places, pharoensis nas encountered 390 tlnes in the Nile Delta, of which it was recorded alone 7o tinEE-(rgTt. It was nostly associated with one anopheline species (-t:n:Prosus) and nine culicine species. In the Canal Zone, pharoensis was encountered 22 tioes of which Lt was found alone only once (4.62.). Fwas rnostry associated wlth nulticolor and tenebrosus as well as wlth eight culicine specles. The associationgr@ithE;E;;-iiandotheranophe11nesinFaiyunandtheoasesof the rrestern desert is shown undEi-217-ZT-ove. In a recent study ln Faiyun governorate, El Said et al. (L986) conpared the entonological parameters lnvolved in malaria transmission in two vlllages; Abheet and EI Zavya situated 1 kn apart (see under 3.6/3.7 below). parallel to a;opheline adulr populations, larval sanpllng nas extended regularly for a period of over one year in eight Productive sites in each village conmencing February 1983. The oost commonanopheline larvae encountered ln both villages were those of pharoensis and sergentii. Larvae of the t!'osPecieswereco11ectedfronMaytoJanuaryi.nbothvtttages,b@ggex!ended its exlstence into the winter aonths. Larvae of two other specLes: nu-Iticolor and tenebrosus were found only i.n Abheet. Both had short seasonal preva6i-ffih nulticolor encountered durlng April-June, and tenebrosus ln May only. Ralnfall ln Faiyun i- practically nil, thus mosquito breeifffiT?soclated principally wlth irrigation naler. Larval breedlng sltes were much nore abundant in Abheet than ln EL Zavya wlth oost sites occurring close to houses. In Abheet, the most productive sltes for all three anopheline species were five low-lylng areas where drainage nater accumulated. Most of these contai.ned algae, low grasses, sedges and other herbaceous plants around the perlphery. Anophellne larvae ltere Eoat abundant ln these sltes durlng l.lay-June and october-December when the nater level was hlgh. Durlng July-August these sites dried up considerably and breeding was llntted. Abheet village also contalned a permanent pond, but larvae were seldoo found. El Zawya vlllage did not have large areas of standing nater, wlth the vBc/90.2 MAL/90.2 Page 83 exceptlon of one seni-peroanent pool 0.5 kn south of the villages. Breeding sites 1n El Zavya consisted prinarily of snall pools of seepage nater fron irrigation canals. Secondary sltes lncluded lrrlgated fields of sugar cane and other crops. Rice flelds in EL Zawya harboured nunerous larvae of pharoensis during July-September. Rice rdas not cultivated ln Abheet durlng the period of study. 3.3 Swarning and nating No infornation could be traced concerning the swarroing and nating of Pharoensis ln nature whether ln Egypt or elsewhere in its area of distribution in the WHOEastern l'lediterranean Region. . 3.4 Dispersal Kirkpatrick (1925) was the flrst to polnt to the long dlstance fllght of pharoensis in Egypt. He lndicated that it was found ln large numbers ln the western desert, far from any r{rater source, havlng been blown by the constant northerly sunmer wind. Much later, Garrett-Jones (1950) reported that on two nights (28 July and 25 August L942), there were nassive mosqulto tnvasions of the caops of the 8th Arny in the western desert of Egypt. Inspectlon of the tents on the followlng day showed dozens of nosqultos resting in each tent, the najority belng pharoensls. Garrect-Jones considered that the swarms were carried by wind, slnce there nas no large troop Eovenents that could have accounted for the sudden arrtval of nllllons of mosqultos. A guard on duty on the nlght of 28 July said that there ltere no nosqultos in the early part of the night, but bet!,teen 0200 and 0300 h, nosquitos arrived fron the north in a cloud which looked like a dust storm by noonlight. The nearest possible breedlng place fron which these nosquitos could have originated was a snamp near Alexandria knowa as Mallahet l{aryut situated at 29-45 kn fron the canps. Garrett-Jones (1962) discussed the posslbllity of active long-distance nigratory fllghts by pharoensis ln the llght of new data reported fron Israel by Sallternik (1960) and fron Gaza by McKenzle Pollock (1960). In L959, 2l fresh cases of malaria were recorded durlng July-Novenber at several sltes along the Israell coast, an area fron which nalarla had been considered eradlcated. The cases lrere scattered over a strip of about 130 kn long, fron Gaza ln the south to Tantura (a settlenent situated about 35 kn fron tlaifa) ln the north. Routine larviciding operatlons lrere carried out in Gaza, and entonologlcal surveys carrled out late ln 1959 falled to detect any anophellne adults or larvae, whlle a survey of adjoinlng territory to the south showed the presence of uulticolor larvae only. Thus, Gaza could not be the place of origin of any other nosq.iffi. Ln the Israell coastal plaln, routine oil larvicidlng of all pemanent breedlng places was strtctly observed. Followlng the nalarla outbreak, a thorough survey was carrled out in Lhe autunn coverlng all posslble breeding places of anophelines. Breeding of pharoensis was detected ln 22 LocaLLtles; Ehe breeding places were almost entirely small, temporary collectlons of water that were not covered by routine larviciding. This species has only rarely been observed tn Israel (and fornerly in Palestine) and this was consldered the northeastern llnlt of its range, where it was regarded as a non-vector. The recognlzed forner vectors of nalaria ln Israel (and Palestine) Irere g$j211!, g!g1gg, superplctus and -ry.!l!, none of which were found in the 1959 autunn survey in thecoasta1p1a1n.Thus,thereI'astheinescapableconc1usionthat!@wasthe species responsible for transnlsslon of the 21 fresh infections. Suscepttbility tests carrled out on pharoensis larvae in Ashkelon district in November 1959 showed that the specles was susceptible to DDT but resistant to dieldrln. Crops ln t.his dlstrict were sprayed 1n Aprll 1959 with gama-HCH. llowever, the presence of pharoensis in April or durlng the perlod when HCHwould have contlnued to be a potent seleccive agent, Itas consldered unlikely. If the species reached the coastal area only ln July, it ls reasonable to conclude that the tnvadtng females were already dieldrln-resistant, and the presence of dleldrln reslstance in pharoensls in several localities of che Nile Delta was degonstrated (clting Zahar & Thynakls, 1959). Enamination of ueteorologtcal records showed that there nas a strong rvind on the nlght of 23 July 1959 blowing fron the west or northeast on the coast of Israel. It was accoupanied by raln, although July is a rainless Donth. From Gaza, it was reported that a strong wind blew froms 15 to 18 Septenber 1959 and that it brought rrith it a nave of moequltos (not identified) which attacked people. During Ehe two unusual neather condltlons a full moon occurred on 20 July and on vBc/90.2 MAL/90.2 Page 84 17 Septenber. If lt was certain that the 21 fresh malaria infections ln Israel were due to local transmission by pharoensls, it nlght be surolsed that the infected mosquit.os could have arrived from the Nile Delta. This would entail flights of up to 280 km, the distance fron Port Said to Tantura. Ihere nas no place nearer where in 1959 the conditions of nalaria prevalence and vector abundance were such as to offer a rnore acceptable explanation of the outbreak. In his discussion of these observatlons, Garrett-Jones felt that this hypothesls nay be unfaniliar and therefore may appear far-fetched to nalarla epideniologists, but it would be nuch more readily accepted by insect ecologists. Sone examples of uigratory fllghts in aphids and Aedes nosquitos were clted and the factors stlnulating such flights were discussed. Garrett-Jones further referred to another objectlon that has been raised concernlng Ehe enormous nigration that would be necessary to produce the fresh cases of nalaria in Israel. Ile nade theoretical calculations assuming chat the sporozoite rate of pharoensis at the place of its original flight was 12. These calculations showed that it would require a population of 10 000 females in the production area to produce each case of malaria ln the lnvasion area, or l0 roilllon females ruight be sufficient to cause an outbreak of 100 cases of nalaria. He belleved tha! insect ecologists would agree that thls figure of 10 roillion females ls only a very snall populatlon of any insect enjoylng a rich breedlng ground to which it is fu1ly adapted. 3.5 Local spatial and seasonal distribution Recentsurveyscarriedoutdur1n8L978-L979confirnedthatP@isw1de1y distributed ln all governorates of the Delta and the Nile Valley ln Upper Egypt including Aswan (El Said & Kenawy, 1983 a & b). It ls also present in Faiyuu governorate and extends lts exlstence to the oases of the lrestern desert (see 3.2 above) where sergentii acts as a oaln vector of nalaria. In chls connection, Halawanl & Shawarby (1957) explained that the varylng ecological condl.tions in Egypt lnfluenced the longevity of pharoensis. In the oases where the average relative huuldlty durLng sunner rnonths (neasured over 25 years) is only 302 as compared vith 757" in Lower Egypt, the longevity of pharoensls ln the oases seems to be short. In the east, it ls present in the Suez Canal Zone (Port Said and IsnailLa governorates), but has not been recorded ln surveys in the Red Sea governorate (Gad & Salit, L972, and Gad et a1., 1987). In Sinai, lnltially Kirkpatrick (1925) recorded pharoensis frou Bir Fuwara (east of Isnailla) and from Aln llusa (near Suez). Salen (1938) only caught adults of this species fron tents on the sea shores at EI-Arish, during July-August. In his survey of August 1951, Abdel-llalek (1956) dld not encounter pharoensis in northeastern Sinal. Gad et al. (1964) collected large numbers of pharoensls from a few houses and tents at El-Ta1 El-Ahnar and Gilbana, situated at 10 and 20 kn east of Qantara respectlvely. No breedlng places were found ln thls area, and Qantara East was free of mosquito breeding. The authors suggested that lt is hlghly probable that these mosguitos were carried by wlnd fron places on the ltestern side of the Suez Canal. 0n two consecutive days pharoensls adults were abundant, but on the third day none was seeen, confirning the absence of breeding in the locallty. Probably the range of dlspersal of pharoensis ls more than 20 kn, and it night have reached El-Arlsh (where it was recorded previously) by the wind or passlvely by transportatlon. The authors did not flnd breeding places of pharoensis in the central and southern parts of Sinai, and the previous record from Ai.n Musa could not be confirned. I'largallt & Tahori (1973) ln thelr survey of Sinal dld not flnd any breedlng places of pharoensis but captured adults by light trap on the eastern bank of the Suez Canal, probably arrlvlng there by wlnd fron the western side of the canal, confirning the observations of Gad et al. (1964). On seasonal prevalence, pyrethrum spray collectlons and observations by outlet wi.ndow traps conducted by Zahar et al. (1966) during 1959 ln Glza governorate in Egypt, showed that p@ig denslty nas at lts lowest level during Decenber-ll,arch when t.he mean daily temperature nas about 17.50 C. About the beginnlng of Aprll, the populatlon started to lncrease stead1ly. Breeding conditlons became more favourable with the connencelDent of rice cultivatlon, and the denslty peak was reached during July-August. Wlth the drying up of rice fields and the decrease of temperaEure ln October-November, the density decreaeed and coustanl took over. Ttre apparent peak of ualarla transmission observed in October may haveTeffie to lncreased longevity of the aglng population of pharoensis. vBc/90.L MAL/90.2 Page 85 In Faiyun governorate, Solinan, Rifaat & Ibrahin (L967) during 1960-196f collecting mosquitosrestingorbitingso1diers1nbarracks(at1800-2300h)foundthatP@ density reached a maximumduring August and Septenber when the nunber of fenales caughrTnan-hour was 150 and 130 resfectlvely. The density fell to 3-8/uan-hour during January-April. Thus, cold condltions were unfavourable for pharoensis and the data of adul"t catches were in line wlth those of larval. densities (see 3.2 above). Recently, El Said et al. (1983) studylng the seasonal prevalence of larval breeding of sone anoph"lin.s in three governorates in the Nile Delta, the Canal Zone and Faiyun gou",,,o,iteduringIg78-|g1gconfirmedthatP@breedsthroughttheyear,witha peak durlng August when the waler teroperature was 30-38o C. In contrastr coustani larvae, though present throughout the year, lts peak denslty was reached in wi.nter when the temperature was 17-230 C. It was also confirned that pharoensis bred in rice fields, but disappeared when rice plantation was terminated' and its place was taken by coustani.Inotherbreedingp1aces,@.continuedtobepresen!inwinterbutina ffi density. In a more recent study !n Faiyuro governorate, El Said et aI. (1986) deterroined the seasonal distribution of pharoen"is and sergentii frou spray caPturer nan- and aninal-bait capture (see under:.0/:.2 Uefow). In this governorate, it was confj'rned that both specles act as aain vectors of malarla (see under 3.11 below). In an early study by light trap ln the Nile Delta, some infornallon was provided on the seasonal prevalence of pharoensis (see 3.8 below). In Israel, Saliternik (L974> polnted out that pharoensis had rarely been found in the past and was not consldered of any lmportance ln nalarla transmisslon, but ln 1959 it lpp".i.a breeding ln abundance foilowing a perlod of strong wlnds, with an outbreak of malarla along the southern coastal plaln as well as ln Gaza (see under 3.4 above). At Dresent. pharoensis has alnost dlsappeared as only three posltlve breeding places were i.r""t"a i11 lt6[ and one in 1965, but none Ln L97L-L972. In recent surveys rePorted on by pener & I(ltron (1985b) ln northern Israel, phargensls larvae were encounlered only once breedlng in a single locality durlng the period 1974-1983. 3.6 Restlng behaviour and 3.7 Bit.og beh.tlo"r. From observations carried out by Zahar et al. (1956) in a study area in Glza governorate in Egypt durlng 1959, the resting-and bitlng behaviour of pharoensis was Itgat"a. Partlal pyrethruxo spray collectionsl in houses ylelded low numbers. Analysis of data showed that 677"of the capture statlons were negatLve, 20% had 1-2 pharoensis fenales, 7% had, 3-5 fenales and or.J-y 47"had 6-10 females/roon. This indicated that pharoensis is very selecttve ln choosing day-tine indoor-resting shelters, with marked houses were ltrore iffice for aninal shelters. Farms containing snall numbers of productive than vlllages with large numbers of houses;171 roons and sheds surveyed in i.-" gave an lndex of 1.8/roon, while 426 roorns surveyed in vlllages gave an index of 0.9/roJn. Collectlons obtai-ned by spray capture from houses showed a higher proportion of fed than gravid, glvlng an indication of the exophlllc tendency of pharoensls, at least 1n the later part of the gonotrophic cycle. Conflruation was obtalned by ltindow traP observations and searches in natural shelters. l{orning and evening collections by outlet-lrindow traps were carried out durlng July-August 1959, i.e., during the seasonal abundance of p!@. In inltial observations, relallvely higher density was recorded in rnorning coffffiiT the nunber of pharoensis fenales collected from three bedrooms in the uorning was 1193, whlle the sane traps yielded 72O ln the evening. Since morning collections reflected the exophillc behaviour of the species, Lt was decided !o continue ;;;;iG rrap observatlons only. Fron 3-oonth observatlons' lt was clear that Part of pharoeisls populations leaves the house ln Se11a2 stages 2, 3 and 4, whlle the rest by two f-F"-ffi1-pf.rhrum spray capture was made by a cJ.oth sheet 80 x 80 cm suPported stlcks. The sheet was spread and moved around by one collector whlle another sprayed 0.22 pyrethrins solutlon ln kerosene. For collection from lhe underside of beds and other iurnlture, the sheet was spread on Ehe floor. The index derLved fron this nethod is roushlv about 25-30"1 of t.he total room density as determined by the standardlzed spray sheEt irethod ln which the whole floor of the rooo ls covered wlth sheets. (1920) 2. See the descrlption of the blood dlgestlon stages and ovary developnent of Sella vBc/90.2 MAL/90.2 Page 86 remaLn lndoors. The greatest exodus occurred when the fenales reached Se1la stage 6, inplylng that the endophilic portion of the populatlon leaves the house before reaching the full gravld stage, Sel1a 7. In two of the three rooms (roons 1 & 2), a consiscently endophilic pattern was observed, whereas in the third room a larger exodus of bloodfed fenales was invariably recorded. Samples collected by hand caPture gave a more endophilic pattern from room 1 where the fed (stages 2, 3 and 4) to gravld ratlo Iras approxinately 0.85:1. In roon 3 the ratio was about 1.73:1. Searches for pharoensis in natural shelters rdere not productlve during l1ay-June 1959. Farid Ln 1942 (unpublished observations) found pharoensis resting on rice plants, and thLs was confirued by searches in July 1959 ln riceErtiffaving plants 50 cn and higher. A cubical lent neasuring 14.3 x 143 co and 155 cu high, wlth its roof and door made of nylon netting and its walls of canvas, was used for sanpling pharoensLs fron rlce flelds on a standardized basis. The pharoensis density in rice plantations gradually decreased ltith the drying-up of the fields towards the end of September when coustani predoninated. In another area (Qalubyia governorate), searches nere made in natural shelters early in the season (April-June 1960), when pharoensis was only scantily found resting during day-ttne on various plants, such as clover or young rice, but the density progresslvely increased in July-August when most of the outside resting was concentrated in rice fields. Tenporary outdoor restlng at nlght was observed on the outside surfaces of walls and doors, as well as on vegetatlon in the vicinity of houses in the study area of Giza governorate. Wide night searches on vegetation in a radius of about 100 n fron houses showed that the plants nost preferred were cotton and okra. Fifteen-uinute collections every hour froo these plants were conducted for three nlghts. A total of 305 pharoensls fenales were collected of which 105 were unfed, 111 in Sella stage 2, 45 in Sel1a stages 3 and 4, and the renalning in Sella stages 5-7. The flrst appearance of freshly fed fenales was observed about one hour after sunset, coinciding wlth the peak of biting outdoors. There was a progressive increase in the proportlon of unfed and bloodfed, as the night advanced. This populatlon conpletely disappeared with sunrlse, and no day-tine resting was observed on these plants. These flndlngs suggest that such restlng is only a temporary stance, until a further move is oade to the appropriate day-tlne resting sites indoors or outdoors. The phenonenon of pharoensis teuporarily resting on cotton plants nay help to explaln the reslstance of thls specles to DDTand dieldrin that was recorded ln unsprayed areas. Cotton plants nere treated wlth organochlorlne insecticides in sunner, coincidlng wlth the season of pharoensis prevalence. The temporary resting would expose uosquitos to the lnsectlcide, creating selectlon pressure on the populatlon. It is probable that the breedlng places were also contaminated, producing heavy selection pressure on the larval populatlon. Observations of nan-bait capture indoors and outdoors durlng July-August 1959 showed that: (a) pharoensis is an early biter. Outdoor biting started 20 Dinutes after sunset and ruickly reached peak intensity so that 20-402 of the total bites/nan/nlght occurred in the ;lrst three hours. Indoors, not more than 32 of the total bites was recorded in the first three hours afEer sunset, but bitlng lncreased gradually until, towards nidnlght, its lncldence indoors and outdoors nas alnost equal. Before they retire, Dost of the lnhabitants stay ouldoors, lhus beconlng exposed to the early biting peak, then become exposed to the peak lndoors about nidnlghr. Thls apparent adaptation of the feeding habit of the mosquito to the hablts of the people must have an inportant influence on the actual nan-biting rate as defined by Garrett-Jones (1964a). (b) there was a tendency lolrards renewed attacks outdoors on man and anirnals in the last hour before biting activities ceased, half-an-hour before sunrise. (c) the estinated bitlng rate on a man statloned outdoors varied fron 556 ln July and 388/uan/night in August. The bitlng rate on an aninal (caoel) was 2500 and 688/nlght in July and August respectlvely. A sinilar pattern of bitlng actlvlties of pharoensls indoors was observed by Sollnan, Rifaat & Ibrahio (L967) ln Falyun governorat. iffiffiust-Seprenber 1961. ri.ting started shortly after sunset and contlnued throughout the night and durlng the early 2300-2400 h, after whlch perlod the acrivity T9I{t+$iclecllned as!!"-P:"!^gL!1t1$_!as-around tne mornlng approached. wc/90.2 r4AL/90.2 Page 87 Recently, observattons were conducted by El Said, Sobhl & Gad (IgB2) on the bitlng behaviour of pharoensis ln Kafr El shelkh governorate and the Canal Zone. The resulti, in general, agree with those obtained by Zahar et al. (Lg66) in Giza governorate, except for sone differences in the Canal Zone. In Kafr El Sheikh, observations carried out in-Et.lo villages from June to October conflrned that pharoensis ls an early biter as it started biting 30 nin after sunset. The naximum Uitinl-?Zffiron all-nlght nan-bait caPture was recorded in June (31 bites/nan/hour) when the records of meteorological condltlons were (nean values): temperatute 22.70 C, relative hunldlty (RH) 97.87., and wind speed 31.7 n/5 nin. Subsequently, the bltlng rate decreased untll it reached a minimuu ln gctober (1 bite/nan/hour) wfien the condltlons were as fo1]ows; tenperature 19.40 C and pJl 94.57". The bitlng rate rras rnuch higher outdoors than indoors. Some observalions were nade with nan-baited nets in conparison with aninal-balted nefs during June-Novenber. Of a total of 483 pharoensis collected, 15.77. were from nan-balted nets and 84.37" from aninal-balt.d .r"tsJrrdlcating the zoophllic Eendency of this specles,. IIn this- be taken into conparison. -Inthe su;face area 6f r".r ani aninal available for biting should accbunt.j the Canal Zone, pharoensls also started bitlng lnnediately after sunset at a high rate - 10.1 bites ourdoorF-Zi?fZi bites/nan/hour indoors. Thereaf ter, bltlng steadily decreased reachlng 4.5 bltes outdoors at 2100 h, and 5.3 bttes/nan/hour indoors at 2200 h. Subsequently the blting rate increased to 8.4 at 0200 h outdoors and 11.8 bites/oan/hour ar 0300 h lndoors. IThe blting rates as lllustrated graphtcally by the authors are qulte dlfferent fron those glven ln the text and the tabulated data which are shown here. In particular, the graph ehows a higher blting rate (about 18) outdoors than lndoors (about 9) ln the first hour after sunset. ] E1 Said et al. (1986) noted that serological surveys for rnalaria carried out 1n Egypt showed that nalaria was endemic ln Falyun and that parasltologlcal/serological surveys carried out during 1979 ln two adjacent villages (1 h apart) in this governorate: Abheet and El Zavya gave contrastlng results. The paraslte rates were 3.3"A and 0.82 and the sero-positlvity rates vere 422 and 2LZ in the two vlllages respectlvely, with both P. vlvax and P. falciparun belng pre6ent. To further check this nalaria situatiot, 2Q7"of itreTo6.inha_1tantsofthetwovi11ageswererandom1yse1ectedandtheirb1oodexamined nonthly durlng 1983 (cltlng Hassan et al. - unpubliched data). Fron Abheet a total ot 72 cases rrere detected (22 P. vlvax and 50 P. falciparun, whlle tn El Zavya only 2 cases were recorded (1 P. vivax and 1 P. falciparun. Therefore, detalled entonologlcal sludies were slnultaneously conducted by El Sald et al. (loc.clt.) to conpare the anopheline populatlon dynanlcs ln the two vtllages and to identify the factors causlng the observed dlfferences in nalarla prevalence. During these studles o11 larvlcldlng contlnued to be applied by health authoritles. Several entomologlcal technlques were utllized simultaneously for one year starting fron February 1983, wlth observatlons conducted twice nonthly. The results of larval survey have been shown under 3.2 above. All-nlght rnan-balt captures were conducted lndoors and outdoors, collectlng attacking nosqultos for 30 oln each hour throughout the night. Four donkey-balted traps qrere operated in four sectors in the thto villages; collectton of mosquitos fron these were made every trro hours throughout the night. Mosqultos restlng in day-tlne ln houses and animal sheds were collected by . pyrethrun spray capture uslng the lndex sheet nethod in whlch the sheet measured I mz. As shown above, the sheet supported by two stlcks was moved around the room and placed under furniture by one operator whlle another sprayed a solution of 0.27! pyrethrun ln kerosene. This nethod ls co qonly used in Egypt, and samples only a proportion of nosquitos restlng in a roon, ln contrast to the pyrethrul spray capture rnethod described 1n the WHOManual (1975) ln which the floor is covered by cloth sheets. In each vl11age, six fixed sanpling areas were selected at random, and ln each, 12 houses and 2-5 animal sheds were sanpled at each visit. Sanpling of outdoor-resting nosquito populations nas done by a battery powered aspirator (described by Nascl, 1981). A series of 5-nin collections was nade 1-2 hours before sunset and agaLn in the morning. Sanpling was conducted within a radlus of 400 u around houses covering vegetacion surroundlng houses, along lrrigatlon canals, and ln irrigated fields. Laboratory processing of oosquitos collected from man- and anlnal-bait-capture lncluded identificatlon of the specles, examlnation for inseolnation status, deterninaElon of the parous rate using the nethod of the ovarian tracheoles (Detinova, L962). Parous fenales were further examined to deternlne the nuuber of folllcular dllatatlons (see under 3.10 below), and their sallvary glands were examlned to deceruine the sporozolte rate (see under 3.11 below). Longitudlnal saupllng by dlfferent techniques provlded lnfonoation on anopheline fauna of the two vlllages, seasonal prevalence, biting behavlour lncluding the bltlng cycle, and the resting behavlour of specles encountered as shown in the following: wc/90.2 MAL/90.2 Page 88 - Anophellne fauna.. Both plglglg and sergentll were abundantly Present ln Abheet, whlle pharoensls was the oost predonlnant specles tttth -ggg1!!! scantily Present ln El Zarqya.--E-er specles encountered were multlcolor and tenebrosus, both of which were found in snal1 nuobers ln the two villages. - Seasonal distrlbutlon: llonthly lndlces of spray caPture, nan-baLt capture and aninal-balted traps were presented graphlcally to lllustrate the seasonal trends of the predoo1nantspecies,pharoens1sand.9sIgg'g11.1nAbheetandP@1nElZavyaas shown ln Fig. 4r. The blting rates of pharoensls exhlblted blnodal dlstrlbutlon in Abheet wtth two peaks reaching 4 and 7.2 bLceslnan/nlght ln June and Noveuber respectlvely. In the sane village, sergentll appeared ln fairly low nan-biting densities fron l-lay Eo December, wlth the exceptlon of a peak of 2.7 bltes/nan/night in Novenber. In E1 Zawya, pharoensis exhibited a dlfferent seasonal nan-blting trend, with peak biting rates of 2.7 and 3.2 ln June and August respectlvely. No bttlng actlvitles were observed in this village after October. Donkey-balted Eraps showed sinilar seaeonal trend in Abheet wlth two peaks of pharoensis appearlng in June and October resPectlvely. ln the sane vlllage, sergentli ln donkey-balted traps also exhlblted two peaks, one in July and the other in October, unlike nan-balt capture 1n whlch thls specles exhibited one Peak in Novenber as shown above. Fig. 4. Seasonal dlstributlon of the predonlnant Anopheles species deteruined by nan-bait capture, anlual batted traP and Pyrethruo in Abheet and E1 Zavya vlllages, Falyun governorate, Egypt, March-Aprll 1983. 'l ABHEET HUXXi SAITS ETZATYYA - a& slllcit .l --- A!"EEi I 'J C - '1 - t, = A c, t, e- t. rli \ 0 u, AlilHAt InAPS t0, (:l E a c a tsE I ci- I 0 ItJJrtor0rIJJrsoto sPf,AYClPrmt il fiotsts l.l A r.l i\ | i \',, ^. I i I \. /'\ ,,; ,/ \ | 2-\r\l 'r,t' 0.4 / \ I 0: ,,,,A^ ] 0L I OJII TfiT}I 1. Reproduced by petmlsslon of Dr Sherif El Satd and the Journal of the Anerlcan Mosquito Control Associatlon fron the paper of El Said et al. (1986). vBc/90.2 |{LAL/90.2 Page 89 - Biting behaviour: Linited nunbers of anophelines were collected by man-bait capture during the whole period of observations. The nean biting rates [indoors * outdoors] as calculaEed fron the authorsr data (nean of 84 rnannights in Abheet, and 80 nan nights in EI Zavya) were.' 0.81 bites/nan/nlght for pharoensi.s and 0.33 for sergentii in Abheet, versus 0.475.for pharoensls but zero for sergentll in E1 Zavya. Indoor and outdoor biting rates were similar, with the exceptlon of seiEintif ln Abheet, the indoor component of which was 0.23 bites/bait/night. with donkEy-:b-aite-Z'traps, rhe calculated biting rates (nean 54 trap nlghts in Abheet, and 56 trap nights in El Zavya) lrerei 2.7 bices/bair/nighr for pharoensig and 3.4 for sergentll in Abheet, versus 1.86 bites/bait/nlght for Pharoensis and 0.02 for sergentii at EI Zawaya. No calculalion was nade ior the biting races of multicolor and tenebrosus, as they were found ln snall numbers in both villages. rhe relat?6i?f,T!-TetweenTf,fr?frGnd anlnai biting rares were presenred in rerns of rarios (anlnal:hurnan) as follows: pharoensis 1.8:1, sergentii 5.1:1, multicolor 4.7:1, and tenebrosus 2.4:1. Inforoation on the biti.ng cycle was derived fron data recorded in both Abheet and El Zavya fron donkey-baited traps during Aprll-October 1983, grouped into 2-hour periods of observations throughout the night. The peak of biting activities of pharoensis (371! of a total of 247 collected) and sergentii (32'l ot a total of 186 collecreElGfrlErved during the early Part of the night, 2000-2200 h, while the lowest bitlng activities occurred during 0400-0600 h. I'lan-bait capture gave different results as 6O'l of I04 pharoensis and 79% of.28 sergentii were collected durlng the first three hours after sunser. - Resting behavlour: During t.he whole period of observatlons, pyrethrum spray collectlons in houses and ani.nal sheds recorded t,hree species: pharoensis, segeotii and nul!1cglor, wlth-hlgher densitles ln Abheec. In thls village, sergentli ras ttre predoninantsPeciesconstitut1ngover80Zand907"otthe1ndoorffinganophe1ines collected from houses and animal sheds respectively, while In El Zawya only seven sgrgentii were recorded. While pharoensls lras present at low density in Abheet, lt was the predoninant indoor-resting speciE-Tn-lL Zavya. An. oultlcolor was collected in snall numbers ln both villages (totaI 29 speclnens) during E Fdgust, wlth only one specioen ln October. Outdoor-restlng searches were preforned in over 200 collections by the nechanlcal asplrator for 5-oin each. These yielded 66 pharoensis females and only 1 nu1t1co1orfena1e.MostofthespecinensI'ereco11ecteffis1tes1nirrigated G'ia€, and ln vegetatlon along lirlgation canals. Classiflcatlon of the blood digestion stages was made on saoples collected fron indoor- and outdoor-resting shelters. of 59 females of ggrgenttl collected fron houses, 29l( were half-gravld and gravid, indicating i'ts endophilic tendency. Ithe proportlon of fed fenales not shownJ. Although sergentil ltas the most cornmonspecies restLng indoors, lt was not found ln outdoor-restlftG In conErast, pharoensls was the least endophillc as only 6Z of 34 feoales collected resting indoors were gravld, while hdlf of 22 fenales collected from outdoor-resting sites were half-gravid or fully gravid. The significance of the differences found between the Ewo villages in relation to the malarla sltuaEion is shown under 3.11 below. 3.8 Sanpling of nosquiros in flighr Only two studles could be traced ln the use of llght traps for sanpling of nosqultos ln Egypt. The flrst was by tlurlbut & Weltz (1956) who observed seasonaf ana geographical distrlbution and feeding habits of conmonmosquitos, in conjunctlon lriE.h a study of the epideniology of West NlIe vlrus infecti.on in the Nile Delta. Most of the collections were made in Barada' Sindbis and Quaranfil villages about 30 kn north of Cairo. New Jersey llght traPs were oPerated fron sunset to sunrise, usually four nights/week. The power was suppli.ed by 6-volt' 300 aop-hour storage batteries. Each trap was equipped with a 15 warE clear glass bulb, and a fan whlch rotated at a speed of 2200 rpn. During the period April 1953-March 1954, the total nunber of fenale nosqultos collected in 608 riap-nighrs was 16 362, of which pharoensis constituted 99.4%, and the renalning were culicine species.C91ex-a9tennatus,Cu1exu@andPharoensj'swerethemostabundant species a"ffiffiGt"-er.@nnatFand rarvae and pupae of cx. univlttatus pharoensis and were collecEd-fG?Illunbers early in ieiruary.-Thi" agreed vBc/90.2 t4AL/90.2 Page 90 in general with the seasonal. trend depicted by monthly light trap catches nhich erere nll in February for the three species. During Septenber-October 1954, a portable stable trap (of Bates, L944) was operated at Barada for 26 nights fron sunset t'o sunrise, with a man actinS as bait. A light trap was operated slnultaneously in the saoe vicinity at a distance sufficient to prevent lnterference. An. pharoensis and the four culicine speci.es were collected by both traps, with Cx. antennatus predoni.nating. Precipitin tesEs run on 94 bloodneals of pharoensis ltror u6ttr traJffiwed that 977i iere positive for nan. The Percentage of pharoensis with blood in stomachs in the man-baited trap uas 77%, The other study was carried out. in Abu Rawash, an agricultural village at 15 kn northl{rest of Cairo in Giza governorate by Zinnerman et al. (1988) to deEernine the host-feedlng, patterns of mosquiEos in rural areas. The viJ.lage is situated aE the desert edge with three sides facing the Nile Valley farning area. Six solid state army mlniature traPs (SSAI"Itrap), one at each site, were baj.ted with dry ice suspended in covered 3.8 f cans ldi.th punctured bottoms. These were placed directly above Ehe light. trap. Traps were placed at nearly equal distances fron fanily li.ving units and associated animal structures and areas. All. hosts were equally accessible. The craps were operated fron l{arch 1983 to February 1984. Very large numbers of nosquitos lrere collected representing five culicine species; and An. tenebrosus as che single anopheline species encountered. Collections fron walls and vegetation around buildlngs by a mechanical aspi.rator yielded four culicine species and tenebrosus. No explanatlon was given for the possible reasons for the absence of pharoensis in this area. 3.9 Host feeding patterns During the studies of Zahar et al. (1966), preclpitin tests were made on samples of bloodneal snears of pharoensis collected fron different shelters durlng August 1959 and Lri.th the following results: Site of collection Smears Z positive tested Human Aniual Dllxed: man & bovid Bedroons 144 81.3 18.0 o.7 Aninal shelters 140 8.6 90.7 o.7 Outdoor shelters (plants in- 299 L9.4 79.6 0.7 cluding ricercottonrokra etc. ) These results together with those of bait capture, sho\r that pharoensj-s i,s indiscrininate in 1ts biting habits, as it will bite nan and aninals according t,o which is more readily available. Consldering the smears taken fron all resting shelcers, the hunan blood index (HBI) of pharoensis ln the study area of Giza governorate before spraying was about 32.L1! calculated on the basls of the weighted mean, but the method of unwei.ghted oean (Garrett-Jones, 1964b) gave a value of 48.7%. The nunerical ratio of man to donestic aninals in the area ldas about l:7 which was hitherto representative of average condit.ions in the Delta region. In view of the high density of pheiroensis in the cattle sheds, and the large ProPortion of fenales feeding outdoors, it is probable that the true HBI Is less than 322 in August. It Bay well lncrease, however, in t.he autunn when pharoensis becomes more endophilic as rlce plantacions approach harvesting In the lists of records of preclpitin tests, L97I-L978 consolidated by Garrett-Jones, Boreham& Pant (1980), no data were shown for pharoensis excep! fron Ethiopla in the Afrotropical Region, 1971. As mentioned earlier, a series of studies on host-feeding pat,terns of mosquilo populations has been carried out in different areas of Egypt (see 2.9 above for sergentii and nulticolor in Siwa and Gara oases). In Faiyun governorate, Beier et al. (1987) saupffiosq,tL-tos for precipitin testing fron the two study villages: Abheet and El Zavya in Sinnuris district. The two villages contained about 650 houses with 2500 inhabi.tants. In both villages, about 751( of. the households contained one or rnore large donestic aninals, and half of the houses contained one or &ore rooDs in wnich animals were kept at night, as colnDonly oberved in Faiyun villages also. llany dogs were observed in both villages, but were not kept in houses and sere not counted. Bloodfed mosquitos nere vBc/90.2 !{AL/90.2 Page 91 collected in both villages from houses and animal sheds as well as from outdoor-resting shelters twice nonthly froro April to December1983. Saropling fron indoor shelters was roadeby the index sheeE nethod (described under 3.6/3.7 by E1 Said et al., 1986). Collecti-on of outdoor resting mosquitos was done by a battery-powered aspirator (a1so see above). Bloodfed fenales were identified and placed in 1.5 ml tubes (up to 50/tube) and frozen at -70o C within two days of collection. As shown under 2.9 above, the nethod of identification of bloodneals followed that of Tenpelis & Lofy (1963) and details of screening procedures were described. Identification of bloodneals covered six culicines and three anopheline species; the latter were: pharoensi-s, sergenti.i and oulticolor. Only the results of anophelines are surnrnarizedhere. Forage ratios were calculated for the commonoutdoor species to provide a standard index of host selection. This ratio was calculated for each host category as the percentage of positive bloodneals divided by the Percentage of available hosts. Ratios of more than 1 indicate preference, and ratios less than 1 indicate avoj.dance, and ratios approaching 1 indlcate litt1e preference or avoidance following the rnethod described by Hess et al. (1968). While the three anopheline species were found in houses and anirnal sheds, only pharoensis was collected outdoors. A11 bloodmeals gave a positive reaction and thus were ident.ifiable. The proportion of bloodneals of sanples drawn fron houses that gave positive reaction for man Itere: 527"of 31 pharoensis, atd 347.of 64 sergentii tested, but there rdere only two specimens of uulticolor, of which one rras positive for man. None of 11 bloodneals of Pharoensis aod, 7 of sergentii collected from animal sheds was positive for man, but 8Z of. 239 snears of sergentiL from animal sheds were positive for man. The results of samples from animal sheds indicate that 86-100% of the three species had fed on large domestic mammals(cow, buffalo, sheep/goat, and horse/donkey). None of the bloodroeals gave positive reaction for dog, cat or rodent, and only 4% of sergentii bloodmeals gave positive for birds. Fron the outdoor-resting population of pharoensls , L7.9'l of 39 bloodneals gave a positive reaction for man, and thls was close to ttre proportion recorded previously by Zahar et al. (f966) ln Glza governorate (see above). The forage ratio was calculated for pharoensis and three culicine species collected resting outdoors. The Percentage of hosts in both villages !rere.' 69.37. hunan, LL.87" bovine, 7.5% ovine, and IL.47" equine. The forage ratio for pharoensis was much below 1 for man, 0.28; O.94 for bovinel 2.44 for equine; and the highest 5.56 for ovine, indicating the zoophilic tendency of this species. In their discusslon, the authors pointed out that the co[uDonmosquito species co.Llected resting in houses showed a tendency to feed on man. However, the number of bloodneals fron large donestic marnmalssuggests that nosguitos move from room to roon within bouses in search of hosts, and animals were kept inside most of the houses saopled. It has been shown above that engorged fenales frou ani.nal sheds had fed chiefly on large mammals, with the exceptlon of 297! of Cx. pipiens and 8Z of sergenlii. bloodneals which contained hunan blood. If each blotope is considered separately,the proportion of man-fed pharoensis fron outdoor sltes was 0.179 in contrast to 0.516 fron houses. No nan-fed Pharoensis was obtalned fron aninal sheds. The proportlon of nan-fed sergentli was 0.344 frorn houses and 0.084 fron animal sheds, but thls species could not be collected duri.ng 21 h collections by the mechanlcal aspirator. If all tested smears are consi.dered, the HBI [weighted rnean] for pharoensis would be 0.28 and for sergentii 0.14. Despite their zoophilic tendencies, both speci.es are vectors of malaria in Faiyun governorate. Regarding nulticolor, the sanple size lras too sna11 to be considered as menlioned above. The authors underlined the lmportance of the HBI ln quantltative epideroiology, and rightly lndicated that this index ls sometimes poorly estinat,ed because the inadequacy of sample size and bias in sanpllng procedures. Finally, the authors remarked that despite the fact that larval densities were high throughout the sarnpling period in Abheet, relatively few bloodfed fenales were collected. Further investigation on resting behaviour was suggested as this would facllitate sanpling of nosquitos for host selection studies of oalaria vectors in this area. In Aswan governorate in Egypt, studies on host feeding patterns of 11 culicine and three anopheline speci.es were carrled out by Kenawy et al. (1987). The Anopheles species ltere: pharoensis, multicolor and tenebrosus. Results sunmarized here are for these lhree spe.cies on1y. Indoor-resting nosqultos were sarnpled by pyrethrum spray capture using the sane technique of the lndex sheet described above. From January 1983 to May 1984, 10 houses were sanpled twice nonthly in 31 localities in four districts including 21 localities i.n Aswan ltself. Outdoor-resting nosquitos were sampled using the sane type of battery-powered aspiraEor used in the above study in a series of 520 collections (5 nin each). Both indoor and outdoor collections provided infornation on mosquito species conposition in the study area, but specimens selected for bloodneal identlfi-caEion were vBc/90.2 rllJ,l 90.2 Page 92 sanpled fron April 1983 to January 1984. Preservation of bloodfed nosquitos was as described above, but the specinens were air-dried for several days before being placed in the vials, and most were held dry for one or two months before freezi.ng at -70o C and final processing. Bloodneal identification followed the sane xoethodreferred to above. A11 bloodfed fenales fron the outdoor sites nere tested, but since nuoerous C. pipiens and pharoensis were collected fron houses, only specimens collected fron ltarch to august f983 were used for testing. Specinens of the tno species were randooly selected by taking 10 fenales fron each vial unt.i1 about 200 individuals of each speci.es were tested. All bloodfed fenales of other species fron indoor sites were tested. In sanples from houses, pharoensis accounted for 2.52 of the total specimens of all- species collected (19 641), nulticolor O.77( and tenebrosus 0.12. In sanples fron the outdoor sites, pharoensis constffit;d4.97"ot.G-totarspeciroensofai.tspeciescol1ected(8640i,@1""" than 0.I7 atd tenebrosus_0.32; the sauple size of the last species tested fron the indoor-and outETr-resting sites was too small to be considered relevant. Ihe host-feeding pattern of pharoensis and multlcolor differed betneen indoor and outdoor sites. While Pharoensis had fed predominantly on man in houses, 62.6"1 of 198 positi.ve bloodneals' multi.color shoned only 102 nan-positive bloodneals of 70 tested fron i.ndoors. Other hosts i.ncluded large doroestic nanmals (bovines, ovi-nes and equines). Avian feeds were detected in bloodrneals of the two species. Outdoors, pharoensis predominantly fed on man, 502 of 44 bloodneals tested. No bloodfed nulticolor ril-iollil"d fron outdoor sites. In their discussion, the authors underlffi-the inportance of studying nosquito host-feeding Patterns in Aswan, since this area remains receplive to endemlc disease occurring in the Sudan, pointing in particular to the spread of nalaria through the invasion of An. garnbiae s.1. fron Sudan during 1942 and 1950, and the spread of nitt valley fever during 1977-1978, probably through transportation of infected animals from the Sudan via Aswan. Malaria is frequently diagnosed in Aswan among travellers fron the Sudan, but autochthonous cases are sometines detected. The area is free from ganbiae $t. s.l. through the continuous surveillance by the Egyptlan Ministry of Health [in collaboration with M0H, Sudan] and control neasures are directed against local anopheline species. 0f the three species recorded in Aswan, pharoensis appears to be important as a possible nalarla vector. Its HBI as shown Uy ttre present study was 0.63 for the indoor- and 0.5 for the outdoor-resting sites, the latter index is nuch higher than that recorded fron the outdoor collection in Faiyum governorate (0.18) as shown above. An. nulticolor was found only in houses and its HBI (0.1) was much lower than that of pharo6FTZE-roultlcolor and tenebrosus nere much less abundant than pharoensisl ttreii- vEEtoEat potenETTllE-rs to.ffiliGil. 3.10 Longevity In their studies in Egypt, Zahar et a1. (1966) deternined the physiological age of pharoensi.s popuJ.ations in two areas: the field training area (F.?.A. ) in Giza governorate, and Marg locality in Qaliubyia governorate. The foroer area was pur under DDT spraying after collecting Pre-operalional data during a brief period in 1960. The latter area was kept unsprayed for comparison. Based on deternination of the parous rate by Detinovars and Polovodovats techniques in samples drawn fron the populations of pharoensis in the two areas, the following theoretical parameters rdere calculated: p = The probability of survival of a female nosquito through one day (= the p_robability of da1ly survi.val) estinated by the nethod of Davidson (1955): @,wheregisthedurationofthegonotroPh1ccyclewhichwas estinated as 48 hours (see below). Pn = The probability of survival through the duration of the sporogonic cycle with n denoting the tine in days needed for the conpletion of the cycle (Macdonald, 1957). This paraneter nas estinated for P. vlvax (the predominant infection in the study area), according to the mean teDperature at the time, from the tables of Oganov-Rayevski (reprinted in Detlnova, L962, p. 128.). I = The expectation of life in days (Macdonald, L957). -1o9" P The data of the parous rate and the calculated parameters from the sprayed and unsprayed areas during 1960-1961 are shown in Table 17. It should be noted that while DDT spraylng continued to be applied in 1962, the unsprayed area had a very sna1l population vBc/90.2 vLAL/90.2 Page 93 of pharoensis due to unexpected restrj.ction of rice cultivation. Hence, the nurobers of pharoensis dissected froro the unsprayed area in 1962 were too snall (11 specinens during the whole season) to be of value for determining the parous rate under natural conditions. Therefore, the results of the sprayed area in 1962 (not listed in Table 17) had to be conpared with those obtained from the same area in 1960 when favourable response to DDTspraying was observed. Isee Subsection (ii)r1 below]. Table 17. Parous rate of pharoensis deternined fron window trap samples and calculated paraneters for the sprayed area (F.T.A.) and the unsprayed area (l"larg), Egypt 1960-1961. 1960 (spray on 28 June) 1961 (spray on 6 June) 3 weeks- 1-8 weeks 1-9 weeks 1-9 weeks 10-f7 weeks Area Pre- post- post- PosE- POsE- spraying spraying spraying spraying spraying (June) (Ju1-Aug) (Sep-Nov) (Jun-Jul) (Aug-Oct) l"leantenperature 25.5 27.2 26.6 27.6 26.2 oc Window trap Dor- 81.5 54.4 74.9 37.6 tality (Z):l Proportion parous F.T.A. 25.7 15.8 27.4 18.6 37.9 (374) (265) (332) (274) (6L7) (No. dissected) Marg 15.6 19.7 36.6 3L.4 52.0 (e0) (ees) (48e) (s4) (1e6) Value of p t.l.A. 0.507 0.397 0.523 0.431 0.616 Marg 0.395 0.444 0.605 0.560 0.72r Value of pn F.T.A. 0.0016 0.00062 0.0029 0.0012 0.013 Marg 0.000092 0.0015 0.011 0.0097 0.053 1 F.T.A. L.47 1.08 1. 54 1.19 2.06 =iogeP Marg 1.08 L.23 r.99 L.72 3.06 * Inmediate and after 24 h holding period. It is clear fron the above data that in June the populatlon of pharoensis was young at Ehe beginning of the season, and this explains the low probability of malaria transolssion at that tixoe, as indicated by parasitologi.cal evidence. The longevity of pharoensis populations i.ncreased fron July to SepEenberwith a parallel increase in malaria transmission recorded. Fron July onwards the relative hunidity steadily j.ncreased prouoting longer survival and the appearance of larger numbers of potentially dangerous fenales. But even during the season favourable to malaria transEission, Ehe life expectatior of -p@ig was low. After September, a rapid decline in vector outPut occurred, leading to a terlporary imbalance in the proport.ions of parous and nulliparous mosquitos. For this reason, no assessment is founded on the parous ProPortions recorded beyond Septenber. Age-gradlng of pharoensis populations using Polovodovats Eechni.que, applied on window trap samples from the unsprayed area, showed that out of 1980 specinens dissected 66.7"1were nulllparous, L8.67" had one dilatation, Q.L5Z had two dilatations, 0.05"1 (one specinen) had three dilatations and O.05"1(one specinen) had four difatatj.ons. The renainder appeared with folllcular sacs, renderlng their age indeterninable. The paucity of aged individuats shows that although pharoensis aPPears in high density with exaggerated bitlng rates during the favourable season, females of an epideniologically dangerous age are stil1 scarce in the population. This nay explain the low sporozoite rate (0.33"1) recorded by Barber & Rice (f937) during an epidenic period (see 1.11 below). From all these observations, 1t can be concluded that the seasonal increase in parity is closely correlated wlth the increase of relative hunidity. The intensity of nalaria transmission effected by pharoensls oay vary fron place to place and from year to year dependi.ng on the relative hunidity and the presence of reservoirs of infective cases. Rice cultivatlon is a very inportant factor influencing the density of vBc/90.2 r4AL/90.2 Page 94 pharoensis, both by the extension of the breeding areas and by enhancing the huoidity conditions to a level favouring adult survival. Sinilarly, 1ow parous races were recorded in pharoensis in an unsprayed area in Kafr E1 Sheikh governorate with extensive rice cultivation in the northern Part of the Nile Delta, where Shawarby et a1. (1967 a & b) conducted insecticide field trials during 1965. The parous rates detenoined by these authors by dissecting sarnples from roan-bait caPture nerei 8.82 1n the first half of Juty, 33.37" Ln the first half of August' 48.L"/"in the latt,er half of Septenber. 0bservations on the duration of the gonotrophic cycle in pharoensis ltere carried out during base-Line studies in Giza governorate ln 1959 by Zahar et al. (1966). During July-August, linited entry of mosquitos was allowed into rooms at the tine of early evenlng biting peaks. Ihe rooms were sealed thereafter and mosquitos exiting in window traps were collected periodically on the following days until exodus ceased. A11 nosquitos collected were classified accordlng to Sellars stages. It appeared that the najority of the fenales could reach Sella stages 5 and 6 in about 24 hours fron biting. The latest exodus of gravid females (Sella stages 6 and 7) took 4L-56 hours. Likewise in the course of susceptibility testing, it was observed that Dost of the fenales of pharoensis captured in SelLa stages 2 and 3 in the morning reached stages 4 and 5 in the evening and stage 6 by the next urorning. Ihese night have fed any time during the night before capture and then 12 nore hours would be needed to reach Sella stage 7. Thus, i.t is reasonable to estinate the duratlon of the gonotrophic cycle in pharoensLs at 48 hours on the assumptlon that the hosts and the ovlposltlon siles are found wit.hout delay, i.e. r the time needed for the first and third phases of the gonotrophic cycle (see phases under 1.10 above) is negllgible. The mean tenperature during the suromerDonths when these observations nere made was around 26.40 C. Age-grading of pharoensls, 933g!.1L and oEher anophelines existlng in two villages in Faiyun governorate was carried out ln the course of studies conducted by El Said et a1. (1986) applylng the nethod of the ovarlan tracheoles and Polovodovars technique during April-Decenber 1983 as mentioned above. A11 sanples dissected were drawn from man-bait capture and donkey-bait traps. The parous rates of pharoensis nere: 42.32 (279 dissected) in Abheet, and 33.87" (L39 dissected) in El Zavya. Aged individuals were absent; the parous portion in Abheet conslsted of 17.92 l-parous, 2.5% 2- parous, and 21.9% with follicular sacs; and in El Zawya there vere 2O.L%parous, O.7'l 2-patous and 13.02 with follicular sacs. For sergentll, the data showed that in Abheet the parous rate lras 48.77" (234 dlssected), and only a single nulliparous female was available ln EL Zavya, For nuLticolor, only in Abheet where an adequate sample was available the parous tate vtas 252 (48 dissected) of which 14.62 were l-parous and IO.41( with follicular sacs. The duration of the gonotrophlc cycle was estimated fron laboratory observations which gave a period of four days at temperatures above 22o C (citlng Beler unpublished data). Based on this estimate, the value of gwas calculated for the period Aprll-December as 0.806 and Q.762 for pharoensis ln Abheet and E1 Zavtyarespectively, and 0.835 for sergentii. in Abheet. EstinateJ of g froro samples collected in November, the peak period of blting activity I'ere:[email protected] estioated for tenperatures below 20o C. 3.11 Natural infectlon In the past Barber & Rice (1937) recorded an average of O.337.sporozoite rates in pharoensis (1513 dlssected) collected fron tents of a hospital encampmentat Qaliub' in ;G-so-ft;n part of the Nile Delta. The tents were known to harbour carrlers of gametocytes of P. falciparuro. They retrarked that no sporozoite-posltive phqrgensis were found in their surve]rs in fgypt except in this encamPment, and it was surprislng to find a very low sporozoite rate in view of the fact that a large ProPortion of the speclmens in thls locality showed a very high oocyst rate. During a malaria outbreak in Gabal El Asfar locality also in the southern part of the Delta, Madwar (1936) recorded ln July 1936 a sporozoite rate of L.47" (L38 dissected) in pharoensls. Subsequently, no sporozolte-positive speciuens of Pharoelsis^!3"9 been reported ln Egypt unril-E1 Sald er al . (f986) recorded a sporozoite iate oFO.36"l (279 dissected) in frorn Abheet, Faiyum governorate. At pharoensls-e collected by oan- and aninal-balt capture ffi- time, a sporozolte rate of O.852 (234 dissected) was recorded in sergentii collected fron the sane village but no sporozolte-Positive uulticolor was detected vBcl90.2 ULAL/90.2 Page 95 identlfy the entomological (48 dissected). As the nain obJective of this study ltas to parasite tat'e (72 nalarla cases) factors that can explain why Abheet had a higher huuan t km apart (see under 3'613'7 El Zawya(2 cases), even though the two vlllages are than inoculation rate the authors res;rted to the calculatlon of the entonological above), the nan-biting (EIR) (Macdona1d, 1957). This rate is sinply calculated by nultiplying qharqer.rsis and-ggentii conbined was rate x the sporozoite rate. th" ...,luttlng rate of in nf%w-va-ror th: perlod abour 30g bites/nan/night in Abheer versus 128 uites6liET![T conblnid sporozoite rate of 0'585 of seasonal activity (Apr11-Decenber). Based on the as 1'80 infective (3/513) for rhe two'veciors ln Abheet, the EIR was estlaated El Zavya slnce gland dissection of 139 bltes/nan/season, but no esti'ate be nade for "orria two vl1lages, nulticolgr and females or pn.ro"o"is !..r. ,r.g"tive results. rn the not account for significanr tenebrosus occurred at such low densities that they could not considered vectors of ualaria in nffitransmission. Moreover, the trto specles are pharoensis and sersentii served to Egypt. Thus, the presence of che recognlzed vectors: maintainahigheriateofna1ariatraninissionin^c,un.ffis1z;G-EEre to low malarla pharoensls doninated. A further entonological factor that contributed carried out concurrenCly in the transmission came from studies on host-feeding Patterns above). Whereas the zoophllic same two villages. (Beier et al. 1987 see,toa"i 3.9 the llBIrs for the tlto vectors tendencies of pharoensis and Sj@!L were demonstrated' caPture and by donkey-baited respecrively '"."-[176-.116 9.1[- -!-rvatj.ons by oan-balt E1 Said et al' conflrroed the zoophlllc tendencies in both specles' traps further nalaria in (loc.clt.) that factors responsible for maintenance of hypoendemi'c suggested As i;itG-;;;Id iEserve furrher consideration if nalaria control ls to be effectlve' shor'nabove,occurrenceofbothpharoens1sand.@1nAbheetservedtooaintain ma1ar1atransn1ss1onatahtgtrer-ffitn@Theextensivebreed1ngs1tesin Abheer were obviously responslble for higher nosgulto densl8j'es in this village' Ioproving drainage of waters associated wlth lrrigatlon rtas suggested as the best long-terD solutlon for lnterrupting ualaria transmission. 3.L2 Vector reslstance to Lnsecticldes - TRS' The reports of the WHOE:rpert Coomittee on Insectlclde Resistance (wHo, 1980 No.655,andWHo,l986-TRS.No.737)showthat!@fronEgypthasbeenreported resistant to the followlng insectlcides: DDT, dieldrlnTHCH, malathlon, fenilrolhion' fenthion, chlorpyrlfos, bionophos, and carbamates. From Israel, pharoensis has been reported resistant only to dleldrin/HCll. Nonewreportsofsusceptibil1tytestscarriedouton!@inthePresent geographlcal area have been recelved by wHo during 1984-1988. L959 (Zahar' 1960)' Orlglnally, ln Egypt ltas suscePtlble to DDT before $@ This It nas later found to be resislant io DDT and dieldrln even ln unsprayed areas. lnsectlcides doubfe resisgance was closely related to the extenslve use of organochlorine leaf worm, !o control a voracious attack on cotton plantations by the cotton Probably' the aPPearance Prodenla litura (Zahar & Thyoakis, Lg62 and Zahar et al., 1965)' years can also be related to the of OP and carbaoate resistance in pharoensis in recent far been undertaken ln agrlculto:FNo U'iocheoical have so use of these coupounds "tndi"" to lnvestlgate the mechanisms of resistance in Pharoensis' 4. Secondary and susPected vectors or suspected The available infornalion on the bionornics of most of the secondary detalled to warrant vectors in Ehe prersent geographical area is not sufficiently of vector proflles adopted for najor suumarizing it under the standard subject headings is nade as follows: vectors. fnus, a-siaple revlew of the available knowledge 4.1 An. hYrcanus of whether dlfferent In the ussR, Artenlev (1980) pointed out that lrrespective they are treated as a single forus of hyrcanus oay eventually_be proven good species, of Gutsevlch (1976)1' This specles, eo. nyt"=.rr,r'" i.ii.", fltfowing the recotmendations 50o N' rt occurs in Moldavia' specles r" ria.rffit;il;;J ln the uEsR south of cenEral Asia, and around Lake Zaisen southern ukraine, northern caucasus, Trans-caucasus, 39-40' 1. iee VOL. I (VBC/88.S-MAP/88.2),under 1.2, PP. vBc/90.2 t4AL/90.2 Page 96 region of in the Far East. It is considered a secondary rnalarla vector in the southern rnalariae and least the USSR. It can be eas11y lnfected wlth P. vivax, less so with P. 'ith!:--!@'.A1though1tgenerattyactsasasecondary.'.6I-IiT6Epresenceofa nalaria in cerCain najor vector, it Day play a large role in the transDission of P. vivax areas. larvae The optluun temPerature for larval breeding ls 25-30o C, sinilar to that of the upper of the An. nacullpennls complex, but wlth the lower llnit being 12o C and but in the llnlt :ffi]--o.th, hyrcanus breeds ln waters heated by the sun, places are: boggy sites south it prefers shaded siteffipreferred tyPes of breeding rice supplled by surface lrater, flood plain puddles, river bends, and |n Particular tieias. Nearly all these ltaters have abundant aguatic vegetation. of the In cold regions, its larval developnent is slow due to the slow heating Asla' nater, hence the adults do not aPpear ln large numbers until July' In Central hyrcanus adults attain high densitles |n late Uay and earJ'y June, but the denslty decllnes in i" e"g"st and the species even disappears ln the hottest areasr followed by an increase is September-October. Females of hyrcanus hibernate ln natural she1Eers. When the ltinter even in central Asia' In warn, they nay feed repeatedly ;i-5E6iI, but this 11-re1y happens (pre-hlbernating) feuales aPPear about the the southern part of Central isia diapauslng end of Septenter and reach a high dnesity in October. By nid-October, nan-biting activlty and gonoaitlvity come t'o an endl In cooier regions, diapause starts somewhat earlier. Adult.s of hyrcanus prefer to rest outside huoan habitatlon. Their natural resting sites are; grassE-, b,rshes, banks of lrrigatlon canals, and crevlces ln fences constructed but of rnud. They nay ctang. thelr restlng slles dependlng on the outslde tenPerature, remaln strlctly exophilic. They feed on Ean ln the open. There are rePorts lndicating - Asia it feeds on rnan on a large scale that 1yryieeds-on small animals, but ln Central in s.ffiEnt-s partlcularly those sltuated near boggy sltes or rice fields. DDT resistance was reported lon hyrcanus in Central Asla, but no rePorts on possible DDT reslstance ln thls sPecles fn ottrer reglons of the USSRare available. In Romania, Cristescu et al. (1975) studied the btology of hyrcanus in the Danube. Delta reglon durlng LITO-L973. Nearly the same blologlcal features as those found in the USSRwere recorded. It breeds ln shallow ltaters wlth abundant vegetation. The first generatlon appears in May and the density reaches a Eaxtmuo in July and early Augustt iollowed by a gradual decllne untll It enlers hibernation ln October. It is an exophilic, eurygamous, exophaglc or endophaglc species accordlng to circuustances. It ls clearly ,oopttftfc as lndlcated fron precipitin tests run on bloodmeals of fenales collected froo thatched fences between houses and anioal shelters, so that the hyrcilg females could feed on elther 11anor aninals. The proportlon of bloodneals that gave positlve reaction for uan vas 4.67.. It is consldered unimportant as a Potential veclor in Ronania. Confirnation nas obtained in the present study froo determinatlon of its physlological age durlng July-septenber 1972 and during the saoe period in 1973, using Polovodovars technique. The proportion of females wlth a maximuo number of three dilatations was only 0.32% (S3a ats"ected), i.e., these fenales were at an age when they start to become have any role i-r potentially dangerous. This supports the assumPtion that ]lJs cannot nalarla transrnission in the Danube Delta reglon, but lt renalns one of the x0ost annoying mosquitos in the Delta. As it exhibited low susceptiblllty to organochlorine juvenile or by lnsectlcldes, the use of B. thuringiensis H-14 and analogues of hormones dra1ningsha11owsr'amPsn'ffi-easureareconoendedfor1tscontroI. In Turkey, Postlgllone, Tabanll & Ransdale (1973) showed that h)'rcanus ls abundant plateau. I! was founc in the coastal plains and extends its dlstribution to the Anatolj'an rice flelds' breeding in coastal and inland oarshes with dense emergen! vegeEation, in association drainag- and road-side dltches wlth or without vegetatton. It was found Although no speclfic studies have been made nlth sacharovl , -g!!g.pis and algertensis. inTurkeyontherestingbehav1our@"",itisknowntobepredooinant1yexophiIic; populations are rarely the degree of exophily ittt.." between-iGffi Indoor-restlng found in the observed 1n the southern and wescern coascal reglons, but are coromonly area' plateau provlnce of Corum where there ls extenslve rlce cultLvation. In thls hvrcanus mav be found in buman dwellings and ln stables. Little is known on the generallv.regardec fr6'3iHilii6 piti.i"-.i-rty*. in chJ Medirerranean zone, where it is out in as a w1ld mosquito ttavtn!_llttt. contact with nan. Some observations were carried vBc/90.2 r4aL/90.2 Page 97 Ugurlu village, Mugla province of southeastern Turkey. 0f 238 hyrcanus females collected simultaneously by man- and cow-baited net traps, 982 urete obtained fron the cow-baited trap. At the same time, nan-balt capture conducted in the sane village inslde and oucside houses, where nunerous cattle and other domesti.c animals are available, as commonly observed in Turkish villages did not yield any hyrcanus. However, when the same human baits rrere stationed in the open at a distance of 250-300 m from the village, they ltere qulckly attacked by nunerous hyrcanus. This showed that nan being away fron the protection of donestic herds, can readily becone a target host for hyrcanus. Postiglione' Tabanli & Ransdale (loc.cit.) further polnted out that ln view of 1t.s extra-dooestic habits, hyrcanus has never been regarded as an important malaria vector in the l'lediterranean reglon and very few lnvest.igations (none in Turkey) have been carried out on lts vectorial efficiency. ln this connection, reference was trade to Horsfall (1955) who cited a single record of a sporozoite-positlve specimen of hyrcanus fron Italy [1/113 dissectedl. Both hyrcanus and sacharovi are particularly abundant in the fertile plain of lukurova which occupies nuch of the provinces of Adana and Igel on the I'ledlterranean coast. In this plain, hundreds of thousands of seasonal ni.grant labourers work and sleep in cotton fields, where Ehere are few anlmals. Thus, an unusually close contact exists betveen man and both species. Although sacharovi is the more dangerous of che two, the posslble lnvolvement of hyrcanus in nalarj.a epidemics in Ehis area cannot be ignored. In Israel, Barkai & Sallternik (f968) during their survey in 1963-1965 found hyrcanus breeding In abundance in flsh ponds, seepagbs, leakages, springs and lrrigacion channels. The breeding places were usually stagnant and seroi-stagnant waters covered wiCh vertical vegetation. Larvae sere found frou llarch to November with a slight increase in surrmer. Most of the breeding was ln Upper Galilee. An. hyrcanus Itas not considered a malaria vector in Israel (cttlng Kligler, 1930). In Lebanon, Gramiccia (1953) polnted out that although sacharovi and superpictus existed in areas of hlgh Dalarla endenicity as in Bouqaia, Oronte valley cowards che Syrian frontlers, these trro recognized vectors nere assoclated with hyrcanus which readily bites nan. Ic is a wild nosqulto, and lt was difficult to find sufficient sanples froa natural shelcers for dlssection 1n order to reach a deflnite conclusion on its role in malaria transulsslon. Thus, lt should be treated as a suspected vector. In Syrla, Abdel-Malek (1958) encountered hyrcanus along the Orontes valley froro Homs to Aleppo. The most northerly breedlng place was at Jisr-el-Chagour in Aleppo, where its larvae were found in assoclation wlth those of sacharovi in a shallow srrarnplrith energent and fl.oatlng vegecation at two villages in ctraU-aEJtre most southerly record came from a village on Hons lake, where its larvae were associated with sacharovl and superpictus in a slranp at the edge of the lake with very abundant grasses and reeds as well as patches of floating algae. Mults of hyrcanus were frequently encountered in snrall nurnbers i.n houses, together with sacharovi. Females of hyrcanus attacked man and douestic animals voraciouslynears*'aopFr1rrgthenightunti-aayureat<.0ccasiona1outdoor-bitingwas recorded in daytine during sunny hours. The author did not give any inforroation on the possible role of hyrcanus in nalaria transoission in its area of distribution in northern Syria. The reports of the WHOExpert Coumittee on Insecticide Resistance (WHO,1980-TRS. No. 655 and WHO,1986-TRS. No. 737.) showed that hyrcanus is resistant to DDT and dieldrin/HCH in Turkey and Afghanlstan, and to DDT in the USSR. A wide spectrum of cross-resistance has been reported to the following insecticides: fenitrothion, fent.hion, jodphenfos, chlorphoxln, phoxim and carbamates i.n Turkey, but reslstance to carbamales has only been reported fron the USSR. No reports have been couounicated to WHOduring 1984-1988 on neld cases of lnsecticide resistance in this species from the Mediterranean Basin. 4.2 An. claviger s.1. In the USSR, Arteniev (1980) showed that An. claviger has a wide distribution in the western part of the country, lrestern Siberia up to Tonsk, the Caucasus and Central Asia. The northern part of its range passes just below the southern range of nesseae. In the south, claviglr is usually found in the mountains; the southern boundarfE-oFlts distribuEi-G deternlned by an annual mean temperature of about 2oo c. vBc/ 90.2 t4,AL/90.2 Page 98 The usual breeding places of claviger are sprlngs and wells. The species thrives in cool waters: the optimun temperatur" ..nge r" 14-160 C, the lower temperalure threshold is 7-8o C and the upper is 21o C. According to various authors, the larval stage takes 18-20 days in Turknania and 32-33 days in Moscowat the optioal temPeratures. The preferred larval habitats are shaded sites, and the larvae are indifferent to Ehe presence of vegetation. The larvae can tolerate waters polluted by decaying vegetationr but are sensiEive to pollution by nitrogen. Larvae overltinters ln the 3rd or 4th instars. ln the south, the development proceeds without dlapause. In the plains of southern Central Asia' adults of clavigei appear only in the spring and fal1. As the EemPerature drops in the autumn, cti-vig.r probably migrates frou the nountalns to the plains and remains there to overwintEi-and give rise to adults in the spring. These die in the sunmer or nlgrate back Eo the mountains. Adults of claviger are acEive at temperatures ranging fron 10 to 260 C, with the highesr acrlvityffi-1ar I3-19o C and 5l-95% RH. Norrnally, they do not f1y far away fron the breeding habitat. They f1y into houses for feeding, but show Particular preference for stables as they are attracted to the soell of aninals. Ihey aret therefore, more attracted to cattle than nan. The adults are exophilic, and leave the indoor shelter after feeding to conplete their gonotrophic cycle in ouldoor-resting natural shelters such as vegetation, daup banks of canals and other danp sites. As Eegperatures in such places are low, blood dlgestlon is prolonged, and the gonotrophic cycle lasts about 5-6 days. Swanoing and nating of claviger occur in the open. Because of the ecological characterj.stic of .g}9g!g., lts role in nalaria transnisslon in the USSRrras consldered slight. It was only on rare occasions that this species was able to transnit nalarla when Lts breeding places were locaEed near human settlements. Malaria outbreaks occurred |n the sourroundlngs of Baku Tyen-Shan foothills and on the Black Sea coast of the Caucasus where claviger was the pri.nciPal vecEor. In the USSR, an autogenous and a nonautogenous form oE@ggr have been observed. In the south, Anopheles habibi, which was nisidentlfled by entonologists as claviger is very likely to be present. No resistance to DDT or any other insecticlde has been reported in clavlger ln the USSR. In Turkey, Postiglione, Tabanli & Rausdale (L972) Presented a detailed study of the distributton and ecology of claviger ln the counlry. Urban situations suitable for breeding of this uosquito do-i6EFist in Turkey, and even i.n vlllages water supplies do not rely on wells and cisterns. Consequently, claviger ln Turkey is confined to rustic' extra-domestic situations, where donestic anloals are abundanc. Reference rtas nade to CoLuzzL (1962)l who classified the An. clavlger group into two lndependant sPecies: claviser s.s. and Detragnani. To ascertain the identity of the Turkish populations of ffiIEer s.1., nara?EEfr-f-Freserved specinens existing at E,heMalaria lnstiEute in Adana fiTEFriginaled from varlous areas of the country, as well as larvae collected fron breeding places in lrestern, southern and eastern Parts of Turkey, were exarnined. This showed that all Turkish populations sanpled belong to claviSer s.s., thus providing additional evldence on the restricted range of petragnani which has so far not been detected in the Easlern t'tediterranean Basin, where claviger s.s. exists in Balkan, Turkey In and rhe ltlddle East [See Fig. 1l in SECTIoNII in d;;G;;-vBc/9O.1-]'tAL/90.11. all areas of Turkey, claviger could be occasionallay found resting indoors, as it is largely exophilic. ft teffi-a certain extent, in villages, but. it generally attacks uan or donestic anlmals wherever they are available in the open. The contacE t{ith man is usually accidental and occasional. AJ.thoughwidely distributed in Turkey it prevails in the warmer parts of Che councry, but its densLty is narkedly reduced in summer. An exceptional situation occurs at Savur in southeastern Turkey, where nany sPrings in extensive poplar plantatlons provide ideal and perEanent breeding places for claviger. During the summer uonths, large numbers of people work and sleep in poplar Plancations, where they becone heavily attacked by clavlger amongst other sPecies. It is quite possible lhat in such sltuat,ions, claviger has some role in malaria transmission in fornerly malarious areas, aLthoughGerous gland dissection failed to find a sporozoite-positive specimen, thus it could not be consldered a good vector. Slnce the environmental conditlons ln Turkey differ narkedly from those found in urban areas in Ehe l{iddle Eas!, bu! closely reseuble those found ln the Balkan countrles, it was concluded chat claviger in Turkey is of ninor importance in malaria lransoission, and has little influence on the recepEtvlty of areas where transmj.sslon has been inEerruPted. - 1. See VOL. I, pp. 34-36, in Docuoent VBC/88.5 MAP/88.2. vBc/90.2 t4aL/90.2 Page 99 In their study of the anophelLnes of the Maghreb, North Afrlca, Guy & Holsteln (1963) dlscussed the role of claviger 1n oalarla transnisslon in the light of the results of detenolnation of the physio@T age made on samples collected fron the mountainous regions of Algeria and Morocco. Epidenlological evi.dence supPorts the view that claviger takes over from labranchiae and lransmits nalaria in late autunn (see under 2'10 above)' Gramiccia (1956) presented a detailed accounc of the ecological features of claviger and the assoclating epiderolotogical sltuatlon in countrles of the Middle East, where thls species is widely distributed. Withln a small area of 1ts dlstribution, clavlger exhibits a variety of ecologicaL features as follows: (a) In tolrns, it breeds j.n underground nater reservoirs, and lt is chiefly a donestic species as its adults rest in houses. (b) In rural areas, it breeds in water reservoirs, and it is chiefly extra-domestic as its adults rest nostly outdoors, especially after feeding, or on the walls of wells, but in the autuun it becomes donestic, and engorged feoales are frequently found indoors. (c) As a natural water breeder, it is oostly a wild specles unlnportant in nalarla transmissi.on. The host-feeding pattern of claviger ls probably dependent on the availabllity of hosts near lts breedlng sites, but tt attacks man readily in the open and ln daylight' wlth varylng intensity depending chlefly on the season and prevailing tenperature. In case of situatlon (c) above, lt passes the wtnter chlefly in the larval stage' but a few overwintering adults have been found ln outdoor-restlng shelters. In cases of (a) and (b), however, it conllnues lts larval developnent and adult actlvltyr lncluding natlng and feeding, throughout the wlnter as the nicrocllnate lnside the wells permits. Grarniccla (1oc.cit.) further showed that glglg1 had been reported in the past to be a vecLor of nalaria in certaln areas (PalestGffii-rus, Lebanon, llesopotauia, southern Italy, Baku-Azerbaldjan) and had been consldered a non-vector Ln oany other oalarious areas (Central ltaly, Greece, Balkans, Iran and others). It was rarely found alone as a vector species, usually belng assoclated with the recognlzed main veclors, chiefly: @,[email protected] recoraea in Cypr"s (citing Stratnan-fhonas, Barker & Carter,1936)' Taranto, Italy (citing Hargreaves, L923), and Mesopotanla (citlng Chrlstophers & Short, 1921). [This last record fron Mesopotaula whlch appears also ln Boyd (1949) could not be conflroed - see l'luir & Keilany (L972) belowl. Gramiccla (loc.cit.) further added that there was full epidenlologlcal evidence that claviger lras a vector in Palestine; Jerusaleo, for exanple, was among clavlger-lnfested palestinlan towns. An. claviger was the only anopheli.ne species prilent, .od lts abundance and the tryperendenrcrty of malaria hltherto recorded during 1912, left no doubt as to lts role as a vector. House wells provided suitable breeding for clavlger, whlch was probably able to produce hyperendemic malaria because it had llttle ctrffiTfeed on anythlng else but man. Larvlcldal treatnent of wells' eater plping and the destruction of unused wel1s in subsequent years brought about comPlete control of rnalaria. 0n the other hand, gleylg. was not a vector ln areas where lt was breedlng in nalural waters and where nanfr-lternatlve hosts were available. In Lebanon, Graniccia strongly suspected clavlger as a vector in some hllly vlllages where several wells were present. On the ottrer hand, claviger together with suPerPict-trs-were found in almost every coastal, hilly and mountalnous area, wherever there were wells uP to 1200-1500 n altitude, and rhe dlstribution of claviger had no direct relation to the malaria endenici.ty in the area. This was an exanple of "unstable anophelisn without malaria". In a linited number of localities on the dry llmestone hi1ls of Lebanon, both spleen and parasite indices were recorded. Although superpLctus fenales migrated at one tlme or anoCher to nearly all these villages, [see 2.4 above], thelr numbers and activity nere too smal1 to account for the malaria infectlon there. An. clavlger was the only abundant indigenous species in these localities. Thus, it was presuoed, but not deflnitely proven, that claviger was the princlpal or the only nalaria vector there. The spleen and parasite indlffiever, were so low and so uneven in the dry hill villages that tt was consldered possible that claviger would be unable to Daintain nalaria transmission indefinitely ln a sedentary population without visits from time to tlne of ga6etocyte carrlers fron elsewhere. In Dedd6 village situated on the hills of southeast iripoli, all cases of parasitaemla were recorded anong children who had not left the village during the preceding tno years. Dissection of 433 claviger, however, proved negative. After antilarval treatment of cisterns that started in July 1953r the parasite vBc/90.2 t4aL/90.2 Page 100 rate dropped to zero during October-December. Regardlng control, Granlccia indlcated that restdual house spraylng rras not found to control clavlger, while larvlcidlng did. Thist in the light of Ltt" pr-u.ui1ity thaE glgvlg can-iffi-ln occasional transmlssion of malaria for some tine after the connencement of house spraylng, larva1 control sinultaneously with residual spraying prograrnne should be irnplenented for at least the first two years. The cost of such larva1 control would be nuch less Ehan that of extending the residual spraylng progranune for a prolonged period. In Israel, Saliternik (I974) recalled the observations of Barraud (f921) ln Palestine which showed that glgylger was the most abundant domestic nosqulto, breedlng principally 1n shaded cold riln water of the courtyard clsterns or inslde houses. Under such conditionsr.g!g;!gg1 became in close coiltact ltith tranr readlly biting hin and transnitting nalaria. It responded readlly to control measures carrled out during I9L9-L926 (hernetic seallng of cisterns, provision of piped water, larvicidinB oPerations etc.). Now, clavlger ls no longer inportant in nalarLa transui.ssion. It is found nainly in the north of lJriel and often away fron huuan dwelllngs. No norphologlcal differences could be found between larvae of claviger collected from cisterns and streaDs. In the recen! report on anophellne fauna of northern Israel by Pener & Kitron (1985b), larvae of clavlger rdere ldentifled frorn 106 breedlng places in the course of surveys nade during 1978--i98'5- Ihis specles has been collected ln increasing nuubers ln recent years with lts relaElve frequency ranglng fron 7 to 302. It was generally restricted to spring-early sunmer breedlng, and was the Bost or second most cotntlon oosquito fron March to July. An. clavlger was often found wlthln or near Arab vlllages where wells and clsterns are present 1n Safed and Acre reglons. It is less coumon in the Jordan Valley. In the Safed reglon, couslanl was always present, but algerLensls which was prevalenr untll 1980, decltned anGF!6sslbly replaced Uy ctavigEr Uy t98t-t983. In Acre, lncreased as algerlensis decllned. An. claviger was found '1 claviger and -:g35g!g. 13 tlnas in the sane locatl.ons and months ln 1982-1983, whlle algerlensis was found in 1977 (rnostly in the upper Galllee and Acre reglon). In these locatlons, claviger was absent Ln L977, while algerlensls was absent ln 1982- 1983. Thus, 1t seems that an actual replacenent of algeriensis by and to a lesser extent by superPictus nay-have taken place, but-TI-authors cautj.oned"I*1€S=r that hls cannot be proved in the absence of experinental data. In Syrla, Solinan (f960) reported the results of observations carried out during October 1957-Sepcenber 1958 on the seasonal dlstribution of clavlger and its susceptibillty co lnsectlcldes. The observalions were conductEa at Der El-Asafir villaget 10 kn south of Damascus, where claviger was found breedlng ln open uarshes around some natural sprlngs. Following Gramlccia (1956)r.9}g!g. in thls area could be considered a natural breeder, hence a wl1d nosqulto unimportant in oalaria transmission. The seasonal distributlon was studied through weekly larval sanpling. The area nas under DDT house spraying. The results were suonarized as follows: - As indlcated froo larval catches particularly younger instars, the density of claviger fluctuated Ehroughout the year, wlth no partlcular decline during winter. - The breeding activity reached a peak ln JuJ.y, and the lowest densities were observed in April, August and September. - The changes ln the seasonal distributlon rrere not related to DDT spraying, as this nosquiEo was considered exophagtc and exophllic. Larval suscepribllity tests showed chat glg:!E: was coupletely suscePtible to DDT and HCH. It was concluded that the lack of response to residual house spraying while claviger remains susceptible to the insecticide would suggest that larviciding would be ttre neas.tre to use for effective control of this specles. However, the applicatlon of such a measure nas not reconnended for this area, since lt proved to be non-ualarlous. Muir & Kellany (L972) clted several authors indlcating that glglger has been regarded as a vector of malaria ln urban areas and in villages ln Syrla, Lebanon, Jordan and Palestine, but there lrere no records of lts actual lncrlnlnatlon ln these countries through flnding sporozoite-positlve specimens ln nature. Reference was oade to Boyd-, (1949j who llsied one record fron Mesopotania of one sporozoite-positive among a small number of clavlger dissected by Christophers & Short (1921). Checking the orlglnal publicatlon of the tso authors, Muir & Keilany (loc.cit.) could not lrace such a record' vBc/ 90.2 trAL/90.2 Page 101 and thought that lt oay have been a nisquotatlon. In October 1970, a nalarla outbreak occurred in Al-Bellora vlllage on the outskirts of A1eppo, shere 58 indigenous cases of P. vivax sere detect.ed among 113 inhabitants. An. claviger was Lhe only anopheline found in ttre area, and its breeding was found in welliliffitErns in the limestone bedrock. Dissection ot 20 fenales of this specles yielded two sporozolte-positive speclmens. This was the first confirroed i.ncrinlnation of claviger as a vector of malaria in the area bordering the eastern littoral of the Medilerranean. Oll larviciding ln wells and cisterns in t.he aboverentioned village led to interruption of malaria transmission. In North Africa, Senevet & Andarelli (1956) gave the distributlon of claviger in the Mediterranean Basin including I'1orocco, Algerla and Tunisia. In the last two counEries, it does not exist very far fron the sea, the farthest point being in valleys abou! 30 kn fron the sea. In l'lorocco, iE extends to the Atlas up to 2560 o. altitude. Ic was found to breed in freshwater at shaded sites even those having no vegetation, and suall pools forned in mountainous streans, as well as in wells ln the dry regions. In Algeria, j.t was found breeding in winter in waters at tenperatures of 1l-160 C, and durlng its full evolution in the autumn at 19o C. It nas found practically all year round in Algeria reaching a maxi.mumin winter and spring and a nlninun in surnmer. Some records of naEural infections reported fron ltaly in the past were cited, but none fron North Africa. Guy & Holstein (f968) showed Ehat glg]g finds favourable conditions in the Moroccan Atlas; it was found breeding in streams descending fron this trountaion range. It was also found slightly above the 31o N latltude in the pre-saharan regions. Age-grading of a sanple of claviger obtained from the mountalnous regions in Algeria and Morocco where this species occurs ln abundance, showed that only 0.72 of the fenales could complete flve gonotrophlc cycles, whi.ch theoretlcally ean allow the sporogonlc cycle Eo be coupleted. Thls raises a questlon whether claviger has a potential role in nalaria transnission durlng the autumn, but the sanple dlssected was too snall to lead to a valid conclusion - (see more details sunder 2.10 above). An. cl.aviger has been lncluded among the anopheline vector species that have not been reported to have developed lnsectlcide reslstance (WH0, 1980 - TRS. No. 655) and no susceptlbility test reports lnvolving thls species have been cormunicated to WHOduring 1984-1988. 4.3 An. hispaniola Senevet & Andarelli (1956) lndlcated that the main area of the distribution of hispaniola is the lrestern part of North Africa (l'lorocco, Algeri.a and Tunisia) where 1t extends frorn the Mediterranean llttoral to Tananrasset right into the Sahara. Ir also exists in the Canary Islands. In the lloroccan Atlas and Algeria lt is conmonly found fron 0 to 1200 o altitude. Although the Edn. and Et. Sergent brochers found a sporozoite- positive in hispanlola, the role of this species in malaria transmission in North Africa could not be establi.shed with certainty as it is aloost always found in associ.ation with the naln veqtor, labranchiae. Moreover, hispaniola is a zoophlllc and exophilic nosquilo, although it can under certain condltions enter houses and bite man, but lhis seems to be episodic. Thus, the role of this species appears to be linited. In Libya, it was recorded fron Tripolltania and Cyrenaica ln Libya (Dlacdonald, L982). It has never been recorded in Egypt except frou the high nountain (above 1200n) areas in Sinai (Margalit & Tahori, 1973). In IsraeJ., i.t was rarely found in the past and was not considered a vector, and it could not be found in surveys nade during 1963-1965, (Barkai & Saliternik, 1968). Guy (1963) referred to the single record of the Sergent broEhers (shown above), and pointed out that on another occasion sporozoite-posicive speclmens were found in hispaniola during a circurnscribed malarla epidenic that broke out in 1948 in Midlet, llorocco, where it was the only anophellne species present. On the other hand, precipitin tests showed that only 0.7% of hispanlola fenales had fed on nan. Epldeniologically, this nas a favourable characteristic bLcause .hi-gg!g.}g. is nost widespread in llorocco and in Algeria.Susceptibi1itytestsshowedthat.@'wascomp1ete1ysuscePt1b1etoDDT. Guy & Holstein (1968), trying to flnd evidence on the role of hi"p.n|ol" in malaria transnission, age-graded a large sanple of this species collected fr6i-aitterent areas ln llorocco (see under 2.10 above). Under the.clioatic conditlons of the transuisslon in llorocco, none of the hispaniola females could survive to the completlon of the sporogonic wc/90.2 MAL/9A.2 Page LO2 cycle. This led to the concl-usion that hispaniola does not seem to be a natural vector of nalaria in l.{aghreb. ln Algeria, Ramsdale (1972) renarked that hispaniola is a wild oosquito, noroally having no contact wlth Ean; it is not considered as playing an imPortant role in malaria transuission. In Tunisia, before the nalaria eradication canpaign, it ltas thought that labranchiae and hispaniola nere the principal vectors, but later evidence showed that hispaniolg d1d not play anylnportant role in nalaria transuisslon as indicated by Wernsdorfer (1973). No reports have been communi.catedto WHOlndicating the presence of lnsecticide resistance in hispaniola. 4.4 An. drthali This species has a widespread distrlbution (see SECTIONII, under 2.2.3 in document VBC/90.L-MAL/90.L). In the l'ledlterranean Basin, it was recorded in North Aftlca (l'Iorocco, Algeria, Tunisia and Libya). It has noE been recorded in Egypt except froo the Sinai by several authors. In Israel, it rras rarely encountered in the past and ltas not considered a vector; it rras not found in surveys Dade during 1963-1965 (Barkai & Saliternik, 1968). No nalural infectlon has been found ln drthali in any counEry of the Mediterranean Basin. In llorocco, Guy (1963) lndicated that d'thall was flrst recorded in 1959, and it was a suspect,ed vector of nalarla, but sone sar:.iEilgrand dissec.tlons were negative. It exisced 1n association rdith sergentil but ln a nore restrlcted areai ZLz and Draa streaEs. It appeared late ln the season and dld not last for a long tlne. Its anthropophilic index uas thought to lodlcate lts proba0le role in malaria transmission. Precipitln tests nade ln 1961 at Zagora (at the sane place where sergentii was tested a oonth later) showed that 21.2"A of L6O females of drthall had fed on man. Al.1 that has been said about seI€ggii. south of the Atlas applies also to dfthali in that it has the same breeding tra5GEid' adult resting places in houses as serg-entll . Guy & Eolstein (f968) polnted out that drthall was recorded in northern llorocco in the lloulouya valley. Because of the obllque Ffi." of the Moroccan Atlas, there is a clinatic barrler that would oppose the extenslon of the drthall range of distribution from 1ts traditional habitat in Ehe south of the Atlas to get established in the area of large rlvers in the north close to the I'tedtterranean coast. However, dtthali remains a suspected vector playing some role in nalaria transmission south of the Atlas. ln Algerla, drthall ls more wldely dlstrlbuted in the southern than in the northern oases (see Tables EE, under 2.5 above). Ransdale (L972) described 4]!@!! ts. desert nosquito, never incrininated deflnitely as a nalaria vector, even shere it is abundant. 4.5 An. multicolor The general distributlon of nultlcolor and its status as a suspected vector on epideniological grounds have been it SECTIONII, under 2.2.4. (in the sane document as above). It ls repueed to tolerate"tr"r hlgh salinity in breeding places, although it can also breed in freshwater (see under 3.2 above). In l"torocco, Guy & Holstein (1968) showed that Eulticolor extends its area of distribution in the southern Atlas to colonize the plains sltuated between Marrakesh and the Atlanti.c, and further north to Tanger spreading abundantly in pockets along the }1editerraneancoast.Itseemsth"t@playsaroleinnalariatransmissionin I'lorocco and in certain oases ln souttrern Algeria, but so far lt has not been incriui.nated except on an epideniological basis. In Algerla, Holstein et al, (I97O) found that sooe of the early records of nultlcolor and igs assoclation with the nalaria epldenlological situation in the Saharan oases appeared to have been based on erroneous ldentificatlon of a norphologlcally abnormal forn of larvae of hisplanlola, whlch resembles mulEicolor. Ransdale & Zulueta (1983) supported this vlew, as they observed that nulticolor is not as wldespread as the early records lndlcate, at least ln Hoggar and Tassili. The oosc recent dlstribution vBc/90.2 t4AL/90.2 Page 103 records of nultlcolor in the northern and southern oases of Algeria ldere Presented by these authoFffif,-own ln Tables 13a and b respectlvely. Holstein et al. (loc.clt.) further polnted out that whlle some early workers associated Eulticolor alone wlth endenic-epidenic conditions of malaria ln the Sahara, there Itere orhers who found that although nulticolor was abundantly present, malaria endenlcity nas very low. Investigatlon-s carried out by the authors ln Tasslll, Iloggar, Tlnlnoun and Biskra in Algerla, led to the conclusion that nalarla encountered 1n lts low endemicity with epidenlc bouts in these areas was due to sergentll. It is often dlfflcult to provide evldence on the role of a species such as sergentl.l because it has a very short season corresponding exactly to the season of epideniological manifestatlons. This can explaln why nulticolor which breeds prollfically in bracklsh ltater and has a long seasonal prevalence (even its Larvae are found in winter) was lncriminated as the obvlous speci.es present assoclated with epideuic episodes. Intensive studles undertaken ln Biskra revealed the absence of nalarla transmission ln oases where nultlcolor stands alone all year round. Thus, lt is necessary that investlgations should be carried out on malaria transulssion occurring in the oases of the Sahara at the tine of seasonal prevalence of sergentii, 1.e., during Septenber-November. Raosdale & Zulueta (1983) polnted to Ouargla oasls ln northern Algeria as an exanple of situations where nultlcolor has been regarded as a vector on epidemiologlcal evidence. In this oasis, a low level of P. vlvax transmlsslon perslsted and was studied by nany workers for several years, durGlTfrlch nultlcolor was the only anopheline found. However, evidence for the lnvolvement of-iFrtrcoror 1n soue other places ln Algeria has been less convincing. In Tunisia, Wernsdorfer (1973) lndicated that the dlstrlbutlon range of oulticolor covered the southern part of the country and Sfax governorate, as rrell as part of l(airouan region, but its role iu ualarla transmlsslon could not be ascertained except on epideniologlcal grounde. It seems to have contributed to nalarla transuission in the foci of Sayada/Smara ln 1971 and E1 Mendria in L972, nhere lt was found iu high densiEies. In Llbya, Goodwln & Paltrlnlerl (1959), who descrlbed the nalarla sltuatlon before the conoencement of the nalarLa eradl.catlon progranne ln 1960, polnted out that whlle nu1ticolorhadaw1ded1str1but1on,sergent1iex1stedsporad1ca11y.4g:-@has never been definltely proven to be a vector, but ln the Fezzan reglon oalaria was found in lsolated oases where nultlcolor rras the only anophellne encountered. A very high density nas apparently necessai@"nsulsslon to occur. It was found breeding in snall pools tolerating hlgh salinlty; the total chlorlde contents ln the breedlng lrat,er vas L4.4g/L. The tolerance of this specles for sallnity probably accounted for lts wide distribution in the oases where the uaJorlty of the rrater uas saline. The species was found i.n great abundance in the dry season breeding ln snall sali.ne pools of standing ltater resultlng from surface evaporation. It was found to be anthropophlllc and readily rescs indoors. More recent Lnfornation on nulticolor ln Llbya has been lncorporated with that of sergentii under 2.5 above. maftGiEi.iil[amsdale (f989 - in press) indicated that larvae of uultlcolor in Llbya thrive ln polluted water collectlons in urban areas, produeing high adult densitles whlch can roaintain a signlficanE level of uan bitlng desplte the preference of the species for non-human blood. Sone inforoatlon ls avallable on age-gradlng rnul.ticolor ln Llbya. Shalaby (1973) initlally applled the technique of the ovarian tracheoles on samples from a laboratory colony to study the structural changes ln this tracheal systen after the first oviposition. Subsequently, the rnethod was applied on sanples of field populations of nulticolor collected froo three localities in Fezzan province. The results showed that of E5 otttttcoior females collected fron Sebha locality (February-October f968), 34.9% vere par6ffiferna1esofthesamespec1esco11ectedfronE1Gedidlocal1ty,L1bya (January-Ocrober f968), L6.9"Ardere parous; and of 33 collected froo Brak (SePtenber 1968)' Lz.Li( nere parous. Thus, of a total of 2LL fenales of oulticolor dlssected fron the three loclatiries 23.2'l nere parous. While describlng ttte ctrii!frffirrlng in the ovaries and ovarioles of pharoensis and ggf@ drawn fron laboratory colonies, Shalaby (1971) gave some detalls of ai.ssectlons oade by Polovodovats technigue on wild-caught fenales of multicolor collected fron Sebha and El Gedid during January-October 1968. Of 138 females, ffienull1parous,2l.74i(L-parous,andon1y1.45i((2spec1nens)were2-parous.The area received two rounds of DDT spraylng annually betlreen 1966 and 1969, at 2 g/az Ln each round. [The absence of aged lndivlduals probably reflects the inPact of DDT spraying, but no dissectlons htere made froo an unsprayed area for couparlson]. vBc/90.2 r4AL/90.2 Page 104 In EgypE, Halawani & Shawarby (1957) pointed out that although Kirkpatrick (1925) considered multicolor to be a vector on epideniological grounds, and even though Barber & Rice (1937)-?"--o"na aifficulty in infecting rnulticolor experi.mentally, this species has "o never been shown to act as a natural vector of nalaria in the country. In fact, Barber & Rice (1937) nentioned that although they could infect nulticolor in the laboratory fron gatretocyte carriers of P. falciparun, it was not foundEffiin nature, buE the number dissected Iras very snall (13 specinens). Sinilarly, despite the fact that in recent laboratory experinents in Egypt by El Said & Farid (1982) oulticolor could be infected from P. vivax patients producing very high sporozoi.te rates Isee VOL. I, document vBc/88.5-MAP/88.2, pp.153-1541, no sporozoite-positive specimenscould be found in roulticolor during an investigation by E1 Said et a1. (1986) in one of the villages in Faiyun governorate. At the same time, sporozoile-positive females rrere recorded in Pharoensis and sergentii in the sane village, but the nunbers dissected were nuch larger than in the case of nulticolor (see under 3.11 above). Larvae of trullilele! in Egypt were found to breed in waters having a wide range of sa1inityuPtow/1(see3.2above)anda1soawiderangeofpH,6-l3.The preferential breeding places were found by Gad et al. (1982) to be: seepage waters - the most favourable, followed by bracklsh waLer pools, small water collections, drains and we11s, while rice fields gave the poorest yield (0.O7% of the total larvae collected). Some infornation on the resting and biting behaviour of nulticolor was given by E1 Said et al. (1986) fron their observatlons ln Falyun g.""r"or"t" (see 3.6/3.7 above). The zoophllic tendency of nuLticol.or was shown by precipitln tests run on linited samples collected frorn Slwa and Gara oases as well as Aswan governorate respectlvely by Kenawy et al. (f986 e 1987) (see 2.9 and 3.9 above). On its spatial and seasonal distribution, multicolor was shown by llalawani & Shawarby (1957) that it was found all over Egypt and was nore abundant tn the oases. It appeared to be more prevalent during the colder part of the year, fron October to Aprll, presumably because its favourite breeding places, Ehe seepage lraters, dry up during the warner nonths. In the Red Sea western coast, Gad & Salit (1972) found nulticolor breeding at Qoseir in sroall and noderate sLzed pools exposed to the sun iffiffigetation. rt was also collected frorn Wadi El-Aobag, 8 km west of Qoseir. This wadi ls a depression between mountains, where freguent sprlngs and brackish seepages exlsted in many scattered sites. In their survey of the Red Sea governorat.e, Gad et aI. (1987r) after lntensive search, found only eight larvae of nulticolor at l'larsa AIan and two larvae at Qoseir ln April 1982 and July 1983 respectivel]-f,ilarvae of multicolor were also found breedlng ln cesspits containl.ng high sewage contents, the watilffif,Eh was brackish. The associated species was Cx. piplens [The sarneconditions was observed by Raosdale (1989 - in press)]. In Sinai, all authors who surveyed this area recorded nulticolor in several localities, the last of whon were Margalit & Tahori (1973) ("ee rrndeF2.2 abo.re). These authors recorded nulticolor breeding in waters with very high salinity at En Unn Achned. No breeding FG'cesJor- this species Itere encountered on the eastern side of the Suez Cana1, but its adults were collected by light traps. It was assumed that these adults were probably carried by wind fron breeding places on the lrestern slde of the Suez Canal. In this connection, Kirpatrick (1925) polnted out that Dulticolor can travel for considerable distances aided by wlnd, as he found it in ttre 6s--aesert about 8 miles (12 kn) fron the nearest possible breeding place. In Israel, Saliternik (1974) noted that nulticolg has been suspected as an occasiona1vectoronepidenio1ogica1groundsiffiEr.Itsd1stributionwasmain1y linited to brackish water containlng up to 3.52 salinity. In hotter and drier years the number of its breeding places rose ln consequence. In the recent report of Pener & Kitron (1985b) nulticolor was found breedlng only in flve localltles in northern Israel, representing 0.4% of the breedlng places inspected. Data were not sufficient to depict lts seasonal pattern. With regard to its reaction to insectLcides, the reports of the WHOExpert Co nit,tees on Insecticide Resistance (I.iH0, 1980 - TRS. No. 655 and WHO,1986 - TRS. No. 737)showthat@isresistanttoDDTandd1e1dr1n/HCH1nSaudiArabia1toDDT, malathion, fenitrothion, fenthion, chlorpyrifos, and bromophos in Egypt. No new tests have been reported to WHOduring 1984'f988 on this species fron the Medlterranean Basin or elsewhere. vBc/90.2 t4AL/90.2 Page 105 Subsection (il): EPIDEMIOLOGYAND CONTROLOF MAL.ARIA 1. Epideoiological studieg and control operatlons the status of ualaria eradication and problems associated with inported roalaria in continental Europe have been dealt with in SECTIONI under paragraph 1 (docunent VBC/90.l-llAl/90.1). The present subsection covers principally other countrj.es of the Mediterranean Basin, for which an overview of the malaria situation has also been given in SECTIONI under 2.1. The availabl.e infornation on epidemiological studies and malaria control or eradication operatlons in these countries, as well as information on the most recent nalaria situation as communicated to WHO/flAPiy tne WtlORegional Officesl are sunmarized here. It should be re-enphasized that insecticide field trials wheEher conducted on a village or a larger scale, whi.ch were evaluated only entonologj.cally, i.e., without a corroborating parasitological evidence are omitled fron this review with a few exceptions. . In Turkey, following the nalaria epidenics that broke out in Ehe nid 1970's, attention has been focused on the underlying factors as a basis for inpleroentlng rational renedial measures. Ransdale & Haas (f978) briefly revielred the nalaria situation in Turkey following the establishnent of the nalarla eradication programme in 1957 which becameoperati.onal in 1960, after oany years of nalaria control. As a result of this programme, the incidence of nalaria decreased annually, nalarious areas becaroemore restricted, and the transmisslon of P. falciparun ceased. By 1973, the total number of ma1ariacasesdetectedwas2438,and-TIiffi1yasroallareaintheextremesou!heast of Turkey renalning under the attack phase. With the decline of malaria as a major probleo, and because of denands of other aspects of public health importance, and as resources were limited, the malaria service becaue under continuous pressure to reduce expenditure. On the other hand, there nere signs indicating deterioration of the epideniological situation, for resurgence of nalaria occurred i.n various areas of Turkey under t.he consolidation phase. In 1976, the number of nalaria cases detected increased to 37 32L. The most serlous developneot occurred in Ehe flrst eight months of 1977 when outbreaks of 83 383 cases were detected. This necessltated the reinstlt,ution of attack operations in the large and econonically inportant region consisting of the Chukurova and adjacent plains. Reorgani.zation of the nalarla service in Turkey should be done on ttre basis of the receptivity and vul.nerabillty to reintroduced nalaria, since conditions varied between places. To assist this task, the authors considered the factors interacting in ualarla transmission with special reference to Turkey. - Factors relat.ed to che parasite: Previously P. falciparun occurred in all countries of the Mediterranean Basin, but lts reguirements of reJ.atively high tenperatures for coropleting lts sporogonic cycle linlted its northerly distribution. In concrast, P. vlvax which requires lower teoperature could extend its distribution to northern Europe. Temperatures below which development of the sporogonic cycle is indefiniEely retarded 1ie between 14.50 C and 160 C fo. s!g, and 160 C and 19o C for P. falciparun (citing Macdonald, 1957; lloshtov*ffi0; Pampana, 1.963). Refere-nce was also oade Eo Macdonald (1957) wbo considered that in reglons wigh narked winters, the risk of P. vivax transnlssion remains sllght untll the mean temperature reaches zLo C. With @e'"P,theriskoftransnissionrenainss1ightunti1temPeratures3-4oChigher (i.e., 24-25" C) are reached. Using data provided by the Turkish inleterologlcal Service maps nere consEructed showing the nonths in which mean temperatures of 24o C and 2Oo C are attained. These tenperatures are 10 C lower than the crltical tenperatures, j.n order to allon a uargin of safety in the delinitatlon of high risk areas. In all areas of Turkey, Eemperatures fall during Septenber-October, but because of the existence of already infective nosquitos, malaria transmission could continue even though ternperatures have fallen below the critical levels for sporogonic developmenc. However, areas having longer and hotter sutlmers will be, in general, aore recepEive to reintroduced transmission with either P. vivax or P. falciparuq. With the exceptlon of the Aras valley near the Soviet and lranian borders, areas with tenperatures suitable for che transoission of P. fal.ciparun are restricted to llarmara, Aegean and }lediterranean l1ttoral, as well as the reJ.atively low-lying reglons of southeastern Anatoli-a which occurs at t.he extreme north of the great plain of Syria and lraq. Areas of establishment of P. falciparun in the inlerior part of the country are very linited, bei.ng confined to the large river va11eys, l. This information has'been provlded through the cooperation of l'1r J. Hempel, MAP/EI'IE. wc/90.2 r4AL/90.2 Page 106 principally thaE of the Euphrates. Although occasional iroported cases of P. falciparun were sti11 observed, all indigenous cases of roalaria Ln L977-L978 were P. vivax. Different authors referred to experiments that indicated that Europ.an iio-!ffi.tes are refractory to exotic strains of P. f=l"Lp"*.. 1 However, the authors believed that the apparent inability of P. falcipaffi to re-establish itself in lurkey must be largely due to the relatively short season durlng which conditions are suitable for cornpletion of the sporogonic cycle. On the other hand, transmi.ssion of P. vlvax ls possible over a nuch greater part of Turkey. However, conditions favourable for transmission for more than three months (i.e., where the critical level of temperature is attained before July) occur in a more restricted area. This area includes some of the Black Sea coastal plain and the valleys of some of the larger rivers that penetrate into the plateau, in addition to the areas suitable for P. falciparun transmission. In large tracts of northern and eastern Turkey, summertetrperatures are never sufficiently high to support P. vi.vax transmission. Also, the suulner ls so short in areas where the critical temperature of 20o C is not attained until August, that the parasite would have great difficulty in establishing and rnaintaining itself. The rest of the central plateau, Che eastern highlands and the Black Sea coastal areas, where the critical temperalure is reached in Ju1y, can be regarded as narginal with regard to P. vivax transmission, wit'h malaria outbreaks amenable to renedial measures. In fact, ranyffi? transmission which occurred on the plateau were elininated without difficulty, despite the presence of vector species in abundance and a high incidence of inported cases ln at least one area. In regions with 1ong, hot summers, the tenperature rises rapidly early in the year, mean temperature levels of 20o C and 24o C are often reached at the same time. It ls in these regions that conditions are most suuitable for transmission of P. vlvax and P. falciparum as well. Entonological investigat1onsshowedthattheriskEiffi7_1ariaffi-beforeJu1yaresIightinthe European part of Turkey as well as in other inland villages, and that the peak of the transmission season in these areas would not occur until August or September or even October. It is only ln the Aegean and Medlterranean coastal plains where nild winters and long sunmers prevail that transmission can occur earlier. - Factors related to nosqulto vectors: An. sacharovL ls the iDportant vector in Turkey. Other species of the An. macullpennis conplex, An. superpictus and An. hyrcanus roay play a role in malarla transmission in certain situatlons but none approach sacharovi in vectorial importance. The authors sunmarized the available knowledge on the breeding habitat, spatial and seasonal dlstribution, and restlng and blting behavlour (see above under1forA'.'"@.comp1ex,2fotsuperPictus,and4.lforhyrcanusinTurkey). Theauthors@[email protected]!he size of the parasiEe reservoir, the duration of the sporogonic cycle, and the density and longevity and the degree of contact with nan of the nosquito vector, nost of which are difflcult to estimate in nature. In order to estlmat.e the risks of nalaria transxolssion by sacharovi in Turkey, the authors resorted to theoretical calculations using some estinated entonologlcal paraneters. Since residual house spraying has been applied in Turkey, vecLor density cannot be reliably estlnated fron daytine capture of mosquitoes resting lndoors. Instead, denslty estixoates were based on catches nade by uan-baited and aninal-balted nets operated sioultaneously outdoors. To iron out fluctuati.ons in the relative proportions of the total catch in successive collectlons fron these net traps, the unit of oeasurenent adopted was the density per bait per nlght (i.e., the mean nunber caught in the two nets). None of the Turkish anopheline vectors are predominantly anthropophillc and all feed outside. From tenperature records and sacharovi density estimates obtained fron l(avakll village ln Central Anatolia during 1967, calcul.ations were made to determine the earllest.posstble d4te at which sacharovi can inflict an infective bite as shown here in Table l8a. (Fig. 5a has also been reproduced to show the locatlon of different areas and population moveroent in Turkey as shown below). re;TOffi docurnent vBc/88.5-l'lAP/88.2, under 2.8.2(li), pp. 158-J.60. 2. Table 18 and Fig. 5 have been reproduced by peroission of Mr C.D. Ransdale and the Transactions of t frorn the paper of e more clear (personal comnunication, 1989) . vBc/90,2 r[aL/90.2 Page 107 Table 18. l{odel showing seasonal trend of risk of acquiring An. trans- "."6.rovi- nitted malaria due to P. vivax in the village of Kavakli (1010 n), in Central Anatolia during 1967, ffin-ing that all mosquitos would become infected at the observed bloodroeal, and a daily mosquito nortality of 7O%. Density/night of Date of observed sacharovi Duration of Date of earliest --..- bloodrneal EaKrng PossrbJ.y extrinsic possibly (0bservation infected cycle in infective Infective period ) bloodneall days2 b loodmeal density3 I May 24-26 1. 00 35 June 28-30 0.003 II June IJ-Ib 4.88 26 July 7-10 0.39 III July 4-6 L6.75 25 July 25-27 1.83 IV July 25-28 550.88 10 Aug 11-14 9r.45 V Aug 14-18 L733.75 24 Sept 3-6 210.30 VI Sepr 5-7 981.00 indefinite _ VII Sept 25'27 46.00 VIII 0ct L6-L7 0.25 Calculated as: denslty in man baited trap net plus denslty in anlnal baited traP net, divided by 2 Calculated by the nethod of Oganov-Rayevsky (Oganov, L947), cited by Detlnova, L962, assumlng a Eean tenperature durlng the extrinsic cycle equal to: mean tenPerature during the observation period plus mean temperature during succeeding observation ^ period, dlvided by 2 J Assuming a daily nortality of IO7" during the extrinsic cycle, and that all surviving mosquitos would be infectlve This table rras presented as a nodel for the type of calculation that can be nade for the onset of the transmission season. It was not meant to portray the actual risks of P. vivax transmission, since the area has been free of malaria for at }east 20 years. E6iilrrer, the data show that even nhen the risk of transuissi.on is grossly exaggerated, bI assuming absolute anthropophily of the vector, and a parasite reservoir coxoprising the enlire human populatlon, the probabillty of acquiring an infectlon in July would be slight, and that the rnain transmisslon season could not start until August or reach 1ts peak in Septenber. This represents one month or Dore afEer the tenperature has risen to the crltical level above which transmission of P. vivax could occur. The tenperature again fel1 below the crLtical level in Septenbeffi-the size of the bitlng populatlon had also started to decllne. In thls part of the plateau, anophellsn wlthout malaria has been known for a long tlme even ln the absence of control measures. Nevertheless, transtrission can occur up to, and above this altitude, as ltltnessed Ln L972 when an outbreak of P. vlvax occurred near Bor ln the east, the causes of which are sholtn below. Because of tEffiy short transnisslon season, Dalaria aoutbreaks at thls altitude nere easy to control, even when large veclor densities exLsted. To compare t.he projections made for lGvakli, calcul-ations ldere also made using data of femperature and sacharovl biting densit,les recorded at five villages situated in dlfferent parts of Turkey: l,lavit, Arill (first catchuent area), Kutchuk l(aratash (Chukurova), Balluja (Chukurova), and Golyaka. The seasonal density trends of potentially infective (vlvax) densities of sacharovi in the five villages nere presented graphically. This showed ttrat at l'lavit, where sacharovi was abundant in 1968, and at Arili' where lower densitles lrere recorded ln 1970, the probabitlty of receiving an infecti.ve bite before July was remote, and that the peak of the transmission season would have occurred in Septeqber. The critical level of temperature for transoisslon of P. vivax (20o C) was reached in July ln the parts of southeastern Anatolia where these villages are located. In the coastal plaln villages of Golyaka, Kutchuk l(aratash and Balluja, Ehe critical temperature for P. vlvax transmission was reached in May, thus the apPearance of vBc/90.2 MAL/90.2 Page 108 potentially infective vectors began earller, and by June when the critlcal teEperature for i. f.l"j.p"i,tr transuisslon rras attained, the potentially lnfective rnosquitos were already and southeastern tffitffiinstead of continuing to rise to an autumn peak as in central Anatolia, densities of sacharovi in all three villages declined, and by August and Septenber, potentially ir,f""tfve mosquitos became rare. The considerable reduction in nosquito densities during the sunnnerresulted frou crop sPraying, in the absence of which potenEially infectlve sacharovl density would have increased to a late sullmer or autumn peak. - Factors related to the humanhost: (a) Aspects of human ecology influencing man-vector conEact.' In Turkey, cattle and other donestlc aninals are abundant in every village and this substantially reduced man-vector contact. During the summerseason cattle are stalled outside, between houses, naking then readily available to mosquitos. Several examples ltere given to illustrate the degree of man-vector contact under varied conditlons in Turkey. On the plateau, inhabitants in villages sleep indoors Ehroughout lhe year, often on uPPer storles' the ground floors belng reserved for cattle and storage. Under t.hese conditionsr residual house spraylng reduced man-vector contact, as mosqultos that can succeed in penetrating the aninal barrier and enter sleeplng rooms, becone irritated or killed by the insecticidal deposits. In the hotter parts of Turkey, people sleep out of doors during the surnrner. Residual house spraying ls not as effective in these areas as it. is in the plateau. Both hunan and anlmal hosts are found out of doors, and the vector populatlons also exhiblt narked exophlly. Nearly all these villagers sleep under nosguito nets. Although t.hese nets are sometlmes in bad condition or ioproperly tucked 1n, they provide a certain degree of protection agalnst nosqulto bltes. However, all the human populatlon spends the evenings out of doors eating, drlnklng or talklng, thus becoming exposed to nosquito attacks. An. sacharovi was able to rnaintain malaria transnisslon in villages' desplte the presencJof cattle and ln the face of deflclent spraylng coverage. However, treatgent of paraslte carriers together with resldual house spraylng had an irnrnediate effect on transDisston. This was observed durlng the attack phase oPerations in southeastern Anatolla between 1967 and 1970, and occurred equally in areas under HCH, dleldrin or DDT spraylng. In southeast Anatolia, there ls a vast rugged area lying on both banks of the Dicle (Tlgris) rlver. This area consists of dry rocky plateaux broken by hills and deep ravlnes through which streams flon. Where there 1s sufflcient soils, rlce fields are established on both banks, producing enoroous nunbers of vector populations includlng sacharovi which 1s restrlcted in lts distributlon. An. superpictus, though occurring ln nany places fron which sacharovi is absent, is also restri.ctea to the proxlnlty of the streams. On the dry ptatea.rnffitheastern Anatolia, wheat and barley are grown. As the nills for grindlng these crops are drlven by lrater polder, they are sltuated near streams and are usually in rice cultivated areas. Because the distance involved nay be considerable, farmers take their fanilies wlth then and camp outside the roill, awaitlng their turn to grind the croPs.Dur1ngthisperiod,theycomeinclosecontact'[email protected] the risk of transnlsslon is at lts peak. Close contact with the vectors also occurs in the hotter regions of Turkey during the autumn when cotlon and rice are harvested. Another area of epldeulological lmportance is the lower Merltch val1ey which is a centre of extensive rice cultlvatlon. The Meritch rlver fonns the border between Turkey and Greece, but its flood plain lles within Turkey. Although no rice ls cultivated ln this part of Greece, both Greek and Turkish villages overlook large areas of ri'ce cultivation. Cattle and other donestic animals are abundant ln all these vi11ages. people engaged in the maintenance of the lrrigaElon canals and punps live throughout the sutrmer in pernanent and sernl-permanent houses ln the valley, but large numbers of temporary workers camp on the edge of the rice fields during harvest. Most vlllagers (roen, women and children) relurn to their houses to sleep, but during the harvest they reach the fields at. darrrl and return only at dusk. An. sacharovi is much more nurDerous in places on the va11ey than ln vlllages, and is active at daltn and dusk, as well as in shady the edge lt tn. fields by the lnhabitants for a nid-day resE. Entornological "[os"tt investigations revealed that most', lf not all, of the malaria transmission in this area in occurred in the fields. During four years of a malaria outbreak that occurred the l{eritch valley, only one case was found in the Greek border villages. The only difference between the two sidis of the frontier nas that the vitlagers on the Greek side spent every vBc/ 90. 2 r4AL/90.2 Page 109 night in Eheir villages, whlle those on the Turkish slde worked and ofcen slept in the val.ley, particularly during the harvest. During the past 20 years, vast agricultural developnent occurred in Turkey. In the larger coastal plains, and also in some other areas, marshy or wasEe land has been drained and reclained or inproved. In these areas, the ecologleal conditlons have been coropletely changed wiE.hnater being available through the construction of dams or exploitation of sub-surface water supplies. Traditional farning has been replaced by cultivation of single cash crops, especially cotton or rlce. In the Chukurova plain which rePresents the largest of these areas, the resident rural population has reached about 0.5 nillion people Iin 1978]. Nevertheless, the demandfor agricultural labour cannot be met locally. For thi.s reason, there i.s an lnflux of abouc 750 000 seasonal labourers coming trostly fron southeastern Anatolia. These labourers sleep in the open outsj.de vi.llages where no domeslic animals exis!, thus they come in close contact with sacharovi and hyrcanus which are abundantly present in the pJ.ain. Although the absence of animals is an important factor contributing to conditions favourable to malaria cransmission, malarla actually occurred atrongst herdsmen sleeping in the open. As roentioned above, an outbreak occurred in the upland plaln of Bor, in Central Anatolia, ia I972. lnvestigations showed that all cases were atrong herdsmen and cheir faniLies who sleep outside vlllages. Each night, cattle belonging to several fanilies are dri.ven into enclosures distrlbuted throughout this narshy plain. Around these enclosures, fanily groups sleep ln flinsy, temporary, open shelters. Mosquitos, Predonlnantly @,attractedbytheanima]'shavetoflythroughtheringofherdsmen,andfeed sufficiently on nan to naintain malaria transmisslon. Another factor that contributed to the development of this outbreak was the Eovenent of menbers of fanily groups of herdsnen to the nalarious plain of Chukurova, seeking work in cotton fields. Thls ensured a high rate of iomportation of cases into the Bor area. Because of the short duration and the relatively cool conditlons in the surmer season ln the upland plain of Bor (1250 n), the outbreak was brought under control and curtailed wlthout difficulty. (b) Aspects of hunan ecology influencing the dlssenination of the parasite reservoir: As the human host is the principal vehlcle for dissenination of the parasite, a detailed knowledge of populatlon movement is iuportant for the planning and organization of the malaria programme. Population Dovement ln Turkey takes many forms. There is a contj.nuous flow of peopJ.e fron the countryside to larger urban centres, prlncipally Istanbul and Ankara. Thls movement is well documented, but is not of great imporEance in the spread of ualaria. On the other hand, traditional ooveoent by nonads following seasonal grazing, or by semi-nomads taking their flocks to upland pasture areas for the summer, have been the means by which the nalaria parasite nas carried fron the low-lylng areas of the coast or southeaslern Anatolia to the central plateau and eastern hignlands. These xoovementsare less well docuoented. The authors gave soDe examples of population movenents in relation Eo ehe dissenination of the rnalaria parasite, in the hoPe that this sould forrn the basis for more detailed sEudies of this aspect of epideniology. A map was presenE.edto lllustrate the directions of different population movernentsas shown here in Fig. 5. vBc/90.2 MAL/90.2 Page 110 ';; i----.::-:,i'-'o l i^'-.^-=' ,,\A l\li i 6tn '\i otr a 6 ,.' i i'r OE.A}4 .l +J Oq C) "".Y.'i"f:, O ..{O O i fal" O AA Fl .n JIO 9r tL I .9';q o r!> tr +Jo i""/ ,ff''d g{ Od E \. qt o+J 'i I- c q.{.... q,} lz. o oo ..1 t{ 0) +J Uto o Y (d +Jx +r e 5t 5 t{ E9 F ru it lr(l)o tJ F : .d >Fl IE Otd O ! E}{ E r'l t ! +J, q, o. F'".-. (,€ 6! q, I r+1 > o OF{ n-^ tr> EJ l.o & > u o $C') l.l & !tg t^d o o. Ei tq z Ot. l.l:.: (/:r! 7^z d o F> lr@ Q- of U frl O.r{ trB FT z 4 .F{ o u il E1 ord & oh F] uiO Jd b0 lr H .dF H I .AE ca o l H tn I E h0 I t ]r ol J* *ta\ ?1 4. H & 6,q !,o ..s-- !$geg lt{ r.. (P, "b vBc/90.2 t4}I/90.2 Page 111 In Van provlnce at a minimun altltude of L725 m, the sunDer season is short and grazing in winter is poor because of the extreme cold and heavy snow. Therefore, people starting from August move with their herds down to the valleys to spend Ehe winter on lower ground near the borders of Syria and Iraq, and they return ln the spring. They pass through rice growlng areas of souEheastern Anatolia 1n Septenber, often canping on the edge of rice fields. Untll recently thls 1ow lying region was lntensely nalarious. Many nalaria cases detected in the east and southeast lake Van contracted the infection in this region. In the Van lake area, sacharovl is absent and clinatic conditions are narginally suitable for roalaria transmisslon. Traditional seasonal populatlon novenents occur in all Parts of southern and southeastern Turkey. Many fanilies om land on the plain and also in the hlll-s, so that some nembers renaj"n on the plain to cultivate the 1and, while others accomPany the aninals in the hi11s. During the sunrmerthere is nuch interchange betlteen the people on the plain and those in the upland pastures. This movementensures the dlssenlnation of the nalaria parasite. As nentioned above, fanilies accompanying thelr herds often spend the summers in tents canping near water, and in such situatioas sgPigtus was able to maintain ualarj,a transnission ln southnestern Turkey ln areas where sacharovi is absent. Other types of movement of the populatlon ln Turkey include gypsies' itlnerant workers engaged in constructlon, logging and sinilar projects, and camping tourists. These types have been lncreasing, bringlng closer contact between people and the vectorst thus providing anple chances for wide dispersal of the parasite. However, Ehe most iuportant type of Doveuent of the population ls the seasonal nlgratlon of agrlcultural workers to the large irrlgatlon projects. The reasons for the deterioration of the malaria situatton in Chukurova and Hatay plalns could be traced to the malarious areas of mlgrant labourers in southeast Anatolia and particularly Adiyanan zone, which ltas the site of an lnportant nalaria outbreak durlng L968-L972. As the movement of these labourers is ln two directions, they are now lnportlng malaria parasites frou Chukurova and llatay plains to their places of orlgin. Consequently, ualaria has again becone a problen in parts of southeastern Anatolia. In recent years, there has been a tendency amongst, iunigrants in the Chukurova plain to settle on t.he outsklrts of the towns and cities in sub-standard structures constructed on undralned sites where excavations create ideal vector b reedlng sltes. There is a continuous lnterchange of the human population betlteen these outskirts, the cotton fields of Chukurova and che areas of origi.n of the imlgrants, and consequently malaria has becoue a serlous urban problen ln thls area. The irrigation projects of the Cbukurova plains are exaoples of several other projects in the Mediterranean, Aegean and Marnara coastal plains and also in some inland areas, where cotton and rlce are being cultivated. Hence, the demand for seasonal labourers is continuously increasing. plore detailed lnfornation on the Chukurova project is shown under (li), 2 below]. Seasonal workers fron southeastern Anatolia are already being attracted Eo the coastal plaln of'Antalya. This tendency will increase annually, and will soon tnclude other areas of southwestern and western Turkey as shown in Fig. 5, thus facilitating the dissenination of the oalaria paraslte to neur receptive areas. Malaria transoission ln Turkey has been a matter of concern to nelghbouting countries and also Co other uore distantly sltuated countries baving close contact ltith Turkey, because of fear of itrportatlon of nalaria with increased travel. To conclude, the authors underllned that the resurgence of nalaria in recent years in southern and southeastern lurkey has created a new epideniological situatLon ln the country. The nain aims should be the contalnment of the lncreaslngly seri.ous problems, and to prevent the spread of roalarla transmissLon to other receptive areas. onl.y after this is achleved will it be posslble to thlnk again of rnalaria eradication. l,lidespread vector resistance to organochlorlne insecticides (citlng Ramsdale, I975)' but this did not create an j.nsurmountable problen to the progress of the malarla eradication Progratnmet although it necessltated the use of more expenslve and toxic conpounds. On the other hand, incipient resistance to OP and carbauaEe insecticides ln southern Turkey has been a matter of nuch concern, calling for more urgent tasks to contain the nalaria situation before the developnent of a high degree of resistance co these lnsecticldes that would preclude their future use. This reslstance resulted fron the appllcation of agricultural pestlcldes, (clting Ramsdale, L975), and lts further evolution will continue irrespective of antioalaria measures. [In fact, the presence of OP and carbamate resistance in sacharovl in Turkey has been clearly demonstrated in recent years by Raosdaler Herath_& - DavfiIson (1980) ani Herningwayet a1. (f985) - see VOL. I: document VBC/88.5 MAP/88.2' under 2.6.2, pp. 94-98.1 vBc/ 90.2 t4N./ 90.2 Page 112 The authors further pointed out that although the situation of insecticide resistance has been causing nuch concern, the deterioration in the epideniological situation in Turkey must be attributed nai.nly to operati.onal defici.encies arising from adninistrative and fi,nanclal constraints. Cont.ainnent and reduclion of malaria outbreaks will involve increased expenditure, but thls would also be expected in other countries hrith endenic malaria. In this connection, it should be remenbered that the concept of total coverage spraying has been changed to the principle of selective operations according to malariogenic potential and changing conditions. The main target would be the application of renedial ueasures with a minimum of de1ay, and this would go a long way to provi.de more effective operatlons at a mlnimal cost. They reiterated that the reorganization of the malaria service of Turkey was outside the scope of their present paper, but the discussion of the facEors lnfluencing nalaria transmission would provlde the basis for such reformation. As has been shown above, the length of the transmission season is a key factor in the epideroiology of malaria. This is lini.ted by the temperature requirenenls for the developnent of che sporogonic cycle, and vector behaviour. In nost of Turkey, the risk of contractlng nalaria is slight, and the curtailnent of outbreaks is not difficult. When the transnission season is linited, the re-establlshruent of malarla transmission from snaLl origins becomes urore difficult. Hunan ecology has been found to be an i-nportant factor influencing nalaria transnission, involving closer Dan-veclor contact in the hotter Parts of Turkey. It has also been shown thac t,he danger of the spread of nalaria to new areas depeads on population rooveroent.s. The extent of this movement and of the nalaria situation ls continuously changing wlth econonic developnent occurring in different parEs of- the country. Data on population moverDentin Turkey are not coroplete, and the whole sub3ect of human nlgration awaits profound and continuous study. - The WHo (f978 Wkly Epiden. Rec.) surnmarized the ualaria situation in Turkey and the factors that contriuutEa to ttre aerreropment of outbreaks as follows: Malaria almost disappeared in 1968, when only 37 iuported P. vivax lnfections were rePorted. The nalarla incidence, however, started to bulld until "p-gainlradually alarning epidenic proportions nere reached i.n 1976 and, L977 when 28 849 and LOL 742 cases were detected respectively. The provinces affected were: Adana, Igel (Chukurova) and ll,atay (Arnikova) south of Taurus range on the Eastern l"tedlterranean coast wiEh a total population of about three uillion. These areas have been under agricultural expansion during the last two decades, followlng the construction of dans and large irrj-gatlon syscems. The factors that led to this situation include.. - Increased receptivity due to the extensi.on of the irrigation system which favoured the proliferation of breeding places for sacharovi. created by waste waters in drains, r1ce flelds and marshes. - Re-establishoent of oalaria transmission in a few urban centres where rapid and uncontrolled expanslon favoured the creation of new breeding places. - The Presence of parasite carri.ers anong 500-700 thousand labourers who move into Chukurova/Anikova every year froo southeast Anatolla at the beginning and during the transmission season. - Indiscriminate use of pesticides, applied by alr on cotlon fields leading to the evolutl'on of resistance to DDT, dieldrin, fenthlon, bronophos, fenitrothion .rrd propo*rrr. - Inadequate surveillance coverage during L97I-L975 in the highly receptive and vulnerable areas of Chukurova/Amikova. Since L977 every effort has been uade to reorganize and strengthen the national antinalaria servi.ce. Tt L977, and especiatly in 1978 when the assistance of the international co"nnunity and of varlous Unlted Nations Agencies became available, an emergency plan to control the epidenic was loplemented. Diversified control measures have been applied in an attemPt to curtail transmisslon and prevent the spread of oalarla into nearby receptive areas and neighbouring countries. vBc/90.2 r4AL/90.2 Page 113 Following the reorganizatlon of the antinalaria prograilne of Turkey in L971, a large scale control canpalgn was initlated ln 1978. onori & Grab (1930) out a study to deteruine quantitatively "".il.d how the nalaria epidemic night have evolved if contror neasures had not been applied. The antinalaria r""i,r.." ioplfnented in 1978 in the chukurova and Amikova plains were shown to be as follows: (a) all oalaria eases dlscovered in 1977 were treated for a second time in early 1978; (b) nalathion house spraylng (2 g of rechnical nalathion/r2; r." applied twi.ce: the first round during 15-Apri1-15 May, and the second during 15 July-15 Augusr; (c) l.arviciding operations in and around urban centres started in llarch and continuedr but with an interruption of 3-4 weeks during the period of higher gransmission until october. Fuel oil which was used in March-April was rlplaced by tenephos from June onwards; (d) the larvlvorous fish, Ganbusia affinis nas wldely distributed in al1 irrigated areas throughout the year; (e) nass drug distrlbutlon was inplenented ln the most receptlve areas fron May to october, but always with low population coverage and inadequate supervislon; (f) increased routlne surveillance acEiviLles were contlnued throughout the year. Failures occurred ln the course of inplenentlng the varlous field actlvlties. These were due to the very short tlne available for the reorganizatlon of the antipalaria services and to serious loglstlc difflculties. However, the results achieved durlng 1978 clearly indicated that the epidenlc was contained. onorl & Grab (loc.clt.) used a rnathernatlcal nodel sinilar to that of Muench (1959) to project the epldeniological sltuatlon that would have prevalled under natural condltl.ons fron 1978 to 1980. The following slnplifled assurptlons lrere adopted: (a) The forecast ltas developed on the basis of the number of blood slides found posltive for nalarla parasLtes Donthly from January L976 to Decenber 1978, assuning that the nunber of posltive slldes reliably reflected tire nonthly nalaria incldence. It was further assuned that the slide positlvlty rate nas sufficlently low during the off-season, and not excessively high during the transmi.sslon season, thus providing an indirect assurance that the slides exami.ned Itere properly selected and adequate in number. (b) It was assuned that the seasonal dynanics of vector populations remained unchanged fron year to year. (c) Although the evolution of an epldenic situatlon is characteri.zed by a high rate of increase in the annual nunber of cases, it was assuned that Ehls rate decreases slightly with tioe due to developnent of iornunlty ln the hunan population, and probably also because a certaln fraction of the populatlon was not actualJ.y exposed to the risk of infectlon. (d) To facllitate computation, Lt vas further assuned that the population of chukurova and Arnikova plains nas constant and equal to 3 nillion, a irln."- which rras an approxination of actual population esti.Dates for the years rg76-Lg7g. The technique used conslsted essentially of projectlng the trend and determinlng the upper 1lnit of: - the seasonal minlmum nonthry number of cases (in - January)r. the seasonal maximumnonthly number of cases (July/Augusii. For interested readers, the mathematical expressi.ons used for the projection of the mlninuu and maximumnonthly incldence should be read ln the original p.per. The observed parasite nonthly lncidence recorded in 1976-1978, and the projected i;cidence for vBc/90.2 r4AL/90.2 Page LI4 1978-1980 were graphically Presented as shown here in Flg. 61, and the observed and paraslte lncidence lt:j""!:g for the period 1976-1980 lrere rabulared as shown in Table 194' As shown in Fig. 6, the lnpact of the lntervention measures applied i.n 197g Decameperceptible in June. The peak shown in May was explalned by the occurrence of some early transnlsslon that was not controlled by the flrst round of malathlon spraying. Transnission decreased narkedly durlng the slnner months when it should have been at its peak' The benefits from the 1978 intervention were indlrectly quantified by estirnating the number of nalaria cases that would have occurred rn Chukurova and Anlkova plains if renedial measures had not been lnplemented. rn their discussion, the authors enphasized that the evolution of the epidemlc that occurred in this area of southern-i;;"-t;;j;";;i-b;- Turkey in 1976 atd L977 could have been studied and the sltuation in 1978 coutd il;; the use of the baslc reproduction rate of l'lacdonaLd.(L957), if all the variables involved in the transmission dynanics had been estinated. This could not be done because data on nosquito density ln relatlon to nan, lts seasonal variation, vector longevlty and degree of anthropophily ltere not avallable for the period under revi.ew. Thereiore, resort ;as nade to an adaPtation of the catalaytic nodel developed by Muench (1957). io .ppreclate the Potential develoPnen! of an epideulc, as estimat.a Uy thls forecasting approach, the observed and projected annual paraslte lncidences shown in Table 23 should ue- conpaiea. The observed paraslte incidence was Bore than three tiues higher in 1977 ttran in i976. A further increase of 2.L tines was foreseen for Lg78, If interventlon measures had not been^applied; the projected paraslte lncidence/J.000 population would have then reached 100'9 in 1979 and 115.1 ln 1980. tthen the number of nalaria cases actuarly detected in L978 (70 468) was conPared wlth that projected in the absence of inrervenrion (226 252), it couLd be deduced that about 2/3 ot the expected cases were prevented in l97g by the appllcation of the renedial Eeasures. Although the preclsion of Ehis estinate is not knorm, the reductlon of ualarla transnlssion observed ln the Chukurova and Amlkova plalns is indisputable. Flnally the authors underlined that cautlon should be exerclsed when atteDPting to aPPly this enpirical approach to other sltuatlons. Accurate and precise forecastinS ls, however, a Pre-requlslte for the evaluatlon of the funpact of publlc activitlesr health Particularly the cornnunlcable dlseases progranriles. Therefore, sound, valid and reliable forecasting nethods are needed. A report of an evaluatlon neetlng held ln rstanbur during November Lg7g2 recalled that ln a previous Deetlng ln copenhagen ln Noveuber 1978, the nalarla prograrme in Turkey in L977 was revlewed and the country rras dlvlded into four epideulological strata according to the level of nalariogenic potentlal. Accordlngly, the folrowl.ng defined: strata rrere - stratun I covers provlnces the of Adana, Igel and Hatay. stratutr ra whlch had 101 867 cases in L977 rePresented the nucleus of the mararia epldenic, and stratun rb covered the whole of southeast Anatolia where localized outbreaks also occurred in 1977 (11 131 cases). - Straturn Ir considered to be at high nalarla risk, included the whole nestern part of Turkey prus the province of Nllde, ttevg-nir and Kayserl in the central part of the country. - stratun IIr covered rnalnly the hlgh plateau of the central Anatolia. The nalaria risk was considered to be low, but nlnute focl were recorded in a few localitles in Lg77. - Stratun IV included the northeastern part of Turkey and the provinces of Zonguldak, Kastamonu and slnop on the Black sea coast. The oalaria risk was considered 1ow. to be very Accordlng to the most recent infornatign recelved fron Turkey, these epideniological strata have been napped as shown in Flg. 73. 1--epFo"Cafby pernlssion of Dr E. onori fron rhe paper of onorl & Grab (r9go) in the z' AIIEloaJ'aria Progranme-in-Turkey. Report on an Evaluatlon Dleeting, Istanbul, 6-8 Novenberr979. unpubllsheddoiuueni wno/iun6-,-iuilupoooz. 3. Redrawn by Mr J. Henpel, liAp/EME, WHO,Geneva. vBc/90.2 t{AL/90.2 Page 115 Fig. 6. Monthly incidence of nalaria-posi tive slides observed Lt I976-78 and incidence projected for 1978-80, Cukurova and Aolkova plains, Turkey. -o-Obrdad incidGE | 000000r --o-- Proilctrd incid?G (in tI th! rbem ol intcryGntbnl i t 0.8 | 00000 l- o E 0.7 o 0.5 o 0.5 ; I I 0.4 M.in intanutbn fi|.E'G z 24 6 8 l0 f2 lil 16 t8 20 22 24 26 2E 30 32 34 36 38 4{l 42 tl4 '[6 '18 50 52 54 56 58 60 62 1976 1977 1978 1979 1980 ycsr and month (t) [email protected] Table 19. Observed and projected annual parasite incidence in $ukurova and Amikova plains, Turkey, 1976-1980. Rotio of successive Annuol porasiteincidence voluestor onnuol Year per 1000 parosite incidencea Obsened Proiected t976 ll.l . 1977 35.9 . 3.23 I 97E 24.5 75.4 2.t0 1979 . 100.9 1.34 r980 . I l5.l t'.'o Upper limit r29.4 r.00 o ln the absenceof intervenlion. vBc/90.2 MAL/90.2 Page116 lrt* lo lo l*. l,t l.\ @ oh x lr ts ru u tr ! a H H -1 H H (! o =E E oo +) +) t{ k +) E J' q o :ii:::::.ii tl o iit*i; tl frl ri:riii. ti @ fi fi9H HHH EEE +) +) +) (6(6d kt{l< +) .J +) NSi** vBc/90.2 t4AL/90.2 Page 117 From a report of a roeeting held in Ankara during February 19851, the nalaria sltuation 1n lurkey and future plans were discussed. The report shows that with the collaboration of WHO,a new plan of action was prepared ln L977 ar.d the concept of malaria control was accepted as the new strategy. Following the inplenentati.on of various conErol activities, the number of nalarla cases dropped to 29 000 in 1980. However, due to various constraints and problens, there rJas a gradual increase in the number of cases which reached 66 000 in 1983. With sustained efforts, the number of cases decreased co 55 000 by the end of 1984. The report also shows that the Turkish Government has set the objective of nalaria control as "interruption of nalaria transnission Ln the country by 1989". As Turkey is one of the countries that expressed the will and delermination to adopt and inplernent the social Earget of "Health for A11 by the Year 2000", the Turkish Government has adopted the PHCprinciple as the rnain strategy to reach this target, and has declared that malaria is one of the priority public health problens. This decision has led to the reorganlzation of PHCstructure and services at central and peripheral levels, together wlth Ehe integration of the Malaria Control Servlces into the PHCServlces. This has created the need for reconsideration and replanning of ongoing Balarla control activities. The scoPe and aims of the neeting were shown as follows: - "Revision and evaluatlon of the present nalaria situatlon and antimalaria measures in 1984 in each nalaria stratum of the country. - Evaluation of the actual functionlng of the new PIIC/MALintegrated approach and future aspects. - Assessment of the constraints and urgent needs in physical and human resources for reaching the ultlnate objective and adjustnent of such a plan of action to resources available by selectlng prioriEy actlons in prlority areas of lntervenEion. - Deteruinatlon of strategy for 1986 and the needs required to lnplement it." The two najor itens discussed in the neeting were: Evaluation of 1984 actlvlties and ldentiflcatlon of constraints: (1) Antlvectorlal Eeasures: a. Residual house spraytng constltuted the Eain antivectorial activities. With Ehe exception of che Adana region, Ehe spraying operaEions were not perforued as planned. In Stratun Ia in particular, plrirniphosrethyl replaced malathion, though costlng 2-3 tines more, because of the conmunity reslstance to nalaEhion spraying, and the additional advantage of alrborne toxicity of piriniphos-nethy1. However, the spraying coverage s/as almost the same. In oost places, the application of the correct dosage and designed spraying rounds was not achieved due rnainly to the shortage of trained and notivated personnel, inadequate amount of insectlcides and transport difficulties. Comnunity resistance to house spraylng, in general, contributed to the ineffectlveness and coverage of insect.icide applicatiou. b. Sone winter fogging and space spraying were carrled out on a focal basis. c. Bacillus thuringiensis H-14 and larvi.vorous fish (nainly Ganbusia affinis) were tried aJ biologtcal control measures. LL proved to be extremely effective provided that repeated applications are nade, but this would entail a financial burden including the high cost of the original fornulation. Production of B.t. locally will be difficult to achleve. Horlzontal vegetation reduced the effectiveness of G. affinis which is bred and widely dlstributed ln Chukurova. Further attempts roay be rnade involving the concomittant use of herblvorous fish, wlth the cooperaEj.on of t.he General Directorate of Fishery Products. ffiEva1uationofl{a1ar1aContro1Activ1tiesinTurkey.ReportonaJo1nt "[Ii.nistry of Health and Social Assistance - I.IHO"Meeting, Ankara, L8-22 aFebruary 1985. Unpublished document WHO/EURO. vBc/90.2 t{AL/90.2 Page 118 d. Larvlcidi,ng neasures nere carried out by the nalarta personnel, and in some instances by the nunicipality staff in urban areas of Chukurova and in special situations in other strata. (2) Measures against the nal.aria parasites.' Surveillance activitles were nainly based on acEive case detection (ACD). When conpared with 1983 activities, it was realized that while the nunber of slldes collected in 1984 by ACD remained alnost the sane, the number collected by passive case detection (PCD) decreased, and by activated passive case detection (APCD) increased. While nore slides were collected in Stratun IV and less in Slratum I, there was a decrease in t.he toEal number of slides collected and slide positivity rate of APCD. Although less slides and less accuracy in identification were observed in 1984, health centres personnel showed progress in surveilLance activities. Malaria treatment has been carried out as follows: - Radical treatoen! (3 days chloroquine.' Eotal 1500 qg a L4 days prinaquine , 15 mg/day). - Mass radical trealnent (same as above)' - winter radical treatmen! (14 days prinaquine' 15 ng/day). Singls dose prophylactic treatment (600 ng chloroquine * 50 ng pyrinethanine/single dose). It is believed that radlcal treatnent has not been properly carried out, because of frequent interruptlon of therapy due to its long duration and has resulted in relapses. Prophylactic treatment could not reach the entire target population, and it was difficult to follow-up due to population novement. The problen of G6PDdeflciency in Turkey has always been a najor source of rlsk and entailed hesitatlon in glving radical treatment. (3) PHC/MALinregrated approach: There have been Eany constralnts relatlvely specific to antinalari.a activities, and sone others that have been counon to PHC servlces ln Turkey as sholrn in the following; a. Shortage of man-power (e.g., malarla workers) has decreased to a grea! extent the effectiveness of 1984 actlvities. Although 2700 new workers lrere recruited in 1984, the delay in thelr appointnent, thelr training and dlstsrlbution to health centres, as well as the lack of experlence of health centres to carry out specific antinalaria activities, have created problens. b. Inadequacy of the anount of insectici.des purchased for 1984 operations and the oan-power to apply the available quantltles have been the main reason that contributed to lnadequate dosages, rounds and spraying coverage. c. Integration of the services that began in 1984 has created a certain degree of confusion at field and central levels. The integration of an entirely verti.cal progranme into a horizontal one, rrhich by itself is in the phase of development, has certainly been a dlfficult but a fundamental step. There will be a mutual adaptation of the nalaria and PHCstaff in the way of their tralning, inplenentation and supervision of Lntegrated activities. d. Lack of proper training has been one of the nost inportant issues not only for the ant.inalaria activi.ties but also for PHCservices. Regular training on malaria has been carried out for nedical officers, laboratory technicians and personnel directly involved in specific antlmalaria activiEies. e. Transport has been the comon problen for al1 PHCservlces. Most of the health cenEres do not have adequate transport facilities (vehicles, gasollne, or drivers) which reflected on their performance of antimalaria activitles, resulEing ln delays in cransportatlon of slides, feedback and supervision. vBc/90.2 r4AL/90.2 Page 119 f. Evaluatlon has not been carried out sufficiently. This has been nalnly due to the lack of adequate and relevant epiderniological knowledge and shortage of qualified staff. Evaluation fron a central level of all field activlties in the slightest detailr resulted in loss of tine and efforts and caused inaccuracies i.n the evaluati.on. g. Inadequacy of community participatlon and intersectoral cooperation has been a najor constrain!, creating adverse lnpacts in particular on source reduction activities. Inlersectoral cooperation has been started a long tine ago and resulted in effective nodlfications such as the construction of a dam dike by the State Hydraulic Works (DSI) but needs further lmprovenent and sfrengthening. The sane applies to comnunity participat.ion whlch is expected to benefit fron massive and intensive health education planned to take place in forthconing years. h. Supervision of nalarla activities was done by both PHCand malaria personnel which 1ed to the problens of duplicatlon at the beginning of integration. i. Population movement as characterized by the seasonal movement of rnigrant workers in malari.ous areas, created a huge nobile reservoir of lnfectlve cases. Because they are not residents, migrant workers are not registered, followed up or controlled by health centres, even though they llve in the same catchment area. j. Lack of research faclllties ruay lead to the risk of lnabllity to follow the trends of the impact of control neasures on the parasite and the vector. Connents and proposals for 1985 plan of action.' It was sErongly erophasized thaE considerlng the deslgned strategies versus the actual flnancial allocatlons, whlch deternlned the amount of lnsectlcide avaLlable (402 of the amount required), it w111 be rather difflcult, if not lnposslble, to reach the Earget of "Interruption of malaria transnission ln Turkey by 1989". Therefore, attention was drawn to the urgent need for lncreaslng the budgetary allocatlons for PHC activities incJ.uding malaria control. Even lf thls requlrement is met, the strategies should be changed, priorities should be set for progranme actlvities and areas wlth the redistribution of resources, based on analysls of rlsks, bearlng in nlnd that the progranrne is meant to be a control programne and not an eradicatlon caupalgn. This should be done to achieve the target. The change which nay lnvolve soae rlsks, ca1ls for an urgent political co-.itment. Health services ln Turkey are passlng through a transitional period: vertical services are inevitably being integrated into a horizontal systen whlch is in the process of developnent. Apart fron prlorities to be given to actlvitles and increase in financial allocaclons, training appears to be the activlty of highest priority to achieve this integration and reach the target,s. Cornrnentsand proposals for orientation of actlvities in 1985 were shown as follows: (1) Antivectorlal oeasures: Residual house spraylng remains one of the nost effectlve antlvectorial neasures if done properly. The quantlEles of tnsectlcides purchased for 1985 is not sufficient (240 tons), bearing in nind that the amount requlred for Strafum Ia alone is about 640 tons, and this calls for an urgent need for providing addltlonal quantities of the insecticldes. The expenses incurred oay be provided by seeking suppleroentary resources, natlonal or lnternational. Care should be given to allevl.ate the conplications of bureaucratic procedures that nay delay the purchase of additional lnsecticide stocks. The anount of insecticldes consumed ln 1984 also lrould guide the manpower requirexlents. About 3 500 spraynen are needed to conpLete the spraylng rounds, while there are 2 700 workers for all malarla actlvlties, most of whomrequire tralning or retraining. The dosage applied is also very important. If the dose of 2 g/az is not achieved, spraying can hardly be justified considering all the expendlture and efforts Put into it. Addltlonally, shortenlng the tlne of spraylng rounds ls strongly reconnended. Pirlniphos-nethyl offers certaln advantages over maLathion, but a specific study is reconnended to evaluate its effectlveness in certain areas, then it can be expanded to other areas watching for lndications of fallure. Partial spraying of houses and total spraylng of stores and stables would be an effectlve strategy of applicatlon. Malathlon may be used in areas where it is accePted and has proved to be effective. vBc/90.2 t4,^L/90.2 Page 120 Space spraylng, winter fogging and ULV application uay be discontinued. Also, biological control nethods rnay be dropped unless the probleos menEioned under (1)c are solved. Self-help oeausres such as the use of bed-nets inpregnated with insecticides rDay be effective provided that the community is uotlvated to use such slnple devices. Larviciding should be carried out in urban and peri-urban areas with the direct involvement of nunicipalities, other related sectors and comnunltles under the guidance of health personnel. Direct lnvolvement of malarla and other health personnel i'n source reduction activities should be avoided. As in larvicidtng, a rnultlsectoral approach should be observed in source reduction activities, witb the chief efforts belng nade by the nunicipalitles, other sectors such as DSI and cornmunity particiPatlon, under the guidance of health personnel. This would seem t'o be the most appropriate and effective strategies. (2) Measures agai.nst the nalaria parasltes: Every effort should be nade to provide facilitles for diagnosis and treatnent of nalarla cases. Case detection activitles should be carried out by health personnel in alL health institutlons with speclal enphasis on PCD. ACD should be discontinued in malarious zones, bearing in nind that people are aware of roalaria synptons and will go to health centres whenever they have fever. PCD should be the main case detecti.on activity; uidwives and other health personnel, including laboratory staff as well as doctors working in hospitals should be trained to undertake proper malarla detection activlties. llicroscopes and vehicles nay be redeployed to malarious zones for strengthening case detection accivltles. Treatment of all suspected ualaria cases musE be nade after taking blood slides for uicroscopical examlnation. Radical t.reatment with 3 days of chloroquine (total dose 1.5g) + 5 days of prinaqulne (15 ng/day) would be most suisable. Long radical treatment always has t.he rlsk of interruption and/or failure. Mass radical treatment wlth the dosages described above nay be reserved for nLgrant workers. In the presence of appropriate radlcal treatment activities, winter radical treatment is probably not warranted. Presuoptive treatnent Day be dropped, and 1n places where antinalaria treatment on clinical diagnosis is needed, 1.5 g of chloroguine nay be used under the nane of clinically based treatnent. This is probably not required in places with very low parasit.e lncidence (as in Stratun IV). Cherooprophylaxis is unlikely to succeed on a long teru basi.s, because it is dependent on Lts regularity, and may lead to dangerous levels of chloroquine accumulatlon. If chenoprophylaxis trust be done, pyrlmethanine oay be deleted fron the regimen. As an overall plan for malaria control ln Turkey, the roeeting agreed on vari.ous activities that should be undertaken in each of the following areas: (a) Urban areas: - Larviciding: Direct involvenent of nunicipalltles, other sectors and the community with the technlcal assistance and guidance of health personnel would be the nost effective strategy. - Source reduction: same as above. - Radical treatment of cases detected by PCD: proootlng the use of health servlces and active involvement of personnel of health centres (HC) is requlred. (b) Rural areas: - Residual house spraylng: good coverage supported by supervision of HC personnel is recommended. Radical treatoent of detected cases: same as above. - Cheuoprophylaxis for mlgrant lrorkers: health centres and nobile teams should play the major role. N.B.: The above actlvlties are meant for rural areas which are malarious (e.g.' Chukurova). In areas where malaria is not a major problem, some activlties can be deleted. vBc/90.2 r.taL/90.2 Page 121 (c) Rural areas with development projects: Ihere are some rural areas where some development projects rnay have an imPortant inpact on malaria control activi.ties (Lower Seyhan and Urfa). The main role of the Ministry of Health should be the guidance of the authoritles and sectors involved ln the projects. (d) Tourist areas.' Municipalities should receive support fron the Minlstry of liealth in the way of technical guidance and trai.ning of personnel in nalaria control activlties. llotel ma4agers, menbers of other private sectors and the connunity should actively contribute to malaria control. in tourist areas. Activation of sanitation projects in tourist areas of the Mediterranean coast nay give addltlonal support. The oeeting underlined and enphaslzed the ioportance of two inportant aspects suggesting their improvements as follows.. - Infornation systern: Sone of the forns used for recording infornatlon on malaria and its control have been 1n use si.nce the commencementof the malaria eradication There ls an ""rpaign. urgent need for sinplification of these forms. In 1985, the same systen will be inevitably used wlth few changes. I,llth che establishment of the new pHC inf6rm.iio"- systeD' the nalarla control lnfornation system w111 also be taken lnto consideration. After establlshing the new information system, rnodlfications and updating should be nade accordlng to needs. - Epidenlological investigations: The flow of infornatlon without careful epideniological evaluat,lon and investigation has llttle, if any, value. Epideoiological lnvestigatlons should be directed Eo localities on the basis of priority (e.g., age-groups affected or apPearance of nalaria in a locallty which prevlously had no infection) and should be carried out by qualifled personnel. On thls basi.s, in areas with a serious malaria problen such as Stratr.u I, epideniological investigatlons should be carried out by the personnel of Conmunicable Diseases Control Dtvision and nalaria subdivision in the Provincial Health Directorate ln order to analyze trends and nonitor the problen in various 1ocal1ties. Epideniologlcal investigation of individual cases should be conftned to strata II-IV and carri.ed out by qualified personnel. This is probably not warranled for Stratuu I, and should be avoided to rninlnize loss of tine and unnecess"ry utilization of resources. The neeting further proposed a set of actlvities for each of the five epideniological substrat,a as follows: - Substrata Ia and Ib: High priority for fu1l activities should be given to malarious zones as ln Stratun Ia. It was the concensus of opini.on that Stratun Ib should be consldered just like Stratun Ia, beari.ng in nind that there is a potential risk arising fron the Southeast Development Project (cap), and that an epidenlc will be harder to control in Stratun Ib than ln Ia. Thus, ongoing actlvitles should continue in Stratun Ib as in 1984, and resldual house spraying be done in selected areas where nalaria is an inPortant problen. Malathion nay be used on the basls of 1ow conmunity resist.ance to its spraying. Efforts in ACD nay be nodified as mentloned above. - Stratutr 1I: Speclal attention should be paid to areas with high risk based on social and ecological conditions. In other areas, vigilance should be insti.tuted and active control oPeracions nay be disconElnued. In tourist areas, a multisectorial approach as showa above would be the roost effectlve strategy. Although trigrant workers do- not seem Eo create a special problem, vigilance should be instituted and Village Health Connittees should nonitor the movenents of rnigrant workers. Personnel of health centres in lhose areas should be guided and motivaEed to provide proper health care and attention to migrant workers. - Strata III and IV: Care should be given to the trro strata by applylng vigilance activities and epidenlological follow-up. Depending on local conditions, certain measures nay be applied in 1985 if necessary. vBc/90,2 t[AL/90.2 Page L22 Table 20. Malaria cases recorded in Turkey in 1987 from the five epideniological strata. TnAi - Re- fmported Intro In- Un- Period Stratum LaPSe duced Glptic 9enous classi Total a la fied st quarter Ia 5UU 766 115 I 1183 Yh Jan-Mar 5 142 5.'u 1 1 tl 550 II 10 20 1 JJ III 4 I z l9 rv J 3 Total 315 914 )zt 5 1 o IJ LttJS 2nd quarter Ia zzJ> 631 159 1 SUqb Apr-June Ib 1381 88 t2t8 I7 4 135 2847 II t6 z3 I 113 ) 1 I 220 IIl 45 I z oz 2 4 t25 IV I 13 I I T6 tRn Total 3758 3 1555 26 I 1 t' 135 6254 3rd quarter Ia 2066 r34 1 220t July-Sept 4079 15 4 I 898 11 zz 95 6r24 II 179 1 195 I5 t2 6 410 III 26 L Z.t 3 24 ltJ 2 1 198 IV z9 21 3 53 Total 5379 tb LU 237 3 52 6 96 8986 4th guarter la 510 29 539 Oct-Dec Th 1579 510 ct 7 5 2212 TT 109 1 94 7 1 I 22t TTT 13 5 20 2t OI r22 1V 5 7 5 l7 Total zz tb 7 5 760 4I l> I 6 3111 Total 1987 I ZOO6 r687 18 5225 t24 136 1 25 z)u 0134 a = frorn abroad b= from areas with or without anti.malaria measures from areas i n I'ha consolj,dation phase vBc/90.2 \tAL/ 90.2 Page 123 On the basis of all the above cornmentsand proposals, the meeti.ng nade a series of conclusions and recon'endations including the need for international supporE,. The nost recent data on the nalaria situation in Turkey in 1987 as conmunicated to 1.;Ho are shown in Table 20. The data show conslderable reduccion i.n the nunber of nalaria cases anounting to about 36Z of the total cases recorded in 1984 (55 000). Stratun Ib alone produced 11 733 cases constituting 582 of the togal cases detected in all strata in L987' About 347" of the total cases recorded ln this stratum were inported froro other endemlc strata, rePresenting the infection carried nalnly by rnigrant workers. The data also indicate clearly that nalaria transnisslon occurs chiefly in the 2nd quarters and reaches a peak in the 3rd quarter as already shown above. Further i-nforroation fron Turkey became avail.able just before the flnalizatlon of Ehis document for reprod"!!1o.: Akaba, Kasap & Kasap (1990t-: i;-;;;";ti re-enpirasized rhar each year trore than 100 000 seasonal agriculturil workers oigrate to Cukurova area fron southeast Anatolia. These sorkers sleep outdoors wit.hout bed-nets and usualry neglect taking the antinalarial drugs delivered to thetr. During 1985-1989, piriroiphos-nethyl was used for house spraying and tenephos for larviciding. -hloroqui.ne'+ prinaquine for radical cure. l'lalaria cases reported fron Cukurova uostly originate 1n Dogankent area hlhere' as in other Parts of Turkey, a signlficant reductlon in malaria norbldity has been observed si.nce 1985 (fron 42.6/LOOOin ltg5 n 4.4/L000 in I9g9). The norbidity among rocal inhabitants of Doganket decreased fron 56.6/1000 in 1985 to 2.L/Loo0 in 19g9, but in nigrant workers norbidity decreased troa 27.2/Looo ln t9g5 to 7.2/LOo0 ln 1989. However the percentage of nicroslopically conflrned ."r"ii"-"ases greatly lncreased anong ,ig..rri workers (fron 30'52 in 1985 to 73.87! Ln 1989), while it decreased anoang Local inhabi.tanrs (fron 69'52 in 1985 to 26.92 in 19s9). nataria prevarence lras high in sunmer a peak in Jury, -the reaching and the disease affected uottr sexes and age-groups. Kasap et al. (l990?-subultted for publication)I reported on vlllage-scale rr1als wlth plriuiphos-oethyl carrled out to assess the effect of thls inseciicide currently used for house spraylng pukurova in areas, agalnst sacharovl populatlon. The insectlcide- rras applled as "-- euulsiflable concentrare (EC) at aoEEFgf 0.5 glmz and,O.;-gj;l--]J-;; nater dlspersible powder (wdp) at a dosage of L.-6g/n2. rn !."r, tro""., at" rirr1ng rooo, bedroom, kitchen and entrance/haLl were partially sprayed, but the rest of the dwelling Itas sPrayed coupletely; coverage ltas 69.72. entonoiogtcal evaluation of these treatments conprlsed susceptlbility tests, estlnatlon of day-ti.oe lndoor restlng density of determinatlon #larovi, of parous rate and carrylng out contact bioassays on ei-ght dlfferent tyPes of surfaces. Ao. strowld lonplete suscepribirity to plrlnlphos-uethyl; "."h.tg.r! the dlscrlnTiftr-!-doFge that-gave-1002 norrairtv r." o.5z fot 30 uln' Plrloiphosaethyl applled at a dosage of 0. 9 g/n2 gave the uesi r.s.rrrs for ir produced an appreclable reductlon ln the parous rat;, 96.92 reductlon ln eqchelovi denslty, resting and more than flve weeks resldual effectlveness on rlnewash and more than seven "iI;ffi;;;;, weeks on cement briquettes, wood, zinc, plywood and brick. Guy (1963) .-^-1" YoTgcco, analyzed Ehe parasltologlcar data collected during rhree years (1960' 1961 and 1962) preceding the establlshoent of the rnalaria eradicatrlon prograrnne in 1963' ltalaria was found 1n all dlstricts at a varyLng degree of endenicity according to cllnatlc condltions. The central plaln region was-the most endemic, followed in descending order of nagnitude by the Dountalnous reglon, Ehe pre-Saharan zone, the Atlantic coast' and flnally the lledlterranean coaat whlch was the least endernlc. During the three years P!=tly"* ranged frou 55.3"1 to 70.57., P. falciparuo fron .14.2i( co 2g.gil and P' nqlqriaq trotffio 18;52. Fron the curve' of nonthly records of mar.aria cases, ir was deduced that ualarla transnisslon in the lrhole of I'torocco extends frou }lay to ocrober with a peak in July, with the seasonal decline occurrlng ln liovenber. The season of P. nalariae was found to be late, prinary lnfections were not seen until JuIy. Benmansour (L972) noted that nalarla in Morocco i.nereased in 1971. The total nuuber of blood slides corlecred in 1970 and l97l was I 119 439 and I 118 956 respecrively, the latter represented an aunual btood examlnation rate (ABER) of 7.22, vhereas the optlnun ABER ln oalaria eradlcation is r0z. The slide positlvity rate rose from 0.48"1 in 1970 l. suuoarles of the two papers were kindly provlded by prof. E. Ibsap (personal connunicatlon, January 1990). vBc/90.2 t4AL/90.2 Page L24 to 0.94"1 1n 1971, a nearly 2-fo1d lncrease. The najority of the positive slldes came fron seclors having previously been known to contain potential malarla foci which had not been subjected to DDThouse spraying. The lnportant factors that influenced the revlval of these foci were as follows: (a) Survelllance: Different nedlcal missions indicated that surveillance actlvities were not functioning correctly durlng 1971, and even not carrled out at all in certain sectors. (b) Treatnent of nalarla cases: A good number of personnel responslble for antlmalarla activities were charged with other duties during the nalaria transmission season. Thus, they were not able to undertake radical treatment or carry out mass treatment correctly where it was deened necessary. (c) Rainfall: The year 1971 was exceptionally affected by excessive rainfall. The amount of rainfall in the rainy seaaon (0ctober-l{ay) of a nornal year (409 mm) was exceeded by about 183 nn in 1971. I'loreover, the spring ralnfafl tn 1971 was about 309 on which is excessi.ve for a normal year. However, in all regions that have been subjected to DDT spraylng, malaria transnission ceased or Itas considerably reduced, notably in Tetouan, Taza, A1 Hocelua and Tanger provinces. The plan of 1972 envisaged rlore systematic case detection and treatment of Patients' trainlng of new malaria nlcroscopists, exlension of DDT spraylng, classlfication of water collections, installation of equipnent for dlspersal of taivftides by vehicle, drainage work, and entonological studtes in many provinces. Naji et al. (1985) analyzed the sltuation of lnported nalaria in Morocco. The classification of nalarla cases as belng inported has been a dlfficult task because of the uncertainty of local contractlon of the infection. It has been fairly easy to exclude P. P. ovale -+ _falclPerun, and & eal.ariae lnfections, as these had disappeared fron Morocco before 1978. The difficulty rEnalns-Eth P. vlvax, because the patlentsr cards do not give any lndication of nalarta eptsodes beEffiarturebe departure fromfron the endenic zone outsLdeorrrct.ta Morocco. Fron January 1978 to Decenber L982, lt nas possible to classify I40 cases as inported and 953 as autochthonous, thus the inported cases constltuted, L2.8"Aof the total cases recorded in Morocco during this period of five years. The nunber of iuported cases steadily increased to 50 in 1980, but declined ro 33 1n 1981. The najoriry of inporred casea were P. vivax and P. falcioarum infecti-ons, respectively 67.852 and 26.42"1, with one mixed i;fec-ffi; or tEffilffifces (0.722). p. ovale consrlrured 4.28j( and p. nalaFlae only 0.722 (L case). Most of the inporteaEEi6-rlginated fron rropical-Africa, nocably Equatorial Guinea (97 cases) and Zaire (11 cases). Unfite the situation in Europe where inmigrants constltute a large proportion of the inported cases as they contract the infection when spending holldays ln their countries of origln, the Moroccans are themselves the main source of inported nalarla as they conlract the lnfection during their professlonal travel in tropical Afrlca. The decllne in the number of inported casei in 1982 was attributed to better explanation of the value of prophylaxis provided to travellers. The lapse of tine between the onset of nalarla syrptors .na tn" date of return to Morocco from an endenic zone was studied in 100 patients of inported malaria. The average period was 15 days for -P. vivax and three nonths for P. f"l".p.r*., but there IJasade1ayofoneyearin4cases@s:p.*and2P.vivaiFTf,IEEi1dindicate that the period of contlnued prophylaxffi]i-E6 no-nchs afffirrn to Morocco would not be sufficlent. Synopsis of the malaria situation in llorocco during 1982-1985 was shown in SECTIONI, under 2.1 ln document VBC/90.I-MAL/90.1. tr'ron the recent infornation communicated to I'IHO/MAP,the data show the nalaria sltuation in 1987 as follows.. (populatlon given as a ni.d-year estimate in thousand). - Total populatlon: 23 376 - Population of orlginally malarious areas: L2 932 - Population clained to be freed fron malaria: - - Populatlon under nalaria control programme: L2 832 - Population protected by house spraying: 109 - Populatlon protected by other anti-vector neasures (larvicidlng & biological control:701 - Population under surveillance: 12 832 vBc/90.2 r[AL/90.2 Page 125 - No. slides exanined: g93 g05 - No' positive slides.' I 287 (705 P. vivax, 576 p. falciparun, 1 p. nalariae, 3 p. ovale & 2 uixed) - Effid total number of cases: I 2g7 The epideniological situation in 1987 was narked by resunptlon of uararia transmission in the old foci of Khouribga, Fds and MeknEs, r"rr is an increase in the inported cases' Autochthonous cases were "" detected in the following provlnces: Fes e27t, chefchaouen (169), MeknEs (115)' Khouribga (72), Larach (50), Tetouan (9), Beni Me1la1 (8)' and El Hoceina (6), naking-a total OSO in 1987. Conpared with the total nunber of cases recorded in 1986, lhere "t """"" was an increase of 492 in 19g7. NevertheJ.ess, the nunber of cases regressed by 341 i.n chefchaouen, 202 in Beni Mellal, 7O"l Lrt Larache, and 427"in A1 Hoceina. rn addition the number of cises decreased i.n two other provinces: by 75"1 in Kenitra ar,d 4oz in Khenissat. on the other hand, the nunber of inported cases increased considerably reaching over 600 conpared wlth 97 in 19g6. the nalaria eradicatlon ,-^ -tl llqlllt, progranme nas started in 196g and since then has progressed satisfactorily ir except-for-ceitain problens whlch were investigated deal't with in tlne. The report of ptruti" the Mlnistry oi Healrh, Algeria (1g73)r ""a--rhat Itas presented to the Antinalaria coordinatlon of Antinalaria activities ln the countries of Maghreb, 4-6 Decenber 1973, showed that the Algerian ualarla eradication prograrnme during 1973 followed closely ine Plan of l,ctio., oF-rn. 3rd addenduo of the plan of Operation as follows: - Annaba Wilaya (Departnent): 2nd year of consoli.dation phase. - constantlne-and-Aures wllayat (Plural of wllaya): 2nd year of - serif attack phase. and rizi-ouzou w'rayar: 2nd year of .itl"t phase. - Arger, Tirleri and El-Asnln noltayair p."p.tirlry ptrase. rn the rest of the councry, the classlcal nalarla control activitles contlnued especlally the focal spraylng 1n the more uararlous zones ln order to linit the extension of the important foci which were detected in 1972. As ln previous years, 1g73 was quite favourable for malaria transolssion, particularly ai ttre end of suumer in the strata' The epideniological littoral aata outitned in rgig-"p to october fron confirned arl territories the favourable evolutlon of the nalaria sltuatlon in all the regions under the eradication progranne, but recrudescence of oalarla transmlsslon occurred in the rest of northern Algerla desplte the appllcatlon of DDT spraying protecting more than 3g0 000 lnhabltants llving in the more endernlc foci. The report outlined the varlous activities and the results recorded in each wlraya.--Briefly, ttre epiaeniological situation up to the end of October 1973 was summari.zedas follows: (a) In regions under the nalaria .eradication programe: - Total population of Algeria 15 - , 000 000 Popuratlon by Protected attack measures or surveillance activitles of nalarla eradication operations: 6 500 000 - Popularlon prorecred by DDT g3O - spraylng: 2 000 Slides exanined: 292 245 - slide posirivity rate (spR): 0.01g2 (53 posltlve srides) A11 the cases were P..vlvaI, but six cases were classifled as autochthonous. slides examlned froiEEiiEi None of 52g1 were positlve. rt"",-tt. evoluti.on of the epideniological situation in the vast naiorlty of tne Atgertan teirltory in 1973 was satisfactory regression of infectlon and the from sPR of o.4gz in 1971 ti o.olz tn L972 and provlded evidence ro 0.0lgz in 1973 of the effrcacy of nataria measures. "i.ar."tron (b) The rest of the country: The renalnlng part of the country that was not covered by malarla eradlcatlon operations constltut.ed almost the western half of northern Algeria, and the saharan region, with a total populatlon g or ooo 000 lnhabltants, of whon about 3 000 000 were under nalaria risk. The plan of actlon of L973 envlsaged diverse measures aioing at reduction of the foci detected folrowing ttre eplaenlc exacerbations that r' Permisslon to use information contained in this report rras granted by Dr E.H. Benzerroug, Divislon du Paludlsne et aes llaiaaies-paiasrtalres, rnstitut National de sant6 Publlque, Alger. vBc/ 90.2 ttaL/ 90.2 Page 126 occurred in the sumrnerof, 1972, princlpally 1n the Wilayat of El-Asnam The neasures were as follows: and Mostaganen. - DDT house spraying to protect - nore than 3g0 000 lnhabltants. Activatlon of pCD. - Presuntive creatment. - In regions where cases rrere rare' epideroiological investlgations and radical treatoent given. r{rerecarried out and barrier spraying in the ,or,"] ll.i::::::.measuies norrh of Tlencen and in rhe border - Mass investigations. preParatorv phase activities arger- :l:Tl:;3:]il. were inplemenred in the witayar "pt""t of As nentioned above, the year 1973 was qulte favourable for nalarla-rransmissi.on, particularly in the Mediterrlnean zonesr.ria a""pite ttre application or these nalaria incidence continued neasures the to increase 1n the western and southern cases detected zones. The nunber of in 1972 was around 2000, but 1n reality the number uuch exssgded figure' rn this 1973, the nunber of rerapses nas added to high, and when the nunber of new cases was it, the total nurnber of cases detected-ii, oalaria ttr" territories not subnitted to eradj'catlon oPeraEions exceeded 3000. oi--tt."", 11 were reported froro the saharan region' No cases ltere recorded in Tlencen wilaya, Jespite the presence of epidenic manifestatlons in the-nelghbourine-11ovince of o,ri5a in Morocco. This provided evidence that the rneasures applled in this Wilaya lrere Regardlng p. falciparun infectlon in all areas, It "ff"iti.r". narkedly regressed to 29 cases and,2,ri.aTiffii#,9l 6 nixed Ln L972. and In conclusion, the following polnts were underlined: (a) The roalaria eradication Progranure in Algeria has glven good difflculties especially results despite nany those oi .r, adninislraelve nature runnlng whlch affected the snooth of the operations' rn the wllaya of Annaba whlch was in the second year of the consolidation phase, transmission was resumed in Berrahal (Darra of Annaba) glving a total of eight cases, of whlch rise to four were lntroduced. The necessary were applied and pursued. renedial oeasures (b) rn the wllayat under the attack phase, the evolution of the epideniologlcal situation was saElsfactoryt but great efforts were needed in order to ensure totar coverage populatlon by surveillance acEivlties, of the so tha! these wilayat can safely pass consolidation phase. into (c) rn the western part of northern Algerla, which has not been covered by nalaria eradication operationsr control neasures applled certainly prevented the exprosion of serious nalarla epidenics fron a large reservoir of infecti.r" thac the favourable condltions exlsted during for transnission ln the past tero years.".""" (d) The progresslve decrease of the susceptibility of labranchiae to DDTnades it necessary to cover urgentJ'y the areas of north Algeria not included in the rnalaria eradication Progranme, before DDr - resistance becoies an insurnountable probren. reason' the plan For this of action of. L974 envlsaged the initiatlon Hilayat of the attack phase in the of ritteri, Alger, El-Asnan and Mistaganen, and total coverage spraying in foci discovered in the last two years a1r in the wilayat of oran, Tlencen and riaret. Ransdale (1975) ln a nission to_Algeria during Jury-August Lg75 rested susceptlbllity of labTanclr-l1e the to DDT ii aitfereii'.i."" sprayed of years prevlously recentry or for a number wlth-DT rhe tests showed that observed the increased lolerance to DDT in 1970 and L972 seens to have stabilized. progressive This was probably due to the reductton in the use of DDT ln agric,rii,rre fotlowing the-iecision nade Ministry of Agrlculture. This cooperatlon by the - would be extrenely valuable for the antlnalaria programne as it pernits the conservacion of DDT for house spraylng over a proronged in areas under attack or in case period of revival of transmisslon ln certain the consolidation phase. foci in areas under oddo (1981) ln his unpublished report to wIIo on a ulsslon to Algerla 1981 durlng Novenber to asslst in the evaruation of the epldeniological sltuatlon of mararia and in vBc/90.2 t[AL/90.2 Page I27 drawlng a plan of action f,or L982, descrlbed the development of a malaria outbreak of vivax in-the health f' sector of Meftah, Kherois-el-Khechna locality, wilaya of Blida, and two cases also of P. vivax in the health sector of Thenia in the .ij""".rt wilaya of Alger' The appeari'iE-oFthe focus of Khenis-e1-Khechna was surprising to the authorities of the antiDalarla PrograBDe, because it occurred in a territory which had been free of nalaria under the consolidatlon phase for about 10 years since the termlnation of the attack phase. The zone of this focus was situated in the val1ey of oued-er-Hamiz, a river which descends fron the northern slopes of the Mediterranean Atlas and pours into the sea after traversing the Algerlan llttoral. plalns M6tidja, fornerly known to be a highly malarious zone in northern A1geria. Thi area affecied rdas situated in the terninal portion of the niddle section of the ri.ver, just before it enters the p1ain. rn the upper part of the river, there is an artificial uair.ge with its reservoir supplying the irrigation systern in M6tidja plaln. rn t.his arla, there lrere 16 aggloneratlons having a sedentary populatlon of 3 I47 inhabitants with Khenls-el-Khechna Ueing the principal locality. The first nalaria case of P. vivax appeared in July 19g0, and a further case of the same infectlon was detecled in the-dltE-?;s'irls, health ie"tor of Reghaia, Alger wilaya in Septenber 1981. Through an epidenlologlcal lnvestlgatlon made by the epideniology section of the Bureau central d'EraJicatlon du paludisne (BcEp) and the preventive tean of health sectors concerned, 48 nore cases of p. vivax were detected naking a total of 50 cases distributed in t0 of the ro ro"aiitffi.t distribution of the cases lndicaced that the of the epidenic was"-""1i"rl*-ii" in the area of three contiguous locallties: Aoaurla, "pi".it.r Barrage and La cave, where the inltiar infections were contracted about the beglnning of the transnlssion season in June 19g0. Subsequently, transmisslon occurred ln the other localities introductlon of the valley before the of renedlal oeasures. rt was ;1;;; til"t""*r"o tt" evolurlon of rhis epldeniological situation arose fron the revival of.a paraslte reservoir which unfortunately remained undetected because of the failute io-exanini-niiioidoplcally abour 2000 blood slides which could not be traced later. on the other hand, there was a fairly high nunber of asynptoDatlc parasLte-carrlers ln the previous (8 out of 50) who-probably rernalned unknown vlais. The ientiJ-or-rtri"-.piiJriJioEi"ii"iiiir5iiiiior, ro be the locallty of Ananria whlch "pp.".ed was conposed ol fllnsy scattered structures and inhabired by seasonal workers who-came fron reglons of the high ilgerian plateaux, notably froro the wilaya of Mtsila. ?his raises thA question whether these trigrant workers acquired Ehe lnfection through their noblle rnode of llfe or in thelr place of origin. Longitudinal case detectlon carrled out for nany years in the wllaya of origin (Mrs1la) of t.hese workers has not revealed any indiienous case of nalaria. Nevertheless, remembered it should be that the reglon of the high plateau used to be regarded by forner nalariologlsts as the "ch6teau dreau; for nalarla. Benzerroug & w6ry (1985) - carrled out a seroepideu,iorogical inve'tigation in the focus of Kheois-el-Khechna during 1984 to ascertain ttre eiiicacy of control neasures appJ-ied for three successive years. Thls focus ylelded the majority of the autochthonous cases recorded in 1981 ln Algeria (51 out of a total or 5: cases), all of which were p. vivax. control neasures coroprised: radical treatxoent of the 5r positlv" of 250 collateralsl and DDT spraying of all houses ln the focus for",ru:""|"r")-i.ffir".,a ihree years, 1981-1983. Through surveillance 18 cases were detected in L982, of whlch 4 were classlfied as relapses, and no autochthonous cases were recorded in of t9g3. The objectives the seroepidenlologlcal i.nvestigation of 19g4 were.. (a) estimatlon of the seropositivity rate and comparing the results with parasitological those of lnvestlgations carrled out ln the localities of che focus; (b) analysis of the seropositlvlty rate by age-group, and assessing the changes in its levels (before and after the transnission """"ooj; (c) comparing the serologlcal resurts obtalned with two blood sanpring techniques: serulD on fllter and eluted PaPer dried blood, and deternlnlng the differences betrreen two antigens used in rFA test, viz: P. faLciparun culture strain, and p. vivax strain from a patienE origlnatlng fron Indla. Briefly tbe results 1ed to the following concluslons; : th9 superlority of the seroepldemiological study over the parasitological examination in the analysis of the- situatloi in the prevlous nalaria focus of Khenis Ej. Kechna was demonstrated. vBc/90.2 MaL/90.2 Page128 - the analysis of the serological findings by age, locallty, and time provi.ded evidence that the reservoir of lnfective cases was elimlnated and transmission completely interrupted. At the same time, 470 blood slides examined parasltologically were al1 negative. - conparison of the serological results obtained by two blood sanpling techniques confiroed the reliability of the uethod of collecting blood on filter paper. - comparing between the antigens revealed that the proportion of seropositive samples was sigtlificantly hlgher (P<0.001) when P. falciparuu antigen was used conpared with P. vivax. This poses the problen of the level of sensitivity of P. vi.vax as antigen originating frorn a dlfferent geographical area. To investigate this problem, Benzerroug, Denedts & W6ry (1986) made a double-blind serological study on 16 sera sampled fron the above-mentloned Khenis-el-Khechna focus of P. vivax in Algerla, and 7 sera from patients with proven P. vlvax lnfection contracted in rnEFitre reactlvity of each of these serun samples ras Fea uy rFA test using dlfferent batches of antigen, including 3 batches of P. vivax antigen prepared with isolates fron Zaire, Africa, Indla and SoloxnonIslands respectlvely. For the detail.ed results the original paper should be consulted, as it is sufficient here to give the highlights of the findings as surnmarlzed by the authors. Anong the 15 samples from Algeria, the percentage of seropositlves decreased from 1002 uslng the honologous antigen originating fron the saoe continent (Africa) to 86.62 uslng the honologous antigen fron the Soloroon Islands and further to 63.32 using the honologous ancigen from India. Based on the results of thls study, lwo aspects were underllned: - in seroepideniological studles, sensltivity could be inproved by the use of a homologous antigen fron the same geographical origln; - in detectlon of c1lnlca1 cases of malaria and species ldentification based on serology, t.he prersent results point to the need for caution tn interpretlng serological tltres and for taking into account. the geographical origin of the isolates used as antigen. The Saharan region of Algeria has recelved attentlon in the past and ln recent years. Of the early studies, reference ls made to a report by LefEvre-Witier (1968) describing an epidenic of malaria ln Tassili NrAjjer during 1965. Tassill NrAjjer ls an area situated between 23o and 260 N latltude and betlreen 50 and t2o longitude, forming the northeastern part of the sandetone plateau which surrounds the volcanic nassi.f of Hoggar. The clinate of Tassill NrAjjer dlffers fron that of Hoggar in that it is influenced by the Sahel. It ls very dry and has a continental cllnate. Rainfall at the foothills of the plateau ls about 15 nn/annun on an average, mostly falling i.n one or tlro bouts of violent thunderstorns during the hot season, but in the absence of actual measurements, the amount of precipitation ls probably double. The mean minior.rm tenperatures are between 4 and 60 C in January ln the areas surroundtng the plateau, but range froro 1 to -5oC on the plateau itself. The autumn (Septenber-l5 October) is as hot as ln sunmer, but subsequently cotd weat.her prevalls. The mean naximum temperature reaches 40o C ln Djanet. VegeEation is represented by poor pasture, as in Hoggar. Sone well ltatered zones support relict of Mediterranean flora. At the tine of E,helnvestigatlon, the population consisted of l0 000 inhabltants, about L/3 of whon were concentrated in Djanet oases, whlch is the adninistrative caplt.al situated at the foothills of the plateau. The other 2/3 t''tasconposed of semi-nonads who exploited some micro-centres for cultivation, and noroads who owned nothing but thelr herds. Aoong the cultivatlon centres in Tassili, two were typical: Aharar and lh6rir, located at the basaltic foothills of Adrar. They were the nost important centres of resurgence of nalaria. In fact, it was at lh6rir (wich 200 inhabltants that a wave of a malaria epidenic was observed. During the first oission to Tassili NtAjjer in April 1965, no larvae or adult nosquitos were found, but towards the end of Septenber of the same year, mosqultos became numerous and many fever cases were found.. At the beginning of October, a survey was conducted for one week, during which pertod the spleen lndex was established, blood filns were collected fron children and adults encountered, presumptive treatnent given according to age (nivaquine * pyrlnethanlne), and larvae of Eosquitos collected. The findlngs suPPorted by tabulated data showed the following: (a) The overall spleen lndex (children and adults) was about L5"tr. vBc/90.2 r4AL/90.2 Page 129 (b) Ot 2L children (age-group 0-5 years) 18 were positlve; of 13 children (5-10 years) 13 were posltive; and of 83 persons (10+ years lncluding adults) 47 vere positive (571[). The parasite species identified in the 74 positive slides ltere: 90.5"4 P. falciparun, 2.72 P. vivax, 2.7% P. maLariae and 4.IZ roixed (P.f. + P.n.). Thus' it seems that P. falciparurn was responsible for epldenics at this latitude, particularly in Iassili N'AJF-The;C results also indicated that children rrere the mos! affecEed at Ih6rir, but there were no deaths. On the other hand, there was not a single case of pernicious manifestations encountered. Enquiry fron the inhabitants and the study of nedical reports and publications concerning this region, showed the existence of favourable cllnatic conditions for the developnent of repetitlve seasonal naves of malaria. Taking into account the high probability of contraction of p. t"lSfp"r"t. infection annuaily, the clinical pi-cture that was observed at Ih6rir ;ust have been due to the developnent of a certain degree of inmunlty. Contrasting with this prenunition of the population of Tassili, the severity of clinical oanifestations due to P. falciparum were rare among the populations of other regions of the central. Sahara. (c) The larval co]lections showed the presence of nulti.color, a species known to breed i.n saline waters and this was confirmed at lh6rir. Reference was made to some o1d records obtained fron the Saharan region. While multicolor was reported froo lh6rir in 1941, only drthall was found in this locality in 1958, but in the adjacent locality of Aharar sergentii together rrith hispaniola were encounlered. In contrast, sergentii was [email protected],butthisspecies association rras never fouolG-.ffill N'IIJ;-- 1929 when a malaria epidenic broke out at Djanet, Anopheles rufipes broussesi, was Ldentlfied fron this locality and also from Arharar. An. ganbiae s.l. has never been observed in Tassili NfAjjer. (d) In view of the geographical differences, the problen of nalaria and its control in the oases of Djanet mus! be distingulshed froo thaE of the localities dispersed on the plateau. In Djanet, control measures that have been applied for a long Eime consisted of constant surveillance of irrlgation basins and channels (s6guias) (clearing of vegetation and enptying every 10 days), besides whlch house spraying with llndane, larviciding and filling ln of depressions and abandoned s6guias. On the plateau, the measures that have been adopted since 1946 consisted siuply of the administration of nivaquine to persons encounteredbynedica1officersandthedistributionof@i. gueltas (ponds) of lh6rir. It was lnpossible to carry out the Deasures of clearing veget,ation, sprayi.ng of houses or treatment of breeding places; the accessibility of most of the cultlvation centres has been extremely difficult. In conclusion, the author Pointed out that in the rnountainous part of Tasslli NtAjjer, there exists an annual rhythn of aestivo-autuonal. malaria with light variation according to the amount of rainfall. The Dajority of nouads and semi-nomads are the victins, while the inhabilanls of Djanet oases have been relatively protected for the past 50 years. In the other regions of the central Sahara whether mountainous or not, malarla manifests ltself in severe epideuics due to contraction of infection through movement of the population for animal raising or for trade. The nonads of Tassili NrAjjer are ln permanent contact with the neighbouring regions of lloggar, Ouargla and In Salah in Algeria; Tibesti in Chad; Ghudanls and Fezzan in Libya; and AIr in Nlger. The focus of Tassili NrAjjer deserves profound studies because of the danger of disseuination of P. falciparun in Algeria. Holstein et al. (f970) who described the anopheline fauna of the Algerian Sahara (see under 2.5 above) remarked that nalaria endeulclty is weak in this region, with the exceptlon of a few villages with cultlvation ln lassill and Hoggar. In these tlto areas, malaria is mesoendenic with annual recrudescence in the autumn. Sti1l, the proliferation of the vector under exceptional clinatic conditions could bring about epidenic eplsodes. These epidenics were studied ln the past by different authors as they were revealed to be extremely serious causing high deaths. the parasite involved being P. falciparun Ln 907" of the cases provides an lndication of lts inportation fron an African origin. As shown under 2.5, the authors considered the responsible vector is sergentii, but multicolor was suspected by some workers. Thus, it rras recornnended that studies should be concentrated on sergentii duri.ng its season of abundance, Septeober-November. Zulueta & Raosdale (1975) who surveyed some localitles of the Algerian Sahara during October-November 1975 (see under 2.5 above), provided informatlon on lhe malaria situation prlor and during their visit. Yearly records of blood examination lrere tabulated covering che period L966-L975 for the following localitles: Ouargla, Djanet, El-Golea, El-oued, vBc/90.2 r4aL/90.2 Page 130 Ghardaja, rn-sa1ah, Laghouat, Tamanrasset, and rouggort. sirnilar records were also given for two other localities: Adrar and Tininoun but only up to Lg75. From these data, there were only three P. vivax cases out of 5611 srides exanlned fron the first group in !914, two of which cam*EiTuargla (658 slide".*.rirr.aj ana one from In-SaIah (1696 exaroined). In the sane year, none of I98 and 2704 slides examined fron Ardar and Timinoun resPectively were positive. In 1975, all 3 836 slides from the first 8 villages were negative. In the authorst survey carried out during November1975, none of g63 slides collected fron Silet (Tananrasset Wilaya) and Djanet and Ih6rir (ourgla Wilaya) were positive, alEhough the blood examination rate of all age-groups including infants was 13'87" of a population total of. 6 25Q inhabitants, and sanpling included fever cases and a population originating fron !{aI1. The authors tried to find an explanation for the absence of infection in their survey. It is generally accepted that in the oases of the Sahara, flare-up of rnalaria transmj.ssion occurs for a brief period following increased precipitation. This was confirned by the finding of 170 cases of p. falciparun, 56 ar.d l:^YiY.* 2 nixed in 1969 at Tinirooun (1685 exanined), Maruro & Fellahi (1969). "iid.s From the available meteorological data (Tananrasset station),"ilT-rrg the annual rnean rainfall in a norroal year is 37.6on. The authorsr survey was carried out in a nearly normal year when the annual nean rainfall was 32 on in f-gZS and the preceeding year 31 nn' This assunption was supported by the fact that the density of anophelines during the aulhors survey lras very low, except at lh6rir, in which the investigation could not be pursued (see under 2.5 above). FurEher blood surveys covering 2O7!of the population to be carried out in the favourable season (Septenber-october) sirnultaneously with investigation on the biononics of sergentii, preferably at rh€rir were recommended. Recently, Benzerroug & Janssens (19S5) presented the oalarla situation j.n Algeria with special enphasis on the saharan region. The nalaria eradicatlon programme succeeded in reducing the annual incidence from about 100 cases/roO 000 inhabilanls in 196g ro less than 0'5/100 000 froro 1976 onwards. rn t,he last few years, the epideniorogica.l- siruarion was characterlzed by the perslstence of residual foci of transmlssion in the northern part of Ehe country (see studies of Khenis-el-Khechna above), and the detection of an increasing number of cases in the saharan region. The progress of the malaria eradlcation in the Programrne northern Part of the country, the developnent of the hearth services and the estabrishnent of specific antinalarla inirastructure ln different wiraya conEributed to anelioration of surveillance activities. Sinultaneously, frequent field malariometric and entooological investigations have been carried out. The reinforce'ent of the surveillance activicies arose fron the need for extending the beneflts of the nalaria eradication to all Parts of the country, and for preventing the risk of reintroduction of malaria transmission that may arise from movement of the populatlon through the trans-saharan route connecting Algeria with count.ries of south of the Sahara. The Saharan region which covers abou! 2 nillion square kilometres in Algeria, has been procected by classical antimalaria measures (see above), and those focl which are detecged, receive relnforced measures. For assessment of the epideniologicat sltuation in this region, the following sources of infornation were utilized: - active case detection activities underlaken by the health services of the Saharan region, as well as the results of different malariometric investigations; - the entouological findings obtained during missi.ons undertaken in different areas of the Sahara; - statistical data concerning the movement of the population anci traffic as recorded at the princlpal frontier posts of south Algeria (see under 2 below). To conpare between the northern and southern regions of Algeria, the annual parasite incidence lr.,t che two regions govering the period L977-L984 were tabulated as shown here i.n Table ?1(^)', and Table 21(b)a which shows the classification of rhe cases recorded in the Saharan region during the same perioci. fTEproaGa-uy peroission of Dr E.ll. Benzerroug and the Bulletin de la Soci6t6 de Pathologie Exotl ue from the paper of Benzerroug & Janssens (1985), with some modifications. vBc/90.2 r[AL/90.2 Page 131 Table 21(a,) Annuar parasite incidence in northern and southern Algeria. Year Region Population No. cases Incidence/100 00 Betio (S/N) r977 North t6 4L2 330 15 0.091 64.40 -- (s) 1978 North 16 887 106 L4 0.082 25.84 L979 North L7 452 339 47 o.269 L2.85 r980 North L7 975 908 l1 0. 061 51.00 1981 North 18 5r5 r87 5t 0.307 3. 91 r982 North L9 070 640 46 0.24r L2.L6 r983 North L9 682 605 l0 0.050 72.88 1984 Norch 20 273 083 0.034 81.17 South 904 420 25 2.760 Fron the above data, it can be seen that of 4r0 cases recorded in the whole country during L977'r984, 203 or about 502 cane fron the saharan region. The annual incidence was at least l0 tines higher in the south, and it even increased to about 80 tines in 1984. The increase of incidence in the north in lggl was due to resunption of transmission i.n the residual focus of Khenis-el-Khechna. vBc/90.2 t4AL/90.2 Page132 Table 21 (b). Classificarion of malaria cases recorded in the Saharan region of Algeria during L977-L984. Year Total Indigenous Imported Unclassified No.cases No.cases "l No. cases L977 43 .tJ 100 r978 16 8 50 ; 50 L979 27 15 55.5 10 37 z 1980 3 L2 22 88 r981 10 1 10 8 80 -l. L982 25 8 32 15 60 2 1983 32 L2 37.5 l3 40.6 1984 25 4 16 2L 84 Total 2O3 94 46.3 97 47.8 L2 The unclassified cases amounted to 5.9% of the total cases and could not be deterroined due to inadequate epideniological investigatlons. The nunber of the indlgenous cases was nearly egual to that of lnported cases. Of the 94 indigenous cases recorded during L977-L984, 64 or 682 vere P. vivax detected in Ouargla oasis which constituted the principal focus of nalarlaE-Ee-sahara and received speclal control measures until transmissi.on ceased in recent years. These cases rrere recorded in 1977 (43 cases), 1978 (7 cases) and 1979 (14 cases), but none rrere detected in this oasls frorn 1980 to 1984. Of the remaining indlgenous cases, 26 cane fron Adrar Wllaya whlch were ldentified as 19 P. malariae-If and 7 P. vivax. There were also tero cases of P. vlvax recorded ln In Salah only rtre iZfation of the 97 inported cases rGFea auring Lg77-L984 showed that 65 (677.) vere due to P. nalarlae, and I (12) to P. ovale. The origin of infection of the lnported cases was detffiFs 88.7i( ftom Marr ii?-rige-er , LZ fror each of senegar, Benin, Tanzania and Indla, but the origin of the renaining 7 cases could not be deternined. Regarding the entonological findings, several investigatlons pointed to the presence of six Anopheles species in the Saharan region: multicolor, sergentil ,3j@, hispaniola, rhodesiensis rupicolus and rufipes broussesli tThe preserrce of labranchiae in the Saharan region of Algeria based on only two specimens collected by early norkers was doubted as being due to nisidentification - see under 1.5 above]. The authors referred to the widespread distrlbution of nulticolor which had been suspect,ed in t.he past as a nalarla vector in Algeria. n ciffiffi vlews of Holstein er al . (1970) the role of this species in nalaria t.ransnlssioq is debated on account of its presence all the year round in oases where malarla transoission is absent (see under 4.5 above). Thus, .9g:gg3!.1:_has been considered the principal vector of Saharan malaria. Reference was also made to lhe suggestion of lknsdale & Zulueta (1983) that sergentii in the Sahara could consist of two species sergentii s.s. and sergentii nacnahoni with the forner belng possibly the vector of nalaria (see under 2.5 above). However, the results of recent entonological surveys conducted during 1980-1984 provided evidence that serggl!! as well as uulticolor existed in localities where autochthonus cases of ualaria uere detected, hence the rol.;f each of these two species is as yet to be deternined. The authors further underlined that An. gambiae s.1. has so far not been found elther in the southern border area nor in the rest of the Sahara. Benzerroug (1985) following the appearance of chloroquine reslstance in P. falciparum in Tanzania, arranged for an epideniological investtgation on a group of 80 sorkers [Algerians ?] by teaos sent to Tanzania for slx weeks wit,h the cooperation of the Tanzanian authorities. During 1982, these rrorkers stayed in the island of Songo Songo fron January to April, and in Kiobidji province in Tanzania from Uay to Deceober. Fron May to November 1982, 16 cases lrere suspected to have contracted malaria, of whon there were.' vBc/ 90.2 \4AL/90.2 Page 133 7 cases confirned by the BCEPlaboratory; 3 cases hospltalized and confirned as P. falciparum lnfections by Claude Bernard hospical in Paris after a stopover in Frana-- 6 cases were found negative after confirmatory examination. Detailed data were tabulated showing the age and sex of each of the seven confirned casesr their place of residence in Algeria, date of onset of illness, date of blood examination, parasite species and density, quantity of chloroquine received in Novenber 1982, date of microscopical exaroination after treatnent and parasite density. From these data, the author sunmarized the findings as follows: (a) the predoninant parasite was P. falciparum, as only one P. vivax was diagnosed; (b) the first case rras detected in May 1982, but the renaining cases were diagnosed later according to the date of appearance of synptons; (c) the patientsr residence 1n Algeria were diverse, 7 Wilayat out of 31; (d) two Patients ltere found to be gametocyte carriers, of wbom one received in l"lay 1982, 1650 rog chloroqulne without parasitological evidence; (e) after several parasitological examinatlons following the treatment given in November 1982, one patient was regarded as the carrier of a P. falciparurn chloroquine resi,stant straln as proved by the standard ln vivo test (R II). The history and follow-up of this patient unril cured was given in deET[f The.oajority of the-patients declared that they were taking chloroquine prophylaxls at a minimum dosage of 300 ng/week during their stay ln Tanzanli. In conclusion, itre author stressed the need for careful surveillance of iuported cases for detecting chloroquine-reslstant P. falciparun which constitute health hazards Eo the patient hinself and the sqnrnqnt!y partiEularly in countries where malaria eradication has been achleved or progressing towards its goals as in Algerla. The probleD of i.uported rnalari.a would call for strengthening vlgilance, taking i.nto account the receptivity and vulnerability of different areas. Synopsis of the malaria situation ln Algerla during 1982-1985 has been glven ln SECTIONI,under 2.1 in docunent VBC/90.f-MAL/90.I. Frou the data communicated Eo MAP/WHO, the most recent oalarj-a situation in Algerla is shown in Table 22. These data show that of 63 cases recorded in 1987, ll were classifled as indigenous, 1 induced and 52 inported. AJ.l the funported cases gave a hlstory indicating that their infectlons were acquired in tropical Afrlca, with the exceptj.on of one case (P. vivax) which showed travel to rndia. of the indigenous cases, 3 were recorded in thls6Ftrern oases under relnforced control Eeasures, and 8 were tn the north in areas under the maintenance phase situated in seven Wilayat. The two indigenous cases of P. vivax detected in the 3rd quarter of 1987 ln Guelma and Djelfa respective:.y actuiffiilracted the infection while canplng at Guerbes locality in sector Azzaba of Skikda Wilaya under oaintenance/consolidation. Epideniological investigation in this Locality led to r.he conclusion that a resldual focus existed for which renedial measures were implemented. During a lrass blood survey conducted in the 4th quarter of 1987, another case of P. vivax was discovered in this focus. To assess the efflciency of PCD, the ABERtr"" 0.64"1 (73 991 inhabitants) ln the lst quarter, 0.56"1 (6 449 lnhabitants) in the""l"G[ffii 2nd quarter' O.5LZ (58 813 inhabitants) in the 3rd quarter and 0.57"1 (65 848 inhabitants) in the 4th quarter 1987. The low survelllance activities in the 3rd quarter was attributed to the absence of epideniological inforoation from Batna Wilaya and an insufficient nunber of bLood slides collected from the Wilayat of Annaba, Laghouat, l'1rSi1a, Constantine, Oum-el-Bouaghi and Alger. In the lst quarter 1988, only 11 cases were recorded, all of which were classified as imported fron tropical Africa trostly detected in the areas of reinforced control in the south. In Tunisia, base-line studies conducted during the pre-eradication surveys that started in June 1957, as descrlbed by Wernsdorfer (1973), showed that the whole country was under malaria risk. Sone hypoendemic foci were located ln the northern and cenEral Parts of the country, while the endenlcity in the reaaining areas varied froo neso- to hypoendenic levels. The ualaria transmission season was found to extend fron llay to the beginning of November. Regarding the species of the malarla parasltes, P. vlvax was preva1entint'henorth,fo1].olredbyP.fa1ciparunand@,wh11e-ffitrecentra1 and southern zones P. falciparun and P. vivax occurred ln nearly equal proportlons, but P. nalarlae was virtually absent. The principal vect.or was labranchiae in the nort,hern vBc/9a.2 t{AL/90.2 Page 134 rJ- ._t a _t d t o (t l( E (! C)A .h FlltS o (!r+{o o oF{ !J !{ .,1 .c O) trtr{ u O.+J! o O .'r dd srdS(dc .F{ c) d lr..too o, OJ O O ..1 ..1 c)lr ]J OqoJ!+r trO +J H 'r.t r+{ d g ol !d tr 'o c (r, ..1 ..{ .-l O-.{ d oo o +JFIF{ dFt J4 Fl c,) F{ fiF F{F{ rd (! 0J ! -{nt'cocx Q C' E.-tE Fl ONOO.{-lO !rO tuFt..{ q E-C > a 0) ET O rr-l! 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(! 5rdl] = H+J lr c G FJ !*{ t C ru ll{ toroot! Ft lo|!(itu F{ Fl l.t C r.9 (!(l} c cnc lr e ! cn-n lr E 5(ulU F{ g.F{(U'Od I cF lJ r!-ro'qd 3 3 hhc ir lU 0) no b 4(J< F{ 4la u o lr io o r+{ l+i q, o v o ltl ttlttl td ri o N Eo 'u rtal rrtttl lr H o +JE L ,{O '|l qt o o+) it:t:rrr o0 r! tr o.l o.l o.lc.ln p.l:l r{o ttl l\ ln l | | (r) N rdor .s tvlt')-F - HE N t/) 'u H |! o oo ! Og{ o(d rtl r! -.1 rtt ttt OO tr x @ o o o o o o >l"jl r I t | | ?l?l il t{ AIo.I o.lp.l al Etr H F{ E t' ! d 6l c') o^ N otrE '\O! o'* . q) (d !a z9i o) s 3f, .o .o'rrov?HES o ! ? iE ts o : O 6 tr tr.-t trd .F{= +r(n od o td : ii'. - Sl- O C- - ut = : ! Cu ! I .; a tr'u,qL) r\ R E ,^ '6 < 'dt'6t ! o & E ta 6nd FI o !o hqj- Fi ! co(,,.F tr IJ rd oos € >' -9(!trtu Fi (!$ er.a6J 6 ${ (du H 'p aEUt t. ! E r! ur€ o0 d g !r{ lr H d 6l(d d tr od ..r .F{.F{ tr. ..{ lJ Fr tr o !o o$(!! uc) FO = .F{ !J Otl f+r 4tr..{tr c .H .Fr .r{ .F{ tr | I rtr a EtsT! v)(!ru(d J< rr .H .r{ O ..{ (! .r.l ..1 .r{ (! tJIJtr! Otrtrtr U oooo .r{ t}l rt ll q) oo.o) !< r+t ur d q{ || 1d ! E tt) o t{ .e ir4 $f o 0) 6 o a F o E o o rJ H lr c, !E ..{ o o+J trltrl lHl H ru lr .t.t.l :l il (u ho alo.l al tul a. l do. HE (nN € H o oo o OO{ oru tr t! -l oo & o tr vt o c) ah o c o o Ur tl +.1 o lr H = e 6l N trcro (U cJv o tr lrd m 0.loo |! u$.t lr= (d tr u A ..{ .r{ tr $oo Fr EtrU @! @O oan U lr OG o o ca t! t .r{ t! >\ Et(!lr (d I o.o I tr tr El] (! (!o (! =(! e tJ 3 dlJ ..{ r! EVF .:r 3E ; vBc/90.2 t{AL/90.2 Page 137 and central zones, while sergentil appeared to be the principal vector in the south, but the role of nulticolor could not be ascertained. Upon ternination of the pre-eradication survey, the p-Larr-fr1'erations was signed in 1966 .ttd ch. malaria eradication programne L/as started at the beginning of L967 in a pilot zone covering certain parts of Sousse and Kalrouan governorates with 600 000 inhabitants. DDT house spraying was the principal measure of attack. Subsequently, the programmenas extended to other parts of the count.ry passing through the classical phases of the eradlcation progranme. By L972, the progranne covered 10 governorates in the north and centre reaching the consolidation phase. In the south (Gafsa, GabEs and M6d6nine), the activities were linited to PCDand radical treatment as well as epideniologlcal studies and control measures in foci of transmission until 1972 when it becarne possible to advance the progranme in this zone in what was considered a pre-consolidation phase. Fron 1970 onwards, the annual parasite i.ncidence (API) in Tunisia fe11 to less than 0.1/1000 population, and t'o check the nalaria situation a parasitological/seroepi.demio- logical longitudinal study was conducted during I970-L972 as reported on by Anbroise-Thomas et al. (L976). A total of 18 localities was selected in eight governorates grouped in four prlncipal regions ArBrC and D as shown in Fig. 8r. For conparing the results, the same sanpling procedures nere utilized in all investigatlons conducted every six nonths: in Apr11 and ln Septenber/October, (i.e., during the period of the naxinun incidence of relapses or new cases respectlvely) in each of 1970, 1971 and L972. Fig. 8. The distriburion of 18 localities studied parasirologically/ sero-epideniologically grouped in 4 areas (A-D). The hyphen- ated line demarcates the northern and southern governorates of Tunisia. l. Reproduced by permission of Professor P. Aobroise-Thouas from the paper of Ambroise-Thooas et al. (L976) in the Bulletin of the World Health Organizacion. vBc/90.2 ytAL/90.2 Page 138 As surnnarized by the authors, a total of 13 044 persons in the 18 serected localities were exanined parasitologically for the presence of malaria parasites in the peripheral blood, and serologically for the presence of malaria antibodies by t.he fluorescent antlbody technique uslng the heterologous Plasnodiun cynonolgi bastianelli antigen. Slx surveysr'ereconductedat6-nont1y1ntervaationsy1e1ded only one P. vjvax infection (L/2L7I in the 1sr examination ana itt 10 873 slides in tne 2nd exaniffiiTere negative), the initial seropositivity rate at a titre level of)-20 was 18.771 and 8.82 at a titre level of )40, with generally higher seropositivity in the eastern maritioe and southern regJ.ons. There was a clear age gradient, showi.ng higher seropositivity, qualitatively and quantitatively, in the older age-groups. The seroposltlves detected in the first survey was followed up, the re-examination rates varying between 68.57"and 75.42 per survey with 166 persons (40.9"1) participating in all six surveys. The serologlcal results indicated residual malaria transmi.ssion in one locality in the sunmer of 1970. In the other localities seroposirivity ()40) declined fron the first survey onwards, showing a regression rate that is very sinilar to that of the nat.ural regression of malaria infectlons after interruption of transmission. Whena discrj.minative titre level ot )20 was used, nonspeclfic tltre rises were seen, usually in che summerseasons and normally confined to the lowest titre (I/20). The serological results were evaluated and related to the past and the present epideniological si.tuation in Tunisia. The serological pattern corresponded to that of disappearing roalaria in the absence of new infections. In this flrst seroepidemiologlcal longitudinal study under conditions of disappearing nalaria it has been shown that the serological techniques are suitable for conplenenting epiderniological assessment and would be particularly valuable in antinalaria programmes once the parasite rate has dropped below the level ai which classical evaluation through mass surveys in indi.caEor areas becomes neaningful. Chadli, Kennou & Kooli (1985) and ln nore detail (1986) presented a review of the efforts made for the control of nalarla In Tunisia since 1903 cuhoinating in a successful malaria eradication canpaign fron 1956 to L972, with enphasis on the nalaria situation in recent years. The ualaria eradlcation canpaign achieved its objecti.ves si.nce the last focus was Located in Jendouba, where 16 cases of P. vivax were detected in 1975 and six cases in 1976. The last indigenous case lras a."tiffi-t979 in the sarne town. since 1985, no more focl of active malaria transmission have been observed in Tunisia. Ilowever,the survelllance activities still continue with case det.ectj.on covering the huroan population in all territories of the country. In this respect, the Pasteur Inst,itute of Tunisia receives annually between 30 000 and 40 000 blood slides for microscopical examination whlch rePresent about 2O7"of. the total slldes collected fron different governorates. For vector control, the Potentlal breeding places are constantly inspected and treated when found positive for veclor Larvae. The number of nalalia cases detected annually fron 1973 to 1985 were presented graphically as shown in Fig. 91. 1. Reproduced by pernission of Prof. A. Chadli and the Pasteur Institute, fron the paper of Chadli, Kennou & Kooli tI986) in Arch. Inst. Pasteur, Tunis. vBc/90.2 MAL/90.2 Page139 Fig. 9. Malaria cases detected in Tunisia durlng 1973-1985. No, cases _ TOTAL - ---I;rrported (P . v. ) 30 ...... ---Autochthonous -...-.-Transfusional (P.m.) 20 ro During 1978-1985, 68 inported nalaria cases were diagnosed, of whon 852 ltere persons who resided in Africa, 77"in Arab countrles and 7Z in Asia. Classification of these inported cases by profession shoned tbaE 34i( were Tunisians worki.ng abroad, 272 students, 172 diplonats, 7Z foreign technicians, L4"/"marine personnel and 77"others. A new problen has been posed in Tunisia which is t.ransfusional malaria. In 1985, three cases were recorded as follows: - a case of P. f"f"ip"rrr in a woman who bad a high fever after her return from France where she had una@iE@cal intervention; - two cases of P. nalariae in patients who received blooci transfusions from Tunisian blood donors. The infection of these donors was identified by IFA tests. vBc/90.2 t'tAL/90.2 Page 140 The diagnosis of transfusional malaria is often difficult because postoperational fevers are usually attributed to bacterial origin. On the other hand, systematic detection of infection i.n donors by the classical technique is confrontect with the difficulty of the presence of the malaria parasites at submicroscopic levels. The authors concluded that wi.th continuous efforts and Ehe availability of nanporrer and malerial, nalaria transmission could be brought to an end. Surveillance should be pursued and the specialized servj.ce of nalaria should be integrated in the general health services. This process of intetration is not yet conpJ-ete, since for exanple, the malarj-a microscopists are sti11 working for their own field while they should be nade polyvalent. It is suggested that this integration shoul.d proceed progressi.vely taking lnto consideration the epideniological situation and the health infrastructure of each region. Surveillance should be extended to cover travellers coning from endenic areas. As mentioned in the INTRODTJCTION,Farld (1937) in an unpublished document ro llHo presenled malaria profiles for each country of the WHOEast Medlterranean Region.l The country nalarla profile of Tunisia was shown as follows: - Population: 7.5 nilllon 1984 1985 1986 - No. slides examined: tr;Toz tffioqt not available - No. positive slides: 5 2L - No. falciparun cases: 4 9 - P. falciparuo resistance to chloroquine: nil - Vector of nalaria accordlng to vectorial inportance - information on lnsecticlde resistance : An. labranchiae - DDT An. sergentii (south) An nulticolor (south - on epideniological evidence) Main vecEftGGl-neasures! Directed towards nosquito nuisance and other vestors nainly through ULV applicatlon. Case detection: PCD Development of PHCat peripheral level: Good Development of PHC at referral level: Good l'lalaria control: is lntegrated with oEher parasitic diseases control progrannes. l,lalaria tralning cenlres: not available Trained rnanpower: Available but not sufficient Special problens: inported rnal.ari.a In Libya, according to Goodwin & Paltrinieri (1959), a malaria control programmerras conducted during 1954-1957 in certain malarious oases of Fezzan province (see map of Libya Fig. 3 above). No malaria statistical data were available before this programne, but i! Itas assuoed that control by house spraylng reduced the incidence of malaria in those oases that were covered by this programme. Subsequently, a pre-eradication survey was conducted during 1957-1958. P. falclparun and P. vivax rrere the only parasite species encountered occurring at a ratlo of 3:1. The malaria incidence rdas not high and epideroics had been rare in the Past. l.lany of the farners abandoned cheir farns and nigrated to Trlpolltania. When farus were abandoned, the dug wells and other sources of i.rrigation Itater were also abandoned. It was expected that this would increase breeding pl.aces suitable for anopheli.ne vectors, and consequently the roalaria incidence would increase. At the tine of the pre-eradication survey, malaria was classified on the whole as hypoendenic 1n Fezzan oases. As showa under 2.5 and 4.5 above, the vectors in Fezzan are sergentii and nulticolor, the latter was lncriminated only on epidenlological grounds. .In a review of the history of nalari.a in Libya, Gebreel (1982) nored chat based on rhe pre-eraciicat,ion survey, nalaria occurred in each of the three regions or governorates of Libya: in 25 villages in Fezzan, 4 vlllages ln Tripolitania and 2 villages in Cyrenaica. In 1960 a malaria eradication programne was launched aiming at the following: 1. Supplenentary inforroation has been added by the nriter in some country proflles. vRc/90.2 t4AL/90.2 Page l4I (a) To achleve cooplete eradlcation of malaria in the whole country by applying appropriate Eeasures: - resldual house spraying, ant,llarval Deaaures and chenotheraPy; - epideniologlcal surveillance in order to ensure total case deCectlon and treatrDent. (b) To pronote trainlng national personnel of varlous categories in malaria eradlcat,lon techniques. (c) To develop wlthln the natlonal health servtce a oechani.sm for actlve vigllance against the reintroductlon of malarla following lts eradication. As a report on the oalaria sltuatlon Libya by Kedlkl & Ashraf (L972> ls not avallable' an abstract of this report 1n the Tropical Dlsease Bulletin (TDB) 1974' 71(8) Abst. 1688' pp. 787-788 is reproduced herer. The abstract nas nade by Prof. L.J. Bruce-Chwatt who also commented on t,he report as shown beLow: "I(ADIKI, O. & ASHRAF,M. llalarta in the Libyan Arab Republlc. 84 mineographed PP. 1972, Sept. Departnent of Endemic Diseases, lllnistry of Health' Trlopoli' Llbyan Arab Republie. " "This is a useful review of the past and present malarla situatj.on in Libya. It couprises a descriptlon of the country, the prevlous hlscory of malaria, the progress of the eradlcation progranme and 1ts future prospects. Out of the total populatlon of over 2 nilllon (ln 1971) about 150 000 llve Ln ualarious areas, roainly ln the Eezzarr, but also in northern and eaatern Tripolltauia and in eastern Cyrenaica. In the 1950s, oalaria surveys showed a paraslte rate of the order of 37. The nain vectors were [email protected] 1959, and in 1963 the overall annual paraslte lncldence fell to 0.32, but during the followlng cno years, because of the considerable auount of loported and introduced malarla, the lndex rose to 2.12. Slnce 1956, subsequent to renewed antioalaria actlvltles, the nuuber of cases of oalarla decreassed steadily; during the perlod I969-L972 only 3 lndigenous cases of malarla were detected, whlle 39 cases were ioported froo various parts of the world. A further 2l cases, so far unclasslfied, were reported in the eastern region Ln L972. A strict vigilance system has been organlzed to prevent the inportatlon of malarla. It L972, the western and eastern reglone (Tripolitanla aud Cyrenalca) were in the nal.ntenance phase of nalaria eradlcaclon wh1le the southern reglon (Fezzan) was ln the consolidatlon phase. [Thls is a valuable report although marred by oany typing errors. The laxonomic [email protected] findlng (1n f95i) of a fers specioens of A. ganbiae at Edri and Ubarl in the Eezzan, norEh of the 27o N parallel ls of considerable interestl." It seeos that the date of flnding An. gaublae s.1. was a misprint as it should read 1935. Howeverr the flnding of An. gaulbiae s.1. has not been supported by further surveys (Shataby, L972 and Rarnsdale, l98g: in press). The only reference ci.ted by the last tlto authors was tha! of Lodato (f935) who recorded An. ganbiae s.l. at Edri in E1-Chati area and Ubari in Wadi El-Adjal in Fezzan province. Ransdale (loc.cit. ) doubts the valldity of this record and thinks that it night have been due to oisldentification. Gilles (1982) advlsed on protection from nalaria tnported into Libya, since a high level of nalaria control has been achleved and autochthonous cases have becooe rare. Receptive areas where transDission could recur if funported cases are introduced, pose a great danger. The biggest threat for the reintroduction of malaria in Libya coues fron the large number of nigrant labour groups orlginating froo oalarious areas, lllegal nigratlon froo contlguous oalarious countries, and Eo a lesser extent froo Libyans who visit malarlous countries for various reasons, and have been inadequately protected. The foJ.lowing prophylactlc measures Itere advocated: (a) Libyan nationals: A11 natlonals visltlng nalarious areas should take ProPhylactic drugs one week before departure, throughout their stay and for four weeks after thelr i. Reproducea by pernlssion of Dr Carolyn Brown (ed.), Tropical Disease Bul1et1n and Prof. L.J. Bruce-Chuatt. vBc/90.2 vt}J'/90.2 Page I42 return. Chloroquine 300 og weekly ls satisfactory excepC for chloroquine resistant P. falciparu! areas. If visltlng these areas Maloprln (pyrlnethauiue * daPsone)' I tablet i-eeElflnsteaa of chloroquine should be prescribed. (b) lllgrant labourers: A11 nlgrant labourers on regisEration and/or arrlval ln a receptive area in Llbya should be glven presumptlve treattrent for oalarla as follolt6: Day 1: chloroqulne 600 ng (slngle oral dose: 150 ng base X 4)' Day 2: prlmaqulne 30 ng (single oral dose: 7-5 ng X 4). If they develop a fever and are found positlve for ualaria' they should be given radical treatment. (c) Illegal migranrs: This group ls difficult to identlfy and manage. If they develop fever and are found posltlve they should be given radical treatDent. Gebreel, Gilles & Prescott (1985) reported on a seroepidenlologlcal study for malaria in Libya. In the past 10 years, considerable socio-economic developrnent in Libya has created favourable condltlons for the posslble recrudescence of nalaria lransoj'ssion. There has been an extension of water bodies of all tyPes arising froo agrlcultural and housing developments, coupled with a heavy lnflux if iunlgrant labourers from nany Parts of the world includlng malarlous countrles, with rtaDy Persons havlng asyl0PtoDat,ic parasltaeni.a or potentlally relapslng lnfections. In 1978, health screenlng ot L6 207 inmigrants ana tnhabttants 1o Sebha, the prlnclpal town of Fezzan provlnce revealed the presence of 46 positlve slldes: 44 P. vlvax and 2 P. falclParuo. Of these, 28 were foreign lnnj-grants nalnly fron Indla, Paklstan and tropical Africa, the reuainlng were Libyan natlonals. A11 forelgn cases were P. vlvax excePt one !!glg!4 fron pakistau. In Septenber-October 1980 a snaffiliES-reak of oalarta, tnvolving 18 persons' occurred lon Zuara, a coastal town surrounded by uarshland, approxlnately 120 ks west of Tripoli and 70 ko east of the Tunislan border. On 5 September two Tunisian lnmigrant 36 days a further 16 cases workers were found posltlve fot s!g; during the foltowlng of P. vivax nere diagnosed. ltrel-ou-prtsed 11 Llbyan resldents, none of whom travelled out&iETi5ya, one Sudanese, one Indlan and three more Tunlelan i.@igrants. No vecEor species could be dlscovered. Ilowever, lt was clear that local tranaulssion had taken place wlthln a receptlve area. Thls outbreak suggested that, aLthough malaria transmlsslon was ,tntomon ln Llbya, there is a rlsk of recrudescence, and possibly the relntroduction of malarla arlslng directly from the large nuobers of imigrants currently arrivlng ln the country for perlods varylng fron slx months to one year. To assess thj-s rlsk, a seroepldeolologtcal lovestigatlon tras carrled out durlng August-septeober 1981 using IFA test wlth blood specloeus collected by the fingerprlck, fllter PaPer nethod. The specinens were taken fron 330 imigrant workers, none of whon had resided in Libya for Dore than slx oonths, and 106 natlve schoolboys, none of whou had ever left Libyarnor even their birthplace. Sanpling covered the following localities as shown in Flg. 10.r. - Zuara: 100 adult labourers, all frou Indla, enployed on Port and sewage treatment construction sites; the locallty ltas the slte of the 1980 outbreak. - Ghat: 8l adutt labourers, all from India, euployed on a hospital construction slte in the Iocality whlch ls a snall town in Fezzan, adjacent to the Algerlan border' approxlnately 1000 ko southwest of Trlpoli. - Derna: 140 adult l@lBrants from non-Asian orlgin (Algerla, tsulgarla, Gaubia, Niger, Tun1sla and European Turkey). They were employed in various tyPes of work related to urban building constructlon. Derna is a coastal town about 300 kn east of Benghazi. - Ghat: 106 natlve schoolboys, 6-10 years old' . For prluary screening P. fleldi antigen was utilized as a deteclor of unspecified malarial infecrlon 1n ttre FaiG?E-"era, tested at a dilution of 1:16. Thus, all non-reacting sera were classed as malarla-negativer indlcating a lack of exPosure to oalarla of any type. All prlnary screen reactors were further tested at 1:64 dilutlons aga1nstbothi.fierdrand}@'ant1gens'anyofthosereact1n8strong1yatLi256 Tropical l-ledlcine and 1. Reproduced bY Permission of Dr A.O. Gebreel and the Annals of (f985). Parasltology frou the PaPer of Gebreel, Gllles & Prescott wc/90.2 t{!J-/90.2 Page 143 Fig. 10. Areas of seroepldeulological studles in Libya. MEOITERRAN€AN TUNISIA )-z*io .--..$'suroto Dcrno / bnotronTouorerro! Ecnghorr "*i Sirfc Ghodomes : t f RtPOUtfAHta \ aLGERra( .aro* EGYPT CYRENAICA t scbho LIB Y:A . Murlul Ghot FEZZAN Kufro a NI6ER CHAO SUOAN was further tested at dilutlons of L:LO24 and 1:4096 agalnst the relevanr antigen. Those sera reacting strongly to P. falciparun and lees strongly to P. fleldi were classed as fa1ciparrroposit1ve.convffite-reactingmorestrongr|E.-.rie1diwerecIassed as non-lglgl}$ Poslt1ve. It would be possible to define the fnaiviauaf narure of rhese latter infections by use of species-speclflc antlgen, but in this context it is necessary only to distinguish between P. falciparun as a dangerous parasite, and other specles which are less directly dangerous b"t nore eenaclng from an epideniologlcal standpolnt since their human carrlers rnay relapse and lnltiate transmi.sslon. Roughly half of the iDDlgrants fron India, 47"Aand 46.92 from Zuara and Ghat respectively, yielded IFA Positivity in the prinary screening, whilst those fron a varlety of other origins outside Llbya, yielded a ralio of only LO.77,. Those sera reacting at a tltre of L:64 or greater uere considered as indlcatlng recent and/or heavy infections, even, possibly as)'nptogatic parasitaemla. The native schoolboys acted as a control group havlng been born after the malaria eradlcation canpalgn of the 1960ts, and not having travelled outside Libya, nor even very far frorn Ghat; chey were all 1002 negative. In all iomigrant groups, there appeared to be a rate of P. falclparurn posltlve at 1:64 or greater averaging 2.82. Indian inmlgrants presented a posltivity rate of strong reactions at 1:64 ot greater ranging froo L2.42 Eo L9Z in respect of species other than P. falc]2gg. This rate constitutes the Polential relapse rate. r*igrants origlnatln!-ffiito,tntrles other than India ylelded a Positivlty rate of 3.47, at ) l:64, to non-Slg.lg or potentially relapslng species. Thus, all short-term inuigrants from unspecified oalarlous areas nay be considered to Present a risk of ln;roducing elther relapslng or non-relapsing malarla to Libya of che order of 37. Indian imigrants, in partlcular, present a rlsk to the Llbyan comunity of relapsing nalaria, principally P. vlvax, as high as 192. Furtheruore, the native connunity at risk, particularly the schoolchildren, would appear to have little or no ionunlty to malaria as a result of the previous effectlve eradlcation caopaign. vBc/90.2 r4AL/90.2 Page L44 To conclude, the authors considered that a high degree of control of nalaria transnj,ssion has been achieved in Libya, to the extent that autochthonous cases had becorne unconmonuntil 1980 when an outbreak occurred in Zuara, in coastal tripolitania. The ouLbreak indicated the possible danger of the resurgence and establishnent of nalaria transnission as has occurred ln several countries in different parts of the world, following earlier effective control. There are many receptive areas in Libya where transnissi.on ui.ght occur if active human infection were introduced. The princlpal threat comes fron large groups of innigran! lrorkers originating fron distant malarlous areas, and to a lesser extent froro neighbouring countries, as well as inadequately protected Libyans who spend periods in nalari-ous areas abroad. The present investigation demonstrated that nearly half of innigrant workers fron India probably had been exposed !o malaria infection and that as many as 192 have antibody levels suggesEing recent and/or heavy infection; a najority of these persons have been exposed to relapsing types of plasnodiunr infection. Whil-e it wouLd appear that imigrants fron other geographical areas presen! a lesser threat in terns of the numbers of potentially relapsing infections, it is clear that the immlgrant labour force from malarious countries on the whole present a rlsk to the connunity particul.arly in area such as Ghat, where the entire population of schoolchildren nay be non-imnune. It nay be assuroed that vector populations will have recovered from the inPact of the previous spraying campaign, and that modern developnent would assist in extension of breeding places of vector populatlons. In addition to serglll:L and multicolor in Fezzan, labranchiae could prove to be a particular thrEf in coastal Tripolitania narshland. Thus, a thorough anopheline survey is needed to deteroine the current distribution and density of the nai.n vectors. Moreover, an expanded imigrant and resi.dent antibody survey sfunilar to that of the present study would assist tbe fonnulation of nalaria control policy in future. In his recent review of anophelines and inported malarla in Libya, Ramsdale (1989 - in press) recalled that Fezzan province has a long history of epidenic oalaria, with nany outbreaks of P. falciparun brought by carriers transported by caravans coming from the south and transmitted by loca1 vectors (cltlng Gebreel, unpubllshed). P. vivax used t.o be most Prevalent near the coast. At the present tlme, most inported nalaria ls of P. vivax infectlon, though there are soue cases of P. falciparun. Moreover, most parasite carriers quickly disperse frou the ports of entry, now nainly airports, making al.l parts of the country equally vulnerable. The desert specles sergentii and nulticolor considered to be the main vectors of malaria are sufficiently prevalent to xoaintain malaria transmission in oost of Libya. Although direct proof is lacking, epidenlologlcal evidence points to the vectorial role of multicolor, and thi.s species ls able to naintain a low level of oalaria transtrission over a long period. In contrast to llaghreb where labranchiae is the principal vector and is still responsible for residual foci of P. species in Libya is funportant only Ln a very restricced area. Almost aU iffi?lFof"i.--Jhis this species and other marsh breeding mosquitos are found in a circumscribed coastal area around Touarga in Tripolitania. ln the unpublished document of Farid (f987), the country nalaria profile of Libya was shown as follows: - Population: about 3 nillionl Population at risk: nll 1984 1985 1986 - No. slides exauineci: 70% 5 862 n6ilavailable - No. positive slides: 117 7L - No. falciparun cases: 7 2 - P. fal.ciparuu resistance to chloroquine: nil - Vectors of malaria according to vectorial lnportance - infornation on insecticide resistance: An. sergentil, An. multicolor (the latter considered vector on epideniological evidence )- An. labranchiae (in a very restricted area in Tripolitanla). For resj.stance, see be1ow. - I'lain vector control Deasures: DDT house spraying 1n foci of transmission; teDephos larvielding. - Case detection: llain1y through PHC - Development of PHC at periferal level: Good - Development of PHC at referral level: Good 1. This figure was revised later (see below). vBc/90.2 tLN'/90.2 Page 145 - I'lalaria training centres: Non-existant - Trained manpower: Available - Special problens: Inported malaria Fron recent infornation communicated to WHO/I'IAP,the malaria situation in Libya in 1987 show the following: (population given as a nid-year estioate in 1000s). - Total population: 4 000. - Population of originally nalarious areas: 1 400 - Population protected by house sprayi.ng: 100 - Population protected by other anti-vector measures: .L00 - PopuJ.atlon under surveillance: 4 000 - No. slides exauined: 4 699 - No. positive slides: 75 (64 P. vivax & 1I P. falciparuo) - all inported from abroad. The epideniological situatlon remained satisfactory in 1987, as no autochthonous cases have been detected, and only imported cases were recorded (fron troplcal Africa, India and Turkey), cornpared with 57 in 1986 (54 P. vivax & 11 P. f"fglp"r*.. The vectors remalned suseeptlble to DDT. ln EgyPt, it has been shown above (see under 3.5) that pharoensis is the main vector of nalaria in the Delta and trile Valley. It i.s joined by sergentii as an additional vector in Faiyun governorate, while sergentii acis as the ilETilllector in the oases of the eestern desert. An. ganbiae s.1. probably An. arabiensis, (the species whlch has been identified rrot sGiffinv"aed upper egypt-GEnril ir was exterminared in 1945 through an lntenslve canpaign during L942-L945 as showa bel.ow. llalawani & Shawarby (1957) reviewed the history of malaria in Egypt fron the tine of the anclent EgyPtians until 1956 including the ganbiae-eradtcation canpaign. The parasite species recorded during 1940-1953 were P. vivax, P. falclparum and P. nalariae at a ratio of 13:18:1. The last paraslte speci.es haa a linired distriburfon, EEin[-Toun=i- in Siwa and tsahariya oases as well as Faiyum governorate, though a few cases were also reported from the Suez Canal zone anc the eastern part of the Delta. P. ovale was recorded only on three oecasions, but tlto of these were of doubtful tocat-@T The available data on nalaria incidence during 1940-1953 were not nalarionetrlcally standardlzed, hence not always conparable. Nevertheless, the data could indicate that Lower Egypt has always been more malari.ous than Upper Egypt, except for the epidenlc caused by the i.nvasion of ganbiae s.1.. into Upper Eygpt (1942-f945). The data also showed rhar nalaria has been slowly regressing durlng the prevlous 40 years, a great drop in incidence lras particularly noted since 1950. D The authors further described in detail special campaigns for the control of malaria in the oases of the ltestern desert an campaj-gn. No sergentii could be found for two years after the di.scontinuation of tne Iarvicidal neasures, despite active searches durlng the breeding season, although ogher anophelines lrere still present. After 1953, the nilaria incidence declined draitically from an iniEial I5Z it Dakhla and 6"/"in Kharga t.o practically nil. However, a slight rise j'n nalaria incidence was observed later in Dakhla, together with the reappearance of sgrgentil which probably was relnt,roduced fron Bahariya oasis, and gradualJ.y spread from the point of reappearance. Residual house spraying carried out in 1.951successfully reduced again the nalaria inci.dence. [This experience with sergentii in the oases supports the viev that. the success achieved wlth the externination of an exotic species such as An. ganbiae s.1. should not be exPected to naterialLze with the eradication of an ina:.gen6iE-ffii61 . In the Siwa oasj.s, a roalaria control caopalgn was conducted by applying DDT house spraying instead of larvlciding. Also here sergentii was the main vector which existed together with nultlcolor at a ratio of 2:I. Fron a blood survey carri-ed out in December 1949, the-neanlGlte-rate was I8.8'l wich P. falciparun and P. rnalarlae existing at a ratioof2..1;no.Prvi.vaxwasfoundinthat;*ay:--nrinfan@raterecordedin 1950 was 252. DDGE!'plied in four rounds in 1951, tno rounds in each of 1952 and 1953, and one round only in 1954. The parasite rate fell draaatlcally, with the P. falciparun rate decreasing fron 14.41 to O.I8"l, and the P. nalariae rate fron 5.27 to 1.12, while the infant parasite rate nas zero. By 1955, naliETZFp'racrically disappeared as no cases could be found, while in 1956 only three P. rnalariae cases nere encountered in a snall vil}age. The entlre population of this vi.lfEge (150-inhabitants) was treated and survelllance maintained. The vector, sergenlil, though reduced in numbers' was still Present. The cost of this canpalgn was much less than larviciding. In the Bahariya oasls, examination of 8841 blood slides collected fron all age-groups during April and December 1954 showed a mean parasite rate of 6.32 with P. nalariae being predom1nant.TheincidenceoftheparasitespecieswasP.na1arii@falcipar.,n 2.12 and P. vivax 0.22. P. malariae was present in all;;nt#-6; April ro oecenufrSS+ withapeiffiEpt".b"';@'!'asencounteredatavery1owleve1unti1october reaching its highest level i.n Novenber-December. P. vlvax whlch was practically absent durlng the yearr lras encounEered nainly during octiEF-uovember, but at a very low level. As in the other oases gergentii was the main vector, with multicolor and pharoensis being Present. The prlncipat contror neasure was the adninistraEiffie antiilGFdrugs hitherto available to the entire populatlon of the oasis, but leaving two villages untreated for cooparison. The drug used rras canoquine/primaquine (one tablet containj.ng 0.15 g caooquine + 0.01g prinaquine). During January-ll,arch 1955, the population was treat.ed at fortnighcly intervals, glving three tablets in a single dose to the age-groups above 8 years, and reducing the dose for younger age-groups. The parasite rate as measured from examlnatlon of 514 blood slides fell fron 9.72 to L.77. The same regimen and schedule was administered duning the peak season, Septenber-October, also reduced the parasite rate to 0.92 after it had risen to 42. In the untreated village the parasite rate lras nueh higher (8.62). In Falyun governorat,e, DDT house spraying was applied starting from 1947' but due to nany difficulties lncluding shortage of the insecticide and transPort, and withdrawal of personnel to deal with the cholera epldenic Ln L947 and the reapPearance of An. gambiae s.1., the spraying coverage was inadequate. Nevertheless, the results were encouraging, as the nunber of malaria cases reported fell gradually fron 3 069 in 1947 to 49 in 1952. Fron 1952 to 1954, the nunber of norified cases fell further to 11. llhen the spraying canpaign was discontinued in 1955, the number of cases rose to r01. Followlng the detection of dieldrin/IlCH resistance and subsequently DDT resistance in pharoensis during the early 1960rs, field trials were conducted to assess the operational inplications of these resistances and to evaluate alternative insecticides and nethods of application. The first trial was conducted in Giza governorate in the rural outskirts of Cairo covering a population of 28 000 inhabitants llving in four medi.um-sized villages and about 60 scattered hamlets. The trial nas reported on by Zahar et al. (1966) (see under 3.10 above). The site of the trial was regarded as the field tralning area (F.T.A.) of the former tiHO Regional Malaria Eradicaclon Training Centre. Prior to 1960 no house spraying had been carried out in this area. Pest control was roainly directed against the cotton leaf-worm, using HCH/DDTdust untll 1957-1958. In 1961, a heavy lnfestalion of cotton-leaf worm dictated the use of large quantlties of these and other insecticides lncluding organophosphate and carbamate compounds. The use of lnsecticides in agri.culture seemed to have exerted selection pressure on pharoensis resultiag in che appearance of vBc/90.2 MrJ,/90,2 Page I47 organochlorine resistance initiaUy. Ba.se-line parasitological and entomological data were collected fron the F.T.A. during 19t59-1960. P. vivax was the only infection encountered in this area, with an overall parasite rare of LL.67Z in 1959 (2150 blood slides exanined frorn all age-grouops). Fron the end of June 1960 to L962, the houses of the area received one round of DDT spray'ing annually at a dosage of 2 g/m2, and parasitological/entonologi.cal evaluatj-on, was pursued. Entonological observations rdere maintained in an unsprayed area, I'larg, o,n t,he southeastern side of the l.relta. Conditions in this area were generally sinilar to those of the F.T.A., though wlth nuch rice cultivation and a treater natural output of pharoensis. ln 1961, however, rj,ce cultivaEion lras restricted in the Marg area t;a-t-e density of pharoensis dropped to a relatively low J.evel, and in 1962 rice cultivation was much more restri.cted, hence the density of pharoensis was too snalL to a1low compari.sonwith the sprayed area. Due to liuitation of staff, parasitological stu.dies could not be conducted in the }larg unsprayed area. As surnnarized by Zahar (L974), under the influence of DDT spraying the overall parasite rate dropped in 1960 to 2Q7"of lt,s original prespraying level. of 1959. This indi.cated an adequate regression during the first year of attack, which, if naintained, would ultinately have resulted ln dininution of nalaria to a very 1ow level Macdonald & Giickel, L964). There was evi.dence lhat the insecticide was wearing off in Septenber 1960, when four infants born after spraying became posi.tlve. Except for this temporary reversal, reflecting also operational defects, the overall picture of 1960 was generally sati.sfaccory. The control of vector longevity was satisfactory when the average trap rnortality vas 7QZ or more; it becane unsatisfactory when the average was below 547", (see Table 17 above). In terms of probability of survival through one day (p), resulls nere adequate as long as this index was kept below 0.5. Taking the dat.a of satisfactory j.n resPonse 1960 as a basis for assessuent, the appropriate critical value for survival through the sPorosonic cycle night be approximately 0.002. In 1961, the second year of DDT spraying, the crude parasite rate showed a nuch snaller decline, ind.icating a less favourable response. It fell only from 2.37'A to L.872, the latter being e<1ualco L67. ot the base-lj.ne level, instead of the 4Z thaE would have been expected after tlro years of attack had the initial rate of decrease been naintained. Trap nortality was only slightly over half the 7oZ level required for satisfactory control (37.62, 10-17 veeks PostsPraying). Vector probability of daily survival (p) lncreased to 0.62 and through the sporogonic cycle to 0.013, i.e., over six t,imes the critical value of 0.002 suggested on the basis of t.he data of satisfactory response. In L962, the third year of attack, the genera.L Parasite rate fel1 to 4.52 of the original 1959 level, compared with the expected level of Q.4% had satisfactory control been continuously nalntained. That raEe of decline inplied further low-grade transmission i.n the sprayed area in the third year of a!!ack. The cri.tical levels for the probabi.lity of dai.ly survival and through the sporogonic cycle were exceeded. The trap nortality was only 4L.8"A, again nuch inferior to the 702 required for satlsfactory conlrol. This unsati.sf,actory control coincided with a deterioration in the susceptlbility level of pharoensis to DDT, which lras determined periodically throughout the trial. Further observations by Shawarby et ial. (f965) confirned the ineffectj.veness of DDT spraying even when appJ.ied in two rounds, each at 2 g/m2, in the saDe trial area in f963. However, it was not certain whether DDT resistance was the nain factor responsible for continued transmission, or lf outdoor biting and outdoor resting of the vector population had played a role. Three insecticidal trials were condur:ted i.n Kafr El Sheikh governorate in the northern part of the Delta during 1965 as reporterd on by Shawarby et al. (L967a, b & c). The si.tes of the trials had extensive rice cultivarEion with a high pharoensis output. Three trial areas were selected: one for DDT sith a ;population of 37 785 inhabitants, a second for nalathion wlth a population of 57 132 inlnabltants, and a third for HCHwith a population of 48 842 inhabiEants. A fourth area wit.h 45 846 inhabitants was left unsprayed to serve as a check area. In 1964, pre-operational base-line parasitological surveys in the four areas sirowed t,he following: - DDT area: pre-season (ltay), 2 casers/1000; post-season (October), 3611000, of which four were P. falciparun. - tlalathion: 1-411000 in l{ay 15 p. v:lvax t 2 p. falciparun/5L25 persons examined; 5.o/1000 in JuIy; 2/Iooo in october.lTlG'ses ii-ilffiffio surveys reere P. vivax. - HCH: 1.6/1000 in l,tarch; 7/LO0Oin.Iuly-august (18 P. vivax * 3 arvm/294I persons exanined); 3.8/f000 in October 1,/ P. vivax + 4 P. falciparum/2906 persons cv:ni ncd \ vbc/ 90.2 MAL/90.2 Page148 - Checkarea; 1.5/LO00in l,tay; L.2/LOOOin July (6 p. vivax * I p. faJ.ciparun/5723 Persons exani.ned); f.5/f000 in october (6 P. viva4 + 3 ffiEparuo76FiffilF exanined ) The trials were assessed parasitologlcally and entornologically using different techniques. The results are sunurarized as follows: DDT applied , ,,- in one round during 16 l"lay-6 June 1965 at a calculated dose of 2.9 g/n" gave noderate inpact on vector population up to the 13 weeks as assessed entoroologically, while the parasitological data indicated resumption of nalaria transmission after the 8th week post-spraying. Marked deterioration of the suscept.ibility of pharoensis to DDToccurred, as one hour exposure t.o 4% DDTgave only L.47" aortality in sePEenber towards the end of the season, as compared with 352 nortality at the beginning of the season. - Malathion applled in one round during L5-26 itay 1065 at a calculated dose of L.l g/nz remained effective for 9 weeks post-spraying, although trap nortality cont,inued to be high for a longer period, as assessed entomo.l.ogically. However, parasitological evaluaEion indicated that nalaria transnlssion rdas resumed after the 7th week post-spraying. - ltCH applied in one round during 22-30 May 1965 at a calcuLated dose of 0.44 g HCH/mzproduced moderate effectiveness up to the 7th week post-sprayi.ng, as assessed parasitologically/entouologically, after whlch period nalaria t.ransmission resumed. A fourth trial was further conducted also in Kafr El Sheikh governorate i.n the sane area of HCHtrial as reported on by Shawarby et al. (196S). The alm sas to investigate whether continued spraying wlth HCHon a longer teru would overco&e the double DDT/dieldrin resistance ln pharoensls. Thus, HCHin the foro of lindane was sprayed in two rounds at 0.4 g/nz each: the flrst in June 1966, and the second in August of the same year. In 1967' only one round was applled in July. Entonologically, although there Itas some reduction in the parous rate and the nan-biting rates in the sprayed area, the population of pharoensis tended to recover during Septenber-October. llowever, massive application of pescicides for crop protection night have had an inpact on the vector population as evidenced by narked reduction in the parous rate in the unsprayed check area during July-August in 1966 and 1967. Parasitological evaluation failed to provide evidence, since malaria seemed to have been declining to a very low level in the whole area. In 1966, only two P. vivax cases were detected among L7 593 blood slides exaroined fron the sprayed area. I; l3ffinot a single positive could be found among 1886 slides col'lected fron the sprayed area, and L 648 slldes frou the check area, allhough all erere sanpled from fever cases by act,ive case detection. [These trials showed that none of the hitherto available lnsectlcldes gave satisfactory control of nalaria transmission due to organochlorine resi.stance in pharoensis or a short perlod of effectiveness of oalathion applied at a lower dosage]. As remarked by Zahar et a1. (f966)r nalaria incidence sholred a declining trend in the early 1960fs; the nunber of cases reported in the whole country dropped fron 95 933 in 1959 to 83 22L in 1960, 53 160 in 1961, and 45 875 i,n L962. This was explained as possibly being due to a natural recession of nalaria, and also to the wide-scale discribution of anclmalaria drugs as well as the use of a vari.ety of pesticides in agrlcultural pesC control. In the early 1960ts, Egypc preferred not to est,ablish a malaria eradicaEion programme, but opted to continue malari.a control activities on a long-terD lrith the ultirnate aim beLng malarla eradication. In an unpublished reporr to WHo, Rakha (1984) revlewed the history of nalarla control in Egypt and descrlbed the control activitles undertaken by the Malaria Control Sectlon of the l'linistry of Health. The nalarla parasites are P. vivax and P. {alciparurn wlth the latter belng confined to Faiyun governorate. P. nalarilffi used to exist in the past has been eradicated fron the oases and is no longer found in Egypt. The nunber of nalaria cases detected in the whole country after having been reduced to 1900 (O.27'l of slides examined) in 1969 lncreased again to 4881 (O.73%), 20 783 (1.82)' 23 190 (1.722> and 21 198 (1.57!) Ln 1970, 1971, L972 and 1973 respectively. Subsequently, the number of cases steadily declined reaching 423 (O.O3% of I L23 727 vBc/90.2 t4AL/90.2 Page J.49 slides exanined) in 1982. The Malaria Control Section continued to expand until it includes at the present 100 nalaria unlts (or stations) and 200 sub-units distributed all over the country. The section i.s responsible for the technical supervisi.on of the work of the malaria stations. [Adninistratively, the malaria stations and sub-units are under the responsibi.lity of the provincial health services]. The activities undertaken were outlined by the author as follows.. (a) Surveillance: PCDincludes blood exanaination of all patients attending the malaria stations and fron fever cases attending hospit.als and rural health unils, as well as treatlDent of all positive cases. ACDis undertaken by house to house visits for collection of blood sl1des fron fever cases and giving presumptive lreatment, as well as radical treatnent of positive cases as proved by nicroscopical examination. (b) General surveys and epideniological investigations: Parasitological surveys covering IQl! of. the population are carried out in villages. Epideniological investigations are carried out in conjunction with positive cases. (c) Larviciding operations: The area under the responsibility of each malaria station and subslat.ion j.s larvicided weekly using fuel oil mlxed with Triton X-100 as a spreading agent. (d) Spraying operations: Houses in villages with high nalaria incidence or in areas with rice cultivation are sprayed with oalathion at a dose of 2 glm2. (e) Anopheline larval and inago surveys: Routine observatlons are carried out in Potential breeding places, and lnago collections are nade in fixed capture stations as well as other houses selected at random. [The author did not give any information on imported malari.a, although Egypt has a lot of contact with nalaria endemic countriesl. The country malaria profile of Egypt (Unpublished document by Farid, 1987) was showa as follows: - Populatlon: about 50 nillion Population at ri.sk: 13 nillion 1984 1985 1986 - No. slides examined I Ed-6so 1 180 900 not available - No. positive slides L94 72 63 - No. P. falciparun cases 10 19 19 - P. falciparun resistance to chloroquine.' neither reported, nor suspected. - Veccors of nalaria according to vector importance-information on insecticide resistance; An. pharoensis - DDT/dieldrin; Op & carbamates An. sergentii - DDT (localized dlstribution in Faiyun & oases) - l'lain vector control measures: roalathion house spraying and tenephos larviciding. - Case detection: ACD & PCDadequately conducted in foci of transoission - Developoent of PHC at peripheral leve1: Good - Developnent of PHC at referral level; Acceptable - llalaria concrol: is decentralized as part of PHCsysten and technically guided centrally. - Malaria training centres: available in Beheira, Tanta, Cairo and Faiyun. - Trained nanpower: sufficient - Special problerns: agricultural practices. From lhe infornat.ion comnunicated to WHO/MAP,data of the malaria situation in Egypt in 1987 show.' (populatton given as a mid-year estimate in 1000s). - Total. popuJ-ation.' 51 000. - Population of originally malarious areas: 40 000. - Population of areas clained to be freed from malaria.. 29 000. - Population under malaria control prograrnme: 11 000. - Population protected by houee spraying: 2 000. - Populatlon protected by other anti-vector measures: 40 000. vBc/90.2 MAL/90.2 Page 150 - Populati.on under surveillance: 4 g07. - No. slides examined: 1 190 386. - No. positive slides: 33 (17 p. vivax & 16 p. falciparun). - Estiuated total ntrnber of caffi6' Seroepideroiological surveys were carried out in different governorat.es in Egypt during L977-L979 as rePorted on by Hassan et al. (1983). Anrigen slides nere prepared in London fron schlzonls of P. fieldl obtained from an infected blood of Aotus monkey for IFA lest. Due to an inadequaFliriud of antigen slides, rhe number of ut6i?-sanples for testing had to be linited to 1 4TL samples fron Faiyun governorate and 723 ftom Qaliubiya Sovernorate. The samples represented all age-groups, but abouE 3O1!of the total rdas taken fron children of school age.- In the other [o.rtrnorries of the Delta and the Canal Zone sanpling was restricted to 1000 children of 5-9 years age-group, allocatlng 200 samples for each governorate: Kafr EI Shetkh, Beheira, Gharbiya, Sharqiya and the Canal Zone. Parasitological examination of 1471 blood slides collected simultaneously fron Faiyun showed an overall parasite rate of 6%, with lhe rates in chil-dren of the age-groups 0-4 I:1rs and 5- 9 years being 7.81 (9O exanined) and 8A (524 exanined) respecrively. None of 736 blood slides collected fron all age-groups in Qaliubiya governorate were positive. No b]ood slides were collected fron the oEher governorates fbr parasitological examination. Serologically, Faiyun showed the highest positivlty rate. of 524 children of 5-9 -(3.gi()years age-group, (8.82) 4b were .seroposirive a! a ritre of L/64, 34 (6.51!) at L/256, ZO at I/Lo24 and 5 (tZ) at I/4096. In Qaliubiya, the age-group of 5-9 years (427 exanlnedi showed a naximuu tltre of L/256 with the positlvity rate being lZ. This was t.aken to indicate that the degree of nalaria endenicity in Qaliubiya ,ois much less than in Faiyun. In the other governoratesr the positivity rates were very low and none of the sanples examined fron Kafr El Shiekh and Gharbiya recorded the leve1 of specificity, 1/64, and ooly one was positive at t.his tltre fron 114 and 29 samples exanined fron tseheira and canal Zone respectively, while ln Sharkiya only one of i6 sanples examlneci was positive at L/256. These results led the authors to deduce that in Ehe Delta region, there nere some hidden foci of malaria transmission that could remain undetected. This condition was thought to be due to a combination of factors: lrregular nass application of pesticides in agriculture, drug distributlon which depresses the parasitaemia to a submicroscopical level, and variation in vector density froo year to year. The last factor i.s thought to be due to alternating crop cult,ivation, i.e., rotation between rice and cotton cultivationr as well as other crops every trro years in the Delta. Slnce parasitological examinatlon under such conditlons would be extremely inadequate, it lras suggested chat a serological survey once Per year covering chlldren of 5-9 year should be "g"-gro,rp conducted, preferably 6-8 weeks after the end of the Eransmission season in order to give a chance to latent infected persons to produce detectable antibodies. In fai.yum, the follow-up of the old positive persons and the examination of new individuals gave an indication that transnission is perennial in this governorate. To verify this, it was proposed that newly born infants should be exanined longitudinally to exclude the possibiJ.ity of prolonged or delayed incubation period or the occurrence of relapses. hassan, Mohaned& El Saici (1983) further carrled out a serological study in Aswan governorace. This was in conjunctlon with a case of P. falci.parun detected in a locality ofthecapital,AsIdantown.Basedontheepideniolog]aFnvest18ation,thecase0as c.l'assified as lnported. I'ron the sane locality, blood sanples weie collected fron 207 Persons of all age-grouPs, for parasitological exanination and for IFA test. Parasitological exaninalion showed that all 207 blood filns collected frorn different age-grouPs were negative. Serologicaj.ly, 13 persons were positive: 5 at a litre of I/L6, 7 at L/64 and 1 aE L/256 (over 40 years of age). In order to satisfy the requirements of a high specificity in this area with a low frequency of antibodies, the discrininating tj'tre ot L/L6 was not considered as suggesting recent malaria infection in the populaiion examined. The seven positive cases at the titre ot L/64 and one at L/256 nay suggest recent or concurrent infection. Aswan and the border area wit.h Sudan are being roucinely subjected to Protective measures to prevent the reintroduction of nalaria and che re-invasion of An. ganbiae s.l. These neaaures aLso include giving the inhabitants suppressive drufriiiiFtigations by seasonal IFA tests were recornmended. [The authors did not show whether the seven seropositives had a history of noveoent to an endenic area]. In Sinai, the only available infornatlon on the nalaria sltuation cornes fron past parasltological surveys which were carried out in conjunction with entonological surveys (see under 2.2 above). Gad et al. (1964) poi.nted out that no accurate data on the malarj,a vBc/ 90.2 ytaL/90.2 Page 151 situati.on in Sinai before 1960 was available. In Septenber 1960, 948 bloo Thus, the parasite rate in the whole Sinai was 0.L2% (6/5077). Somecases were thought not Eo be indigenous, e.g., the case of the prisoner at El-Tor, si,nce this was the only case found among the prisoners and in the whole locality in which no anopheli.ne larvae or adults were found. The case of Qantara East was probably due to invasion of the Iocality, which was free of anopheline breeding), by pharoensis flying across the Suez Canal. The two cases of P. falcj.paruro aoong children at El-l.iadi were considered as truly indigenous, si-nce sergentii was the only veclor breeding in the locality and found in abundance i.n houses. Several assunpt,i.ons were nade regarding the origin of the two cases of P. vivax at El-Arlsh. Of these, it was postulated itrat ttrey were iransnitted by the locally breeding multicolor, but this species was incri.ninated only on epideni-ological evidence in North Africa. The other possibility rras an invasion by lrharoensis nnich was support.ed by the entonological findings by analogy of an outbreak of nalaria that occurred in Gaza in 1959, (see 3.4 and 3.5 above). It should be noted that in che norrhern region there ldere Persons ltith enlarged spleens. These nere among labourers ori.ginally fron Lower Egypt working tenporarily in road and railway repair. Most of Ehen gave a history of schistosomi.asis. Based on this survey, the authors considered that maLaria in Sinai was not a najor problen and recomnendedthe appllcaEion of ualaria eradicacion measures. Since the Sinai penninsula has vast deserts with little lrater sources and in nany places no suitable anopheline breeding places exist, the oalaria eradication operations should, io particular, be directed to certain areas proved in the present survey to have oalaria cases, vectors or suspected vectors. These nere outrined as folLows: - Geiderat area where sergentii and superpictus were found breedingl - El-Tor where sergentii was found in aUunaance; - Wadi Feiran oases where sergentii nas recorded; - Localities where mulcicolor was found breeding, e.g., the coastal area between El-Arish and Rafah; - locallties opposite the Suez Canal, namely Qantara and Suez to check t,he infilcration of pharoensis across the Canal. The suggested neasures were larviciding, residual house spraying to act as a barrier agains! nosquito infiltration across the Canal, and surveillance operations during the first year of attack. hlhiLe reporting on their survey of nosquitos of Sinai, llargalit & Tahori (1973) (see under 2.2 and 3.5 above) showed that the parasite rat.e i.n Sinai as recorded fron surveys carried out in L967), was 1.27" (7 positive blood fiLns of P. vivax out of 595 exanined). This was higher than the rate recorded by Gad et af. (fSOAfTfr;localities where the Positive blood slides were found among the Sinai Eedouln tribes were Wadi Charandal, hadi Isla and the vicinity of El-Tor. Since sergentil and superpiclus were prevalent in these Localities, they rJere suspecEed as the magor vectors of malari.a j.n these areas. [These surveys should serve as a guide, as it is tine to conduct a thorough entouologlcal/parasitological surveys in view of the extensive ecological changes associated with development in Sinai. On the basls of such surveys, the appropriate control measures can be plannedl. In Cyprus, the Anopheles eradication campaign which was launched in 1946 succeeded in eradicatlng nalaria. As shown by Zulueta (L974), the canpaign nas based on the vBc/90.2 vtAL/90.2 Page 152 application of 3-52 DDT in fuel oil to all potential breeding places. The success of the canpaign ldas lDostLy due to the thorough knowledge of the distribution and habits of the vectors and to well-planned and oconducted anti.-larval operations. Of the two nain vectors' the less widespread sacharovi was conpletely eradicated, but the more ubiquiE.ous ?uperpiqtus, although nuch reffito a vanishing poinr nas never conpletely eradicated (see under 1.2 above). The last indigenous case oi maLaria was detecied in 1967 and Cyprus ldas entered in the WHoofficial Register for Malaria Eradication in October L967. Despite the fact that the lsland has been free fron indigenous malaria in the past 20 years' the country-wide anti-larval operations have been conti.nued as a precaulion against the reintroduction of nalaria. DDT in fuel oil was gradually replaced by tenephos. This produced a collateral effect by giving a general reduction in nosquito breeding, a point of considerable iroportance in Cyprus, where the tourist industry ranks high in economic terms- Due Eo disturbed conditions occurring in the sunner of I974, the larviciding operations were disrupted in nany parts of the north of the island. As a result, suPerpictus was detected in August 1974 in breeding places that had been negative in previ'ous years. Its breeding Itas checked by the relnstitutton of anti-larval measures, but in areas where practically all the civilian population had fled, no searches were made or antl-Iarval measures carried out. Thus, the breeding of superpictus nust have gone unchecked during the greater part of the summer. Despite ttrFli-entiauy dangerous situatlon, lo lndlgenous cases of malaria have been reported slnce the events of the summer of L974. Since the south of Cyprus had sufficitnt insecticldes, equipoent and personnel, provisions were made by authorilies for the larvtciding operations to take place in the north starting fron April 1975. Shidrawi (1983) (see unaer L.2 above) who vlsited Cyprus ln June 1982, conplled records of anophellnes found in the island since 1950. No sacharovi has been found since its last record in 1952. I{ith regard to sgPeTPictus, the records show its presence only in the Turklsh Cypriot side in 1979, while c.l'aviger continued to be recorded ln the Greek Cyprlot side in f980-f982. Shidrawi also Iisted the number of inported cases ranging froro 2 to 6 in 1980-f982. He concluded that based on the entomological/parasitological records, the nalariogenic potential in the island Iras very low if not zero, since in the absence [scarclty] of the vector, the few inported cases will not constitute a danger of resumptlon of malari.a transmission. However, he recomendeci the application of various anti-larval measures for nosquito control in rural and urban areas, as well as maintaining vigilance in seaports and ai'rPorls. [The question of claviger as a potential vector in Cyprus should be kept in mind since sporozoite-posit.ive specinens had been reported fron Cyprus in ghe past - see under 4.2 abovel. The country nalaria profile for Cyprus (Unpublished document by Farid, 1987) was shordn as follows: - Population: about 0.7 nilllon 1984 1985 1986 - No. slldes examined: ? - ? - No. positive cases: O 1 2 - No. falciparun cases: 0 0 0 - P. falciparun response to chloroquine: not reported - Vectors of ualaria according to vectorial inportance - infornation of insecticide resistance: An. superpictus (potential vector) - Main vector control measures: larviciding with temephosand biological control by Ganbusia Eie derection: very good - Developnent of PHC at perlpheral level: good - Developnent of PhC at referral level: good - llalaria control Progranme: is part of PHC system nainly for vigilance as nalaria has been eradicated frorn Cyprus - t'ralaria training centres: not available - Trained manpower: available - Special problerns: inported malaria. Frorn the lnfornation conmunicated to WHO/MAp,data of the nalaria situat,ion in Cyprus in 1987 show: (population is given as a nid-year estimate in thousands) - Total population: 680 - Population of orlginally ualarious areas: 680 - Population of areas known to be free of nalaria: o80 vBc/ 90.2 MAL/90.2 Page 153 - Population protected by house spraying: - - Population prolected by other anti.-vector Eeasures (larvlcidlng & biological control - Ganbusia: 680 - Population under survej.llance: 680 - No. slides examined: not available - No. positive slides: 2 inported (1 P. falciparun & I P. nalariae fron tropical Africa). In Jordan, as showrr by Zulueta & Muir (L972) the Jordanian nalaria eradication operations ldere started in 1958. Since the early work of nalaria control that nas started in 1949 in the Jordan Valley by the United Nations Rel1ef and Works Agency (UNRWA)for Palestine refugees in the Near East, it became clear that house spraying with residual insecticides was not sufficient to interrupt malaria lransmission and thac larviciding was (1954), (see al.so requj,red, citing Farid -543 under 2.5 above). Judging froro the number of cases in 1964 (644 out of 254 blood slides exaroined), the situation of the Jordanian Programne hitherto was not favourable. This was due to the fact that a decision was taken in 1963, based on the provisions of the previ.ous plans of operations, to virhdraw the aEcack neasures thaE were applied unEil then to the most vulnerable area, e.g. Jordan Valley and Dead Sea area. The decislon was premature as the API in 1963 was 0.34/1000, but it was a clear reflection of the optlnisn concerniong rnalaria eradication prevailing at that tine. lr/henthe nunber of cases rose 1n 19b4, attack operations were reinstituted in all the areas that had been moved to consolidation. Full surveillance operat.lons (with ACD) were naj-ntained, as has been the practice in other mafaria eradication progrannes when reverting to the attack pnase. A steady decLine in the number of cases was observed until 1967, when only 28 cases were detected (128 192 slldes exanined). It was envisaged that house spraying and larviciding operations could be withdrawn from Dost areas under attack. However, this could not materiaLize because of the war of June 1967 necessitating ooveoent of troops and causing displaceuent of the clvllian population and a general disruption of life in the country. It was reuarkable that desplte thls situation, the Jordanian malaria eradicat,ion progranme (MEP) has been able to maintain the gains. The only indigenous cases found since June 1967 nere among nilitary or para.-oilitary personnel, or exceptlonally among civilians directly associated with thern. Outside the nilitary zones there was no malarj.a transmission anong the civilian population for whom the l'lEP lras responsible, thus what remained ln the country lras a nilitary nalaria problen. To naintain this favourable condition, it has been necessary to keep the nost vurnerable areas under house spraying and larviciding. Zulueta & Muir (loc.cit.) anticipated that house spraying and larviciding will have to be applied in relatlvely large areas of the country. Apart froo the expenses lnvolved, this xlay create a problen of insecticide resistance. One of the nain vectors, sergentii which is already resistant to dieldrin, exhibited what could be interpreted as either vigour tolerance or incipient DDT resistance. Laboratory investigations on this phenooenon were inconclusive, but the threat of resistance poses a serious problen if the use of DDT has, as it seems, to be prolonged. In an unpublished working paper to WHO, Tawfik (f987) reviened the history of the nalaria eradication programmein Jordan since its inception, pointing to the progress made and problems encountered up to the present tiue. Following the signature of lhe agreement of nalaria eradication in 1956-1957, the operations were carrled out in four districts: Yarnouk-Jordan Valley, Balqa, Irbid and Kerak. Since 1970, there have been no indigenous malaria cases in the country. A11 cases whlch have been discovered through fever-screening mechanisus were imported fron malarious areas in Saudi Arabia, United Arab Emirates (UAI), Onan, Pakistan, India, Sri Lanka and other countries of South East Asia. Since 1967, several factors necessitated the continuati.on of malaria control and surveillance operations, namely: the unsettled condit.ions in the West Bank, the continuous travel of Jordanian citi.zens to malarious countri.es, the occurrense of sone foci of transmission on the Syrian side of the border with Jordan, and the lncreasing nunber of Indians and Paklstanis settling in potentlally malarious areas in Jordan. The operations and act,ivitles that have been naintained were shown as follows: - Epideniological surveillance operations: Of the various factors that have contributed to naintalnlng Jordan nalaria-free, the very effective surveillance system which has been developed in recent years, is the trost important. Apart froo the usual ACD and PCD, a new systen has recently been adopted for screening travellers comlng fron areas for nhich experience has shown that they are the origln of most of the imported cases in vBc/90.2 r4AL/90.2 Page 154 Jordan. Screeni'ng begins on board aircraft coning, tor exanple, from Saudi Arabla: Passengers are given cards to complete (in English and Arabic). If the passenger came fron a well-known mal-arious area (e.g., Gizan, Qunfudah, Najran, Khaybar) and has fever or there is a suspicion of nalaria, a blood slide is taken and-preiunpcive treatoent given. As the address in Jordan is shown on the malaria cards, these p""".rrg"a" as well as those coning frorn other oalari.ous areas, are followed up and radical- treatnent is given if necessary. A sinilar arrangement has been made for the exanination of travellers conlng fron Saudi Arabia by road at the border post of Midawara. Regarding passengers from onan and UA-E,whether in a direct or a connecting flight, they to conplete a malaria card upon arrival in Anman airport where further aclion"."-r"qrr.ittO is taken if required. The same arrangenents are made at the road border posls of Rarotha and Un-el-Janal. passengers frorn cerEain areas of Egypt are also screened by the same procedures. Special .eas,rr.i are taken concerning Pakistani and Indian nationals, in view of their increasing numbers who come to Jordan to ldork as Labourers especially in recent years. A11 Pakistani and Indlan labourers and their fanilies receive full. radical treatment and nust be in possession of a nalaria card showing that such treatrDent has been adolnistered, otherwi.se perni.ssion to work is refused. To inplement all the above Eeasures, the malaria eradication Programme keeps permanently on duty 1-6 agents at Anman airporr, one aE Midawara, one at Rantha and one at un-el-Jamal, as r"1l ." one agent at Anman rallway stati.on for arrivals by traln. In addition, a number of ageuts are asslgned to follow up travellers coning from malarious areas. This is no doubt a considerable effort, but the results of recent years have been rewardlng. However, a snall loophole in the surveillance or the larvj.ciding or sprayi.ng operations (for example, the huts where the cases lived had not been sprayed) can lead to resumption of nalaiia transmission in a potentially highly malarious areas such as the Kerak Lowlands. This shows the great risks of nalaria that still exist iu Jordan. On the other hand, the duties of the scaff of the nalaria department have been expanded to cover otber diseases. The malaria surveillance agents who are distrlbuted all over the nalarious areas in the country make house-to-house visits fortnightly, looklng for fever cases. During these vlslts, they also collect urine sanples fron any Personr whether natlonal or expatriate, nho is couplaining of haenaturia. The urine samples are sent to peripheral or cencral laboratories for screening for schistosomiasls. If positive, the surveillance agent is instructed to give the appropriate drug and follos up the case until i! proves negative. The surveillance agents also look for any skln leslons ln local inhabitants, and refer such cases to the government general Practitioners for re-exanination and for providing treatnent and follow-up for those found posltive for cutaneous leishmaniasis which 1s endenic in some areas of Jordan. Another task of the oalaria surveillance teams is to col.lect sputum samples fron any suspected tuberculosis case. The sanples are then sent to the tuberculosis centre for examination and providing treatnent and follow-up of positive cases. - Larviciding and house spraylng operations: After more than 25 years, larviciding continues to be the principal anti-vector operation. Since the early work of Farid (1954 - & 1956) (see under 2.6/2.7 above), i.t has been generally accepted that resldual house spraying alone cannot interrupt. malaria transnission in Jordan, due to the outdoor sleeplng habiEs of the local inhabitants and the outdoor-resting of the two nost ioporcant vectors' sergentii and superpictus, hence the need for larviciding operaEions. Although rarviciding is more expensive, it has been found to be nore effectlve than resj-dual house spraying under the conditions prevaillng in Jordan. Since the re-inst,itution of attack uleasures throughout the nalarious areas of Jordan in 1965, the amount of larviciding (supplenented by some dralnage work in the Kerak Lowlands) has not substantially changed. What has been changed is the larvieiding agent used; temephos 5008 repJ.aced 0.52 DDT in diesel oil. In view of the absence of nalaria transmission, the possibility of discont.inuation or reduclng vector control operations was consideied, particularly with respect to house spraying. The prolonged use of this Dethod has produced, as would be expected, some reluctance among the local inhabitants, particularly t.he younger generations who have not seen t,he past ravages of malaria. Despite thls, the average sprgying coverage during 1973 and 1974 was 86 and 882 respecrively. This degree of coverage could be obtained through the efforts and persistence of those in charge of the oPerations. However, the discontinuation of house spraying would reguire a reinforcement of the more exPensive larviciding operations. In this connection, a questlon arises whether larviciding alone can guarantee the Eaintenance of complete interruption of malaria transmisslon. When all these factors were taken into accoun!, the conclusion arrived at, is that as long as the receptivity and vulnerabllity to malaria remain as hlgh vBc/90.2 MLAL/90.2 Page 155 as they are nolt, larvicidlng a.nd spraying operations will have to be conlinued on approximately the Presen! scale (see further j-nformation given at a later date below). As ttith the surveillance agents, the work of larviciding teans has been expanded to cover vector and intermediate hosts of other parasitlc diseases. Labourers in charge of Larvicidlng operations who acqulred experience with dlfferent snails are asked to collect any susPected Schi.stosoma haenratobium snails and send then to the entomological section for ioentification. If the p!'esence of haematobiun snails is confirmed, it is then the duty of the operational section to deal rritt then using [he appropriate nolluscicide. Another main task of the operational section is to apply DDT house spraying to eliminate Phlebotonus sandflies, vectors of cutaneous leishnaniasis in some areas of Jordan. The identificaEion of sandflies an.d estimation of their density in different parts of the country remain the responsibility of the entonologicaL sectj.on. - Enlonological acti.vities: One of the nain tasks of entomological activities is to determine the susceptibility leve1 of nalaria vectors to the insecticides used. An. suPerPictus has so far not shown any sign of insecticide reslstance. On the other hand, recent tests suggest a low degree of DDT resistance in sergentii in addltion Eo the already existing dieldrin/HCH resistance. More tests will be done to verify the 1evel of DDT resistance in sergentii. Larval lests showed that both sergenti.i and gpgglggg are susceptible to temephos. In addition to entomological acti.vities related to malari-a, the entomological section identifies the species of schistosoniasis snails and sandfly vectors of leishnaniasis and estimates their denslties in different areas of the country. The section also conducts training courses in entomology. - Special oPerational problems: The Jordanian prograrnoe has faced sone difficulties along the borders. An exanple cooes frorn the Yarnouk Valley where sacharovi has recently beenfound.Inpreviousyears'theJordan1an1arvic1dingteaoscovmsyri'anaswe11 as the Jordanian sides of the valley. Not only has this been discontinued, but the Presence of oine fields has considerably restricted the larviciding operations on the Jordanian side. A sinilar situation exists near Safi, at the southernmost end of the Dead Sea wtrere, due to t.he presence of mlnes, sergentli breedlng has remained unchecked in recenc years. Despite these constralnts, there has been no malaria transmission during the Past few years in either of the two above mentioned areas. A further problen is related to the Rutenberg dam at the Yarmouk rlver close to its junction with the Jordan river as explained under 2. below. The counEry nalaria profile of Jordan (Unpublished document by !'arid, 1987) was shown as follows: - Population: abou! 3 nillion Population at risk: nil 1984 1985 1986 - No. slides examined effi2 ff7.2a rFoo: - No. positive slides 3L2 458 297 Al1 inported - No. P. falciparun cases 24 63 67 - P. falciparun resistance to chloroquine: nil - Vectors of nalaria according to vectorial iuportance - infornation on insecticide resistance: - An. sergentii d.leldrin/HCH I I potential vecEors An. superplctus l - Main vector control measures: DDT house spraying and Eeoephos larviciding. - Case detection: Very str,ong surveillance nechaniso through ACD and PCD, follow-up of cases, and examlnation of laborurers upon entry. - Developnent of PHC at pe;ripheral level: good - Developnent of PhC at re:Eerral level: good - l*{alaria control progranme: i.s a vertical one - llalaria training centres: not availabLe in the country - Jordan relies on WHO fellowsnips for training staff - Trained manporrer: availalale - Special problens: imporEed ualaria. From the information communicated to wHo/MAP, data of the roalarla situation i.n Jordan in 1987 show: (population given as a mid-year estlmation in thousands). vtsc/90.2 MAL/90.2 Page 156 - Total populatlon: 3 2Zs - Population of origlnally nalarl.ous areas: L 976 - Population of areas clairoed to be free from malaria : g7g - Population under malari.a control progranme : - - Population protected by anti-vector measures: 755 - Populatlon under consolldation phase: 344 - Population under survei.Llance: 399 - No. slides examined: 115 151 - No. posltive slides: 281 (92 P. falclparun & 189 P. vivax - all inported). The lnfornation also shows that Jordan stil1 remains free of malaria transmission as not a single lndigenous case has so far been cietected. All the P. falciparun inported cases that have been recorded are susceptible to chloroquine. I; l%mT house spraying and tenephos larviciding have been disconEinued in some trial areas. This was done following the recommendations of the Workshop for Inprovement of Malaria Control through Applied Field Research that was held in Amnan during 31 March-l2 April 1984. (WHO, 1984). The trial areas were selected in the Jordan Valley and Kerak Lowlands, where IrDT spraying and larviciding operalions have been discontinued in certain parts and larviciding only suspended in others. In all other areas, DDT spraying and larviciding are continui.ng. In Israel, Saliternik (1978) sunuarized the history of malaria in Palestine and the introductlon of vector control nethods slnce 1918. In 1948, when the State of lsrael was established, there were 1 172 fresh cases of malaria detected. In 1949, an Antinalaria Division was establlshed in the Minlstry of Health to deal wlth the planning, organization, implenentatlon and supervision of ualaria control (and later malaria eradication oPerations) in Israel. In 1959, only 36 nalaria cases were recorded. Neverthelessr a ualaria eradlcation campalgn was conducted between 1960-1966 in cooperatlon with WHO. By L962, malarla was practlcally eradicated fron Israel. Sallternik (L977a) explained how the malaria eradlcation campaign ln Israel enployed varlous nethods that devlated from the WHOprlnciples as shown ln the following: (a) There was no oararia eradication Ad hoc comrnittee formed, nor were there malaria regulations issued. (b) The house-to-house ACDnethod nas never established. Hence, there was no presunptlve treatment glven to suspect,ed cases. ACD was only carried out aoong selecEed population grouPs suctr as Bedouin nomads, lmigrants from ualarious countries, and students fron African countries. (c) PCDwas the nornal surveillance procedure, because of the high physician-populatlon ratio (about. l:1400), and over 8O"lof the population benefitted fron health insurance. l'loreover, nedical personnel were malaria-conscious and most malaria cases were hospitalized. (d) Induced malaria caaes were extremely rare, due to selective screening of blood donors as well as keeping transfusion blood refrigerat,ed l0 days before use. (e) No introduced cases of malaria occurred due to perfect vector control. (f) Regular DDT house spraying was ll.mlted to selected locallties, such as those situated along the Syrian and the Jordanian borders and the Dead Sea strip as well as foci of nalaria parasite carriers. Spraying was timed according to the seasonal prevalence and fllght range of the vectors. On the other hand, larval control in Israel reached a high level of perfection through fixing, oapping, treating and surveying all breedlng places. For larval contro.l. residual insectlcides nere not used in order to avoid selectlve pressure for resistance. As a result of these measures, sacharovl, the main vector of nalarla in Israel, conpletely disappeared. (g) Chenoprophylaxis was given during L959-L962 onLy to inhabitants of the Dead Sea strip and to the numerous visitors (about 60 000) who slept on the shores of the Dead Sea. Through all these rleasures, malarla eradication was practlcally achieved by L962. vBc/90.2 M L/90.2 Page 157 Saliternik (L977b) further elaborated on vecior conlrol nethods. For larvicidlng oPerations, llalariol was used which contains fish oil to increase the oil spreading Polter. Indoor DDT spraying was carried out after 1945 in selected localities, such as settlements along the borders, foci of malaria carriers, new settlements established in previous malarious areas, settlements where the vectors had been encountered, and dwellings of nalaria patients. Only a 5Z DDT soluti.on in kerosene rras used for house spraying at a rate of 40 cc/az. The spraying rsas tined in accordance with the bionomics, flight range and seasonal appearance of the local vectors. Vector control was directed to four anopheline species which lrere proved to be iuportant vectors of rnalaria, each one at a different period fron April to December. Their characterj.stics, habits and specific nethods for thelr control were shown as follows: (a) An. sacharovi.' This species was the maj-n vector of malaria in Israel ln spring and late autufilmTe Hulleh area) until 1958. It used to breed in more or less stagnant and unshaded waters covered with horizontal aquatic vegetation. It was regarded as anthroPophilic/endophagic and endophilic species. Early investigations showed that females of sacharovi accuuulated and stored fat body before winter and t.hen mass oigrated in late autGi-ffing nalaria outbreaks in Rosh-Pina, 15 kn frorn the Hulleh breeding 9naop, usually free from Anopheles and nalaria in other seasons (see more details under I.4 and 1.5 above). The specific control Deasures nere: - Avoidance of cutting dense vertical vegetat.ion ln order not !o expose the water surfact to light. - Elinination of aguatic vegetation: Ranunculus, Potamogeton, and Ceratophyllun. ryIigp3ll$ - Introduction of Tilapia fish into pools; the fish ate and destroyed the horizontal vegetation in stagnant rdaters. - Frequent water level variation in stagnant waters. - tr'loodlng soue breedlng places 1n order to lnterrupt, breeding through ralsing Ehe water salinity to above 0.82. - Euptying raln water pools ln April.. - Flushing of slow lrater. - Larvicldlng operations. - Large scale drainage activities. - DDT spraying was applied in Aprll, and again 1n October i.f necessary. (b) An. sergentil and An. superpictus: Both species remained very imporcant vectors. Their breeding hablts, dlspersal, and resting hablts nere summarlzed frou previous observations carried out in Israel (see under 2.2r 2.4r 2.5 and 2.6/2.7 above). The nethods of control of superplctus were sinilar to those of sergentii as shown in the followlng: - Tne lntroduction of t.he larvlvorous flsh, Gambusia affinis into mosquito breeding places. - The clearing and cleanlng of water beds to accelerate the water flow to over 20 cn/second. - Weekly drying up of Lhe nater beds by dlverting the water flow to different dlrections. - The ereclion of dans for periodic flushing of nater beds. - The prevention of overflowing and seepages. - Larviciding operatj.ons. - Snall scale drainage. - The application of DDT spraylng ln June against superpictus and in Septenber against ser8,entii. Investigations showed, however, thaE DDT spraying against sergentii was incapable of preventing nalaria transmission, owing to its exopnagic and exophilic behaviour. It was necessary, therefore, to continue Ehe syslenatic larviciding operations on a countrywide scale. (c) An. claviger: This species used to be an important vector of nalarla in certain .Localities of Israel, ln view of its habit of breeding in shaded and cool lraEers of the courtyard cisterns, thus comlng in close contact with man (see under 4.2 above). The control Deasures for this species nere: - Hermetic sealing of cisterns and wells. - Provlsl.on of piped rrater supply. - Larvicldal operations. vBc/90.2 I,TAP/ 90.2 Page 158 Naggan, Kark & Egosz (1973) reported the results of their study of 239 malaria cases that were reported to che Ministry of Health and the Medlcal Corps in Israel during I967'L97L (3 in 1967, 17 in 1968, 21 in L969, 56 in 1970 and L42 in 1971) from Israel and the Occupied Terri.tories. Epidenlological investigations were carried out in conjunction with 882 of the cases. The clinical- data were taken fron the hospltal files of 857! of the cases that uere hospltalized during L967-L97O. Only the cases for whlch the clinical diagnosis was confirned by microscopical identification of the malaria parasites in blood were incLuded in this study. The trajority of patients were soldiers and reservists undertaking active reserve duty. A11 cases were P. vivax except four: 2 P. falciparun, I P. nalariae and one mlxed (P. vivax * P. nalari$-E'tideniologicat investlStions poGEd-6-E[!northwester''piffi.na-,a1ongtheSuezCana1,asthena1nsiteof i.nfecti.on, as 9O"Aof the patients for whom infornation lras available became sick after a sojourn in Sinai. At least two patients becaue il1 after a stay in the Golan Heights, but lhere lrere no proven cases fron the Jordan Valley. Because of the high nobility of the soldiers and civilians, lt was hard to determine precisely the incubation period. Therefore, a group of 61 patients who stayed ln Slnai only once during the year prior to the onset of their illness and whose stay lras not longer than three nonlhs, was selected for deternining the incubatlon perlod. The ulnimal incubatlon period was defined as the tine between departure from the nalarlous area to the onset of the clinical synptorns of the first nalarla attack. Graphical presentatlon of data showed binodal distribution of the cases, indicating tno incubation perlods: one month ln 13 patients, and 5-15 months in 48 Pat.lents. tlost of the cases becane infected durlng the sumer months, nainly between July and SePteober. Annual norbidity occurred frorn April to October wlth a complete absence of new cases between November and l'larch. l'lost of the cases recei.ved proper treatnent (chloroqulne for 3 days and prinaquine for an additLonal period of 15 days). Long incubatlon periods of P. vivax have been described frou several areas in South East Asia and Europe but never f6;TT; area. Only seven patients had relapses, because of inadeguat,e treatment or oisdiagnosis. Referrlng to enlouological surveys carrj-ed out previously in Sinai by Egyptian scientists and lsraeli workers (see under 3.5 above), the authors assuned that pharoensis was the probable vector which was shown to have a J"ong flight range. As no breeoing places were found in the eastern side of the Suez Canal, pharoensis breeding oust have occurred on the wesEern side of the Canal in swanpy areas along the fresh nater canal, running parallel to the Suez Canal. Pener & Kitron (1985a & b) coonentlng on the reappearance of sacharovi and the gradual increase in the number of its breeding sites in Israel (see under l.5above) together with the influx of nalarla lnported cases, recomnended that continuous surveillance of vector and parasi.te carriers should be malntai.ned and even strengthened. As shown by WHO(I979rWk1y Epldern. Rec.), the number of nalarla cases recorded in Israel Ln L977 was 28 among the civllian population, as compared with 15 cases in 1976 and 9 case in 1975. All patlents aequired the infection abroad (64.32 in Asia, 28.6"1 Ln Africa and 7.12 in the Western Pacific. P. vivax was predominant (16 cases) while P. falciparuu was recorded in 11 cases coifff*rth two cases ln 1976. Further tnforoatlon glven by tlHO (1982, Wkly Eptdem. Rec.) showed that in the past five years (L976-L980), 117 nalaria cases were diagnosed ln Israel. I.Jith no exception, all were irnported cases, of which 74 were allong Israeli citizens returning from abroad, 19 in foreigners visitlng Israel atd 24 in new itrtnigrants. The distribution of cases by pJ.aceof acquisition was as follows: Atrican countries, 87(74.32), Asian ocountries, 2L(L7.92), South or Central Amerlca, 6(5.L7.) and very few from other parts of the world. The uajority of the nalaria cases were due to P. vivax (61.5%) versus 32.52 P. falciparum, 0.9'l P. malariae 3.47" P. ovale and 1.72 mLxedTiffi:n. Contlnued vector contror ana survelffiGEivitieffictuaing case detection, radical treatuent, epideniological lnvestigations and constantly infondng of the nedlcal services are the basic methods used to naintain the country free fron local transnission. .Fron lnforoatlon connuni.cated to WHO/MAP,the data on che ualaria situation and anophellne surveys showed thac there were 94 cases of nalaria recorded ln the civilian populacion ln 1987, consticuting a signlflcant increase over the incidence in 1986 (36 ca6es). All cases were inported: 83 (882 fron Africa - 53 fron Ethiopia) and 10 (112) from the Far East. The nost connon parasite was P. falciparun (58.52) followed by P. vlvax (28.7i1), and there lrere small mixed infections (6.4"A) while sooe lnfectlons remained undetermined (6.42). For the fi.rst tine in lsrael a probable case of airport vBc/ 90.2 r4aL/90.2 Page 159 nalaria was recorded. The patient nas a 26-year old Skyhawk electrician who worked for one night in Septeuber 1987 at a si.te situated a fen oelres fron the terninal where cargo planes arrlving fron Asian and African countrles were unloaded. It was assumed that the infection was concracted that night through the bite of an Anopheles mosquito infected Itith P. falclparun which arrived in Israel in the cargo hold of a plane originating in an endemic area. From anopheline surveys in the whole country, 347 Anopheles breeding places htere recorded in L987, a 302 increase over the record of 1986 (248 breeding places). The largest numbers of positive breeding places were in Akho and Tiberias sub-districts. Of the 347 breeding places recorded, 8.32 were positive for sacharovi, 43.8"/.for claviger, L3.81! for suPerpictus, 2I.97" for sergentii and the reoaining for other anophelines. In Lebanon, Zulueta & Muir G972) showed that in 1951 a jolnt WHo/Governmentmalaria control denonsEration project was established simultaneously wlth sinilar projects in Jordan, Irag and Syria. When the global malaria eradication policy was adopted by WhO1n 1955, these four control prograllmes \rere converted into nation-wi.de malaria eradj.catlon Programmes. This nas started 1n Lebanon and Syria in 1950, in Iraq in 1957 and in Jordan in 1958. In Lebanon, steady progress was made as all areas originally malarious with a population of 856 000 reached the maintenance phase by 1970. In that year only 25 naLaria cases were detected out of 42 620 bl-ood slides examined. MosE of these cases lrere inported and none was indlgenous. The reason for this success was that the nalaria eradication programmewas superimposed in 1956 on a successful nalaria control demonstratlon project, which had thoroughly studied the malaria situation in the count,ry and had thus lald a solid background for the eradication campalgn. Although health facilities in Lebanonr^partlcularly in rural areas, may not have bee adequat.e, the ratio of 1 physician per L 230 inhabitanls indicated rhe'av.ilabllity of qualif-ied nedical personnel. I'loreover, the standard of l1ving ln Lebanon was such that a person suffering from malaria will not remain for a long tine without seeking nedical advice and treatmenE., usually from a private physlcian. These condltlons were nol always found in Jordan, Iraq and Syria. In factr it was arDongSyrian innlgrant labourers that the last indigenous cases were found in Lebanon during an outbreak in che Nahar Beirut area in L962-L963. Since then, practically all cases found in Lebanon were iroported, most.ly fron Africa. Due to the prevailaing conditi.ons, only linlted inforoation is available on the ualarla situation in Lebanon in recent years. The country malaria profi.le of Lebanon (Unpublished documenr by Farld, 1987) shons the following: - Population: about 3 nillion Popularlon at rlsk: Nil L984 -650'1985 1986 - No slides exami.ned 3l-E figs - No. positive slides 18 83 - No. P. falciparun cases I 10 - n-- r. talciparurp resistance to. chloroqulne: Nil - Vectors of nalaria according to vector importance - i.nfornalion on insecticide resistance: An. sacharovi - DDT; dieldrin/HCH; fenitrothion - @ Main vecli?control neasures: i.nformation not available due to the prevailing conditions. - Case detectlon: PCDon1y. - Development of PHC at perlpheral level: infornatlon not available - Developnent of PHC at referral level: lnfornatlon not available - llalaria control progranme: is i.ntegrated i.n health services - Malaria training centres: Not available - Trained oanpower: Available - Special probleus: Prevailing conditions The linited infornation cornmunicated to WHO/MAPon the malaria situation in Lebanon in 1987 showed that, of the total population of 3 nillion the population of the originally nalarious areas, I 019 000 were clained to be free from salaria. Of 33 989 blood slides collected in 1987, only two were positive (1 p. falclparum and I p. ovale). In Syria, the antimalaria activities were revj.ewed and evaluated up to 1980 as shown in an unpublished report to WHoby Khawan, Onorl & Eshghy (1980). In 1949, a nalaria vBc/90.2 rlAP/ 90.2 Page 160 control proJect was started in a rural area about 20 kn east of Damascus conprising 1.4 villages with a populatlon of 20 000. Three years of DDT house spraying led to interruPtion of malaria transmission in an area where nearly 607" ;t lhe popuration had been suffering fron malaria. In view of these excellent results, the Government decided to extend control operatlons to the whole of Damascus and Deraa provlnces. In 1953, oPerations were extended to some areas 1n Hons, Hama, Aleppo p.ovln".s involvlng a population of 380 000. In 1956, a plan of operations for malaria eradication rras signed and a National l'lalaria Eradication Service (NMES) was established. DDT spraylng oPeratlons were started in the same year but without any geographical reconnatssance, while the delinitatlon of nalarlous areas was based on some malariometric surveys carried out i'n dlfferent areas of the country. Inltially, the progranme marked conslsten! success, but in the late l960rs focl of transnission re-appeared ln areas which had been freed fron oalaria, and new focl were discovered in areas considered potentially non-malarious. The situatj.on became critical in 1968, when DDT resistance was found in aI1 areas of sacharovi distributlon. I{ith dieldrin replacing DDI and the distribution of antinalariat i@i-in areas of hlghest transnission, the situatlon narkedry improved during L968-I972. Interruption of transmission was achleved in several provi.nces and very !a1ee and inportant reservoirs of infective cases as in Ghab valley (Hani province) and Rakka province responsible for the flare up of secondary foci, wer! depleted. Llnited foci of transmission, however, persisted especLally in Aleppo and Deraa provinces. By the end of 1972, sacharovi becane^resistant also to dieldrln after four rounds of dieldrin spraying at a dosage of I g/mz La each (two rounds annually). Subsequently, malaria transmission ltas resuned. Comenclng in 1975, nalathion in the forrn of 502 water dispersible powder (wdp) at a dosage of 2 g (active ingredient)/n2 fn 2-3 rounds annually replaced dieldrin spraying. As a result of the unpleasant snell of thls forrnulation, there was a hlgh rate of populatlon refusals. Thus, a 502 enulsifiable concentrate (Ec) was introduced startlng fron J.978. For studying the malaria situation in Syria during L972-L979, the ABERand API were examianed. The daia showed that the srrmlss of slides collected decreased year after year wlth a more uarked drop in 1975 and L979. The deterioration of surveillance actlvltles was reflected by the downward trend of the ABER, while the corresponding API shorred a constant increase. comparlson of the number of slides examlned and cases dlscovered ln each province durlng 1 January-3l July 1975 wlth the corresponding period in 1979 showed a coniistent ioprov-ment in ai1 provinces except Deraa, llaoa, Lattakia and ]tassakeh where indigenous cases were still belng observed. tto accurate lnforoation ltas available on the developrnent and extent of a malarla epidenic that Progressed in the Ghab valley 10 recent years where no properly supervised control activities could be undertaken in 1980. In the light of the above analysis, the epideniological sltuati.on ln Syrla in 1980 was consldered to be serlous due to the Perslstence of the nalaria epldenic in the Ghab valley and the presence of actj.ve foci in Deraa, Lattakia and Hassakeh provinces. In vlew of the worsening epideniological situation fron 1975 ourards toget.her with the deterioratlon of surveillance activities during 1972-1980r iunediate renedLal oeasures were needed to prevent massive resurgence of malaria in Syria. Several adoinistrative, operational and to a minor exlent technical problems that contrlbuted to the det.erioratlon of the epideniological situation were described. Sone of these seem to have persisted in later years as shown below. A plan of action for the acEivities to be undertaken in l98r was prepared. In an unpublished report to t.lHo, Eshghy (1981) indlcated that sacharovi remained resistant to DDT and dieldrin/HcH but susceptible to nalathlon, .ni.E co- propoxur, but a soall survival was recorded in tests na{e with fenitrothlon. In a village scale trial, nalachion EC applied at a dosage of 2 g/m2 vas effective for less than one month on cement surfaces, but there were indications that its inpact on vector densities and longevity lasted for a longer period on mud surfaces. Ihe i.upact of nalathion EC needs to be assessed epideniotoglcally. In view of contlnued nalaria iransnission along the frontier vith Turkey, some observations eere carried out in June 1980 in tlalkiya (northeast of Syria), Ilassakeh provlnce and in Darkoush (northwest), Idlib provlnce. The border between Syria and Turkey is conposed nostly of fertlle 1and. The Syrian border wlth Turkey extends over 808 km and a nuober of villages are at malaria risk. The Syrian villages are sltuated opposite the Turkish villages and the tno sides often share the sane breeding places, and due to seasonal crop cultivatlon near breeding places the density of anophelloes [sacharovi and superpLctus] increases in sone years. Since the spraying operations ltere not applled at the right time and were defectlve both in dosage and coverage, the problen of persistence of malaria transmisslon continued. Moreover, most of the inhabltanls sleep outdoors durlng June-August, thus nost bitlng occurs outdoors during the transmission season (see also rnore details by Eshghy, 1985, undet L.6lL.7 above). uBc/ 90.2 vtlJ-/90.2 Page 161 In an unpublished working paper to tlHO l'larkin (1934) recalled the main problems which faced the nalaria eradication programme in Syria slnce 1980 as shown in the following: (a) Adninistrative problerns - Decentralization of adroinistrative powers to the provincial healch authorities: This was implenented without paying much attention to the provincial nanpower resources which were not sufficient to cake over these najor responsibilities. tsoch the provincial health directors and their assistants for preventive nedicine are not always fully acquainted with nalaria activities and do not provide the peripheral malaria centres with the necessary loglstic and adninistrative support. Accordingly, there is discordance betldeen the Nl"lESin Damascus and the provincial health authorities who are responsible for all the antinalaria activities at perlpheral level. As a result, discipline has become lax. - The annual budgetary provi.sions for t.he NI'IEScould no! cope with the galloping inflation and conti.nuous rise in the cost of living. Wagesand travel allowances are no longer realistic and attractive to personnel engaged in spraylng and surveillance. Funds are not available to Purchase new vehicles; the old cars are subject to frequent breakdowns, hence fleld supervision is fraguentary and inadequate. - With malaria gradually disappearing in most of the provinces, ualaria personnel and vehicles are utllized for the prevention of other comnunicable diseases at the expense of the NI'IESactivlties, nithout paylng nuch at.tention to the antirnalaria operational needs includlng the renedial action Eo prevent the resurgence and spread of the disease. (b) Operational problens - The socioecononlc status of the rural population has great.ly changed. Hence, the rate of refusals of house spraylng has been lncreaslng particularly after the introduction of oalathion in 1975, although the change to nalathion EC has partly solved the problen. After a period of trlal, it has been declded to use perueEhrin on a larger sca1e. - Shortage of qualified personnel has been partly responsible for the poor supervi'sion of all field activlties. The available microscopists and insect coll.ectors have been given refresher training. New cadres need to be recruited fron the Institute of Sanitarians to be trained in mal-aria work so that they can eventually forn the expertise reguired for the continuation of the progranme. (c) Technical problens - The nain probleu is the physiological resistance in sacharovi to DDT, dieldrin/HCH and fenltrothion, but this has been solved by the use of malathion and oore recently pernethrin. - Outdoor transmission when the people sleep outdoors because of hot weather during lhe transnission season. Fron the unpublished report to WHOof Sadek (19S4), permethrin house spraying r{as applied in 1983 at different dosages and rounds according to the ecological conditions prevai'ling in the northeastern and southlrestern regions of Syria; one round in June at 4OO mg/ma in villages along the Turkish border fron Idlib to Malkiya i.n June, and two rounds (l'tay and August) each at 250 mg/nz in Lattakia, Hama, Dauascus, Deraa and Quneitra. The quality of spraying was not as good as it shoud have been due to lack of training and supervision at all leve1s. Nevertheless, coverage lras satisfactory because of the low rate of refusals. On the other hand, pernethrin was appJ.ied without geographical reconnaj.sance (GR) in areas under insecticldal coverage. This hanpered the Proper evaluation of antinalari.a activities and the inpact of the great soci.oeconomic changes. Thus, sluple GR was strongly recornnended not only for t.he spraying operations but also for other activi.tles. For eonprehensive entooological evaluation of peroethrin spraying, two small villages of slnilar ecological condltions 5 km apart nere selected at 70-100 km fron Damascus: one to represent the sprayed area and the other to serve as control in an unsprayed area. The selectlon of these villages not far away froo Damascus vBc/ 90.2 r4AP/ 90 .2 Page 162 was dlctated by the shortage of transport. Although they were not nithin areas of nalaria foci under parasitoJ.ogical assessment, they were both receptive. Pernethrin (EC)"was applied on 5 SepEenber 1983 in the treated vlllage at a target dosage of 25Q Rg/mz. Houses were scattered and built of cement bricks plastered with cenent or covered with line-wash. Aninal sheds were built of mud adjoining houses or nearby. Several entonological techniques rdere enployed simuftaneously in both villages fron Septenber to November, viz: estimation of the indoor resting density of sacharovi by PSCr trap nortallty amongnosguitos exiting in window traps, determj.nation of the Parous rate by Detinovats Eechnique, and contact bioassay tests (in the sPrayed village). ln addiEion' the suscepti.bility of sacharovi to different insecticides including Permethrin was [email protected]/roon one week before sprayingl-dropped to 0.7 after 8 days of spraylng and remained low (6.7-6.8) for more lhan one and a half monEhspost-spraying, while the density remained high in the untreated control vi11age. Thereafter, lhere was a narked drop in density in November, but this rdas attribuged to cold condiEions rather than the effect of PermeEhrin' since a parallel decrease rdas observed in the control village. Observations by window t.raps were inconclusive as the numbers of sacharovi collected fron the sPrayed village tere.rery small (see under L.6/L.7 above).-ffiectiveness of pernethrin (IiC) as indicated by bioassay tesE.s was not of a long duration: after t.he 3rd week post-spraying, the nortality was reduced fron 63.5% to L8.L1! and 8.4% atter one and a half months and two nonths respectively, despite doubltng the exposure time. Whttewashed surfaces proved to be better substrate than cement, giving a residual effect of about tno months. Mud gave the best results, remainlng effectlve for more than two and a half oonths. Susceptibility tests indicated that sacharovi. was still susceptible to Dalathion. With pernethrint exposure to 0.252 co.ri6-tr"tioo for one hour gave 9L.T-IO\Z nortality, indicating the presence of tolerant individuals for which confirmatory tests should be conducted [see belowl. Sadek further atteopted to use the nethod proposed by Garrett-Jones & Grab (1964) for assessing the lnsecticidal lnpact on the vectorial capacity, but with modification. lnstead of calculati.ng the densi.ty factor of the inpact as a derlvative of the exPectation of Life fron data of the sprayed and unsprayed villages, Sadek used the indoor resting densities indices directly estinated by PSCin the two vll1ages. The use of PSCdata instead of nan-biting rates was due to admlnistrative difficulties that hanpered the night work. The following data were utilized.' Density index % Parous Per room Period of assessment Sprayed Unsprayed Sprayed Unsprayed One week before spraying 53.5 67.0 Mean post-spray(8-66 days) 4.l3 37.03 41(65 77(rO4 dissected) dissected) The density factor was calculated as follows: tsc/D ^l where A = unsprayed area before sprayingl B = unsprayed area after spraying; C = sprayed area before spraying; D = sprayed area after spraying. llence the density factor of inpact (ratio unsprayed:sprayed) = 7.L6:,L. The longevity factor was calculated fron the parous rate. The duration of the graphs shown in Macdonald exrrlnsic cycle for slg (9 days) was derlved frorn the (1957) according to ttre nean temperature ln the observation area during Septexober-October. Based on the assumpti.on that the oean duration of the gonotrophic cycle in sachargvi was 2.5 days, the probability of daily survival and expectation of lnfectiveEfETEie deri.ved froo the graphs shown in Garrett-Jones & Grab (1964). Thus' the longevtgy factor of inpact was calculated as 2.76:L. Accordingly' the total iupact of permethr1n would be 7.16 x 2.76:L = L9.76:L, i.e., the rate of distributi.on of infective bites per case per day by sacharovi population would be about 20 less than in the absence of spraylng. vtsc/90.2 ttAL/90.2 Page 163 Eshghy (1986) in his unpubllshed report to wHo listed a series of susceplibiLity tests carrj'ed out on sacharovi with different insecticides in several provinces of Syria during July-Septenber T9BFif,i results of these lests were communicated to wHo, a summary of which is shown in Table 12. Someof these tests indicated the presence of peraethrin r:s::-tance in sacharovi in certain localities in Hamaand Aleppo provinces. IThe extent or Enls resistance in areas under pernethrin spraying in Syria needs to be delinited and flnal confirnation should be obtained fron .."Lgni""E laboiarories. rf confirmed, welJ'-organized entonological/parasitological obiervati.ons should be conducted to determine the operational inplicatlons of pernethrin resistancel. The country nalaria profile of syria (unpublished docunent by Farid Iggl) was shown as follows: , - Population: About 11.6 nillion Population at ri.sk: 4 nillion 1984 1985 1986 - No. sl.ides examined 44rcO - 3gffi96 27-46L No. posirive s11des g40 435 273 - p. No. falciparun cases 5 2 3 - P. fAAP"t". t""istance to chloroquine: Neither suspected nor reported. - Vectors of malaria according Eo vector inportance - infornation on insecticide res]-sCance: An. sacharovi - DD1/dieldrin; fenitrorhion An. suDerpictus - l'lain-a?ToftitE-1 neasures.' House spraying with pernethrin and larviciding. temephos - Case detection: Borh ACDand pCD exist - phC Development of at peripheral level: fairly developed - pHC Developnent of at referral 1evel: fairly aevetopei - l"lal'aria control Progranme: is integrated with other parasit.ic disease progran'nes, decentralized and vertical. - l'lalaria trainlng centres: A nucleus exists in Damascus for sub-professional slaff, nainly nicroscopists. - Trained manpolrer: Insufficient - special problens: Agricultural practices, vector resistance; experienced key personnel are lacking. Fron infornation conmunlcated to WHO/MAp,data of the nalaria situation in Syria in 1987 show: (population gi.ven as a uid-year estinate in 1000s) - Total population: 12 036 - Population of originally malarious - areas: 6.500 Population of areas cLianed to be freed from - mar.aria.. 4 000 PopuJ-ation under maLaria control progranme: - 2 500 Populatlon protected by house spraying: 500 - Population protected by other anL.i-vector - measures: ? Population under surveillance: 12 036 - No. slides exanined: 23L 344 - No. positive slides.. 150 - Esti.nated cot.al number of cases: 150 The classification of cases of. L987 showed that 55 were indigenous, g0 relapses, 14 inported and I' introduced. A11 indigenous cases were P. vivax. of the 14 irnported cases, were.,rila.rc:ipgrun. The f_r1e inported cases originareffiFropi""i ei.i"a, sourh Easr Asla and Yer0en. The discribution of nalaria foci in Syria was shown as follows: llassan Kabbir, Aleppo (86), LactakLa (27), |l,a1kiya on the northeasrern border witn Turkey on De3la (20)' river and there were sporadic cases in Tartous (1), Hana (1) and ltaqqa (I). Resistance of P. falc run to chloro ine in the Mediterranean Basin The nost uP-to-date p. records of resistance of f"lci.p".ur to chloroquine in the world have been projected in a nap by wHO(198s, wuy npll6liEEs shown in Fig. 11. As can beseen.nochIoroquineresistancei.ninaig@caseshavesofarbeen recorded in counEries of the I'{editerranean aasinl--ifriffinported case of p. falciparum resistant Eo chloroquine was reported fron Algeria Isel under'(rr), r.b;";] vBc/90.2 rrAP/ 90.2 Page 164 3. Malaria and its conlrol in wacer-resources and other developuent projects Many large dams have been constructed in several count.ries of the Medlterranean Basin as can be seen in the World l(egister of Dams (1978). A literature search including the comprehensive bibliography of Deom (L982) and the availabl-e unpublished reports coveri.ng studies on malaria specifically or as a component of public health activities in water-resources projects in countries of Ehe I'tediterranean Basin under malaria control or in advanced naintenance phase revealed only llnited infornat.ion except in a few cases where more details have been given. As part of development, the available information on the inplications of hid,hwayconstructlon is also surmarized here. In the USSR, two articles rrere presented in the neeEing of the lnternational Scientlfic Project on Ecologically Safe l'lethods for Control of Malaria and its Vectors dealing with prevention and control of nalaria in hydraulic engi.neering projects and irrigation schemes. As these articles are quj.te detailed, they can be read in the original. OnIy orientation to their contents is given here. Tiuofeeva (1980) after introducing the problen of fornation of ponds in the course of construction of water reservoirs and ln relation to breeding of nalarla veclors, dlscussed the following aspects: - The influence of various parts of lrater reservoirs on mosquilo breedlng. - The necessity of nalariogenlc forecasts and their significance for antimalaria Deasures. - Selection of dam construction sites and marklng of nomal backwater level. - Antinalaria hydro-technical rneasures. - Selection of the site of human settleoents in the zone of rrater reservoi.r influence. - Prophylactic and treatnent measures ln plaees where the nalaria situation is expected to deteriorate. - Vegetation control during the perlod of water reservolr exploitatlon. - Prevention of mosqulto breeding in other hydraulic schemes. - The significance of sanitary-epidenlological supervision during construcEion and exploitation of hydraulic schemes. The other article nas presented by Bandin (1980) dealing with Ehe effect of changes in ecological conditions on anopheline fauna and density under the influence of human economlc activity. After lntroduclng the experience in the USSR, Bandin discussed the followlng aspects: - Antimalaria hydrotechnical works. - Sanitary supervision to prevent waterlogging. - Zooprophylaxis. - Selection of sltes for human setllements and their design. - Mosquito breeding in irrigated agricultural areas. - Factors influencing the malaria situation in irrigated agricultural areas.' social factors; parasitological factors; entouological factors. - Duties of entonologists and sanitary hydrotechnologists. In Turkey, Lassen (1982) in an unpublished working paper to WHO,described and reviewed ttre ualaria situation in the area of Chukurova/Anikovasi in Turkey, where uajor agricultural developoent has been taklng place. The area covers the provinces of lgel, Adana and llatay in the south of Turkey. The area is surrounded by the Taurus mountains in the north (reaching al altitude of 3585 u), the Anti-Taurus mountains in the east and the lvledlterranean ln the south. In the 1960rs, a large project known as Lower Seyhan Irrlgation Project was est,ablished, pernitti.ng agricultural and hydroelectrical development in the area. The lower Seyhan plain is linited in the east and west by the Seyhan and Berdan rivers respectively. The area betlteen the tlro rivers is a relati.vely flat, alluvial delta at less than 50 m above sea level with slopes varying between LZ atd O.L"l. This delta covers about 22O O0Oha of land of which about 170 000 are irrj.gat,ed. The. flat landscape is fron time to tine interrupted by snall, isolated h111s, and a narrohr band of sand dunes running parallel to the coas! l1ne, obstructing Ehe natural drainage of rain water into the sea. The dunes are inBerspaced with lagoons and sttamPyr poorly draloed areas. The largest of these lagoons, Akyatan, is more than 16 kn 1n length and covers abou! 5000 ha. A11 excess nater fron the irrigation project is collected in three oaln dralnage canals reachlng the sea or the two uain lakes: Akyatan and Tuz Gdlii. The najor malarla problen ln Chukurova is caused by the height of the water-table, whi.ch in vBc/90.2 r4AL/90.2 Page 165 0 'a g O E! E\O 9c E: c'! -rg9Er a: E€ E€ i,r Rs '!- I €,.s_:! ES .: €. tr stC.: \E .9oEf 3'6 i9 .=6 ?:a E'c EE v, 9o :s Eg oel <.3E-s -€ F! o0E 'dN vBc/90.2 r4aP/ 90.2 Page L66 many areas is less than one metre below the surface, and consequently the draining dltches always contaj-n water. Phase III of the Lower Seyhan Project which has not yet be-n implemented (in 1982) due t,o financlal constraints would involve punping out the rrater to the sea, and by itself would relleve many of the drainage problenq by lowering the water-table over Chukurova. Ihe surface of the area is 38 506 krnz. According to the 1980 census, the total population is 3 185 945 inhabitants llvlng 1n 1380 lociliries, of whoo about 51% live ln urban areas. In addition, about 700 000 seasonal workers increase the total population by 22% and the rural population by 45%. As agriculture is the nain activlty ln the area, migrant workers are found at different seasons, as they usually arrive in waves. The fi.rst group arrives about the niddle of Aprll and by the end of June-beginning of July they leave Chukurova to return to their places of origin or they go to work in other areas of the country (Antalya or Aydin). The second group arrives in Septenber and leaves for southeast Anatolia by the end of October. Somewill stay for a longer period until the end of the agricultural season, while others settle down in Adana attracted by the opportunity of finding pernanent jobs in the industrial areas of Chukurova. Socloeconooic studies carrled out during L978-L979 clearly showed an excesslve exPosure of the poor nigran! workers to the risk of malaria, as the nan-biting rales indoors and outdoors ldas several tines higher in the tents of nigrant workers t.han in Permanent houses. However, housing ls not the only socioeconomic faclor precipitating the malaria risk, as there are also Eany other factors like incone, occupation, education etc., t{hj.ch play an equally irnportant role. Another inportant problen is the urbanizaEion of Mana city. This city has 72 dlstrlcts and is the 4th largest city in Turkey. however, 23 dlstricts are classified as squatter areas, where environmental conditions favour the development and spread of several comnunicable diseases. The cl.inate of Chukurova plain 1s of the l'lediterranean type, having a high hunidity throughout the year with hot sunDers and moderate ninters. The highest ralnfal] is in December (120.2nn) then the raln decreases gradually until it reaches a oini.num (about 4.5 un) in July-August, thereafter it lncreases from September. Historlcally, at the start of the ualarla eradicatlon canpaign, the number of malaria cases detected ln the Adana regl.on was 5128 in 1958. The attack phase lasted until 1963. Fron 1961 to 1963, only 25 cases were reported and the whole region was passed into the consolldation phase during which focal spraying was applied only in villages where posicive cases occurred. By the uid 1960rs, a warnlng was signalled about the danger entailed in the arrival of infected workers coming annually from southeast Turkey where malaria transmission sti1l persisted. However, by 1970 t,he nr.rmberof nalaria cases detected in the whole count.ry rras very low (1263 cases) which led the national and lnternational authorlties to believe that the dlsease was totally under control. The organizational structure of the nalaria eradication service then became weakened by reductlon of not only the financial support, but also the manpower. In fact, during the same year of 1970 the number of cases detected in Chukurova rose fron 49 to 149 and this passed unnoticed. Meanwhile, the establishnent of irrlgation and lndustrial development projects gave ri-se to an increase ln the population of the Chukurova area. As showa above, the agrlcultural and industrlal expansion demanded an increase in the labour force, either seasonally for cultlvating reclained land, or permanently for new industrial developoent. As a result, malaria returned gradually co the area and an epidenic (L vivax only) hit the area during L976 and 1977 when the malaria cases recorded were as follows: L976 L977 Chukurova/Aroikovasi 30 852 101 867 Turkey (other areas) 37 320 r15 5L2 A national energency situatj.on nas then declared in the whole country, and intensive control aeasures were applied [see Onori & Grab, 1980, under (1i)11, above] with the assistance of other countries and int.ernatlonal organizations. As a result of these measures, the number of positlve cases narkedly decreased ln 1978 to 70 468, and in 1979 to 18 828. During thls perlod, Turkey experienced adninlstrative problens and a severe economlc crisis. Therefore, the lnpact of control measures was only relative to the epideolc 1eve1, but it was later lnpossible to maintaln the downward lrend. Despice the efforts deployed by the national authorities, the malaria situation in Chukurova/Anikovasi in recent years is stl1l perturbing as lndicated fron the nunber of cases detected during 1980-r982: vtsc/9Q.2 14L/90.2 Page 167 1980 198r 1982 (first 6 nonrhs) a t r tt 24 250 37 081 LI LI I With regard to agricultural developnent of Chukurova, lwo nat.ional organizat.i.ons are in charge: - The state Hydraulic works (Dsr)r which is responsiole for the design, construction' oPeraEion and rnaintenance of irrigation and energy-rt-sh6u1a projects (water reservoirsr drainage, irrigation canals, energy plants etc.). be noted principal that the perlod of irrigation is June-Augustl-i.e., the peri.od of lowest rainfall. - Soil and Water Development (TOPRAKSU)2whlch is responsible for providing technical assistance to farners for iupleoenting efficient agriculturai. procedures that would render maximun benefit per uniE. of cultiv;ted land. Lassen (roc.cit.) further described Ehe anti.malaria measurescarried out in the Adana region as follows: (a) surveillance and chenoprophylaxis.' The generar plan of surveilrance in Chukurova in 1982 estimated the work output per surveillance agent as follows: once a nonth.' 5000 persons to be visited by one agent per month. Twlce a month: 2500 persons to be visited by one agent. per DonEh. The responsibilities of the surveirlance agent are nurtlple involving.. treatnent and forJ'ow-up of nalaria cases, house nunbering control, population census, ,oass chenoprophylaxis where planned and health education. It should be noted Ehat several ethnic grouPs fron the surroundings are represented in chukurova. rn some settrements, the G6PD-deficiency was recorded in a relatively high proportion of the popuration, a problen which may cause difficultles i.n the r;dic;l treatnent of nalaria cases with prinaquine unless great care j.s taken. (b) House spraying: spraying with rnalathion at 2 g/s2 is carried out twice yearly. The quality of che oPeration decieased during 1979-198r due to several facrors, anongs! which was the relucLance of the population to accept the spraying of thei.r houses. (c) Larviciding.' A variety of sacharovi breeding places exists in chukurova such as rice fields, irrigation and drainagE-EEiZS p.m.r,.rrt rand depressions, rdater poors, I'arge nan-made burrow-plts, road eibanknent" .t". rrrigation canaLs nornarry do not pose an important breeding problen, but sonetines over-f1ow or leaks through the Joints of canalets or Ehrough failures in the systen may eventuarly create pools of stand1ng water. obstructed irriSatlon siphons can, alst create a probren. Two types of larviciding fornulations have been used.' 12 tenephos sand granules and 50% leneptros EC, at a rate of 110 g active ingrerdient,/ha. Granules a." ,r""d where emergent vegetat.ion is present. (d) Fllling: sanitary filllng as a nethod of larval control is underraken by Adana llunicipality. A large land depressi.on in one of the bands of the seyhan river is used for garbage disposal. DSI and TOPRAKSUalso carry out sone filling of inportanr land depressions in the vicinity of nain towns, but this activity is lirnited by the inadequacy of the nunber of earth movlng equipnent in both organizations. (e) Canal naLntenance.' Clinatological and huroan factors pJ.ay an inportant rore in the obstruction of canals. DSI has a department responsible for canal uaintenance of the irrigation system. Inforoation is available in lhe department on the different types of energing vegetation, the speed of growth, the optirnal interval between the consecutive silt reooval operatj-ons and the mechanical output of each engine used for maintenance of the (linear canals uret.res of canal cleaned per engine per cross-section of the canal). Silt cannot be renoved in the rainy season. vegetatj.on returns in less tnan tno months. l. Turkish Direccorate of state Hydraulic work, of the Ministry of Energy and Natural Resources. 2. Turkish Directorate of Irrigated Agriculture, llinisrry of Village Affairs. vBc/90.2 vttP/ 90.2 Page 168 - ifl Drainage.' This 1s not a routine operation, neither for SDI nor for TOpRAKSg. In the past some land depressions have been drained. (g) Water puraping.'This operation is carried out only during ernergeocysituatlons in Adana city when flooding occurs. (h) Water reservoir maintenance: Several natural and man-madereservoirs exist in the area. Very 1itt1e or no maintenance operations are carried out in nalural reservoirs. There are two natural water reservoirsl Akyatan lake and Tuz Gtilij as well as land depressions in Bahge and Karatas. In addition, there are tno nan-made reservoirs: an artificial lake constructed for the agro-energetic project of Adana (DSI), and the equalizing ldater basin of the saroe irrigation system. The shores of the man-made lake are properly maintained by DSI, and these do not pose a mosquito problen. The shores are not maintaj.ned on a routi.ne basis, nei.ther the bott.on of thi.s reservoi.r which is enpcied and fill'ed uP every year according to the irrigati.on needs. The reservoir is enptled at the end of the irri.gation season (Novenber) and for a certain period i.t remains dry except for the river bed (Seyhan river) which continues to run southwardly. The nelting of snow and the heavy rains duri.ng December-l"iarch replenish che main reservoir, but tbe equalizing reservoir is not filled until Apri1, when SDI opens the gaEes of the oain dan lare to fill the equalizing reservoir conpletely for the irrigation season. The nain problern of this artj-ficial lake is the energent and horizontal vegetation. Due to the condiEion of the water bed wbich consists of mud, it ls very dlfflcult for the DSI tractors and bulldozers lo oPerate on it to cut Ehe vegetation and labour force is thus needed. This kind of naintenance was already Eried in 1981, but ln a feu weeks tine, Ehe vegetation grew back again to the original level causing the stagnation of large masses of water at sites where horizontal vegetation exlsted and a very high density of sacharovi larvae rdas encountered, and subsequently malaria cases in the dlstricts ttrffiIfficreased. During 1981 a "rorrnd , larviciding Prograrme carri.ed out through the use of a rowing boat provided a saEisfactory degree of control, reducing the larval denslty, and consequently the number of malaria cases decreased. (i) Space spraying: - outdoor sPace spraying by Swlngfog with nalathion 400 TF: As indicated by nortal'ity of caged mosquitos, there was practically no penetratlon of the fog into houses, even when the doors and windows were left open. It was found that fogging was effective when the Swingfog passed about 1 n fron an open window. - Indoor winter fogging by Swlngfog with Neopybuthrin: AJ.though rhis treatmenr applied at 15 days intervals during January-February 1982 apparently reduced considerably the build up of sacharovi density ln Ehe spring in uost areas, this reducti.on occurred also in untreateTailas due to ralnfall being 6nLy L/4 of the normal anount during January-April l'982. The dosage used was 50 nl Neopybuthrin/ha, but the coverage r." ,,or deternined. This technique, however, started to be used in L982 in those suburbs of Aciana where high nunbers of nalaria cases were detected during the previous transmj.ssion season. - Indoor ULV by Fontan wiEh perlniphos-roethyl: Prelirninary trlals showed that a good kill was obEai.nedin houses treated at a rate of 200 nl of 502 piriniphos nethyl/ha, but in open stables no saEisfactory kill could be obtained. It should be noted that there tras been no systematic reporting of either indoor or outdoor space spraying applications, and likewise epideniological/entonological assessment was lacking. Finally, Lassen discussed the developnent of connunity participation, pHC anci multisectoral cooperation in Turkey as shown under para 3 below. Giglioli (1979) in an unpublished report to WHOreviewed the hlstory of ualaria in Adana plalns of Turkey, and described ln detail the Seyhan irrigation project which was lnitiated ln 1967. The reclaioed area of the seyhan projecr covers about 104 102 ha and in addition 30 000 ha of the adjacent Ceyhan/Aslantas schetre. Ground view of this large Proiect area ltas too llnited to lllustrate the sources of the mal,aria problen. Havlng had the facility of flying over the area ln a nilitary helicopter, Giglioli could illustsrate the problems in t,his project schematically as shown in Fig. 12.1 cittng a previous l. Reproduced by perrni.ssion of WHO/EURO vBc/90.2 MAL/90.2 Page 169 (n I qt = N (9 z I trJ rE (? l^l ll .n U, to q z_ (9 l- 9,1 trJ o lrl a fiE i5 9s lr0 luiT s J@ z eJ sk It t!l ,r -= o t -a) | h t,l I I o trl- Jl a \'F* tf t Fi O-i: ttl J I lrJ J bJJ (4 r! lrl o (2 I t{ lz tr,l () Ir I (n, -*5J ? I utl IJ -.=-r I CJ z o o /fv z t{ /z rlz,to t/ /'o /e. ,J CJ u) 33 trJ lrt F= u 3 <, 6 J.,- E= th v5 ! o = o G o o lr G € = t, ltJ ul .t z (l o (J z (J n| (9 j G € z G o0 z o lrJ h o q- cn = ta q t! 'E t! .G \= tr| o J lrj G z Our 0t> o I ul o @ o o o :"1 @o- o- o N* Q G vBc/90.2 MAP/90.2 Page 170 rePort by WtlO, the Seyhan project is served by 2200 kn of concrele-lined irrigation canals and canalettes wit.h about 3000 road-underpass siphons and roany level-drop boxes. Excess water is collected through 490 kro of 1-1.5 ro wide tertiary canals, 544 km of 2-3 m wide secondary canals leading finally to the sea or the Seyhan river vla 4L2 kn of 5-35 n wide Prinary canals. A11 these drainage canals are unlined and most of the 1446 kn canals built and maintained by DSI contain sufficient lrater for nosquito breeding throughout the year, except those situated above the 20 m conlour north of Tarsus-l'lisis highway, which probably dry up between irrigation cycles at the height of the summer. In addition to the above system, there are oany kilonetres of til.e drains and on-farm qualernary, installed by TOPRAKSUand Daintained nainly by the farmers. Tile drains of plastic or ceoent piping are buried 1.5-1.8 o deep every 80-100 m, and help in draining 45 L87 ha, i.e., about 452 of the project area. They are designed to draw off 2 mn per day, and TOPRAKSUand Teklnel et al. (1975) adnitted Ehat a spacing of 50 crn hras more suitable for local conditions. It was observed that even under the water-logged conditions of January/February, Ehe out.let.s of tile drains were never occluded by their flow of water and usually half of their lumen was left open. During the hot and dry conditlons of the suurmer, it is likely that these drains are used as cool, danp outside-resting sltes by raosquito vectors. This should be investigated in view of the extent of the system. For allocation of i.rrigation rdater, the farner tnforros DSI of his intended crop, area, tine of planting and water schedules. SDI calculates the exact needs for each section and farmer, allowing for an in-transfer loss of L6-2OZ ln the primary, 5Z in the secondary and tertiary canals. Tlne and volume schedules are lhen forwarded to the Dltch Runner of DSI who is responsible for oeasuring the scheduled water to farms ln hls 1000 ha subarea and rePorting the naintenance needs. Therefore, the final responsibllity for use and misuse of this elaborate and expensive irrlgatlon system rests on the lowest man, the Dltch Runner, an unfair and unsafe burden. l'lobi1e and effective supervislon is desirable and could easily be effected by an agricultural engineer. It 1s generally accepted that the farmer uses too much water (up to 2-3 tines his needs), and tha! water infringeroent is not uncommon. The nost inportant. feature of the earlier NI'IESand the present. reorganized service i.n Turkey is the constant lack of experlenced entomologists, hence the lack of longitudinal data on mosqulto blononi.cs on which the control strategy can be based. From the available infornation,@isthemostimPortantvecEorinSeyhan,fol1owedtoaIesserex!ent by hyrcanus, whi.le superpictus is thought to be absent fron the Adana region at the present Elne. An. sacharovi has been reported to breed in aI1 nater bodies in Seyhan, ranging fror fffi-%" water. rts larvae have been recovered fron drainage canals, underpass syphons, tail-end field ponds, overirrigated fields and burrow-pits. As Giglioli visited ghe project area in January-February when no vector breedlng occurred, he collected infornat,ion from colleagues who have visited Seyhan during the nosquito season. This clearly confirned that the water system, nalnly the drainage canals and ancillary bodies of standing nater, are contributing to anophelisrn in the project area as shown in the following; (a)Irrigationsystem:Thefornationofbreedingp1acesfor@during March-October was described, and it was concluded that it ls possible that the apparently harroless irrigation syslem is contributing to anophelisn ln the project area when not i.n use. Frequent i.nspections (weekJ.y) would establish if this is so. (b) Drainage syslen: One najor contributor to anophelisn in the Project area is the oore than I 446 xs of overgrown, earth drainage canals (see Fig. LZ). Even if these were naintained at a high standard they could still produce some mosquitos, but in their grossly overgrolrn condition involvlng about 2 n high emergent Cannae and TyPha in February, and dense beds of submerged Chara and plgggg spp. in suomer, they rePresent ideal breeding places for sacharovi. DSI is responslble for cleaning the canals, nainly by desilti.rg ih"n on a 3-yF6?G, but in practice thls is done every 5-6 years. l'laintenance is done by the use of herbicides, drag-li.nes and hydraulic excavacors. - Herbicides.' The use of herbicides by SDI ls confined to the cotlon off-season (October-Decernber). Due to a shortage of funds, thls applicaEion ls inadeguate, for example, in 1978 the allocatlon covered only 462 of the requirements. The SDI Herbicide unit should be expanded to cope with these resPonsibilities. vBc/ 90. 2 yrAL/90,2 Page 171 - I"lechanical oaintenance: The naln ain of thls operation is periodic removal of silt fron the canals, but fron the point of view of controlling anophellne breedlng, the frequent removal of emergent vegetat.ion and aquatic weeds is rnuch more lmportant,. When the silt is removed fron the canals, hydraullc excavators create large spoil mounds on one side. These should be jolned, Levelled and shaped into roads Eo give access to both sides of the canals for removal of weeds. In the larger canals, the trost sultable equlpnent for this would be hydraulic f1ail cutters wlth a long reach, which can be mounted on most large agricultural tractors. Srnaller dltches (quaternary drains) would be more efficiently maintained by rotary dltch dlggers mounled behind the standard agricultural tractors which exist in the area. Sufficient space should be left on one side of the draln to allow continued malnEenance. The greatest fault in the Seyhan project. lles in the dralnage systen. The best solution would be to line the drainage canals with concrete, as rras done in t.he Pontine narshes, Ita1y. Alt.hough the capital cost seems to be prohibitive, in the long run it would be cheaper than the recurrent expenses of nalntenance of the systen in addition to the cost of vector control. (c) Anc1l1ary Itater bodies: Bodies of water, both naEural and byproducts of the Seyhan project are as inportant sources of breeding as the drainage system. In the haste to develop the area, the landscape has been pocknarked by single and seni-continuous collections of burrow-plts that had been left over frou supplying fill for house constructlon, major roads, farn roads, flood control levees etc., (see Fig. 12). In some placesr the field margins were deeply eroded. Thi.s occurred shere the farner had released excesslve irri.gation ttater lnto an adjacent roadslde borrow-pit., slnply by breaklng the field nargln. Thls created deep furrows, a few Eetres long, having depressions suitable for nosqulto breedlng. ?he net result ls that along manroade el-evations, breeding grounds have been created, whlch should be jolned ln an orderly Danner then connected with t.he dralnage systen. Alternatlvely, spoil fron cleanlng lrrigatlon canals could be used for filling these pits and other depresslons ln and around Adana, and later, around villages to reduce breeding in the proxlnity of settleuents. Another obvious deiect, especially in the flood plain of Seyhan, and near the last phaee of the project (Phase III) was the Presence of suall and large isolated marshes. These should be connected wlth the river, or the nearest drainage ditch, so Ehat the standlng nater can be reduced as much as possible. (d) Rice fields: These are controlled under the "Rice Paddy Law", whlch had been established because of the high incldence of oalaria in pre-DDT days. Thls law, enforced by the Rlce Coumlssion, lnposes that the rlce fields under lntermittent irrigation be situated at a distance of at least 300 n fron the nearest human habitations, and those with contlnuous irrigation should be sltuated at least 3 kn fron habitations. In Selfike, however, little respect for these regulatlons was evident, but perhaps ulore important, was the lack of control over the rice area. The Seyhan plan called for not more than 52 of the area to be devoted to rice, but DSI adnitted that up to L57" was used for rice, whlch is even planted on tile-drained land. Although this is obviously a bad practice, DSI had no authority to linit or even withhold nater 1f che farmer nants to misuse it by subnerging reclai.ned dralned land, and consequently flood Ehe drainage systetr in that area fron April to Novenber, a practice whlch encourages nosguito production. (e) The poorly drained so1l of Phase III: There appeared to be a strong wish to reclalm the boggy lands of Phase III. As cited by Giglioli (in a personal conmunicatlon) Prof. o. Tekinel, Dean of the t'aculty of Agrlcultural Englneerlng, Cukurova Universlty, Adana) was of the opinion t,hat the poor dralnage of thls seaward area, nas inpeding the drainage of the already reclalned lands of Phase I & II. He proposed this as one of the reasons for starting Phase III developmen! as soon as possJ.ble. This being the case, one hopes that the drainage of Phase III area w111 be deslgned to handle much more than the lrrlgatlon lnput, and that all bodles of standlng nater w111 be i.ncorporated. Further, it ls hoped that the developuent of the drainage system will precede the lrrigatlon systeo, in order to gain full benefit fron both Phase III, and I & II areas as soon as possible. Gratz (1987) indlcated that 1n 1984 discussions with lrrigarlon and drainage authorities of Chukurova revealed thac there were no plans to improve the dralnage systen in the area, and to do so was considered excesslvely cost.ly. It nust also be enphasized that such dralnage improvements are beyond the responslbllity, competence or control of vBc/ 90.2 rlAr.l 90.2 Page I72 the nalaria service or health servlces ln Turkey. Gra:z further added that a new dam and irri.gation systen is being constructed in the Uria area to the east of Chukurova plain. This area is already endenic for nalaria, and will undoubtedly attrac! many migrant workers. Whether or not the lessons obtalned frorn Chukurova plain will be taken into account remains to be seen. In Morocco, Prothero (L9641 discussed the problero of population xoovenentin relation to oalaria eradication. He pointed out that irrigated areas need to be known in detaiL because of the importance of water in relation to vector breeding, and the attraction of the economic developrnent connected wlth lrrigation on population movement. He advlsed that very detalled infornation on irrigated areas was avallable ln the 0ffice of Irrigation of I'lorocco and use should be nade of such inforoation when planning malarla eradication. The types of noveuents whlch take place 1n Morocco nay be fltted in the following roajor categories: (a) Nonadisn: This 1s the Dovement of pastorallsts ln which the whole group of people, nen, wonen and children together wlth anlmals, partlcipate. These movementsare for the Illost Part deterrnined by the availability of pasture and wacer for aninals. The general seasonal pattern of movenents nay be the same from year to year but the aclual nrovements are not rigidly defined, as there are very conslderable varlatlons in the pattern from one year to another. The variatlon ln patterns of movementsresults fron variation in envi.ronmental condltions, particularly the lncidence and arlount of rainfall. (b) Labour oigratlon: This lnvolves oovexoent of people who are attracted to lrork anay fron home for linited periods of tlme, prlnclpally by the prospect of economic gain. After working for a certain period they return to Ehelr home areas. Although they nay leave t.o work agaln, ttrey are effectively based in their home areas. These tray foll.ow a regular patlern (e.9., seasonal or be quite lrregular). The movementis made Eo areas of more advanced econooic developnent (agricultural or industrial), where there is a denand for labour. (c) Rural exodus: People are attracted for soclal and economlc reasons to leave the country-side to settle ln towns, resulting ln de-population of rural areas on the one hand and rapid urban growth on the other. In contrast to nigrant. Iabour movements, t.he rural exodus produces a permanent Dove lrlthout periodic return !o houe areas. This peruanent move lnvolves the whole faolly, whereas labour nlgratlon usually involves adult males. (d) TranshumanceS There is a valld distinction between transhumance and nomadism whlch is lnportant for malarla eradlcation prograppes and for the appllcation of public health neasurea in general. Transhuuant oovenents are usually 1n a vertical rather than in a horizontal directlon, i.e., from the plaln to the mountaln and vice versa, controlled by seasonal changes in climate. They are regular and not subjected to marked fluctuations fron one year to anot,her. The routes that are followed are well defined and are adhered to, and likewise the grazlng area used by dlfferent groups. These features contrast wilh those of nomadic pastorallsts, besides whlch there are other inportant differences. In the case of transhunance, people have peroanent dwellings fron which Ehei.r movenenE Eakes Place and assoclated wlth these there ls land which is regularly cultivated. The novement of ani.nals !o various grazlng grounds at dlfferent times of the year does not involve the Boveoent of whole faoilies. Only some uembers of each group move wlth the aninals, and nornally there are always sone people who remaln occupying the pernanent settlement. In l'lorocco, there are Elro najor sub-categories of t,ranshumance: - Surnrnertranshumance: ("estlval") which lasts froru }lay to October and involves movementa froo the lower-lylng valley floors to the hlgher pastures froo which the snow has nelted and the grazLng is good. Only those who are innediately concerned ln the tendlng of the animals take part in the sunoer transhumance, and the oajor part of the populati.on remains in the permanent villages. Transhumance has tended to involve a progressively snaller proportion of the population. - Wlnter transhurnance: This lasts from November to I'tarch and involves movements away fron the Eountains to the lorrer altitudes of the plalns and plateaux that surround them. A greater proportion of the populatlon nay be involved than in suuner transhuoance. There ls a conslderable varlatlon in the movement of dlfferent groups, ciepending on the areas in which they are located. Sone groups, like the Ben Mguild ln vbc/90.2 \rAL/ 90.2 Page 173 the lloyen Atlas undertake double transhumance, noving upwards ln sunrner and downwards in winter, where their perrDanentsettlements are located. Other groups undertake only summer transhunance and spend the winter i.n their permanent settlenents. Prothero further revlewed the available infornation on lhe extent of each type of the above mentioned population movementsin l'lorocco and discussed the malaria risks. ln his conclusi.ons, he pointed out that wh1le pastoralisn (nornadismand transhumance) is progressively declining, other forms of noveoents (oigrant labour and rural exodus) are beconing more itrportant. This trend is likely to lessen the problems of malaria associated with nobility, but che rat.e at which the changes are Eaking place is slow. It should not be difficult to deal with the rural exodus. Likewise migrant. labour associated with nineral and industrial developoents can be checked upon, but those working in agriculturaL enterprises will need more specific investigation. Prothero, however, considered that the types of population movements in I'lorocco were unlikely Eo present problens for nalaria eradication comparable to those to be faced in countries of Africa south of the Sahara. Within the infrastructure being established by the llinistry of Health, it was envisaged that the prograrDmefor eradlcation of nalaria will be integrated into the general prograrnmefor the development of a country-wide public health service. It should be possible to build up and oaintain a botty of data on population rnobiliry and on ocher human factors which are l1ke1y to influence malaria eradication. The detailed local knowledge which t.he "aides sanltalres" are intended to collect should be extremely useful. [A long tine has passed since Ehis study was undertaken. It needs to be updaced Itith a view to elucidating the re.l.ationshi.p between populatlon movement.sand the persistence of malaria transoission in certain foci under the present socioeconomic conditions I . One published epideniological study on one of the nater-resources projects j.n I'iorocco could be traced. This was reported by Deschiens & Cornu (1975) who visited the area of Hassan Addakhil dan situated on Ehe Ziz river 10 kn north of Kasr-es-Souk on the Haut Atlas' at the tine of its construction in 1970 and later 7n L974 aft.er the dam and its lake and the lrrigatlon netltork have been functioning. Detailed description of the dan and its lake was given with schenatic illustratlons presented. Eriefly, Ehe oraximum capacity of darn lake was estimated to be 380 rnillion cubic metres. The lake through its prinary canals (closed or open), secondary and tertiary canals in the lower valley of Tafilalet can irrigate about 4400 knz of land. In 1970, the prevalence of urinary schistosomiasis among schoolchlldren at Tafilalet was as high as 102. tJith regard Eo malaria, there were important active foci. P. vivax was the predominant infection encountered, whiJ.e P. falciparurn was rare.J-y fo""d P. nalariae exceptionally recordeo. The anophellne fauna nas slnilar to that of the Satrara:""d sergenlli!, uulticolor and hispaniola. An. labranchiae which is considered the nain vector of nalaria in l{orocco, was exceptionally found ln the south of the Haut Atlas. The observatioos carried out during 27 May-2 June 1974 showed that: - The temperature of the water of the lake at the surface was 2lo C and the pH 6-6.5, a condition which favours the developnent of Bulinus snails and nosquito larvae. - The temperature of the water at t.he shores of the lake and its creeks vas 22-240 C which reflects the effect of the heat of the sun, a condition whlch favours the growth of vegetation and the developnent of lnvertebrate hosts. Neverlheless, Ehe whole surface of the lake and its creeks up to a depth of. 4-5 m was devoid of subnerged and emergent veBetation. This ltas not surprising because the lake was newly formed in a rocky structure in an arid zone and has been subjected to changes In the nater level. - Neither nosquito larvae nor snails could be found; only some crusEacea including Daphnia and Cyclops were seen. With regard co the ecological and epideniological changes in fut.ure (10-15 years), the growth of aquatic and shore-line vegetation is to be expected. Likewise, the developnent of snail. i.nternedlate hosts and nosquito larval populatlons will undoubtedly occur. This will cornnence in the creeks and valleys of the lake with little deptn, where alluvial sedluent accunulates, and in particular at sites where herds of animals abound. In the oeantime, no huoan population exists in the area except for sooe houses remaining since the construction of the dan which are visited casually. There are also some gardens and vBc/90.2 t'tAL/90.2 Page 174 palu groves i.n the vicinity but no snails or mosqui.to larvae could be found in t.hese sites. In conclusion, with the repopulation of the area especially the lower valleys where new i.rrlgation schemes are envi.saged, careful monicoring should be naintained for tinely control of snail i.ntermediaEe hosts and vector larval populati.ons. INo new information could be traced on the situation in this area at the present tine]. In Algeria, the construct.lon of the trans-saharan highway has received rnuch a!Eention in view of its growing econonic inportance and possible epideniological inplications for countries of north Africa as a result of increasing traffic of vehicles. Enphasts has been nade on the risk of establishnent of P. falciparun transmlsslon from inported cases origination in African countries south of the Sahara, and the introduction of An. gambiae s.1. through the speedy traffic as shown below. It is necessary first to give a resum6 of the available knowledge-on the northernmost llnits of distributlon of the An. ganbiae complex in West Africa. L Coz (1973) gave the northernnost records of arabiensis up to Boutilinit in l4auritania (17035'N latitude 14050'W longitude); arabiensis and ganbiae s.s. at Bafoulabe 1n l4a1i G4o49r N, 10o30t w); and both species at Ayorou in Niger (I4o44' N, 0056' E). Prevlously Hamonet al. (1966) recorded on their naps both species as far as 17o00t N, 7o00r E ln Niger. In norlhern Chad, Rioux (1960) recorded in Septenber 1958 and August 1959 An. ganbiae s.1. in paln groves of Faya-Largeau and as far as the Tibesti l,lassif in the ext.reme north (17000'-22000'N). More recently, Stafford Snlth (1981) carried out a mosquito survey from southern Niger (13006r N) to t,he north (19006'N) includlng the border area of Algeria. He found specloens identlfied cytogenetically as arabiensls 5 kn north of Agadez and_thj-s reprgsented the northernmost record (17000' N) of thls specfes in Niger. Stafford Soith pointed to the inpllcations of road constructlon involvlng exclvatlons that forn large burrow-plts whlch becoue filled w1t,h water durlng the rainy season forning soall lakes. Thls can greatly faclJ.itate the spread of Afrotropical species to the north. Moreover, Itlth nlneral exploitalions, nelr settleDents w111 be established in the north, and with the increased traffic, arablensis Day get established in pot.ential breeding places 1n the north. Also, It is expected that the use of air-conditioned lrucks and contalnerized vehlcles will shorten the travel tine, and wlth the increased movemenE at nlght, there will be a danger of long dlstance transportation of vector speci.es through the Sahara to the southern oases of Algerla. Ransdale & Zulueta (1983) who described the distribution of local anopheline species in northern and soughern Algeria, discussed the inplicatlons of the construction of che trans-Saharan highway - see Tables 13 a & b and Fig. 2 under 2.5 above. Their discussion examined the posslbllities of establlshing oalaria transnlsslon fron funported cases originating in West Africa through local anopheline vectors or the exotic vectors $ ganbiae s.s. and An. arablensis. P. vlvax which is stlll encount,ered in the Medlterranean Basin ls absent frou, or extremely rare ln, I{est Africa. P. falciparun is nost likely to foro the bulk of nalaria inported into Algeria as it is the predorninant species 1n l'lest Africa where the levels of tenperature permit its transmission throughout the year. It is knoun that the threshold of temperature for the sporogonie cycle of P. falciparun is l9oC, below which the development of the parasite is indefiniteLy retarded. In Taoanrasset, south of Algeria, the mean tenperature falls below this threshold during 5 nonths each year. This unfavourable peri.od is shorter at lower altltudes, Iasting only 3 monlhs at Aoulef, but becones progressively longer with increasing latltude. It extends to 5 oonths at Golea, 7 months at Lagouat and Algiers and longer in the highlands of the Atlas. Addltlonally, an important llnitlng factor that may also explai.n the absence of autochthonous P. fal.ciparuu frou the Mediterranean Basin, being the marked refraccorlness of uenbers of the An. maculipennis complex, including 1ab:anchiaetoexoticstra1nsofP.fa1ciParul,aslffirate-dexperimen!a11y,c1ting ffiGGtrors2. The situatlon fr-n the southern oases of Algeria where outbreaks of P. falciparun nalaria transnltted by local vectors were reported previously, citing several workers includlng LefEvre-Witier (1968) [see under (li), 1 above]. The sltuation in northern Algeria ls quite dlfferent where labranchiae ls the vector. Any increased Bovenent lnto and across the desert will inevitably affect the vulnerabillty of oany oases, parElcularly those of Hoggar. Until problerns of vector identification are resolved, the degree of receptivity of these oases will renaln a Datter of speculation. l. For more detalls see PARTI, SECTION III (A) WEST AFRICA in Document VBC/85.1-MAP/85.1, pp.11-15. 2. See VOL. I under 2.8.2 (ii), pp. 158-161, in document VBC/88.5-MAP/88.2. vBc/90.2 tlAL/ 90.2 Page 175 The nost pressing need is for clarification of t,he Eaxonomic status of various populacions of sergentii s.1. [see the suggest.ion of the authors under (i), 2.5 above]. The type forn, sergentij- serBentii can be a good vector of p. falciparun. Ransdale & Zulueta (1oc.cit.) further suggested that even after the coropletion of the trans-Saharan highway, the long journey accross the desert will still be exlremely hazardous for mosquitos, and tne risk of inportatlon of arabiensis and,/or ganblae s.s. into the l"tedi.terranean Basin by road nay not exceed ttrata@ation uy-ZF-nxamples were given of the hist.oric irnportation of ganbiae s.l. lnto Brazil during the 1930rs and Egypt during the 1940ts (see below). However, successful establishnent of introduced species depends on the presence of suitable conditlons locally. It is unlikely that arabiensis and gambiae s.s. would find such condilions i.n northern Algeria, though they nay be able to develop one or nore generations during Ehe summer. The inability of arabiensis and ganbiae s.s. to extend their range into Hoggar illustrates the fornidable nature of the desert barri.er. The journey fron Agades to lamanrasset covering a dislance of 97O km currently takes three or ruore days of travel across hot arid desert, with the possibility of travelling at night being severely linlted by the i1l-defined nature of much of the route. When the highway is opened it will be possible to complete this journey in less than 24 hours, avoiding the worst of the heat by travelling during the night. lf nosquitos are periodically able to exlend their range north fron Agades through the seasonally swanpy Azaouak valley, the distance they nust be transported over and the Eiue necessary for the journey Eo Hoggar will be comparatively less. An i.ncrease in the volume of traffic and the use of insulated vehicles and ai.r-conditioned cabs afEer the cornpletion of the highway Dust make the incroduction of arabiensis and,/or gambiae s.s. into Hoggar probable, even inevitable. rf they are able:E6ffillsh thenselves in Hoggar, their further spread into other souEhern oases rnay be rapid. Because of the salinity of surface water, it is loprobable that these tlro vectors could colonize many of the northern oases aE the present tine. However, fulure development could change the situaEion as seen at Zelfana, where a new agrlcultural conplex was established in 1948 ttith Idater drawn fron a deep reservoir under the Sahara. Studles carried out t,hree years later showed that this new oasis was already populated by seven nosquito species. A deep underground reservoir has also been tapped at El Golea, fornerly a poor place of brackish Idater but now a flourlshing oasis. An. sergentii s.l. has been found breeding in fresh water at El Golea. Chauvet, Hassani & Izri (1985) described the trans-Saharan highway and discussed its inplications for Algeria and countries of the llaghreb. Tnenty years ago t.he countries bordering the Sahara decided to create a trans-Saharan north-south route for increasing and intensifying the exchange of their eonnercial and human resources. The councries which were directly involved.' Algeria, Tunisia, Niger and Mali forned a conmittee for preparing the plan of this project at a continental level. At the Algerian initi.aEi.ves, the work nas started in 1971. In 1979, the dlstance between Lagouat-Tamanrasset (1600 kn) was terminated wiEh Ehe financial. assistance of che United Nations Development Programne (UNDP). Alger could be reached frou Tauanrasset in not urore than a one-day journey by car at a speed of 80-100 km on the newly paved tarmac road. Two laEeral roules were constructed: one starts fron Ghardala to reach southern Tunlsia vla Ouargla and Touggourc, and the other connects Ouargla and Ghadanes. To the south of Tamanrasset, the lrork continues, and at 70 kn fron this town the route branches into ttro; one reaches Gao in l4ali (at 100 krn) via Tin-Zaouaten and Kidal, and the other reaches Agades in Niger (900 kn) via ln Guezzamand Arlit. The importance of this undertaking comes fron the numerous soci.oecononic benefits arising from cransportation of goods, people and animals, developnent of sna1l and nedium industrlal projecls, exploitation of minerals, tourism and the hotel industry. The roule rlill also pernit lrliger and certain provinces in Nigeria to have a newr easy' rapld and less expensive access to the Mediterranean for the European market. The trans-saharan traffic wlrich rdas at a 1evel of 5000 tons (t )/year in 1968 has now reached 250 000 t/year, correspondi.ng to 50 000 trucks/year (about 150 rrucks/day1. It has also been estinated that about 4000 persons are transported daily on this route. This brlght socioeconomi.c prospect is, however, clouded by the risk of trans-Saharan exchange of communicable dlseases. Further, che authors discussed the risks of circulation of ualaria parasites and t.he vectors. - Despite the contlnuous importaElon of P. falci.parun fron the Sudan-Sahel zone, not a single case of this parasite has been found north of the llediterranean. The sane reason shown above regarding the inconpatibillty of labranchiae to tropical strains of P. vBc/90.2 rtAL/90.2 Page 176 falciParun was suggested. The authors further assumed that the loca1 vectors of the Sahara nay also be inefficient in transnitting tropical srralns of P. f=]gip..*. Nevertheless, lhis assumption should be net with cautlon because ofE past severe epidenics of falciparum malaria that broke out j.n Tassill NrAS;ers (citing Brousses, 1930 and LEfevre-lrlitier, 1968), where sergentii and nulticolor were present,. Such assumpt,lons shoul.d be verified experinentattyEffiopnerffiipGcions may consist of strains differing in thelr vectorial efficiency ln the sane way the plasnodial strains differ in their infective capacity. The sane suggestlon was made calling for the need to clarify the taxonomic stalus of sergentii s.1. (see 2.5 above). - Circulation of che vectors.' Exanples exist indicatlng that trafflc circulat,ion led to rapid colonizalion of new hrater sites in newly established Saharan oases in Algeria, by sergentii and roulticolor which are well adapted to such envlronment, (citing Benabadji & Larrouy, 1969). It is possible that the tno species will progress south of the Sahel, but this will not change anything because malaria transmission by An. gamblae s.1. is so int.ense that the role of those two less efficient vectors is negJtgible. AE worst their Presence night prolong the Cransnj.ssion season because they are perfectly adapted to the dry clinate environment.. On the other hand, the greatest risk 11es ln the extension of An. garnbiae s.1. to the nort.h. I'lembers of t.his complex exlst in the Sahel zone up to 16-170 N covering I'laurlt,ania, MaIl, Niger and Chad. It has also been recorded frotr Agades on the Niger branch of the trans-Saharan highway. More perturblng is the record of An. ganabiaes.1. frorn an isolated statlon on the northern slopei of Tibesti near the Libyan border (citing Rioux, 1960 - see above). This author suggested that the presence of An. ganbiae s.1. at this statlon represented a rellct fauna rather than a new inEroduct,ion. Chauvet, llassani & Izri (loc.cit.) polnted to a previous record of An. ganbiae s.1. fron Ghat in Tannezzouft valley in southern Eezzan province, Llbya close to the Algerian-Libyan border, 100 ko as the crow flies froo Djanet, Algerla. [The authors did not give the reference of this record. However, the old record of An. gaublae s.l. south ot Fezzaa could not be conflrned - see under (ij.) 1 abovel. tegaraiffZil- funestus, the second najor vector ln tropical Africa, there is no danger of its introduct.ion in the north, slnce it has special ecological needs by breeding strictly ln freshwater and ls very sensi.tive to water salinity which prevalls in the north. For prevent,ion and conlrol, the authors suggested the following measures: (a) Amplyfying the knowledge of the seasonallty of nalarla transolssion in the Maghreb. (b) Intensifying control oeasures in known foci using different anti-vector Deasures as well as treatment of casea. (c) Using all possible means in the I'laghreb to prevent the introduction and establishment of exotic scrains of P. falciparun and An. ganbiae s.1. (d) In the Sahel, rigorous atteipts stro,r:.a Ue nade for ellnination of oalaria transmission and for Ereatment of cases particularly uigrant populatlons at frontler areas before they proceed north. These lneasures would need an adequate infrastructure served by well-trained and motivated personnel. Equally inportant is the establishnent of an intra-Mrican scienti.fic and operational cooperatlon. In their assessnent of the malarla siEuation in the Algerian Sahara, Benzerroug & Jansens (f985) [see (ii), 1 above], provided inforrnati.on on the movement.of the population and vehicles across the frontier posts with Mali and Niger. The nunber of persons entering Algeria through the southern frontiers has considerably lncreased: frorn 3530 Persons in 1978 (836 natlonals and L423 foreigners) to L2 434 in 1984 (3003 narionals and 9426 foreigners). There was a parallel increase in the number of venicles entering through che same posts: fron 1110 in 1978 to 3413 in 1984. These data reflecr the amounr of oovenent of the populatlon across the southern border as a result of the construction of the trans-Saharan highway which exlends Eo 5929 km to connect Lagos with Algiers. .tsruce-Chwatt (1986) also re-emphasized the rlsk of reintroduction of rnalaria inEo countries of North Africa through the crans-Saharan hlghway. Although not yet completed, this all-weather hlghway has a hard surface of sone 3400 kn, from Algiers, through Laghouat, EJ. Golea, In Salah, Tamanrasset, In Guezzau, and Agades (see Fig. 2). Further south, it branches westwards to Birnin Konni and Niauey (in Niger) and southrdards from Zinder (ln Niger) to Kano and Lagos (in Nigeria). The western and southern junctlons from vBc/90.2 t4AL/90.2 Page L77 Agades are not yet finished, but the laEter is motorable during nost of the year. The Saharan plateau Deasures about 3.5 nillion n2. Its topography varies from rocky wasteland (known locally as harnmada), through an intermediate zone of stone and gravel (serir), to the loose and nainly sandy area with drifting dunes (the erg). The trigttway has been built at altitudes varying beEween300 and 600 ;, except at the Hoggar highland which rises to 3000 n) where the road runs at 1400 n. The clinate varies with latitude and altitude. The ternperature ranges fron 50o C at noon in sunmer to below 0o C at night in wlnter, and the hunidlty is very 1ow. Rainfall is practically nil, but i.n some Parts of the desert sudden slorms erupt and nay create raging torrents in the usually dry valley. In these arid areas, subsurface water may accunulate in 1ow-lying sites and form saline pooJ's. Except in isolated srnall or medium oases, the human population is scarce and nostly forroed of nonadic tribes, who have been greatly affected by recent droughts. I"lost of the oi1 and ni.neral industries are in t.he northeasEern parts of the Sahara, away fron the hlghway. The growing economi.c importance of the trans-Saharan highway is reflected froro the spectacular rise in the number of vehicles crossing road-posts at the borders of Algeria with southern countries of West Africa. of 410 naiaria cases recorded in Algeria over the past fer^ryears, 7QZ vere caused by P. falciparun. A traveller frorn Tanzanla with chloroquine-resistan! P. faLciparuo serves as a reminder of the potential risk of inported nalaria trom Africa-souEh-E ttre Sahara. Isee Benzerroug, 19b5, under (ii)r I abovel. Epidernics of P. vivax have occurred in Algeria in the past, and some sporadi.c cases of P. falclparut-[Fe been common. Of the malaria vectors in Algeria, labranchiae is ttre-nost-To!6Ent acting as the main vector in coastal areas and the northern zone of the Sahara. Someworkers believe Ehat i.nported tropical strains of .--P. falciParum are unlikely to cause resurgence of roalaria because of the doubtful ability ol labranchiae to t.ransnit this infectlon. An. sergentii is also an important vector in ttt"-iffifrTre gulticol.or remains a suspected vector in these oases. The greatest danger is that ttriGli,i6-rious troplcal vectors An. gambiae s.s. and An. arabiensis would establish themselves in Algeria along ttre saEZG n-i.gtrway. The f66GTfffilaric barriers would nilltat.e agalnst their establlshnent ln the northern part of t.he Sahara, but the southern oases of Hoggar, Tidikelt and Tassill would be vulnerable to invasion by these highly adaptable and robust vectors. Air-conditioned vehicles could provide long-distance transPort of these ttro vectors. Mditionally, the increase ln water supply fron deep reservoirs in some new agrlcultural and industrial projects may contribute to Permanent colonization by the two species. Bruce-Chwatt also reninded that the invasions of tsrazil and Egypt by An. garubiae s.1. ln the 1940rs and the recen! transporar.ion of infected tropical vectors by aircraft to airports ln Europe should serve as warnings, calling for greater vigilance and effective preventlve measures. Although the inplications of the trans-Saharan highway were discussed brlefly at the Coordination I'leeti.ng on the Prevention of the ReintroducEion of I'lalaria in the countries of the western lledlterranean, Erice, Italy, 1979 (WHO,f979b), Isee SECTIONI under L.2.2 i.n documenr vBC/90.1-MAL/90.1] nore decislve action is needed since several water iupoundnent projects are being proposed to increase rice production j.n many countries of North Africa. In Tunisia, Wernsdorfer (1973) in his unpublished report recalls that t.owards rhe end of 1970 a smal1-scale larvi.ciding trlal wlth tenephos 500 EC was conducted in the area of Cap Bon barrage 1n the Nabeul region. The larvicide was applied at a rate of. 75 rnl of the concentrate Per hectare at fortnightly intervals. As the result.s were pronising, it was decided to apply this larvicide on a large sca1e, particularly in t,he foci where sergentii Itas Present. ln 1971, the zone of the Bi.zerte dam and Nabeul region were treacea-wittrf,- dose of 75 nl tenephos/hecEare every fortnight during l.lay-October 1971. In foci of transmisslon Ehat persist.ed in Gafsa and Sfax regions the same temephos treatment was applied ln Libya, froo recent observations by Ransdale (1989 - i.n press) (also in personal communicat,ion' 1987), settleoent and cultivation in Fezzan (see Fig. 3) are restricted to places where subsoLl rtater can be tapped. ?radltlonat lrrigation iystens in Fezzan depend vBc/90.2 nAL/90.2 Page 178 on water drawn by means of an aninal-driven bucket systen fron shallon open wells through a series of open channels and snall storage reservoirs. These open wells and residual surface water in t.he irrlgation netnork provide larval breedlng sltes for sergentii and/or Pul,ticolor. The introductlon of poner driven water purtrpssone 20-25 years-affiff-owed lifting increasi.ngly large volunes of water and cultlvatlon of larger plots. Lowering of the water table in the Wadls of Etba and EL Adjal made lt necessary to substitute the wells by deep closed bores. hater is now punped lnto straight sided concrete tanks from Irthich it is distributed chrough open channels or more often through pipes to sprinklers whlch save a 1ot of nater. Even where open channels and flood lrrigatlon are still Practised, the depressed water table and absorbent sandy soll ensure qulck absorptlon of resldual surface ltater. The only standing surface water ln the oases of these wadis is now associated with seltage, hence unsuitable for anopheline breeding. Thus, in an area which includes Sebha, I'lurzuk and Ubari there is no water surface tha! can support the developnent of anopheli.ne larvae. At the same time, sergentli and/or rnulticolor were stil1 breeding in abundance in other oases, where dlffeient aqulfiers are used as in llon, tsrak, Edri, Aiwanat (Serdeles), and Ghat. Io addition to the aquifiers mentioned above, reserves of water capable of sustalning a nuch larger hunan population underlie nuch of the-Sahara. Large scale exploitatlon of these reserves has been very llnited. This can profoundly affect anophellne prevalence. In EgyPt, . the construct,i.on of the Aswan lligh Dan served as a reminder for reinforcing the measures to Prevent the rei.nvaslon of An. ganbiae s.1. from north of Sudan. The history of the northward spread of an. ganUiae s.t. was shown in pART I.I lt is more convenient to recapi.tulate thls lnfornition trere with sone addltlonal details. It is well known that An. ganbiae s.1., a typical anopheli.ne species of the Afrotropical or the Ethlopfan zooge%raphical Region, extended its distributlon to the north causing devastating epidenlcs in Egypt in the early l940ts which necessitated an extensive campaign for lts eradlcation as nas thoroughly reported by Shousha (1948). From this report, when a malarla epidenlc, associated with An. ganbiae s.1., broke out in the Egyptian Nubia ln l'{ay L942 at entomologi.cal survey nas carried out to deEerrnine the extent of the spread of this exotlc species into Egypt. It was soon discovered in several northern localltlesr uP to Assyut city in Septenber and further in November in a small isolated focus in Manfa1ut, a lown sltuated 25 kn north of Assyut, but this focus was dealt with lornedlately. Thus, the northern liuit of An. ganbiae r"" considered Eo be south of Assyut, a stretch about 850 kn along the qouiEE-of-tE-Nlle".1. Valley froro Barlana near the Sudan border, coverlng an area of 4270 kmz, hitherto repreaenting a Darrow cultivated striP of land ln the flood plain of the Nile, lnhabtt;d Uy 3 niffion people. A study of the cllnatic condltlons showed that An. ganblae s.l. had only three months, Septenber to Novenber, when it could prollferat;=-iipper gglptr but the remaining part of the year rePresented a difflcult perlod for this specles. At the beglnning of tire initial campaign, whlch was started in 19422, vector control Deasures and treatment of malaria cases were gravely hanpered by the inadequacy of transport, Paris green and antiroalarial drugs due to war conditlons. Shousha (loc.cit.) further showed that in July 1944 the Gaubiae-Eradication Service was established', undertaking the control actlvltles as a milltary operatlon and followlng lhe same technlques and organlzation as those utlllzed for extermlnation of An.'gambiae s.1. fron Brazil after 1t had invaded the nort.hern part of chat country, as aescriUea Uy Soper & Wilson (f94g)3. Conplete eradication of An. ganbiae froro Egypt was -FmTbc"oent vBc/85.3-MAp/85.3,sEcrroN rrr(D): EAsrAFRrcA, pp. 15-18. 2. Fron ltalawani & Shawarby (1957), the persons who organized and participated in this inltial canpaign vere: the late Dr M. Kha1il, Dr A. Lutfi, Dr A. Halawani,, and Dr A. Shawarby. 3. As aeknowledged by Shousha, the Rockefeller Foundacion delegated the same experts who had organized the gambiae eradlcation caopaign 7n brazll, to work in Egypt. The advice and criticisn of Dr F.L. Soper who visited the ganblae-infested area several tiroes, rrere greatly appreciated. Dr J.A. Kerr became the Di.rector of the Gaoblae-Eradication Service and Dr D.B. Wilson became the Field Director in 1944. vBc/90.2 M L/90.2 Page 179 firrnly established after suspending all control operations during the nost favourable periodr Septenber-Novenber 1945. In his discussion, Shousha cited the observations of Lewls (1944) nade during L942-L943, showing that An. ganbiae s.1. in rhe Wadi.Halfa area of northern Sudan bordering on Egypt, fluciuatea GG?Ilf,and disappeared in wlnter IDonths and that the source of its replenishroent in tladi Halfa was the 2nd cataract of the Nile where large breeding pools existed throughout the ninEer months. Shousha therefore suggested that the northlrard spread of An. ganbiae s.1. Bay have invaded Upper Iigypt prior to L942, and gave the history of severe nafarl.a epfdernics causing large numbers of deaths. No anopheline collections were made at that tine but these episodes indicated that i'n. ganbiae s.l. was probably the responslble vector rather than the local vector, rcs}s.Toconclude,hestated:..Butwhet'herornotgaobiaeeverinvadeddgypt before L942 is rather beside the point. It did so then, ana fffi-iiao so again, unless adequate protective neasures are put into force." He further expressed appieciatlon of the anEi-ggb:lae measures applied with conop.Lete success by the Sudan Medical Service in lhe area of Wadi Halfa extending to 58 kn fron the border to the 2nd cacaracc. Regarding the rnalaria situation, Shousha explalned that during the difflcult year of L942, i.E was found that the number of nalaria cases notified to the public health offices did not agree with the severity of the epidenic. An estinated lncidence of nalaria deaths was calculated on the basls of attributlng the lncreased nunber of deaths in 1942 over 1941 as due to nalaria in the infected area shlch covered the narrow cultlvated strlp of land ln the flood-plalnl of the Nile, with a population of 3 nlllion people. The death rate due to nal.aria ltas estimated as LOll of the cases ot L942 (63 000). In 1943, there Itas a better detection of early cases and a oore liberal dlstribution of antimalarial drugs, whlch had an effect in reducing the death rate to 5"Aof 76 000 cases estl'ated for 1943. In 1944, the therapeutic service was established and both nen cases and relapses were notifled. Subsequently, the number of cases was drastlcally reduced as a result of the eradication canpaign as shown in the following: cases Deaths New Relapses From new ca6es From relapses L944 32 823 733 906 L 789 o L945 28 138 150 7 18 L946 59 2254 4 2 The epideuic caused by the ganblae invaslon caused great economic losses in the lnfested area in Upper Egypt as shown by ll,alawani & Sharwaby (1957). For example, the Kom onbo agricultural company, whlch cultivated an area of about 30 00d acres in Aswan province, was estimated at L.E. 500 000 as a result of a 40% reduction in the labour force during L943-I944 due to ualaria norbidity. The number of deaths of about 12 000 shown by Shousha (1948) ltas an esti.mate that feI1 far short of the t.rue figure, if the secret burlals could be added. Lewis (1949) described lhe measures applied to exterminate 44. ganbiae s.l. fron the t'Iadi llalfa area durlng 1945-1946 ln support of the ganbiae-eradGEi-canpaign ln Egypt, adopting the saoe techniques applled earller in sra;Ffu rhls reporr, Lewri (roc.cii.) discussed the northward spread of An. gaubiae s.1. into Egypt and excluded a suggesti.on that thls nay have been associateaTitl-JFransport from central and west Afrlca, recalllng that An. ganbiae s.1.. occurred ln the Wadi Halfa area for many years and it nay have "occurrea li]-Tffited the old Aswan Reservoir area, which lies oalnry in the tropics, for a 10ng period", cltlng Lewis, (L944). After providing the proof of An. Sanb{ae_s.1. externlnation fron the Wadi tlalfa area by 1946, Lewis (f949) made several reconmendations for naintainlng the area as a barrier to prevent An. ganbiae s.1. spreading into Egypt. 0f these, the need for DDT residuat sprayti!-?rrains coming ro Wadi llalfa fron the south, io addition to pyrethrum space spraylng before their arrival, was enphaslzed. Noting a previous report on 3-year insect collecttons from airplanes at Khartoumwhereby 16 anophelines were found, of which two lrere An. ganblae s.1., he proposed the spraying of aircraft at t.Iadl Halfa and at southern-Fodror"s. I. The narrow cultlvated strip of Nubia south of Aswan was lnundated by tbe lake of High Dan, and the flood-pJ.ain north of Aswan has been transformed into a perennlal trrlgatlon systen. vBc/90.2 \tAL/90.2 Page 180 Lewis (1956) referring to the northward spread of An. ganblae s.1. in a stretch of about 850 kn into Egypt as defined by Shousha (1943), poinred oul that this Erhiopian species reached a point 600 kn inside the Palearctic Region. Until 1942, its northern llnit probably occurred between Saras [about 60 kn soulh of Wadi Ha1fa - a stretch which has now been inundated by Lake Nasserl and Ehe Tropic of Cancer which traverses the souchernpartoftheo1dAswanReservol.r.Inthisarea.@.s.1.apparent1ycould survi.ve relatively cold winters in certain places with long lastlng pools and its distribution fluctuated fron season to season and perhaps from year to year. During Septenber-October 1950 a few larvae of An. ganbiae s.1. were detected at Abu Sfunbel and Ballana near the border with Sudan.T;o"gh r.asures applied by the Egyptian Ministry of Health, this linited invasi.on nas dealt with pronptly by DDT house spraying and larviciding in all localities of the Egyptian Nubia. Subsequent searches were all negative for An. ganbiae s.1. (Zahar, unpublished observations,1951). On the Sudan side of the border, Lewis (1956) indicated that An. ganbiae s.1. did not reappear in the area of Wadi Halfa under control until Decenber of the same year vhen a few of its larvae were detected in Abdln locality, a short dlstance south of Wadi llalfa town. This was thought to be either due to failure of control t'o.cover the breeding place or to spread frorn the south possibly by one fenale transported by a train during that year of unusually heavy rainfall. Larviciding with DDT in oll was innedlately applied as from January 1951 ln a stretch extending 80 kn south of the border as nas suggested by the Egyptian aurhorities. With the construction of the Aswan High Dan in Upper Egypt, Fig. l3l, and the gradual fornation of its lake, (known as Lake Nasser in Egypt and Lake Nubla in Sudan) extending about 500 kn to the south lncludlng 150 kn lnto Sudan and coverlng abou! 6000 knz, great ecologlcal changes occurred. AparE fron faunlstic, florlstic and physical changes, all locallties of the Egyptian Nubla were inundated and their populatlons resettled north of Aslran but Abu Slnbel was saved by re-establishnent at a higher level. Some localities in north Sudan were also lnundated, notably the o1d Wadl tlalfa and environs, the populatlon of rrhich was resettled ln Khashun E1 Girba ln l(assala provlnce while other localltles awaited lnundatlon when the lake was expected to reach its target level of 183 n ln 1974. New Wadl Halfa tolrn lras re-establlshed south of the old slte on the eastern bank of the lake and remalned connected wlth Aslran, Egypt by passenger and cargo boat services sailtng fron a suall port establlshed 3 kn froq the town, passing through the newly establlshed Abu Slnbel locality. The new Wadi Halfa2 torn remained connected with Khartoun by railroad and with the northern province of Sudan by road. Health hazards arising fron the lake recelved attentlon from both the Egyptian and Sudanese healch authorities, particularly with respect to the potentlal risk of re-invasion of An. garoblae s.1., the spread of oalaria and infestation of schistosomiasislsEilal surveys have been undertaken by Egypt and Sudan in the lake area giving special attenElon to the border area. In a review of the hazards of re-invasion of An. ganblae s.1. into Egypt arislng fron he construction of the hlgh dan and fornatlon of Lake Nassar, Shawarby, Mahdi & Kolta if967) gave the northern llolt of 41L, gatrb:lae s.1. in nort.hern Sudan as Kweka, 193 ku southofoIdI{ad1Ha1falc1t1ngan-np,,b11shedrePortbyGadonasurveyconductedduring 1954-1955. At the same t,lne joint teams rrere organlzed to control ualarla by DDT house spraylng and mass drug adnlnlstratlon in the area between Halfa and Dongola. In February L966 a joint cornnLttee of the l'linlstries of Health of Sudan and Egypt net in Khartouxn to review the antl-gg[lgg Deasures conducted by both countries. At that tine the lake had already flooded Saras and its southernmost end was expected to reach Dal, (about 150 ke south of Halfa). Thus, i.ntensLficatlon of surveys and control ueasures by larviciding and house spraying in the area between Dal and Abu Fatma (see dlstances below) and the application of other protectlve meaaures were reconnended Ln the hope that An. ganbiae s.l. would be eradicated fron thls area before 1970. In Aprll 1970 an entonological/parasitological survey was conducted coverlng the newly established Halfa town (replaclng old Wadi Halfa that was inundated) and several localitles i.n a stretch of about 160 kn to the south including Dal, as reported on by l. Reproduced by pernlssion of Dr !1.A. Farld and Acadenic Press fron the chapter entitled "The Aswan Eigh Dau Development Project". In: l'tan-Made Lakes and HurnanHealth, Stanley & Alpers (eds.) (f975). 2. Sioolv referred to later as Halfa. vBc/90.2 MN./90.2 Page 181 Zahar (1970). These localltles nere awaitlng inundation and in the int,erln peri-od rrere covered by DDT house spraying and larvlclding. Intensive adult and larval surveys showed,a ganbiae-free area extendlng froro halfa and lts port to Akasha, l-40 kn south, Fig. 14r, where abundant cullclnes nere encouncered. An. ganbiae s.l. was flrst encountered as larvae (0.5-1.0/10 afps) and as adults restlng indoors (0.4-f.0 fenales,/roon) at Dal, Sarkaaato and Farka. Dal was situated on the Itest bank of the Nilet about I50 ku south of Halfa and thls tras consldered as the northernmost llnit of An. gaobiae s.1. under the condltions prevalllng durlng the survey. Sarkanato and Farka are situated on the east bank nearly opposlte Dal but a llttle to the south. In thi.s area the Nile at the time of the survey was stlll narro!, and fast flowing ltith cataracts among basalcic rocks. Inundatlon whlch started in 1967 did not ouch affect these localities but they were awaiting their turn. Many pools nere seen In this area which reach a maximum during the flood tj.ne but they were at a nlnfunum during the survey. Probably cliuatlc conditions of the dry season durlng whlch the survey was carrled out were adverse for An. garnbiae s.I. longevlty and contributed to the low denslty encountered (tenperature 25-35oC & RH 8-352). On the malaria situation, the hospital records in Halfa ln 1969 showed 10 clinically dlagnosed nalarla cases aoong out-patlents and l0 nicroscoplcally diagnosed cases arnong in-patients. These were probably loported cases fron the endenic areas of Sudan. The dlspensary aE Farka ln the area where An. ganbiae s.1. was encountered, clinically dlagnosed 105 cases of oalarla anrong 9142 attendants 7n L9691, 577 of these cases were diagnosed from October-Decenber. None of L864 blood slides collectec during the survey representing about L57 of t,he total populatlon of seven locallties (4 garubiae-free and 3 ganblae-lnfested), was posltive for nalaria and some doubts were raised about the quality of nicroscopical exaoi.nation. Reconmendations were made for reorganizing and ioproving the larviciding and spraying operations and for testing Fig. 13. I'lap of the Aswan Bigh Dan l. Reproduced from the report of Gll1les (L972) by pernission of WHO/EMRO,(with sone oodifications to the original uap drawn by Dr llustafa Akood, Encouologist, Antlnalaria progrannes, Sudan). vBc/90.2 t4AL/90.2 Page 182 Fig. 14. Area surveyed during 1970 and L97I in the Northern Province, Sudan. ) LAKE fUDIA_ :/" 'r '' t .\ l fiCALErl : 50C.,-'iri- r-, I cOl{PILt-D ilY I iiUiTAFn AK(l00 i'J'i]' \,;' 1! (Fi€uree 1.r. perentheEes are d,istances in ku, ?ir.., sovth of Wadr-1619": '. a1on6' the rirer : il g LocrliLiet wirr !.2rr&r'ee c.l. o4r, F ",.-'?', ,.'J '*!:).\ \( ^,.\- 21or4it- .3 27.t ,';Q i (aci i.Gid Foid n':r,e) ?lo : ti.f E"t dAss18 { rra ) sARJlA {ozt) (rao; 21.", oot ,11' t r 2'!c ltil )i." , oo vBc/90.2 r[aL/90.2 Page 183 larvivorous fish in pernanent pools. Surveys during the favourable season and susceptibility testing of An. ganbiae s.1. to DDTwere suggested. It was stressed that both Sudan and Egypt should maintain their areas of the lake disease-free on a long-tenn basis as opposed to temporary short-term oeasures. As an interim measure, short-t,erm plans should be developed to deal with the changing situation as the lake level rlses and likewise, long-tern plans should be developed for permanent control when the 1eve1 stabilizes. Glllies (1971) reported the resuLt.s of his observations as a WHOConsulEant in the lake area in Egypt and Sudan during October-Decenber 1971. From his revien of previous work in northern Sudan, surveys made later confirned the findings of Zahar (1970) that the northern l1nit of An. ganbiae s.1. was Dal (about 150 kn south of Halfa). Also 3767 blood slides collected in July fron localities between Dal and Abu Fatma (350 kn south of Halfa) were all negative. Frorn this Glllles inferred that little transmission seemed to have occurred in this area despite the presence of An. gaubi.ae s.1. In fact there was llttle malaria in recent years 1n Dongola, a populous centre 80 krn south of Abu Fatma. However, in the few months precedlng his visit, there was a xoarkedresurgence of malaria in the area as si.gnified by the number of microscoplcally dlagnosed cases at the Dongola hospital which reached several hundred per oonth. This suggested that there was considerable risk of nalarla spreading north again unless it could be contalned by active control. Further, susceptlbillty tests made ln July 1970 at Kweka (2L2 l An agreement lras foroulated Ln L972 and signed by the Governoents of Egypt and Sudan for."Health and Medical Cooperation". As part of this agreement, the two Governments agreed to cooPerate in undertaking Eeasures for eradicating An. garnbiae s.1. frou the lake area uP to Abu Fatua, the details of which were glven in a separate protocol. Protective Deasures need to be lntensifled at the Hlgh Dam complex in Asnan, Abu Sfunbel and Halfa :--efiam-fron the report of Zahar (1970) by pernisslon of WHO/EMRO. vBc/90.2 r4AL/90.2 Page184 Fig. 15 l,lap of the Norrhern province, SUDAN IVAOI XALFA Iown {km J I FARXATI 150 ko 179km. 276 kr , U FA Tt'lA 350 lrm. ABoU HAttAD DOIIXOLA KARIHAH vBc/90.2 t4AL/90.2 Page 185 including disinsection of rlverine transport operating between the two countries, as well as disinsection of trains before reaching Halfa. The measures to be continued in Aswan Governorate were also described. In northern Sudan, survey and control operat.ions by larviciding and house spraying should cont.inue in the area betrdeen Halfa and Dal. Surveys and periodical larvlciding of all breeding places ln the area between Da1 and Abu fatna should be continued, besides which house spraying is to be applied using an inseclicide to be agreed upon by the two Goverruoents. Posltive places detected during adult or larval surveys should be iunediately dealt with. The tno Governments are to undertake neasures to keep the area extending from Aswan to Abu Fatua free from oalaria by active case detection and radi.cal treatment of posltive cases. Exchange of reports on survey work, surveillance and veccor cont.rol operations should be nade nonthly. In addition a joint team is to survey the lake shores twice a year: once in April-May and again in Novenber-Decenber, using riverine transport. The ain of these joint surveys is to check the findings reported routinely fron the lake area in Egypt and Sudan. A joint comnittee is to be forned to examine the achievements made and for exchange of technical experience. Farid (1975) who described the Aswan High Dan and its 1ake, Fig. 13, discussed che ecological disEurbances and health hazards arislng froo this project. tlith regard to malari-a, he outlined the ecological and human factors that may favour the reintroduction of An. Sanbiae s.1. into Egypt frorn northern Sudan as showrl in the following; (a) During the seasonal fal1 ln the water level of the Lake which Is estimated to be 5-7 n during January-July, many residual pools are formed. Despite intense evaporation, these pools retaln sufficient rdater for nosqulto breeding, and it would not be economically feaslble to carry out antilarval operations in such extensi.ve pools. (b) The growth of vegetation along the shores or in the pools provides protection to the larvae of An. ganbiae s.1. durlng the very short cold seasons but during the rest of the year, tnfsGtor pEters to breed in snall sunny pools. The local vecror, Pharoensls, prefers to breed in pools having aquat.ic vegetation such as Potamogeton. So far, very few vertlcal and floating vegetatlon has grown in the lake, but the presence of P. pectlnatus in Khor El Ranla lndicates that this aquatic weed will soon becoue established. (c) The establishroent and northward spread of An. ganbiae s.1. ln the lake reguires c1ustersofhuuanhabitations,herdsofdonesticanGForevenw1ldgamea1ongthe1ake shore. At present, these do not exis!, or only in very suall numbers. There are plans to set uP 10 villages for fishernen and a nuober of agricultural settlements with a population of 200 000 or Eore. If this materlalizes, the chances for the establ.lshment and northward spread of An. ganbiae s.l. would be nuch greater. (d) Passlve transportaEion oJ An. ganblae s.1. may occur through boats or Nile steamers oPerating between Sudan and the tligh Dan harbours. At present, the lake shores are arid and hardly have any sizeable human settleoents. Thls condition cannot favour the establishnent of 4n.@. s.1. This situation will eventually change once the level of t.he lake staUittzEl-anl-TFagri.cultura1 and industrial settlenents become established. Vigilance on this vector at this stage should be concentrated around human habitation, in boats and in harbours. The rouEes of camel caravans fron Eritrea and Somali.a to Egypt which nolr operate along the Red Sea and nay in turn operate along the lake, should be studied. Experience elsewhere has shown that An. ganbiae s.l. can hide and survive in the belongings of the nonadlc tribes (folded tents, bo*es, potteries etc.). Recent infornation comes from a report by Shi.drawi (f980) who acconpanied a joint survey team during April-lhy of the sane year. In this report, the ongoing control activities undertaken in the Egyptian part of the lake were described. In northern Sudan, weekly larvlciding continued as planned and DDT house spraying was applied twice annually coverlng a population of 48 000 llving within I/2 ka on each side of the lake or south of che Nile. At llalfa, fogging of all trains and boats has been maintained. Since 1979, it has been outually agreed to extend the control area to Lebab, 85 kn south of Abu Fatna covering an addltional populatlon of about 160 000, naking a total. length of 800 kn south of the lligh Dan. While the annual inspectlon by the joint survey tean found nothing in 1979, research workers frou Khartor:m University collected considerable numbers of An. arabiensis (the only species of the An. ganblae conplex identified so far from northern Sudan) at Dal island (see Flg. 14) during November-Decemberof the sane year. vBc/ 90.2 t4AL/90.2 Page 186 During the survey of the joint team of 1980 ln which Shidrawi particlpated, the breeding plaees were found to have been heavlly treated wlth tenephos as none rdas positive and no adults could be found in houses ln six villages includlng Dal and Farka as well as Kweka (212 kn south of tlalfa). It was only in Attab village that both larvae and ad.ults of An. arabiensis were found and at Sai Island (alnost opposite Kweka) where only larvae of tffi sPe;l€s,tere collected. In chis area (about 200 kn south of llalfa), breeding occurred 1n vegetation away fron the shores in the niddle of the river and obviously were nissed by the larviciders. The positive findlngs provided further evidence that the species could perslst in its nornaL habitat and range of distrlbution. In his concluslons, Shldrawi re-enphalszed that fron the above observations, 4l_Sgb:!gp. has not been eradicated froro t.he project area by the control measures unffiken so f"r and it is doubtful that this can be achleved. lle relterated the previous views that control measures in northern Sudan should aim at keeping the denslty of An. arabiensi.s sufflciently low to nininize its abili.ty to spread northwards into Upper egypt. In this connection, he pointed to the role that can be played by riverine and ai.r transport and also underlined the potential danger when the lake shores become repopulated, lhus facilitatlng the northward spread of the species. Farid (1984) who acconpanied the joint inspection nission, as a I{HOConsultant during February-March 1984, reviewed the control measures undertaken by Egypt in the Lake Nasser area from Aswan to Abu Sirnbel, and by Sudan ln Lake Nubia area (exilnsion of Lake Nasser) from new Halfa to the south lncluding the riverlne area up to Abu Fatna ln the northern province. In hls commenton the findings of the mlssion, Farld (loc.cit.) poinEed out that the absence of larvae and adults in ttre lake areas (although the nost southern part Itas not covered due to dlfficult accesslblllty) as revealed by the mlssion and the records of routlne aurveys, as well as the negative blood slldes obtained fron schoolchildren ln Abu Slubel and llalfa townsr together wlth the fact that every positlve splenic enlargenent was found ln 1 nlgrants from Lower Egypt or Kordofan, Sudanr. all glve an indlcation of the absence of arablensj.s fron the lake areas with the exceptlon of lts unsurveyed southern tip. Tillh-e rlrrerine area south of the Lake, larvae of arablensis of different lnstars were found only at Tombos lsland adJacent to Abu Fatua (a66F5d-tr south of lralfa) and further south at Kurelk vlllage. However, these results should not be regarded as conclusive for varlous reasons, e.g., the inproper tlulng of the joint inspection surveyr the inabillty to survey the nestern rtverine Ehores, the absence of records of routine surveysr the attenpts of the local Sudanese ganbiae control team to larvlcide heavily al1 breeding places before the arrlvaf of tnffiET inspection nlsslon, the 1ow sanpling rate aPPlled by the nlssion in relatlon to the numerous suitable breeding sites, and the very large nurnber of the indoor day-tiue restlng sltes in this heavily populated area. In hls reconnendations, Farld suggested that the tlolng of the annual joint inspection should be within October-November and to last for not more than three weeks. It should be preceded by a one-week oeetlng in Calro or Khartoum !o examine thoroughly the Donthly rePorts subnitted by the fleld staff of the gambiae control project since the previous inspection, as well as any other technical reports (including meteorological, hydrological data recorded in the project area). Such nonthly reports should include the results of entooological and parasitological surveys as well as control actlvlties conducted agaLnst anophellnes in the Egyptian and Sudanese parts of the project area. Exanination of such reports and daEa should enable the jolnt inspection mission to select. certain vulnerable localities in both Egyptian and Sudanese sides for inspection and to draw an ltlnerary to visit these places accordingly. The nost recent lnfornatl.on comes from the report of the annual jolnt lnspection Dission (1987) covering the period 14 Septenber 1987-18 October 1987. The reporr descrlbed the ecological changes and human settleoents in the Egyptian and Sudanese parts of the gambiae control project area. In addition to groups of fishermen previously establlshed on the lake shores in Ehe Egyptlan side, small groups of population occupy certaln localitles and are engaged in linited farnlng. The notable development is the re-establlshment of two villages: Kostol and Adendan on a creek extending fron the eastern shores of the lake. In the two villages a small populatlon started farnlng, but sooe of then left because of the lowering of the lrater level in the lake in 1986. They are expected to return when the project of floating rrater punps ls establisbed. This area i.s considered a Potential danger because of its proxiulty to the Sudan border (35 kn north of Ilalfa), and the expected connection wlth the desert route planned to be constructed along the eastern side of the lake to connect Halfa and Aswan. On the Sudan side, many arable plots reappeared after the water level receded in Lake Nubia, and thls attracted more vBc/90.2 vtAL/90.2 Page 187 SrouPs of people to repopulate the lake and Ehe rlverine areas for faroing or raising donestic stocks. Entonologlcal searshes made j.n several localities in the Egyptian side of the lake did not reveal the presence of arabiensls, and likewise parasitological investigations yielded negative results. otf,E-tn"sna".tese side, the following observations were nade in the three maln parts of the project area: (a) The northern part: fron Halfa to Akama, north of Akasha - the size of cultivated land appreciably increased; - the size of the human population oarkedly increased; - nany potential breeding places and creeks were forned; - in view of difficult navigation, the inspection rnission could not reach by boat beyond the outskirts of Akasha; - all adult and lavral searches vrere negative for arablensis in places inspectedl - parasitological lnvestigations revealed five po"iffiE" (3 P. vivax and 2 P. falciparun) all were classified as inported fron New tlalfa resettlement area, Khashn El Grlba, Kassala province. (b) The central part: fron Akasha to Wan. - arabiensis larvae were recorded in a very low denslty at Dal (about 150 ko - sout.h of ilalfa) [previously regarded the northern linlt of gambiae s.1. see aboveI ; - further south, arablensis was recorded as larvae at Mafraka, Atab and Waw, and as adults and larvae at Kweka, Aboud and Sai island - the density rras very low at all these places; - parasitological lnvestigations gave negative results; - all posltive breedlng places were imrnediaLely treated. (c) The southern part: Abu Fatma. - adults and larvae of arabiensis were recorded in snall denslties in four villages; - parasltological investigations revealed two P. falclparun cases! one classified as a relapse and the other as i.ndlgenous. The total. number of blood slides collected by the mission ln the Sudanese part was 3088 of which seven were positlve as shown above. Several recornrnendations were made of which reference is made to the following: - to continue provislon of ootorized boats in vlew of the large number of potential breeding places in several islands and the rdestern shores of the lake and the river Nile in the Sudanese part of Ehe project; - to survey and larvlclde t.he wells and other non-classical types of breeding places of arabiensis as was revealed by the inspection oission; - to expand the parasitological surveys to cover at least 102 of the human population; the surveys should be conducted once ln Novernber and once in llarch/April; - to apply residual house spraylng in places not covered so far; - to deteruine the susceptibility of arabiensis to safe lnsecticldes used as larvicldes and inagocides; - to fill in vacant posts in view of the acute shortage of the available staff. Bahar (f975) ln an unpubllshed paper to WIIOreviewing the malaria si.tuation in water-resource projects ln the WHOEastern Medlterranean Reglon, referred to a favourable development in Egypt as a result of increased perennial irrigation water through the High Dau. In order to reclaio nore land for production of food crops, the Egyptian Government declded to replace the open dralns wlth covered drains. This rueasure nas inltiated for leaching the land, so as to free it fron salts, and at the same time reducing the co6t of maintenance of the dralns. Hundreds of kllouetres of open dralns suitable for breeding nalaria veclors and snall internedlate hosts of schistosomi.asls, were thus elininated. vBc/90.2 vtAL/90.2 Page 188 11 Jordqn, (f987) _ Tawfik when describing the problens facing the Jordanian progranne [see (ii), 1 above] explained that the area around Rutenberg daroon the Yarmouk river close to the junction wlth the Jordan river has also caused concern. An earth dam was bullt in 1970 to replace t.he gates on the Jordanian side which had been blown up previously. Ihe earth dam, however, has no gates and no overflow system. As a result of thisr the water in the dan reaches a hlgher level Ehan it did before and consequently fields around the village of Bagura on the Jordanian slde becone flooded. Ivloreover, as no clearing is done in the J.ake, reeds and trees have covered an area estimated to be 2/3 of. the surface of the artificlal lake. This together with the flooding near Bagura provide an inportant source of nosquito breeding. Although no sacharovi or any other vect,or has been found breeding in this area in recent years, there-ilGger of reintroducing sacharovi froro areas further up Ehe Yarrnouk river where it is resistan! to DDT and dieldrln in Syria. Tvo neasures would elininate the problem of mosquito nuisance as well as the potential danger of reintroductlon of sacharovj.: (a) to naintain the water in the lake at a lower level by openlng gates on the western side and, (b) !o clear the reeds and other emergent vegetalion 1n the lake by a common agreenent, of the parties concerned. These measures should be done in additi.on to the larvj.ciding which is at least being carried out on the Jordanian side. In Israel, Kitron (1987) extensively reviewed the history of nalarla in relation r.o agrlcultural development and descrlbed its control in Palestine/Israel, Italy and USAwith special reference to the Tennessee Valley Authority. Only information related to Palestine/Israel is sunmarized here. Following the division of Palestine in 1948, Israel underwent a period of extenslve agricultural and general developnent. In 1949, the Anti-Malarla Division rdas established ln the Minlstry of Health. In addition to its responslbllity for all direct rnalaria control activlties, this dlvision was represented in the various agencies that supervised agrlcultural settlenents, water-resources proJecEs, drainage work, use of insectlcides e!c. The Subconmittee of the Organlzation of I'lalntenance of Drainage Projects lras headed by the Director of the Anti-nalaria Division. Moreover, his nembership in the Insecticides Advisory Connittee deoonstrated the interaction between health and agricultural professions in determinlng the pollcy refevant to both. fuiother inPortant aspect of the antiualaria activities in Israel ,r." tir" strong coordinatlon between the nedical infrastructure and the publ1c health organization. It was witnessed that there was no settlement left without some type of health facility. The population nade liberaL use of these freely available health facilities to the extent that oalaria cases were unlikely to remain undetected, even in the absence of an active case detection Programne. The classical ueasure of larval control through source reduction and the use of larvicides renained the mainstay of the malaria control progranme in Israel. House spraying with DDT was applied sparingly and never became the principal nethod of choice. Surveys of different types were conducted, including a coungry-wide survey of all naturaL water sources and potential breeding places of anophelines. Under these neasures, the number of nalaria cases declined rapidly, despite the presence of parasite carriers aoong an influx of innigrants vho al.so lncluded susceptible persons. By 1966, inoigenous cases were no longer seen. At present, Israel is free of indigenous nalaria despite the continuing Presence of four potential vectors: sergentii, superpictus, sacharovi and claviger, and the contlnuing influx of parasite carriers . Kitron & Spielnan (1989) reviewed the neasures adopted for suppression of nalaria transnissi.on through source reduclion of anopheline breeding in lsrael, the United States and Italy, of which reference is made here only to Israel. The authors described the control measures applied in Palestine si,nce the early years of the century. Following the division of Palestlne in 1948, source reduction reoaj.ned the backbone of malaria control in the new state of Israel. Malarlol replaced solar oi1 and Paris green, and several herbicides and algicldes were evaluated as agenta for altering the conditions favourable vBc/90.2 M,^L/90.2 Page 189 for the vector 1n the breedlng sites. Standardized procedures for reporting of field activities were developed, and reports by regional lnspectors to the central dLvision were subnitced biweekly during the breedlng season of mosquitos. DDT house spraying was extensively applied during the 1948 war, when the use of other antinalaria measures proved lnpracticable. Later, it was applied sparingly afler the war, nalnly in three reglons in which nalaria still existed: Jordan valley, Beit-Shean valley and Negev and Arava or southern desert, particularly in siles where inmigrants from malaria endemic countries settled. The appllcation of house spraying was gradually reduced. By 1966, no indigenous cases of nalarla were recorded in Israel, but following the 6-day war of 1967, isolated cases were again reported fron within pre-l967 borders of Israel. For applying antiJ,arval measures, all breedlng places whet.her natural or artificial, permanent or teDporary nere napped and treated regularly. Al.I direct antiroalaria measures were carefully adapted to locaL conditlons and to ecologlcal characteristics of each vector. This reguired a thorough research on the bionomics of various anopheline vectors as weLl as on the course of the disease. Thus, the measures undertaken against sacharovi included the preservation of dense vertical vegetation in order to keep the w"ter-ffiFshaded and the use of TilaPia fish to reduce horizontal vegetation. Measures directed against sergentii included the use of Ganbusia affinis, cleaning and clearing nater beds to accelerate the current. l'leasures .lif:EiE"tror superpictus lncluded drying stream beds weekly by diverting the wat.er flow in dlfferent directions. Restricted water collections that could be drained were thereby pernanent,ly elininated, whlle oil larviciding was applied ln those breeding places that could not be dralned. Large-scale drainage operations were sought for reducigg the abundance of sacharovi and sergentli ln particular. DDT house spraying was carried-out ualnly in the ffnl.Icanpaign-E;Effis-r sachirovi. [See nore details on nalarla control measures ln Israel by Saliternik (1977a & b) under (ii), I abovel. In Lebanon, Metwally (1970) 1n an unpubllshed report to trIHOdescribed in detail the area of Koura - Zghorta plateau and the Akkar plaln where a hydro-agrlcultural developroent Project which was planned to be initiated in 1969 and conpleted in four years. In 1970, i'nvestigations were started to select the sltes for construction.of dams and determlne t.he volume of water to be received. Several infections exlsted in the area such as Ascaris, hook-worm, skin Tlnea (ringworn) and opthalmlc diseases. Malaria whlch has been eradicated frorn the area Ithe oalaria eradlcation programe in Lebanon entered the maintenance phase since 1969] nay reappear as a result of the presence of swamps and stagnant pools arising froo canal construction and relat.ed rrork. Water blockage roay take place if there ls an open canal irrlgation system. Therefore, construction of drains is deened necessary. The dralns will also be sultable for snail breeding due to growtn of aquatic weeds on their side. Vector control is rnainly directed against culicine nosquitos by the Ministry of Public Health, but it would be advisable to have such activities perforrned by the rural health centre planned to be established in the area. No further infornation could be traced on this project or any other water-resources projects in Lebanon. In Syria, although there are 12 daus constructed between 1950 and 1971 (World Register of Darosr 1978), no informatlon could be traced on ualarla in areas under the influence of these dams. However, casual observations were reported by WHOConsultants/Entooologists. Eshghy (1986) uentioned that in Dany locallties several. water sources such as springs and shallow underground water create marshes and swamps of various sizes. Also, poor maj,ntenance of canals and dralns and t.he consequent gronth of reeds and vegetation as well as the erosion of the banks, have slowed down the flow besldes reducing the capacity of the sysEem, thus providing favourable breeding places for anopheline vectors. Further, Sadek (f986) Dencioned that according to hls discussion rsith the Director General of Agriculture and Irrigation ln Ghab valley, Sekalbia/Hana, Syria, the clearance of narginal vegetation fron all dralnage ditches is done once yearly, but the growth of reeds is very rapid, belng nithln a period of three months. This explains the presence of reeds practically all year round. The nost obvious type of source reducti.on is the ellnination of standing water ln which mosquito larvae and snails breed. This can be done by filllng in depressions and deepening peruanent nater bodies. Reviewing the 6th Flve-Year Plan (1986-1990) of the Ministry of lrrigatlon, Damascus, with the Director of Irrigal,ion, there are trro projects under executlon. The flrst ls the deepening of El-Assi river (llana and llons) betlreen Qatina lake and t'tehredah dam, i.e., to form a narron bottoo vBc/90.2 \taLl 90.2 Page 190 or a V shaped cross-section, so that the flow can continue without beconing a meandering channel. The second is filllng in ponds and pools in Rakka and Der EL-zor which is the most satlsfactory nethod for the pernanent elinination of vector and snail breeding. 4. Alternatlve nethods of vector control l4ost of the available infornation that could be gathered fron countries of the l4editerranean Basin under mal.aria control or in advanced maintenance phase, concerns suppleuentary lDeasures or alternative methods to replace the standard oethods of attack on veccor populations. The infornation conpiled here is conveniently grouped as follows: 4.1 Biological control A11 the available inforualion from the area under review concerns the use of larvivorous fish. The lrlHoreport of the TravelJ-ing Seminar on the use of Larvivorous Fish for Mosquito control ln Anti-l'lalaria Canpaigns, Buigaria and USSR, 27 August- 15 Septenber L979 - - sinply referred to here as t{H0 (Ig7g) useful infornation on the availability "orpit.d and efficacy of larvivorous fish ln oany countries of the world including some of those occurri.ng in the present geographical area. In the past, the use of larvivorous flsh, notably Ganbuiia atfrnrs, as a tool for malaria control had been activery pursued by nany c6ffi wrttr the advent of DDT and newer i.nsecticides, interest in the utilization of this fish was decreased and aloost forgotten. However, interest in larvivorous fish has been revlved after the problems of insectlclde resistance in several najor vectors has created operational inplications in a number of antimalaria PrograDnes during the late 1960ts. rn the ussR' Shunakov (1980) - presented the scope of predatory fish in the control of ualaria vectors in areas of intensive agricultural developoent. The constructlon of different tyPes of water reservoirs and the developnent of hundreds of thousands of hectares of lrrlgated areas, including rice paddies in river flood plains and in non-irrlgated tracts has result,ed in increasi.ng the nunber of places of mass breeding of nosquitos and consequently the production of large vector denslties ln addltion to the territorial redistributlon of vector specles. T[us, the potential danger of outbreaks of nalaria and other infectious diseases of oan and anlmals has become ouch greater. At the sane tirue, nosqulto control durlng the naintenanqe of nalaria eradication lras rendered difficult by the fact that highly effective cheni.cal conrrol Eethods were praclicarry excluded on account of the hazards of environmental contani.nation and deveropnent of vector resistance to lnsectlcldes. This situation necessitated the development of an integrated system of rnosguito control of which biological control would represent a main conPonent. The nost prouising among biologlcal control agents is the predatory fish. Gaqbugia has been successfully used for ttre control of nosquito larvae in water reservoj.rs and rice paddies, but its efficacy 1s conflned t.o warm waters. The whi.re amur, Ctengph?ryngodon idella, is the most promlsing fish for the control of overgrown vegetatioo i'n reservoirs. The advanced fry of the whlte aurur can be stocked not only in reservoirs but also in rice fields. The results of rnany years of study have shown that the conditlon of rice plots are very favourable for the development of advanced fry of this fish whlch destroys the preimaglnal phases of mosquitos. The white amur unlike 9+nbusla is a cold-water fish. At present, its northern thernal boundary is along the llne of Leningrad-Moscow-Novosibirsk and the Far East of the soviet Union. Experlence has shown that the white amur can be used as a blologlcal control agent in a much wlder area in the USSRthan the warm-water Gaobusla. The possibillty of raising advanced fry of the white amur ln rlce check plots aiFtre nigh efflctlveness of this tish in destroyi.ng preinagnal phases of nosquitos enabled the developmenr of a technlque for blologicai control of uosquitos. The details of this technique were described which can be read in the original paper. In Grgege, useful lnforroation t'as provided by Hadjinicolaou & Betzios (1973) on rhe hiscory of Ganbusia affinis and on an experiment and observations in dlfferent areas of the country conducted in 1970 to evaluate its efflcacy in controlling sacharovi. The decade 1930- 1939 witnessed an lntenslve canpalgn for establishing r[iF risn which had been inported into the country a few years previously. A nuuber of ponds and other suitable water bodies in every district of Greece were selected and stocked with the fish to serve as natural Gambusia breeding places. These natural hat.cheries rrere soon seen teenlng with Gaobusliffi these natural habltats large numbers of fish were colrected vBc/90.2 uLAL/90.2 Page 191 and released in various types of nosquito breeding places throughout the country. At the end of the decade, the fish was widely distributed and firnly establlshed rhroughout the country. The objectives of this canpaign were not so much to test and prove experinentally the efficacy of the fish against roosquilos, as to distribuEe a well known effective predator in all oosquito breeding places wherever possible. With this objeccive in nind, very few data were collected on the effect of Ganbusia on anopheline density and nalaria incidence. The only available infornation caneEoarrlnerous enthusiasE.ic reports which generally agreed that: - the fish were readily adapting themselves to a variety of conditi.onsl - they were muLti.plying fast in all types of water collections; - they were doing equally well in fresh, brackish and mineral waters; - while t.he fish were able to establish thenselves i.n the pernanent breeding places of sacharovi and naculipennis, they were unable to do so in the typi.cal breeding places of superpictus because the fishes were washed away after heavy rains and flooding (citing Livadas & Sphangos, 1941). There was no quantitative determinati.on of the effect of Ganbusia on the density of mosquitos, only a vague statement nas generally nade inplyingEF-t wtrerever the fish was firnly established, the nosquito density was greatly reduced. In 1936, a general stocking of all Permanent breeding places of sacharovi, which was by far the predoninant species in the lower part of the Lania p1ai.n, was undertaken by the Malaria Section of the l'linistry of Health and the International Health Division of the Rockefeller Foundation. The entonological assessment of the effect of Ganbusia on the anopheline populatlon in the area ltas based on comparison of the larval-iiFad,tlt densltles observed prior or during the distribution of the fish with the densities recorded during subsequent years up to 1940. In 1936, during the process of distributing the fish, sicharovi larvae were so dense in Thernopylae breeding places that one dip in any spot-offiE-reeding place could collect large numbers. In the followlng year, the larval density in the sane breedlng places was consi.derably 1ower, and durlng 1938-f940 the drastic reduction in density rras striklng. If one dipped ln the same breeding place, one would nost probably carch fish rather than larvae. Regarding the adults of sacharov!, regular collection from a stabl.e near Thermopylae produced very large numbers ranging Eron 1000 to 2000 per day during the peak season, July-August 1936. In the following years, the density fell abruptly and the total catch fron the sane stable in the peak season ylelded at the most a few tens of sacl.taroYi. No _ larviciding or any antimalaria measures were undertaken in Thernopylae area during 1936-1940. The steady drop in the adult denslty of sacharovi must have been, therefore, due to the effect of Ganbusla and not t.o weather-En-y other factor. I.lith regard to the effect on malarla ffiGGsion, official documents of the l,iinistry of Health during that period showed a signlficant progressj-ve decline of the spleen rate in schoolchildren of three villages in the lower part of the Lania plain, froro 81.471io L935 to 32.97" h L94L. The parasite rate also progressively dropped fron 34.32 in 1935 to 6"/" j.n 1941. During the years of World War II, the work on Ganbusia came to a standstill. with the advent of DDT after t,he war ended, and its wi.aeElE?Tse which made a spectacular impact on vector populations and conseguently on malaria, the role of -Garobusia was conpletely forgotten or even ignored. By the end of the 1960ts, Ganbusia r"" widespread and could be seen in large numbers in several permanent waFer collecllons in every district in Greece, including the permanent breeding places of sacharovi and maculipennis. It became obvious that in every district, breeding place! of tire two vectors which had no Gaobusia, harboured large numbers of anopheline larvae. This was also confirned ln 1970 when the authors visited several localities J.n Greece, noting the absence of sacharovi wherever Gambusia was present. In Marathon lake which is the nain wacer reservoir for Athens, not a slngle Gambusia could be found. According to infornation provided by the Dlrector of waterworks, Gambuslanas present in large numbers slnce the construction of the dam up to 1954. In that year, Marathon lake was connected with an 1nlet fron Iliki lake, another freshwater lake. With the waters fron Iliki, a speci.es identlfied as Barbus vulgaris (l'an. Cyprinidae) found its way j,nco I'rarathon lake. A gradual but. steady reduclion in the density of Ganbusia was observed until it conpletely disappeared. This provided evidence that B. vulgaris has been an effective predator of Ganbusia. Hadjinicolaou & Betzlos (Ioc.cit. ) conducted a prelinlnary experiment aimed at testlng whether Gaobusia could be transported economically in good conditlon fron relatlvely long distances to a patch of rice flelds. No special effort was roade, at t.his stage, to vBc/90.2 ptAL/90.2 Page I92 guantify the degree of effectiveness of Garobuslaon Dosquito populations 1n this Particular patch of ri.ce fleld. For trai$:ti-ng Gambusi.a, enpty pet,rol cans were cut in half and fi'tted with a wlde perforated 1id for a-riTfon, coverlng practically all rhe uPper opening. These cans Proved very practical, easy to handle and not expensive. In each can a maxinum.of 100 ful1y grown fishes could safely be transported fron the breeding pond to the rice field. Fish nets (sinilar to ordinary entonologilal collecting nets) fitted with long handles were used for sweeplng fish fron the edge of the pond. Altogether 30 cans were transported in a Landrover to the rice field in one trip. No nortality was observed anong fish as the roads were quite good and the distance covered was not more than 25 kn. Ganbusla releases conmenced on 8 July 1970 and continued for 14 consecutlve working aays. -ilil-1otal area of about 860 strenmas (about 85 hectares), 9anbusig was distributed at a rate of 25 individuals per strernma (or about 250 per hectare). In another pacch of 120 stremmas (12 hectares) the fish were released at a rate of 100 Per strernn'a (1000 per hectare). Altogether, 33 700 were released in this rice field. Estination of 1arval denslty Ispeciei not mentioned, probably sacharovi] was roade on 8 and 9 July when the first releases were oade, and periodically thEreafter with 100 dips at each inspection. The 1arva1 index was based on t.he number of j'nstars; the 3rd and 4th younger larvae and pupae were excluded. The larval. index at the tfune of releases was 4.25 Larvae/dip and subsequent inspectlons ylelded the following.. Area treated at 25/strenma Area treated at 100/streroma -28 27 Aug. o.29 I dj-p 0.15/dip - 1 2 Sept. 0. 18/dip 0.03/dip 16 Sept. Nil(onJ.y 7 dips nade) The authors adnitted that due to the absence of control patches these data cannot be interPreted quantitatively. The data, however, nerely show that when Ganbusia i.s present in adequate numbers in rice fields for a sufficient period of tirne, thm deniity can be considerably reduced. This is enplrlcally quite Lttorrr, but it has not been sufficiently proved. Therefore, tt ls necessiry to carry out sysEematic observati.ons for a long perlod of tine 1n a suitable rice fleld with conparable patches as controls. Vassillou, Fytizas & Ioannou (1985) investigated the toxic effect.s of insecticide aerial spraying on Gambusla in Greece. Every sulnmer about 500 000 ha (50 nillion olive trees) are treated ffiE orAnophosphorous insecticides agalnst the olive fly, Dacus j'nvestigation gleae. The of toxic effects was made after aerial application of fenthion by deternlning the brain cholinesterase lnhibition as well as the insecticide residues i.n the body of the fish. Large numbers of Ganbusia lrere found in estuarine areas, irrigation channels and marshes near the applicattoiF About 1000 adults of Gaobusia (2.5 cn long) were obtalned froro a stock nalntained at t.he Benakl rnstitute. ffi,"ere transPorted to the area where the appllcatlon was to take place and were acclinatized, On the day of application, the flsh were placed ln plastic containers fi1led with wacer from the stock colony, at a rate of 50 lndivlduals per container. The containers trere placed randonly at preselected sites among rows of olive trees. A gentle stream of air was constantly puoped into the containers by portabte pumps. The field was properly signalized prior to applicatlon so that a uniforn treatrnent could be perforned. The application rate was 90 g fenthion/ha. Tlso hours after tne application the containers ltere transferred to the laboratory where they were kept in the open air until the tine of determinations was due up to 48 hours after application. After 48 hours, only sna1l amounts (0.29 ppn) of the insectlcide were found, and,93Z of the bratn cholinesterase activity was restored. Relatlvely l-ow concentrations of fenthion in the water (0.123 ppn) resulted in a high inltial concentration (18.4 pprn) in the fish body. However, during rhe first 16 hours the rapid decline of the insectlcide fron rhe fish UoOy (f.83 pin fron 18.4 ppn) did not correspond to a proportional regeneration of the enzyme in the brain (732 ftom 42"Alnitial enzyne activity). These results led the authors to conclude that aerial application of fenthion causes sooe short-term environmental dauage. Longer periods of cesting should show the ecologlcal slgniflcance of this applicarion. In Turkey, Giglloll (1979) indicated that great hopes were placed on larvivorous minnows of Cynolebdias, Aphanius, Rasbora and particularly Gambusia. While reports of control of sacharovi by G. afflnis tn Greece were enco,tragiillresults in Seyhan, Turkey were dlsapp;GG-- uig6;;mies in Ganbusla were observed ln ponds where migranr workers sashed insectlcide containers. I;ffitublished reporr to wHo, onori & l{uir (f978) stated Ehat durlng their visit to Adana plaln uany places rrere seen where Ganbusia vBc/90.2 ttAL/90.2 Page 193 coexisted with high densities of sacharovi in canals choked with aguatic vegetation (chara sp.). rt is, therefore, oEiffi-s cnat the usefulness of Ganbusia under the prevaili.ng condiEi.ons in the Adana plain is linited to areas otFtively open wat.er. As shown under (ii), I, above, the report of the Joint Meeting of the Ministry of HeaLth and Social Assistance, Turkey and WHO,1985, suggested that further attempts may be nade wiEh the cooperation of the General Dlrectorate of Fishery Products to use herbivorous fish concurrently with Garobusia. In roost countries of North Africa, Ganbusla exisls since its inportati.on in 1929-1930, but quanticative evaluation of its efficacy on local vectors is scanty or lacking. According to the report of WHo(1979) G. affinis holbrooki has been established in regional hatcheries in certain countries. The fiih action can be hindered by the presence of aquatic vegetation, but i.n rice fields the density of anopheline larvae could be reduced by 90-952. In llorocco, the WHOreport (1979) shows that Ganbusj.a was inported into the country 20 years previouGly. Its population has been stablel-ffis not been closely evaluated, but it was observed that in 30 large ponds where the fish was introduced, the Anopheles and Culex larvae practlcally di.sappeared. In Algeria, G. afflnis holbrooki exists since its inportation 1n 1930. It is widespread and several authors recom-ended lts fult utilization for larval control in Permanent and seni-permanent breeding places. As nentioned under (i), 1, LefEvre-Witier (1968) indicated that starting fron 1946, G. afflnis holbrooki has been unrilized for control of breeding places at lhdrlr, Tasslll ti'e33ei nalnsaafe Q972) who nade larval surveys at tlto villages 1n Ouargla oasis in northeast Algeria, found that many surface Itater collections contained Ganbusia and were free of mosqulto larvae. Only one larva of multicolor could be found an6i!--7-ense tangle of roots in water containing Ganbusia. In concrast, all surface water collections into which Garnbusia was not iontroduced were heavily infested wlth nultlcolor, the only anophelli-species detected in ouargla. The fish have been present in this oasis for many years, but there was no rational systen for introducing then lnto a newly created sltuation. On the other hand, an expensive oil larviciding Progranne was in operation, which achieved little, as many breeding sites were seen where the oi1 was dunped at one end, or around the edges, whilst the remainder of the water surface was teening with larvae and pupae. Therefore, it nas suggested that antilarval Deasures should be based on the disseninatlon of Gambusia. If this is properly carried out' better conlrol of uulticolor larvae couLd be acllffi-t a fraction of the cost of the current o11 tarvictEffiiGpraying operations. rn ouargla, well-defined and easily traced ltat,er collections exist and Ganbusia is already widely distributed and dense ln places where it exists. It requires a iliffi a bucket and a catching net to transfer the fish fron populated to unpopulated sites. The dlstance involved is usually only a few metres. Nevertheless, because nen lrater collections are constantly being created, the dissemination of Ganbusia should be a contlnuous operaEion which must be followed. Division of the oiffiTo sna1l sectors lras suggested, each of which must be visited by a distributor of fish on the sane day each month. This would facilitate supervision and evaluation of this biotogical control Deasure. At the same time nany prolific breeding sites, especially in bullt-up areas, could be elininated ar little cost by filling. This would be the nost effective and permanent of all anti-oosquito operations. In a further assignmenE, Rarosdale (1973) vlsited Biskra (AurEs Witaya) where the problern of persi.stence of nalaria transuisslon was almost resolved. The ecological conditions in Blskra reglon were significantly nodlfled from those which prevailed in the previous year. The water in screams which remained abnornally high since the flood disaster of L970 subsided considerably and the majority of pits anong palm trees and the trenches in the area of Megloub-Bouchagrounewhlch had constituted rich anophellne.breeding sites dried up. In the area of l'legloub-Bouchagroune and Togla, however, some pits and trenches still contained water, but they rrere treated regularly with teoephos. Tlre long erench systen of Ain Ouroachehas been well controlled by the appllcation of temephos or by the introduction of Ganbusia. The rivers which flow fron Ain Ounache are now without vegetation, and this assurE-uninterrupled flow in them, and at the same tioe pernitted Gaobusia to reach, Itithout obstacles the most lnfested corners. Searches at sit,es which were previously infested with sergentil and nulEicolor produced only some 1st and 2nd instar larvae of culicines. The report of WtlO(1979) showed that c. affinis holbrooki is found in natural habitatsandsmaI1hatcher1esal1overA1geria.ffieagai.nst1arvaeof labranchlae and multlcolor, but detalls were lacking. ln Quelma, considerable reductlon vBc/90.2 t4aL/90.2 Page 194 in labranchiae larval denslty was recorded, and ln Ouragla breeding places were cornpletely negative for larvae wherever Ganbusia was abundantly present. The latest infornation comes from a rePort by Oddo In Tunisia, Wernsdorfer (1973) indicated that Gaubusia fish were utilized on a large scale for the control of anopheline breeding d.trinfTn-ffiriod of the nalaria eradi.carion Programne in all regions where the applicalion of larvicides was inpracticable. The fish were well distributed and contributed to the reduction of anopheline populations, particularly in the southern region. Nevertheless, very large numbers of Garobus1a col'onies were destroyed during L97L' 1972 when nolluscicides were applied E-ilntrot schlstosomiasis snails. It was not knordnwhen Gambusi.acolonies could be re-established. Lruring a visit to Tunisia, oddo (1979) r".ri"r"dEZEivities carried out by the entonological team. These lncluded the disseninatlon of Ganbusia and herbivorous fish. Two new reservoirs for rearing Ganbusia sere establi.shed GlT[-.gions of I'lendjez-e1-Bab and B6ji, ar.d 27 Perrnanent tarvit Ureedtng sites were seeded with Ganbusia. Later, Snolinschi (1981) found that 19 ne\r natural reservoi.rs of GanbusiaGffi-iscovered in 1980 in the regions of Jendouba and Gafsa fron which the dissenGEilf fish into Dermanenr anopheli.ne breeding places progressj.vely proceeded. In Libya, no information ls available on the presence and use of Larvivorous fish according to the reporr of WHO(L979). In EgypF' Ilalawani & Shawarby (1957) Dentioned that the distribution of Gaubusia sp. was anong the nethods reconmended by the Antinalarla Co nissi.on in 1928 tor anopiretine control. When the Malaria Research Station was established at Khanka ln Qaliubyia province in 1930, it started to apply the recornnendatlons of tbe Coumission including the filling in or draining seepage ponds, constructlon of drains, distrlbution of Ganbusia in nosquito infested channels, clearing vegetation fron drains, applying paris crffiil7-atta/or Malarlol as larvicides, and later residual house spraying when DDT becane available in L946. No further infornation could be traced on the use of Gaobusia against anopheJ.ine immature stages in Egypt. only a few experiments nere conduffiT the control of curicine larvae ln wells through lhe use of Garnbusia with success. In Cyprus, accordlng to i.nformation in the report of WHo(1979) Gambusia existed since it was inported into the counlry 30 years previously. The maln stocks are kept in canks and pools and have been dlssenlnated in wells, ponds, natural and nan-made lakes, marshes, st.reans and ditches. The fish has been an important tool in dams and ravines where larvlciding cannot be applied. Through the use of Ganbusia, breeding of anophelines and culicines in places which could not be dealt with by larvicidlng has been elininaled. In Jordan, accordlng to the report of WHO(L979), Garnbusia was introdueed in the late 1950's in the Jordan Valley for larval control in narsf,ilEind the Lread Sea. tsreeding ponds of Ganbusia were established at the Ent,onological Field Station i.n Jerico, and these became the source of supply for Syria. No evaluatlon has been conducted on the efficacy of the fish. Due to adnlnistrative difficulties the active use of the fish has been abandoned. In Israel, Saliternik (f955) ln his review of the biology of sergentii expressed his views with regard to the use of blological control for sergentil. The fish, G. affinis and Tilapla which have frequently been used locally for the control of the immature stages of anophelines, showed very linited success agalnst sergentli, si.nce this species often breeds in very shallow seepages or overflow where the fish cannot survive. Also, it has not. been practical to increase che salinity of sergentii breeding places, because water currents in its usual breeding sites would rapidly dilute and wash away the increased salt concentration. Specific Deasures against the innature stages of sergentii nere not lncluded in the regular schedule of work of the antinalarla inspectors, because the breeding sites were often transient and unpredictable. Instead, some time nas devoted to looklng for suspected breeding areas in order to discover any new source of breeding which may have developed. These new breeding areas, very often artificial in naturer €.g.r vBc/ 90.2 t4AL/90.2 Page 195 overflowlng irrlgation channels, leaking fish ponds, rdere treated with larvicicies and then listed for future inspection and treat.ment if necessary. Saliternik (1957) further gave his views regardlng biological control of sacharovi in Israel. Since the breeding oi this species would cease in water having s"tioiffrT-o.r. o.7i(, it may be controlled in swamps adJacent to the sea by flooding then with sea rrater to raise the salinity above that level. G. affinis nay be introduced and prove effective, but only after horizontal vegetatlon has been cleared. In concrete reservoirs or pooJ.swhose surface is covered with filanentous algae, Tilapia fish nay be i.ntroduced as these w1ll destroy and consuoe the al-gae, thus rendering tlre conditlons unsuitable for sacharovi breeding. For controlling sergencii and superpictus breeding, saliternli@ pointed to the conbined neasures used in Israel, viz: alternating stream flow dlrection, perlodical drying up of streaur beds, i.ntroduction of G. affinis into st.reams, drai.nage and larviciding ope."liotrs. In Lebanon, Gambusia was introduced during L944- 1945 in Nahr Damaver and in Nahr Beirut and in Nahr Ibrahin during L962-I963, according to lnfornation shown in the report of WHo(7979). The fi.sh is now availabe in nalural habitat and streams but no evalualion has been nade. Syriq' according to the rePort of WHO(L979), Gambusia were brought fron Jerico, Jordan in 1962, by the late Dr L. I'lara, then I.rHouata@t. The fish were seeded in a large rrater collection near Aleppo and proved very effective as anopheline larval density decreased drastically. Fron this source, Gambusiawere lntroduced to several areas in the country, nanely Ghab, Lattakia and Tartons-lETlFes. The fish now exisr in principal hatcheries and in natural habitats. Difficulties have been encouncered in handling the fish and ils maintenance in new habltats. From the report of Sadek (19S6), a triai was arranged in August 1982 to seed Ganbusia in nany permanent rdater bodies such as Sen lake in Harison and other localities G-iailSus proui.r"., but unfortunately the follow-up was totally neglected. According to observations by Sadek, the fish t,hrived and was associ.ated with very Low density of sacharovi ln lakes, streans and drains as well as irrigation reservoirs in Harlson, taEFl6vlnce; Ghab, Hama province; El Rooge, ldleb provincel and El-Mazarib, Deraa province. Sadek, therefore, recornmendedthat the use of gP":i" should be pursued to replace larviclding wherever feaslble. To be effective, the fish density should be sufflciently high (5-6 t:.itres/n2). Cooperarion with rhe General Establlshoent of Fisherles ltas stressed as they have the equipnent and experience for large-scale tranaportation of the ftsh. B. thurin was tried in Turkey and proved effective, but its cost could not be afforded by of the antinalaria progranme - see under (ii), 1 above. 4.2 Space sDrayine In Turkey, ouldoor rnalathlon fogging and indoor wlnter fogging with Neopybuthrin as well as ULV appllcatlon wiEh piriniphos-methyl were used in Chukurova plain but these oPerations htere not assessed entonologlcally nor epidenioLogicatly - see under (il), 1 above. It was suggested that these operations may be dlscontlnued as fron 1985. In EgJptr in an attenPt to find a suitable uethod for controlling pharoensis, the maj.n vector of malaria, a trial was carried out in 1966 to apply nalathion iiE- ternepnos Uy aerial spraying as nas reported on by I'lahdi, Taha & Ezz El-Arab (1967). A hanlet of 50 houses with abouE 300 inhabitants, situated aoong rice fields of about 160 acres (0.8 x 0.8 kn) was selected for the trial in lkfr El Sheikh governorate in the Nile Delta. e si'milar area situated at about 20 kn away rras selected as control. Aerial spraying of a mixture of nalathj.on ULV and tenephos at a ratio of 9:1 was applied through 6 flat-fan nozzle tips (size No. 80015) a! a rare of 0.25 l/acre. The flight was 6 n high giving a swath width of 30 n. The applications were made at 10-day intervals fron 17 August to 16 Septenber. Operations were carried out early in the morning when winds were almost nil. The pilot was gulded through two ground flag uen. ?he trial nas assessed entomologically by estirnatlng the densiEy of pharoensis resting indoors by PSC, those exiting in outlet windon traPs installed in local houses, and those biting nan. Parous race deternination was nade on sauples drawn frorn man-bait capture. Pre-operatlonal base-line data were obtained one week before application, and post-operatlonal observations were conducted one and two oonths after aplplicatlon. The density of pharoensis by PSC and window Erap as well as the man biting rate fe1l sharply one month ATter appTication coopared with the base-line and data of the control village. However, all indices rose again two nonths vBc/ 90.2 t[AL/90.2 Page 196 after aPplication. The parous rate (382) remained sinilar to that recorded in the control village (402) one nonth after application and nas even higher (731() Ln the treated village than in the control village (582) two months after ttre apptication. The authors postulated that the lack of reduction in the parous rate nas due to the effect of the aerial spraylng on lhe larval population and lhe outdoor fraction of the adult popuration' In contrastr the actlon of resldual house sprayLng differs in that it reduces the probabi.lity of survival of the house-haunting population. A more prausible explanation ltas offered by attrlbutlng Ehe lack of response in the parous rate to the brief period of the residual effect (i-2 aays) of the aerial spraying being applied at intervals of l0 days. This wourd have been prolonged, if the .ppii"Ition of agricultural pesticides coincided. In fact, aerial application of pesticides'on cotton plantatlons 1n the surroundings early in the season affetted pharoensis populatlons to the extent that the pre-operational Parous rate (base-line) raiaG rearrced in both the trial village (62) and control village (r1z). The authors, however, considered that from a mal.aria transnission Point of view the lack of effect on the parous rate is conpensated by the 1efu9tion.ln Pharognsis denslty. They further assuued that the effecr on nunbers wi1j. be BalnEalned under pressure the of aerial spraying in view of the great susceptibility of to nalathion re5 and the retrote possibllity of selection for 0p resistance under field condltlons. IThis assunptlon was made when pharoensis was still susceptible to nalathion, but things changed later_ as it exhlbltelpronounced resi.stance to op conpounds including nalathion, as well as carbamate lnsecticides - see under (i), 3.12 above]. Another trial-of aerlal spraying was conducted in Marg locality nith extensive rice cultivation near calro durlng augusi 1971, usin!-ioJlt."phos as reported on by Kanel et' al. (L972) Two villages nere selected for a slngre treatment v1.th Z0"l iodofenphos ULV fornulation (Nuvanol N 20 u): one village with 50 ha rtce cu].rivarion was sprayed at a dosage of 3 l/ha, and the other irith 120 ha rlce cultivation was sprayed at a dosage of l'5 1/ha. A thlrd village with conparable conditions reualned untreated as control' The susceptlblllty of phgroensis and cx. piptens to iodofenphos was ascertained using the wHo test Procedures foilarvae ana aaffi-osquitos. Entonologicar evaluation was made utilizing the followlng technigues: PSC ln houses, outlet window traps, man-bait caPture' larval dipping, and exposure of caged adult mosquitos, and larvae i.n paper cups. Deternination of parous the rate was also made on samples drawn from man-bait capture. Briefly, applying ULV iodofenphos fornulation fron a Pilatus porter aircraft at a height of less than five metres over open rice flelds and swath width of 30 m showed that either 3 l/ha or 1'5 l/ha was very prouising. A11 aquatic stages and aduLts of nosquitos nearly disappeared for a period of about 10 days. No other trials of lnsectlcide aerial spraying have been made in Egypt. [Cost-effectlveness of thls type of application vras not deternlned ln any of these trialsl. st"r?' sadek (1986) I: mentioned thar ln 1985, a uLV aerlal appliearion of an i.nsecr growth regulator (Dlnllln) was carrled out 1n Ghaf area during May and septenber at 1l-2r day intervals. Entonological evaluation revealed that pre-application larval density of was not ?i:lttoYi sufflciently high to draw neaningful conclusions after rrealnent. si.nce J'981, winter fogging with 502 plriniphos nethyl EC and 402 Bronophos EC has been applied but no lnfornation ltas provlded ou the effect of this type of appllcation on vecr,or populations. 4.3 Integrated vector control No lnfornation could be traced on lntegrated nalaria vector control tria.Ls or operatlons based on a conbination of cost-effective and safe nethods carried out in any country undertaking nalarla conlrol in the Mediterranean Basin. Only a village scale trial was inpJ'eroented in the southern part of the NiIe Delta, Egypt, but deali nainly with culicine nosqultos and houseflies. 5. Conmunity participation Turkey, Lassen (1982) underlined that cotrmunity participation can only be developed through a well designed health educatlon progranne alued at prlnoting the knowledge, ani changing the attitudes and practices of the people. The persons invJlved in fostering coomunity ParticiPation will have to count prinarily on the support of key figures whi constitute the leadership ln rural comnunities. In Turkey, the potential key flgures are: vtsc/90.2 r4aL/90.2 Page 197 (a) The t'Iukhtar: This is the person elected by the people of a village and paid by the Sovernment. lle represents the vlllage in all dealings with civil adEinistration. He registers deaths, births and oarriages, and is also responsible for notifying the adninistration of any case of communicable diseases detect,ed in his con-uni.ty. (b) The Inan; He is appolnted and paid by the government as the religious leader of the connunity. He thus advises on rellgious and moral matters and is highly respected. His role as an educaEor nake hin an lnportant person in heal-th education. (c) The teacher: He is appointed and paid by the government wlth the responslbility of educating children. llls professi.on nakes hiu a very val-id aid in health education. (d) The nidwife: She is appointed and paid by the government. The rural mi.dwives live in one of the comrnunity groups. The responsibllity of t,he rnidwife i.n health matters is wider than not.her and child care nurse. Her positlon as a health maker, living in the conmunity and being in close touch with every day problems makes her a valuable person for all health Dalters. (e) The conmunity opinion leader.' In a}l cornnunlties, there are persons who adapt nore qui-ckly than others to new ideas and nethods. These people nay influence others and thelr support in fostering changes can be very valuable. (f) The village elder conmittee: Thls is couposed of 8- 12 nenbers elected by the people of the connunlty. The lnau and school dlrictor are de facto oembers but there is not any rePresentatlve for health. The comittee meet.s weeffiiFaiscusses coomunlty problens including health. By vlrt,ue of the high esteeo enjoyed by thls conni.tteer its contributlon to the pronotion of comunity participation ls invaluable. (g) The health cornnittee: At present health committees do not exi6t at village level, although lt ls the lntentlon of the government to establish then. At provincial level, and ln the nuni'cipality of Adana, health cornmittees exist under the chairroanship of the Governor and the Mayor. However, there still remalns much to be done regarding the definltion of terms of reference and authority of these comnittees. In the rePort of the Jolnt Meetlng of the Ministry of flealth and Social- Assistance, Turkey and WHo, 1985, it was stated that lnadequacy oi conmunity particlpation and intersectoral cooperatlon is a uajor constralnt whlch has vital iDpacts especialJ-y on source reduction actlvttles - aee uuder (ii), 1 above. No inforrnation could be traced on cornnunlty partlclpatlon ln relation to malaria vector control in other countries of the Mediterranean Basln undertaking antinalari.a activities vtsc/90.2 r4AL/90.2 Page 198 coNclusIoNs(SECTION IIIA) VaLuable knowledge has been accrued fron studies in several countries of the Mediterranean Basin (see Fig. 1) on vector bionomics, varying in their aims and intensity. Good knowledge has also been accumulated fron epideniologicai studies and control experiences on the role of vectors and their reaction to attack measures. Available information has been conpiled on seven species: atroparvus, naculipennis s.s., labranchiae and saghgrovi of the A{r. naculipennis complex, s"iffi"a ph"rodGF Potentia1oractivemai'nvectors,aswe]'lasrourspecies',"Gtii, d'thari. -- nulticolor as secondary or suspected ,r""tois. rn ffiE--irrEt"r,""", when recent rntornatj-on is not avai,lable, resort was madeto old knowledgeto forn a background,on the basis of which updating studies could be planned. The nost conplete knowledge on aspects of vector bionornics comes fron the USSRwhere several anopheline species act as potential vectors (Artemi.ev, 1980). In continental Europe, as Part of vigilance on potential vectors, studies have recentJ.y been conducted in France (larval surveys), Italy (larval and inago surveys), Rornania (larval and iroago surveys) and Yugoslavia (inago surveys). 0f nenbers of_the An. maculipennis complex, labranchiae extends its existence to North Africa up to Tripolitanil-in-Li5ft-ii-The easr, rF.r" iiicts as an acrive or porenri.al vector in the northern part of l"lorocco, Algeria, Tunisi.a and Libya. The other nenber of the.An. maculipennis complex is sacharovl which occupi.es the eastern part of the Mediterranean Basin acting as an activi vector in Turkey and Syria .rrj . potentiar vector in Jordan and rsrael joined by two other potentlal vectors sergentii and iuperpictus, No ueuber of the An. nagulipennis couplex or An. clavlger gro,rp-Effiin Egypt where Pt-raToensisis iIE nain vector. An. sergentii occuples the southern parts of North Africa actlng as an active vector in tiril?ffiffiio."ol Alg.ri.a, Tunisia, l,iuya and joins pharoensis in the oases of the western desert of Egypt and in Falyun governorate. on breeding habitat and spatlal and seasonal distribution, good infornation cones from Turkey on the urost important vectors sacharovi and superpictus_, but' these aspects need to be restudied specifically in ChukurovffiffiiEia agilcultural scheme where malaria transmission remains an inportant probleru. Some observations have been recently initiated in Chukurova area on the seasonal distribution of sacharovi and its relation to nalari.a incidence (llluioElu, Kasap & I(asap, 1988). These aspects atso awai! updating in llorocco where malaria transmi.ssion persists in several foci with f4branchiae uting the main vector, and in syria where transmlssion continues in a linited o.rrJffiEi with sacharovi and gupefpictu.s in certai.n places acting as the main vectors. There ls also . iE-ETtudy in depth che breeding habi.tat of sergentli in tlre oases of the Algerian Sahara where a sual^ nurober of indigenous cases has recently been recorded. Larval and adult vigi.lance surveys need to be maintained along the trans-Saharan highway crossing Algeria (see below). Receptivity studies are now inportant in Llbya aod Tunisia where malaria transmission has been inlerrupted, but there i.s an influx of irnported cases through inmi.grants (see oelow). Good examples have been provided pointing to envj.ronmental changes that resulted in drastic changes in the breeding habitat and spatial disrribution of potEntial vectors in continental Europe, viz: dlsappearance of labranchiae. fron southeast Spain through discont1nuationofricecultivac1on,j'nproffi!"andagricu1tura1PracEices' application of agricultural pesticides besides residual hous! spraying (Blazquez & Zulueta, f980); disappearance of labr4lrchaie and sacharovi fron certain areas in Italy through elininatlon of swampy arEfrliffiio., ot6ffi1rh indusrrial wasres, herbicides and agricultural pesticides (Coluzzi, 1980); disappearance of sacharovi fron the Danube and Dubrudja area in Romania through residual house spraying t6fffiI--a uy almost complete elinination of many breeding sltes due Lo extension of agriculture and improveroent of wager manageoenE,reduction in draft animals as a source of food as a result of nechanized agri.culture, and the application of pesticides in agriculture and farm houses - these factors have also led to changes in species cortrposition of forner malaria vect,ors, namely g.,messeaeandnacu1ipenniss.s.intheareastud1edinRonania(Bi1bieeta1., rvl6); elimination of maculj.pennis s.s. froro Lamla plain in Greece through drainage work andlandrec1amation,liffie1ininationofsuperpictusfrontheplainthrough di'version of a hilly stream to be used for irrigati.G@lftlcolaou & Berzios, tl73a). on the other hand, examples are available on i.ncidents of spread of potential vectors to areas where they did not exist before or rrere scantily present, viz: labranchj.ae in San Donato area, Grosseto provlnce, Tuscany, rtaly, folrowing rice curti.ra6iliffini et al ., 197g); breeding places wi.ch high salinity populated by sacharovi in southeast l"Iacedonla where this species never existed and oay have migrated across the border from Greece (Lepes & Vitanovi6. f962). wc/90.2 t'tAL/90.2 Page 199 Knowledge on the breeding habitats of pharoensis and sergentii i.n Egypt have recently been updated. Rlce cultivation was found to u" irportant-TaEtoT influencing the density "" of Ptragoensis, both by extension of the breeding areas aod by enhancing the hunidity conditions to a level favouring adult survi"val. Breeding habitats of sacharovi, sergengii, guperpigtusand.91avigerhadbeenwe1IstudiedinthePastinPa1estinffiEiffi"c[- anopheline breeding is stil.l being uonitored longitudinally in Israel as part of vigilance on the reintroduction of nalaria fron inported cases, there is a need for more specific observations on the seasonal prevalence of potential vect.ors particularly sacharovi. This species after disappearing for aluost 10 years as a result of control oeasures, reappeared in 1971, and seems to have changed i.ts seasonal pattern. It was suggested that accurate detenoination of its seasonal distribution would show whether this change is part of its adaptation to its forner habitats (Pener & Kitron, 1985a & b). In Jordin, the densities of sacharovi, sergentii and superpiclus are also contlnuously nonitored as part of vigilance Decause ot the risk of resumption of nalaria transnission from the large influx of inported cases (Tawflk, 1987). On vector dispersal, useful knowJ.edgeis available fron past observations on l.gbf?nchiae in Algeria (Colllgnon, 19t9); sachqrovi, sergentii and superpiclus in Israel (saliternik, 1957 & r974)1 sacharovi in syria-(s;-1iDa;-361t,. and-;;--;G;t1y sersenrii in siwa oasis in Egypt ttrroQEGlF/release/recapture experlmenrs (Abde1-l[alek & aEl&at, 1966). lligratory fJ.ights of sqrgentii and superplctus in Lebanon, and of pharoensis in Egypt and rsrael were descriuea (carrett-.lonEffilrg57 & Lg62). More up-to-dare infornation on dispersal would be useful particularly with regard to sergentii in the oases of the Algerlan Sahara and the western desert of Egypt where it r.y bE possible to eradicate thls species through genetlc contror techniques. on vector biting and resting habits good lnfornatlon has been provided from Turkey on sacharovi and suoerPictus (Postiglione, Tabanli & Ransdale, 1973), Lut this needs to be valldated by speclflc observations ln chukurova/Amikovasl area. usefur infornation rras obtained fron Sicily, Italy on the dlstrlbutlon of labranchiae in indoor and outdoor restlng sites using oark/release/recaprure (Cefali,-iE'.ffica, 1961). Seanty information on biting and resting behavlour of labianchiae in llorocco as werl as sacharovi and.suPerpic!'usinSyria,butnoreintensiveouffiEEiIonthetwoasPectsareffi foci of persisting transmission in the two countries. A1so, lntensive blting and resting observations are needed on sgrgentii and multlcolor in the oases of che Algerian Sahara. Detailed infornation is avafETEi ttre EffiffiI'resring behavlour of pharoensis in Egypt (Zahar et a1. , L966) whlch has been updated and incLuded sergentii i" raiy"t Sovernorate (81 Said et al., 1986). Good knowledge on biting anaFing behaviour of serqentli and its refractory response to residuaL house spraying due to its exophilic tendency that necessitated the addition of larviciding measures, comes fron Jordan and Israel (Farid, 1956 and Salirernik, 1955 & f967). Light traPs (CDC and nodifled types) have been successfully used for sanpling of I'abranchiae and sergentii populatlons in Morocco (Bai1ly-Choumara, L973a & b), and PEqrdffi-PoputiEi?E- ngipt (Hurlbut & I.Ieitz, 1956). Using dry ice wirh New Jersey light traPs lncreased the yield of sergentii in a llnited attenpt in Israel (Sallternil, L967). A single attenpt nade i.n syiEE6-cDC rlghr traps failed. The experience from Morocco agrees well wlth the general conclusion obtained fron some trials in East and Wesc Africa in that the light traps cannot replace the epideniologically relevant technique of nan bait caPture, but may be used as a supplementary tool for collecting mosqui.tos for dissection and for deternining the seasonal dlstribution of vectors, as well as saopling exophllic species that cannot be found resting in houses. On host selecti.on' the oost recen! inforuation coDes froo the results of precipitin tests carried out during I97L-L974 concerniong labranchiae and sacharovi. Even the latest infornatlon concerni.ng sergentii and superplctuffi-IEE-Editer66Basin comes froo earller results recorded during 1959-19'5Zffifr-the exception of a single record of sergentil in Tunisia obtained in 197I involving a small sanple of bloodneal snears analyzed. On the other hand, knowledge on the HBI of vectors in Egypt has recently been pharoensis updated; in Aswan governolate (Kenawy et al., 1987); phiioensls and serlentii in Faiyun governorate (Beier et al., 1986); sergentii and a soa1l s"rpf. of r"lticoloi-1n-31wa and Gara oases (Kenawy et al., 1986). rne eprad-iologlcal relevance or nr-TEaE-s under malaria control or as part of receptivity studies in areas under the xoaincenancephase is quite well known. Therefore, it should be updated taking into account the changes in vBc/ 90.2 t4AL/90.2 Page 200 environnental conditions including nan:aninal ratio associated with socioeconomlc development. At present, the gaps in knowledge of HBI are: - gag.harovi and superpictus in Turkey; - Iabranchiae in Algeria, Morocco and Tunisia; - serge"ffin Libyi; - sacFarovi, sergentii and superpi.ctus in rsrael and Jordan; - sacharovi and superpictus in Syrfa. on vector longevi.ty, interest in age-grading seems to have waned. Apart fron the well known studies in the USSR,attempts nade to utilize the age-grading lechnlques in countries of the Mediterranean Basin were as follows: - Sicily, Italy, to deternine the effect and after effect of DDT spraying on labranchiae popuJ-ati-ons(Cefali, oddo & sacci, 1961 and Valentino & Bruno sniraglia,1965). - Algeria and Morocco, to deternine the vectorial efficiency of claviger, hispaniola and sergentii under unsprayed conditions (Guy & Holstein, 1968)r'but fr attexnpts have been made to determine the inpact of attack neasures on longevity of labranchiae and sergencii populations. - Libya, to deternine the longevity of nulticolor in the oases of Fezzart province where this species was regarded as a vector onfy on epideniological grounds (Shalaby, & 1973) L97I - Egypt, to deternine the lnpact of residual house spraying on pharoensis populations in insecticide trials (Zahar et al., 1966 and shawarby et aL., L967a, b, c & 196g); or aerial'-spraying on Pharoensis populatlons (Mahdi, Taha & Ezz E] -lgjab, 1967 and l(amel et aL', L972); and to aeterni,ne the differences between two villages varylng in malaria transmlssion effected by pharoensis and sergentii in Falyun goi"rrro..ie (Er said et al., 1986). - Syria, a linited trial to deteroine the i.opact of permethrln house spraying on sacharovi (Sadek, f984). The steady ProSress nade towards interruption of nalaria transmission together with the shortage quallfied of and experienced entonologists in several countries in the Mediterranean Basin seem to have minimized the need for deternining the longevity of vector populacions. However, it ls hoped that well quallfied and trained personnel are now available to contribute to the evaluation of current attack neasures incruding t.he aprplication of age-grading techniques in areas of persisting nalaria transmission in llorocco, Syrla and Turkey 0n1y records of sPorozoite rates of all species are old nith the exception of c.Laviger in Syria (Muir & Keilany, L972) and pharoensis and sergentii. in Faiyurn, Egypt (E1 Said et al" 1966). Therefore, it would be highly aesiraUfe to cornuine age-grading of vector populations with gland dissections in the same countries nentioned above and extend this work Eo sergentii and nulticolor ln the Algerian oases of t.he sahara. rn these countries it nay ue worttr tryrng-f,;;FTechniques for detection of sporozoites in nosquitos i.n addition to classical gland dissections (see vol. I, under 2.9). It would also be useful to conduct trials of the new techniques in Egypt in the Nile Delta where seroepidenlological surveys nay reveal the presence of cryptic foci of transgission, and to coDpare one of these techniques with the classical nethod of dissection in Faiyun Sovernorate where transoission is taking place on a larger scale. No new records of lnsecticide resistance in potential or active vectors in the llediterranean Basin subsequent !o those llsted by the Expert Committee reports (wHo, l9g0 & 1986) excePt a few tests indicating a low level of reslstance to pernethrin in sacharovl in a few localities in Syria. This requires confirmation as explained below. a.coTai."g to infornation conpiled ln the last Expert Conniltee report (wHO,1986), cases of insecticide resistance which creaced practical inplicatlons that necessitated a change in control oPerations, are DDT resistance in naculiperylis in t.he UssR, DDT resistanEe in pharoensis and DDT resistance in sergentii inTgypt. ftre last case stl1l awalts conflrnation. The biocheoical basis of OP and carbamate resistance in pharoensls still awaits investigation. vBc/90.2 MAL/90.2 Page 201 A good example of cooperation betereenagricultural and heal.th authorities cones fronr Algeria whereby the use of DDT in agriculture nas progressively reduced. This seems to bave stabilized the 1eve1 of DDT resistance in labianchiae, hence conserving the effective use of DDT for nalaria control (Ransdale, 1975)-- A notable contributlon !o the epidenlology and control of malaria has been provided fron the experlence of countries of the Mediterranean Basin. As 1n al1 contlnental Europe, ma]'aria eradlcation has been maintained in countries of the European Mediterranean, but there receptive areas remained more vulnerable to the lmpJ.ications of inported malari.a resulting in sone episodes of rei.ntroduction of nalaria transmission as observed j.n Corsica, France in 1970-1971, Greece in 1975-1977, arrd.the southern areas of the USSRin 1980-1982 [see SECTIONI, under 1.1 and under 1.2:l(i)]. In contrast, malaria eradication in the Asian part of Turkey after havlng resulted in al'nost cooPlete eliroination of malaria transmission by the late 1960rs, the nalaria situation deteriorated for several reasons and culminated in a severe epideoic that broke out 1n L976-L977- An atteopt was made to describe retrospectively the factors related to the rnalaria Parasite, the vectors and human ecology.Ehat contributed to the deterioration of the malaria situatlon (Ransdale & Haas, 1978). The success of control neasures and reinforced surveillance actlvlties 1n containlng the epidenic in Chukurova/Amikovasi was theoretically evaluated (onori & Grab, 1980). ihe evolurioo of the epideni.c could have been forecasted and early preventlve action taken to curtail lt, if longitudinal data of entonological factors nere available. Subsequent to the epidenic and in recent years several studies have been conducted on vectoi biononics in relation to nalaria transnission in Chukurova area (Prof. H. Kasap, personal communicati.on, January 1990, and reference list of Turkey). Although the malaria situation has greatly i.nproved in recent years under attack lDeasuresand surveillance activities adopied as indicated fron the toEal number of cases (20 134) recorded in 1987 (see Table 20), representing about 361(of thar recorded in 1984' still the nunber of indlgenous cases was high (12 66St of wtrich 96i( caae froro strara Ia (see and rb Fig. 7). Regardlng the lnplications of water resources projects to the malarla situatlon, useful infornatlon has been provlded on Seyhan irrigation project in Adana plain (Giglioli, 1979 and Lassen, Lg82). of the najor probleus encountered is the growth of horizontal and euergent vegetation in nan-made watei reservoirs of the agro-hydroelectrical Project of Adana. Attenpts to cut vegetation failed because it grew again in a few weeks causlng great pulJ-ulation of sacharovl, and consequently malaria cases increased in the district around the artiflcial laE, Tenephos larviclding using a row gave boat satlsfactory reductlon in larval denslEy, and subsequently the malaria cases around the lake decreased. Ihe nain source of breeding-A:.th6ffiTGures of sacharovi is the network of earth drainage canals ltith their overgrorrn condition. to clear the dralns are atleDPted, vegetatlon returns in less than two months. It has been suggested that the drainage canals be lined wi.th concrete. Alchough the capital cost seens to be high, it would be nore rewarding ln the long run than the cost of the current oalntenance of drains besldes the expenditure of vector control (Giglloli, LgTg). Recent infornation obtained in 1984 indlcated that there are no plans t.o improve the drainage systen as this is considered excessively costly (Gratz, 1987). This undoubtedly remains an obstacle facing the goal of interruptlon of nalaria transmission i.n Turkey unless sufficient financial resources are sought. Another adverse factor is the probleu of seasonal workers which remains outstandi.ng unless reinforcenent of surveillance and treatment activities are rigorously impJ-eroented. In 1982, health services in Turkey were passing through a Lransitional period involving the lotegration of vertical services into a horlzontal systen of PIIC for which tralning was regarded as top priority. It is hoped that this has materialized by now and that involvenen! of the conmunity in malaria vector control at least by adopting self-helP nethods has been initiated and encouraged. The shortage of qualified entornoJ.ogists for malaria control has been noted. It is hoped that a sufficienc nunber of entonologi.sts with the appropriate training would oe assi.gnld to update the knowledge on vector seasonal prevalence, vector density in relation to Dan, degree of anthroPophily and exophily as well as determinacion of vector longevity particularly in Chukurova,/Anikovasi area i.n order to contribute effectively to th; epideniological evaluation of attack oeasures. Monitoring of susceptibility of sachirovi to nalathion where it ls accept.able to the population and to pirirniphos-rethyf:FfrG-ft is belng applied is essentiaL. Adjacent Turkey, to malaria transmission persisted in certain foci in Syria but on a nuch sualler scale. In these foci, sacharovi is also the nain vector associated in sone vBc/90.2 NtaL/90.2 Page 202 areas with supgfPictus as an additional vector. Accordlng to the rnost recent lnformation provlded in 1987, the persisting foci are situated in the areas of ualkiya on the Dejla river along the northeastern border with Turkey, Aleppo and Lattakia. Addi.tionally, sporadic cases were recorded in Tartous, Hamaand Raqqa. Because of the hj.gh rate of refusal of the inhabitants to spray their houses wlth nalathion, this insecticide was replaced by pernerhrin with satisfactory resulEs. Yet sone field tests indicated the Presence of 1ow level resistance to pernethrin in sacharovi j.n certain localities in Hana andA1eppoprovinces.Theextentofthisresistanffiasun Of countries of North Africa, Tunisi.a and Llbya succeeded in elininating nal.aria transni-ssion completely with the exception of a smal1 outbreak of 18 cases of p. vivax thac occurred in Libya ln Septernber-.october 1980 in a coastal tonn west of tripoti-lE- outbreak was thought to have origlnated fron iumigrants, elght of whon were found infecteo, and the remalning cases were Libyan resl Of other countries of North Africa, Morocco in 1987 is still recording autochthonous cases in foci distrlbuted ln five provi.nces, and addltionatly resumption of transmission has been encountered ln three old foci (Khourlbga, F€s and Meknds). While there has been some improvement in some provinces represented by a reduction in the number of autochthonous cases auounting to 20- 75il, tine total number of cases in 1987 increased by 49"1 coapated with 1986. It should be noted that the nunber of inported cases reached over 600 conpared wlth 97 ln 1986. I4ost of the foci occur in the northern half of the country where labranchiae is the main vector, but there has been no recen! entornological inforroat.ion to lndicate the inpact of current attack oeasures on the vector population in these foci, and this represencs an important gap in knowledge of epideniological relevance. In A-Lgeria, where large areas have been under the Daintenance phase particularly in Ehe northern part of the country, only nine indigenous cases were recorded sporadically in 1987 (6 in 6 Wilayat in the naintenance phase of which 2 were P. falciparuro, and 3 in ttre southern oases under reinforced nalaria control). It ls well kn6in-EZ-t labranchiae acts as the najor vector in the norlh, and sergentii ls the nain vecror in rheGltf,ffitses. It has been suggested that specific laLoratory studies should be undertaken to ascertain the i.dentity of-sergentii s.1. whether sergentii sergentii, the inportant vector of nalaria exists in the Algerian oases or is associated niEE sergentii. macmahoni which has no epideniologica1ioportance.TheseParationoftne@gicalcnaractersis rather difficult because of intergradation. Also, the situation of nulti.color which exists vBc/90.2 vAL/90.2 Page 203 in several oases of North Africa ln associatlon with sergentii rernains dubious. Although it has been successfully infected experiuentally in EEyp{Ehas never been incrininated in nature except on epideniological grounds. Even this has been debated, and ttrerefore its sj.tuation needs to be clarified by systenatic dissections aided by the applicat,ion of the new techniques when foci of transmisslon exist. A11 countries of North Africa which have achieved nalaria eradication or are progressing towards this goal are threatened by lnportation of malaria whether through innigrants or foreign visitors or nalionals travelling to malaria endenic countries. l"Ieasures recomrnendedby wHO-sponsored neetings and conferences dealing with the problen of inported nalaria should also apply to countries of North Africa (see SECTIONI, under L.2.2). In fact, Algeria, Morocco and Tunisia participated in the coordination neeting that was held in Erice, Italy in October 1979 on the prevent.ion of reintroduction of malaria in countrj-es of the west Mediterranean (WHO1979b). Infornation on malaria in water resources projects in countries of North Africa is Iiniced; only the situatlon in Ehe area of one dam in l'lorocco was described at the initial stages of its construction in the early 1970rs. On the other hand, the construction of the trans-Saharan hlghway extending over a dlstance of about 6000 krn to connect Lagos and other areas of West Africa with the Mediterranean shores, is an important undert.akaing due to its close relatlon !o socioeconomic developnent. The risks arising fron this highway to the malaria situation in countries of North Africa have been thoroughly discussed by several authors (Rarosdale& Zu1uetar 1983; Benzerroug & Jansensr 1985; Chauvet, Hassani & Izri, 1985; and Bruce-Chwact, 1986). with increasing travel, there'is a great llketihood of p. introduction of f.f"ip".* carrlers among the influx of people coroing from pest africa. This constitutes-iETEiSr for the southern oases of Algeria where sergenrii and oullicolor abound, since epidenics of falclparun malaria rrere witnessedE-Ef,ilecent past as in the oases of Tassili NrAjjer (LEfevre-Wltler, 1968) where the source of infection was most probably of Afrlcan origin. For the north, where labranchiae prevails, sone authors mininizedtheriskof1ntroduct1onofP.fa1ciparunfroiffici,extrapo1atingfron the experimental evi.dence indicating ttraC nuropean roenbers of the An. nacullpennis conplex provedtoberefractorytoP.falciParunofAfricanortgin.ttwoffiE-ryusefu1 to repeat the experinents using labranchiae fron North Africa and strains of p. fqlciparun frorn West Africa. The other rist< tiei tn ttre possible spread of An. a..bie.rslGffi $+.eanbiae's.s.w1ththeincreas1ngnunberofair.conditionedveEffiffiigttre highway ln less than 24 hours. The lessons of past invasion of Brazil and Egypi were gi.ven as a remi.nder for increaslng the awareness of this potential danger in North Africa. There i's a consensus that with the increase in freshwater supply for agricultural and industrial developnent Projects, as well as the planned expansion of rlce cultivation in several countries of north Africa, the tuo African vectors will have better chances for colonizing lhe oases of the Sahara. Greater vigilance on vectors and strengthening prevenlive and control oeasures including dlsinsection of vehlcles at frontler posts in elgeria have been advocaied. On the human slde, Ehe measures recoromendedfor dealing with inported nalaria should be strengthened and applied to travellers fron West Africa. It was even suggesred that nigrant populations should be screened for malaria and treated at frontier areas before they proceed to the north through the highway (Chauvet, Hassani & Izri, 1985). Seroepiderniological studies by IFA test proved to be a useful tool for providing complementlng evidence on the disappearance of nalaria transmission as was shown in forner foci in northern Algerla (Benzerroug & tl€ry, f985), and by longitudinal studies in Tunisia (Anbroise-Thonas et al. , L976), or in screening imigrants in Libya (Gebreel, G1l1ies & Prescolt, 1985). Thus, the IFA test Eay be a valid tool for identifying asynptonaric parasite carriers Idifficult to detect oicroscopically]. This screening process can, therefore, be recoumendedin countries which host large groups of inoigrants, particularly those coning, fron areas where P. falciparun chloroqui.ne resistance is present (wHo,1985).r 1. WHO(1985) I'Ialaria Transnlssion; Risk of re-establishoent through imigration. Wkty Epidero.Rec.60:359. vBc/90.2 r4aL/90.2 Page 204 ln Egypt, according to the available infornat.ion, the number of cases detected steadily decreased ln the last decade reaching an insignificant 1evel (194 in L984, 72 Ln 1985 and 63 in f986). This situation is puzzling bearing in nind the very J.arge population at risk (13 nIllion) and that in two vlllages in Faiyuu governorate there were 23 cases of P. vivax and 5l cases of P. falciparun in 1983 (El Sald et aI., 1986). Seroepideoiological surveys carried out during L977-L979 (Hassan et a1., 1983) could help in clarifying the anonaly of the roalaria situation in Egypt. In the Nile Delta, where pharoensis the princi.pal vector prevails, nalaria transmission occurs ln hidden foci that can remaln undetected. This condltion was thought to be due to a combination of factors, vLz: di.stri.bution of antinalarial drugs whlch depresses the parasitaemia to a submicroscoplcal level, and rot.ation between rice and cotton cultivat.ion every two years, as well as irregular application of pestlcides in agriculture. The last two factors produce variatlon in vector density from year to year and fron one place to another. In contras!, transnj-ssion in Faiyun where pharoensls is joined by sergentii is perennial and at a much higher rate. Yet variation has been observed between viUages depending on the relative abundance of the trdo vectors (El Said et al., 1986). Slnce parasitological examination under conditions prevailing in the Delta would be extremely inadequate, it has been suggested (ttassan et al., 1983) that a serological survey be carried out once a year, covering children of 5-9 years age-group. No infornatlon has been provided on luported aalaria in Egypt despite the increasing travel to and from malarla endemic countrles involving also Egyptian nationals. Bearing 1n nind that ig_Egypa malaria became a notlflable disease as early as 1930 (Halawani & Shawarby, L957), enquiry about records of lnported oalaria should be made. A good background knowledge has been provided on the dlstribution of nalaria vectors and the nalaria sltuatlon i.n Slnai, Egypt. Since this has been done Dore Ehan 30 years agor it is tine to update this knowledge under the present ecologlcal conditlons, on the basis of which the appropriate rnalarla control rneasures can be planned if warranted. The history of the ganbiae invasion ln Egypt and the caupaign of its eradication L942-L946 has been well docuoented (Shousha, 1948). It seems that the joint measures undertaken by the Sudanese and Egyptian governments have halted the northward spread of arabiensis, the member of the An. ganbiae conplex occurring in northern Sudan. The latest infornatlon on the results of joint inspection surveys comes frou reports provided up to L987. Therefore, rnore recent reports should be sought, particularly after the unusual- floods that affected the Sudan in 1988. In the Medlterranean Basin, no informatlon could be traced on integrated malaria vector control, nor on comnunlty participatlon. Therefore, it is time that active steps be taken to set trlal and demonstraclon areas for integrated conErol in each counCry where malari.a transmisslon perslsts and current control measures are shorring slow progress. In these areas, comunities should be stimulated and rnotivated to actively participate in control activitles by undertakS.ng, for example, sinple source reduction, culturing and dist,ribution of larvivorous fish and the use of irnpregnated bed-neBs that proved to be effectJ.ve, econonlcal and safe. It is necessary also to seek infornation on the role of PHC in ualaria vector control, and find solutlons to the outstandlng problens experienced so far. vBc/90.2 MAL/90.2 Page 205 SELECTEDREFERENCES SECTIONIII(A) THE MEDITERMNEANBASIN The references of subsection(i) vEcToRBroNoMrcs and subsecrion(ii) EprDEMrOLocyAND coNTRoL oF I"IALARTA are arranged by country in alphabetical order. References dealing with nore than one country or nore than one vector are listed first under GENERAI. Some auchors ciEed previous references dealing with rhe same subgect. rireElJai,inarked in the uargin with letter c. References cited by authors but not seen in the original are narked in the nargin with an asterisk. To avoid repet.ition, for certain references readers are referred to previous reference lists of sECTT0NSr and rr or ANNEX1 of the present issue, or the reference lists shown in VOL. l. GENERAL Boyd, M.R. (ed.) (tSag)1 Bruce-Chwatt, L.J., Garrett-Jones, C. & Weitz, B. (1966)I Davidson, G. (1955) l"leasurenent of the anpulla of the oviduct as a means of decernining the natural daily nortality of Anopheles ganbiae. Ann. Trop. I{ed. Parasir. 4g:24-36. Davidson, G. & Zahar, A.R. (1973) The practlcal inpllcations of resistance of ualaria vectors ro i-nsecrlcides. Bulr. Lrld Hrrh org. 49:475-4g3. Deom, J. (1982) water Resources Development and ttealth. A selected bibliography. wHo nirneographed document ppD/ 92. 2. Detinova, T. S. (LI6DL Farid, I'l'A. (1956) The lnplications of Anopheles sergenti for nalaria eradication programnes east of the l'lediterrar,ea@ 15;g21-g2g. Farid, (1987) G.A. Regional l4alaria Infornatlon. Working paper presented to the Regional Technical Consultatlon on l'lalaria Control and prinary Health Care, Aoman, Jordan, 27 June-2 July 19g7. WHO-EI,1/REG.TEC.CNS.MLC.pHC./4. Garrett-Jones, C. (L964a) A nethod for estj.mating rhe nan-biting rate. Mlmeographed docuuent I,JHO/t4AL/ 45O. Garrett-Jones, C. (1964b)l c Garrett-Jooes, C. & Grab, B. (Lg6q2 Garrett-Jones, C., Boreham, p.F.L. & pant, C.p: (19g0)1 Gillies, (1956) M.T. The problen of exophily in Anopheles ganbiae. Bul1. Wld Hlch org. L5:4b7-449. Gillies, M.T. & de l4ei11on, B. (1968) The_Anophelinae of Africa South of the Sahara (Ethiopian Zoogeographical Region s. No. 54. Gramiccia, G. (1956) Anopheles claviger in rhe Mlddle Easr. tsull. t'Ild Hlr$,Qgg. 15:816-821 Horsfall, W.R. (1955)l ltacdonald, c. (1957)l Macdonald, G. & Gijckelr c.t'l. (L964) The nalaria parasite rate and interruption of transmisslon. Bull. Wld Hlrh Ore. 3123b5-377. c Dlatringly P.F. & Knlght, K.L. (1956)I vBc/90.2 r4aL/90.2 Page 206 * c lloshkovsky, s.D. (L946) The dependence on texoperature of the speed of developnent of malaria plasnodia in the rnosqulto. l'ledskaya parasit. 15:19. c Muench, H. (1959) Catalytic Models in Epideniology. Canbridge, MassachuseEts, Harvard Universlty Press. c Panpana,E.J. (1963)1 Senevet, G. & Andarelli, L. (1956) lqS AnophEles de l'Afrique du Nord et du Bassin l46diterran6en. Editions p. LechevaiierJaris. c Senior-Whlte, R.A. (1954) Adult anopheline behaviour: a suggested classification. Nature (London) L73:730. service, M.tl. (1986) Lecture Notes on Medical Entonology. BlackwelL scienrific Publications: Ox t.lor1dHea1tnorganization(1975)I'[email protected] by the tJH0Divislon of Uafar II, Geneva, WHOOffset Publication no. 13. World Health Organlzation (1979) Report of the Travelling Seminar on the Use of Larvivorou".Tl"f for l'tosquito Control in Antl- l4alaria Canpaigns. Golden Sands, Bulgarla/Tbillsl, Georgian Republic, ssR, UssR. 27 eugust-ii-3"pr"rU"r 1979. tiHo-EM/VBC/ 22-Er4hiAL/1 71, January I 980. I{orld Healrh Organlzation (19g0)1 - TRS. No. 655. c World Health organization (1984) Report on the Workshop for the Improvenent of I'lalaria Control through Applled Field Research. Aoman, Jordan, 3t Uarcn-f2 April 19g4. wHO-EU/MAL/203,Augusr 1984. Wo.rld Health Organizarion (19g6)l - TRS. No. 737. World Health Organization (1989b) World Malaria Siruarlon f986-1987. part II. Wkly Epideo. Rec. 64:249-256. World Register of Dans (1979) Second Updating, December1971. Internarional Conmission on Large Dams, 30 Avenue de llagran - 75009 paris (CIGB/ICOLD). Zahar, A.R. (1974) Revlew of the ecology of nalaria vectors in the wHo Easrern I,Iediterranean Region. Bull. Wld Hlth Org. 5O:427-440. Zulueta, J. de & Muir, D.A. (L972) I'talaria eradication in the Near East. Trans. R. Soc. Trop. Med. I{yg. 66:b79-696. {I.GERIA * c Benabadji, M. & Larrouy, G. (1969) Evolutlon de Ia faune culicidienne drune nouvelle oasis au Sahara. 8u11. Soc. Hist. nat. de I'Afr. du Nord.6e:7. Benzerroug, E.H. (1985) Paludisue inport6 de Tanzanie en Alg6rie. A propos drun cas r6sistant d la chloroquine. Ann. Soc. belge M€d. trop. tr5:85-89. Benzerroug, E.H. & Janssens, P.G. (1985) La surveillance du paludisme au Sahara Alg6rlen. 8u11. Soc, Path. EIot. 782859-867. Benzerroug, E.Il. & W6ry, M. (1985) S6ro6pid6niologie du paludisae au niveau drun foyer r6siduel en Alg6rle: communede Khenis E1 Kechna. Rev. Epid6n. Sant6 Publ. 33:27 6-282. Benzerroug, 8.H., Denedts, p. d w6ry, M. (1996) Detectlon of antibodles ro Plasnodiun vivax by indirect irnounofluorescence: Influence of the geographic oEf;f-a;f'ens and serux0 sampLes. Arn. J. Trop. t'led. 3S:255-2i8. vBc/ 90.2 r4AL/90.2 Page 207 * c Broussesr A. (1930) Contribution i ltEtude du paludisme en rEgion saharienne. Observatj.ons recuelllj.es i Djanet au cours de lr6pidenie de L928-L929. Arch. Inst. Pasreur 4196rie. 8:77-85. Bruce-chwatt, L.J. (1986) New caravans of the old sahara. Lancer, April 19, 19g6. chauvet, G., Hassani, N.T. & rzri, M.A. (1985) problEues palustres et route transsaharienne. 8u11. Soc. path. Exot. 78:852-858. Collignon, E. (1959) Observations biologiques aur les AnophEles de la r6gion d'Alger. Arch. Inst. Pasteur, A1g6rie. 37:263-2g5. Coz, J. (1973) Contribution i lt6tude du A. ganbi.ae complex. R6partition g6ographique et saisonniEre en Afrique de lrOuest. Catr. OnSfOLs€f, Ent. n6d. parasitol.:3-31. c Gillies, M.T. & de Meillon, B. (f968) - see under GENERALabove. Guy, Y. & Holstein, M. (1968) Donn6es r6centes sur les AnophEles du llaghreb. Arch. Inst. Pasreur, A1g6rie. 46:L42-L50. Haroon, J. et al. (1966) Contribution i 1,6tude de 1a rEpartition des Anophdles en Afrique Occidentale. Cah. ORSTOM.s6r. Ent. n6d. Parasitol. 4:L3-7Q. Holstein, !1. et al. (1970) Contribution i 1a connaissance des AnophEles du Sahara. Arch. Inst. Pasteur Alg6rie. 48:7-L5. LefEvre-Witier, p. (f968) Sur l_e paludisne au Tassili ntAjjer (Sahara Central), Alg6rie. Bull. Soq. parh. Exor.61:596-605. *c llaruto, J.F. et Fellahi, lr. (1969) Rapport sur une nisslon a Tiroinoun. novembre-d€cenbre 1969, Doc. non-publi6, OMS/BCPE. Mattingly, P.F. & Knight, (.L. (1956)l oddo, (1981) F.L. Evaluation du progranme dreradicatlon du paludlsne. Rapporr d'une uission en A1g6rie, 7-23 novenbre 19g1. unpublished report wlro/EuRo, ICP/MPD003-3332K. Disrriburion resrreinre. oddo' F.L. (1984) Evaluatlon du prograume d'eradicati.on du paludisne. Rapport drune uission en Alg€rie, 10-21 nars 19g4. Unpublished reporc wHo/EUR0,rcP/MAL oo2/co2-ALc/cDs 002-PNUD/ALc/75/o43-Io36c, Diffusion resrreinre. Ransdale, c.D. (L972) Report on a visit to Algerla, 4 tiay-7 June 1972. unpublished report WHO/EURO,Algeria 2001-EURO2002. F'ansda1e, c.D. (1973) Rapport sur un nission en A1g6rie, 10-30 juin 1g73. unpublished reporr wHo/EURo, Alg6rie 2001-EURo 2006. Ramsdale, C.D. (1975) Rapport sur une nission en Alg6rie, 5 juillet-2 aoot 1975. Unpublished reporr WHO/EIJRO,ALc/MpD/O0I-ICp/l4pD/003. Ifansdale, C.D. (tgll) Report on a qission to the Algerian Sahara to participate in the entornological reconnaissance of the Sahara, 17 October-l2 Novenbet L977. Unpublished report. I"IHO/EURO-ICP/MPD005. Restricted. Ransdale, C.D. (1978) Evaluatlon des risques drune reprise de la transmissi.on paludienne dans les oases alg6riennes. Rapport dtune nission au Sahara A1g6rien, 21 0ctobre-l8 novernbre 1978. unpublished report wHo/EuRo, rcplMpD 005. Restrict.ed distribution. Ramsdale, C.D. & Zulueta, J. de (1933) AnopheJ.lsoin the Algerian Sahara and sooe lnplications of the construction of a trans-Saharan hlghway. J. Trop. I'Ied. Hyg. 86;51-58. vBc/90.2 vrAL/90.2 Page208 Report of "Le PrograrnmeDfEradication du Paludisne en Alg6rie en 1973" MlnistEre de la Sant6 Publique, Direction de lrAct.ion Sanitaire, Sous-Direclion de la prevention, Section Technique du Paludisme. Presented to the "Reunion Internaghrebine de Coordi'natlon des Actlvit6s Anti.paludiques". (Alger du 4 au 6 d6ceibre 1973). Rioux, J.-A. (1960) Contribution i lr6tude des culicid6s (Diptera-Cullcidae) au Nord-Tchad. In:llission Epid6niologique au Nord-Chad. Arts et }t€tiers graphiques, pari s. Rioux, J.-A. & Juniner, B. (1964) Contribution i l.'€rude de culicides du Hoggar. Arch. Inst. Pasteur. Tunis 40:2L7-22L Senevet, G. & Andarelli, L. (1956) - see under GENEMLabove. senevet, G., Andarelli, L. & Rehn, G. (1960) pr6sence de drAnopheles sergenti (Theoba1d,1903)surlelittora1t'[email protected]. Pasteur, A1g6rle. 38:327-328. * c Sergent' E. & Parrot, L. (1961) Contriburion de lrlnstitut pasreur d'AJ.g6rie i la connai.ssance hunaine du Sahara 1900-1960. Publ. Inst. Pasteur A.!gi=i=, AJ.ger. 19-44. Stafford-suith, D.M. (f98f) l'tosquito records fron Republic of Niger, with reference to the constructj.on of the new "Trans-Sahara Eighway". J. Trop. Med. Hyg. 84:95-100. World Health Organizatlon (1979b) - aee reference tisr of SECTIONI, L.2.2. uorld Health organizatlon (1979) - see under GENERALabove. zulueta, J. de & Rausdale, C.D. (1975) Rapport sur une nisslon dans Le Sahara Alg6rlen, 19 octobre-25 novenbre 1975. Unpubllshed report wHo/EUR0-ALc/IlpD 001-rcp/I1pD 003. BULGARIA Dinetchev, D. et aJ.. (1960) Sur la conposltion des espEces de la faune des Anopheles et des varlet6s de A. naculipennls lleigen sur le littoral Bulgare au OarurUe. Folia ned., Plovdiv. 225=lT'- Dimetchev, D. et al. (1962) Recherche sur Ia composition de la anophelienne et les vari6t6s de A. nacullpd. Mg. sur le llttoral Bulgare du Danube. Ins. sup. I16d. "I.P. pl.ovdiv. Pavlovo, ttec travaux. 16:245-262 [In Bulgarian wlth Frenih sunmaryj. Drensky, K. & Col.1ins, R.K. (1934) observations on winter infection rates in A. maculipennis and A. superpictus in Bulgarla. Southern lled. J. 27:549- 55L. CYPRUS Shidrawi, G.R. (1983) Report of a uission to Cyprus, 11-21 Novenber 1974. Unpublished report WHO-E!{/MAL/196,April 1983. * c stratnan-Thoruas, H.K., Barber, M.A. & carter, J.c. (1936) rn.. cyprus, Director of Medical and Health Services, Annual Medical and Sanltary Report, Nicosia. (cited by Grarniccia, 1956). I./orld Health Organization (1979) - see under GENERALabove. ZuLueta, J. de (f974> Report of a nission t.o Cyprus, I4-2I NovemberJ.974. (Unpublished report ro WHO/EI.IR0). EGYPT Abdel-l{a1ek, A. (1956) }losquitoes of north-eastern Sinai (Diprera-Culicidae). Bul1. Soc. Entonol. Egypte 40:97-L97. vBc/90.2 vtaJ./90.2 Page 2O9 Abdel-l'lalek' A.A. & Abdel-Aal, M.A. (1966) Study of the dispersion and flight range of Anopheles sergenti Theo. 1n Slwa oasj.s using radioactive isotopes as markers. Bul1. I.J1dHlth Org. 352968-973. 8ahar, R. (1979) I"Ian-madenalaria i.n the East l4editerranean Reglon. Working paper presented in the Scientific tlorking Group on Malaria. Nicosla, Cyprus, 27-29 November1979. WHO-EM/SCT.WRK.GR.MAL/6. Barber, t'I.A. & Rice, J.B. (1937) A survey of malaria in Egypt. An. J. Trop. I'led. L7:4L3-436. * c Batesr 1"1.(1944) Notes on the construclion and use of stable traps for roosquj.to st.udies. J. Nat. l"lal. Soc.3:135. Beier, J.C. et al. (1986) Host-feeding patterns of Ehe nosquito community (Diptera: Culicidae) in two Faiyun governorate villages, Egypt. J. Med. Enconol. 24:28-34. Davidson, G. (1955) - see under GENERALabove. Detinova, T.S. (1962)l 81. said, s. & Farid, H. (1982) - see reference lisr of vol. r under 2.L.3, p.2a9. El Said. S. & Kenawy' l'{. (1982) Field studies on anopheline oosquito larvae in Egypt. (Diptera.'Culicidae) III. Influence of pH and of ttre breeding rater-o., ".iitity larval density of cornnonanopheline species. J. Egypt. Publ. Hlth. Assoc. 57 (special issues 5 & 6):598-629. Said, S. & Kenawy, l'1. (1983a) Geographical distribution of nosquitoes in Egypt. J. Egypt. Publ. Hlth. Assoc. E (speclal issues I & 2):46-76. Said, S. & Kenawy, M. (1983b) Anophellne and Culicine roosguito species and their abundance in Egypt. J. Egypt. Publ. Hlch. Assoc. E58 (special issues I & 2):108-142. El Said, S., Kenawy, M. & Gad, A. (1983) Field studies on anopheline larvae 1n Egypt (Diptera:Culicidae) IV. Association of anophellne larvae with other mosqui,to species in the same breeding place. J. Egypt. Publ. Hlrh. Assoc. { (special issues 1 & 2):1-45. El Said, S., Sobhl, A. & Gad, A. (f982) Blting behaviour of Anopheles pharoensis anc AnoDheles coustani var. tenebrosus ln the Canal Zone and lkfr El sheikh governorate, Egypt. J. Egypt. Pub1. Hlth. Assoc.. 57 (special issues 5 & 6):4L9-445. E1 Said, S. et a1. (19S2) Field studies on anopheline roosquito Larvae in Egypt. (Diptera:Culicidae) II. Chenical characteristics of the bree El Said et al. (f983) Seasonal prevalence of anopheline nosquito larvae in some governorates of Egypt. J. Egypt. Pub1. Hlth. Assoc. E (special issues I & 2):143-159. El Said, S. et al. (1986) Anopheles population dynanlcs in two malari.a endemj-c villages in Faiyun Governorate, Egypt. J. An. Mosq. Control Assoc. 2:158-163. Farid, G.A. (1987) - see under GENERALabove. Farid, M.A. (1940) l'lalaria infection in Anopheles sergenti in Egypt. Riv. l"talar. 1:159-161. Farid, M.A. (1956) - see under GENERALabove. vBc/ 90.2 TI,AL/90.2 Page 210 Farid, M.A. (1975) Aswan High Dan. In: l"lan-I'lade Lakes and Human Health. Stanley, N.F. & Alpers, M.P. (eds), Acadernic Press. Farid, I,1.A. (1984) AssigilDent report. A nission to the ganbiae projecE area in Egypt and Sudan. 13 February-l5 March 1984. Unpublished ieForc wiro-F-y/vttt/2oA. .tullir 1984. Gad, A.M. (1956) l'losquitoes of the oases of the Libyan desert of Egypt. Bul1. Soc. Entonol. Egypte 40:131-136. Gad, A.M. & Darwish, R. (1959) Mosquitoes collected in southern Sinai. Bul.l. Soc. Entornol. Egypte 41:535-538. Gad, A.!1. & Sali.t, A. (L972) The nosquiroes of rhe Red Sea area, Egypt. J. l'led. Entonol. 9:581-582. Gad, A.I'1., EI Said, S. & Hassan, A.N. (1984) Ecology of Anopheles (Ce111a) sergentii Theobald in the eastern desert. Red Sea governorate, Egypt. J. Egypt. Soc. Parasito1.14:1-6. Gad, A.M. et al. (L964) A survey of rnalaria in Sinai. J. Egypc Publ. Hlth. Assoc. J9:I47 -L63. Gad, A.M. et al. (1982) Fierd studies on anopherlne mosquito Larvae in Egypt (Diptera:culicidae) r. Different types and characteristics of the breeding places in relation to the abundance of anopheline species in Egypt. J. Egypt. pub1. H1th. Assoc. 57 (Special issues 5 & 6) 2541-562 Gaci' A.M. et al . (1987) The distribution and ecology of tlre i.iosiiuitoes in the Red Sea Governorate, Egypt. J. Egypt. Soc. parasirol."ll zZOl-ZZt. Garrett-Jones, C. (1950) A disperslon of mosquitoes by wlnd. Nature 165:285. Garrett- Jones, C. (1964a) - see under CENERALabove. Garrett-Jones, C. (1964b)l Glllies, M.T. (I972) Assignnent report. Lake Nasser Developnent Centre (Health Aspects), Asswan. 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(1972) Ultra low volume aerial spraying of iodofenphos against nosquitoes over rice flelds and villages in the Arab Republic of Egypt in 197L. llosquito News 32:514-5f9. Kenawy, l'1.A. et al . (1986) Host-feedlng patterns of Anopheles sergentll and An. pli:ig.lg5 (Diptera:Culicidae) in Siwa and E1 Gara oases, Egypt. J. Med. Entonol. lJ:>lo->t t. vBc/ 90.2 MAL/90.2 Page 211 Kenawy, M.A. et a1. (1987) Host-feeding patterns of the mosquito community (Diptera.'culicidae) 1n AswanGovernorate, Egypt. J. Med. Entonol . u:41-45. Kirkpatrick, T.|.]. (1925) The }losquitoes of Egypt. Government press, cairo. Lewis, D.J. (L944) observations oo sgPEles_.@biag and other nosquitoes at wadi Halfa. Trans. R. soc. Trop. !te@. Lewis, D.J. (L949) The extermination of Anopheles ganbiae in the wadi Halfa area. Trans. R. Soc. Trop. Med. Hyg. 42:3W Lewis, D.J. (1956) The anopheline nosquitoes of rhe sudan. BulL. enr. Res. 47:475-4g4. l'lacdonald, c. (1957)1 llacdonald, G. & Gtickel, c.w. 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(f982) Anophelines of Libya and their control. Garyounis Med. J., Libya 5:72-7 4. Ramsdale, C.D. (1989) Anopheles mosquitoes and inported nalarla in Libya. Mosqui.to Systenatics (in press). Shalaby, A.M. (1971) Changes in the ovarles of Anopheles nulticolor and Anopheles pharoensis (Diptera:Culicidae) followlng oviposition. Z. ang. Ent. 69:L87-L97 . Shalaby, A.14. (L972) Survey of the mosquito fauna of Fezzan, south-rrestern Libya. 8u11. Soc. Entonol. Egypce 56:301-312. Shalaby, A.l{. (1973) Ovarian lrachearion as a means of distinguishing nulliparous fron parous females of Anopheles rnulticolor (Diptera:Culicidae). tsuIl. Soc. Enronol. Egypre 57:9L-99. * c Vermeil, C. (1953) Contributlon i 1t€tude des culicides du Fezzan ( Libye) .' Presence dtAn. broussesi_ i E1 Berket (Terrltoire du Rhat). Bull. Soc. Path. Exot. a6:445-454. World Health Organlzarion (1979) - see under GENEML above. Zahar, A.R. (1966) Notes on a visit to Libya, 9-20 July 1966. Unpubli.shed reporr Eo WHO/EMRO. t{0Rocco Bailly-choumara, H. (1973a) Etude pr6liroinaire drune r6colte drAnophel-es labranchlae par piEge CDCdans la r6gion de Larache, Maroc. Bufl. WfA @ Bailly-Chounara, H. (1973b) Etude comparative de diff6renres techni.ques de recoltes de moustlques adultes (Dlptera, Culicidae) faites au l"laroc, en zone rurale. ltineographed document WHO/L4AL/73.806- WHO/VBC/73.449.published in more deraili in Bull . Soc. Sc. Nat. Phys., l.{aroc 53:135-187, L973. Benmansour, N. (L972) Le paludisme au Maroc en 1971. Bul1. rnst. Narn. Hyg., Rabat I:(No. 52) 2I-45. Benmansour, N., Laaziri, !1. & Mouki, B. (L972) Note sur la faune anophelienne du Maroc. 8u11. Inst. Natn. Hyg. Itabat 1:(No. 52) LO3-LL2. vtsc/90.2 r'tAL/90.2 Page 218 Deschiens, R. & Cornu, M. (1975) Enqu€te 6pidEnlologique et parasitologique concernant Ie barrage HassanAddakhil et ses an6nagements au Tafilalet (l'{aroc, nai-juin L975). 8u11. Soc. Path. Exot. 68:482-49L. Detinova, T.S. (1962)r c Gaud, J. (1953) Notes blog6ographiques sur la Culicidae du }Iaroc, Arch. Inst. Pasteur !4aroc 4: 7. Guy, Y. (1959a) Les Anopheles du Maroc. M6moire no. 7. Soc. Sc. Nat. Phys. I'laroc, Rabat. Guy, Y. (1959b) Les rapports entre 1'anoph6lisme et le paludisrue. Bul1. Soc. Sc. Nat. Phys. l'laroc 39:83-90. Guy, Y. (1963) Bilan epiderniologique du paludlsne au lIaroc. (Donn6es recueilltes en 1960, 1961 et 1962). Ann. Parasirol-. (Paris) 38:823-857. Guy, Y. & Holstein, 11. (1968) Donn6es r6cente sur 1es AnophElesdu Maghreb.Arch. lnst. Pasteur Alg6rie 46:L42-L5Q. Naji et al.. (1985) Le paludisne drimportation au Maroc. Revue Internationale des Services de Sant6 des Arn6es de Terre. de ller et de lrAir 58:24L-243. Prothero, R.M. (1964) Geographical factors and malaria eradlcation in Morocco. Mineographed documenr WH0/MAL/413[ln English & French]. Sacci, G. & Guy, Y. (1960) R6sistance de comportement au DDT chez A. Iabranchiae au l'laroc. Bul1. Wld Hlth Org. 22:735-74L. service, M.t.J.& Boornan, J.P.T. (1965) An appraLsal of adurt rnosquito trapping techniques used 1n Nigeria, West Africa (Prenier CongrEs parasitologique, Rome, 1964) Cah. ORSTOMs6r. Ent. n6d. er Parasirol. 3-4:27-33. c Sudia' W.D. & Chanberlain, R.i,l. (f962) Battery-operated light trap, an inproved node1. Mosqui!o news 22:L26-L29. I'lor1d Health Organization (1979) - see under GENEML above. ROMANIA Bilbie, I. er al. (1978) Up-to-dare entomological aspects in the previously endemic areas of nalaria in the Danube plaln and Dobrudja, Arch. Roun. Pa6th. Exp. I'licrobiol. 37:389-397 . Bilbie, I. et al. (f983) Laboratory and field investigations on insecticide susceptibility of the anophelines in the previously enderoic areas of ualaria j.n the Danube plain and Dobrudja. Arch. Roun. Path. Exp. Microbiol. 42:343-35L. Cristescu, A. et aL. (L975) Contrlbutlon to the study of the biology of tne Anopheles hyrcanus species fron the Danube Delta. Arch. Roun. Path. Exp. I'licrobiol. 34:27 7-284 . Duport, 1"1.e! al. (I974) Inpact des insecllcldes sur 1es AnophEles vecteurs en Roumanie. Arch. Roun. Path. Exp. Microbiol. 33:79-86. SPAIN Bl5zquez, J. & Zulueta, J. de (f980) - see reference list of SECTIONI under 1.2.1(i). SYRIA Abdel-!1alek, A.A. (f958) The anophellne mosquitoes of northern Syria. 8u11. Soc. Entouol. Egypte 42:591-535. vBc/90.2 MAL/90.2 Page 2L9 boyd, I't.R. (1949)1 Christophers, S.R. & ShortE, H.E. (1921) l'lalaria in }lesopotania. Indian J. Med. Res. 9: 508-529. Eshghy, N. (1981) Assignnent report. Malaria eradlcation progrartrme.Entonological activitles and surveys 1n Syrla. 15 May-30 Septenber 1980. Unpublished report t{Ho - EL"|/I4AL/I79,January 1.991. Eshghy, N. (1986) Assignnent report. I"lalaria eradication prograuune. Entomological activities and surveys in Syrian Arab Republic. 7 August-12 Novenber 1985. Unpubllshed reporr WHO- EM/VBC/4I-E, WHO- E![./MAL/211-E, April 19g6. Farid, c.A. (1987) - see under GENEMLabove. GarrefE-Jones, C. & Grab, B. (L96q2 Khawaro,2., Onori, E. & Eshghy, N. (1980) Report on the syrian National Malaria Eradication Service (NMES). Evaluation and 1981 Plan of Action. Unpublished report to WHO/EIRO,Damascus 3-29 Septenber 1980. Markin, Y. (1.984) CounE.ryreview of the malarla situation and research activities carried out in the Malaria Control Progranme of Syria. f.lorking paper presented to _the Workshop for the Inprovement of lrlalaria Control through Applied Field Research. Jordan 31 March-l2 April 1984. unpublished docunent WHO-E},I/WKP.IMP.MAL. CNT.AFR. / 5.T6A, liuir, D.A. (f982) Report on a visit to syria, 14-19 December 1981. Unpublished report to WHO. Muir, D.A. & Keilany, M. (L972) Anopheles claviger Meigen as a malaria vecror in Syrla. l1ioeographed document l'i.lfto/W Sadek, 11.R. (1984) Assignnen! report. Entonological assessment of residual spraylng of Pernethrln for control of the rualarla vector An. sacharovi and monlloring of its susceptlblllty to available insecticides in conditions, Syria. 15 July 1983-5 January 1984. Unpubllshed reporr"G-ifrdffica-r WHO- EM/MAL/2O6. Sadek, M.R. (1986) Asslgnnent report. Training of the entonological staff in the ualari.a service. Damascus, Syri.a, 4 Septenber-3 October 1986. Unpublished report ro wHo/ElIRo. Solinan, A.A. (1960) A study of the breeding actlvlty of Anopheles claviger l{eigen and its level of susceptibilily to insecticides as a oeasure of its response to the inagocidal indoor residual spraying a! Der el-Asafir, Syria (U.A.R.). Ain Shans Science Bullerin 6:2L-26. Soliman, A.A. (f96fa) A study of the di,spersal of Anopheles sacharovi Favr from a natural breeding source in the Rouge Valley (eleppo:Syri.a, U.a.tt.). Reprlnred froro The Fourth Arab sci.ence congress, cairo - u.A.R., February 1961. Soliman, A.A. (1961b) Variations in behaviour of Anopheles superpictus Grassi to differences in neteorological factors ln Syria, U.A.R. Ain Shans Science Bulletin, Ain Shaos University, Calro 7:L27-L3L. World Health Organization (1979) - see under GENEMLabove. Zah,ar, A.R. (1974) - see under GENERALabove. Zulueta, J. de & Muir, D.- (L972) - see under GENERALabove. vBc/ 90.2 rlAL/90.2 Page 220 TUNISIA Aobroise-Thomas, P. et al. (1976) Etude s6ro-6pid6nlologique longitudinale sur 1e paludisne en Tunisie. 8u11. Org. I"lond. Sant6 54:355-367. Chadli, A., Kennou, !I.F. & Kooli, J. (1985) Le Paludisoe en Tunisie: Historique et 6tat actuel. 8u11. Soc. Patn. Exot. 78:E44-85L. Chad1l, A., Kennou, M.F. & Kooli, J. (1986) Les caropagnesd'6radication du paludisne en Tunisie: Historique et situation actuelle. Arch. Inst. Pasteur Tunisle o3:35-50. Farid, c.A. (tggZ) - see under GENEMLabove. Juminer, B. (1959) Notes sur I'Anophelistre en Tunisie. Arch. Inst. Pasteur Tunisie 36:37-42, Oddo, F.L. (L979) Rapporr drune nission dr6valuation du prograome dreradication du paludisne en Tunisle, 19 janvler-7 f6vrier 1979. Unpublished reporr |,JHO- El'{/l'IAL/163, nal 1979. Sroolinschi, I"1. (1981) Rapport dtune nission du prograronedteradicatlon du paludisue en Tunisie, 20 avril-12 nai 1981. Unpubllshed reporr WHO- EM/MAL/I]. Wernsdorfer, W.H. (1973) Rapport de fin de uission. Progranne d'€radication du paludisne en Tunisie, juin l970-novenbre 1972. Unpublished report WHO- EM/MAL/115,avril 1973. TURKEY Akbaba, 1"1.,Kasap, H. & Kasap, M. (1990?) I'torbi.dlty of nalarla during 1985-1989 in Doganket area, Adana, Turkey (in press?). Bruce-Chwatt, L.J., Garrett-Jones, C. & I.leitz, B. (1966)l Clarke, J.K. (1982) IntegraEed vector control in t.he Adana Project, Turkey. Worklng PaPer presented to the WHOExpert Couroittee on Veclor Control, Geneva, 7-13 Decenber 1982. Unpublished documenr IIIIO-VtsC/ECVIEC|82.LL. Detlnova, T.S. (1962)I Giglioli, 11.C.E. (1979) Irrigatlon, anophelism and nalarla in Adana, Turkey. L7 /L/79-8/2/79. rJr.published reporr to wtto/EURO. Giikberk' C. (f961) Anopheles sacharovi in Turkey. llosquito News 21:101-102. Gratz, N.G. (1987) The effect of wacer development programaes on malaria and malaria vect.ors ln Turkey. IN: Effects of Agrlcult.ural Developnent on Vector-Borne Diseases. Edited versions of working papers presented at the Annual lleeting of the Joint WHO/FAO/UNEPPanel of Experts on Environmental l"lanagementfor Vector Control, 7-11 Septenber 1987, FAO, Rone. FAO docuuent AGL/MISCIL2/87. i(asap, 14. (1987) Effects of photoperlod on soue attributes of immature stages of An. sacharovi. Tiirk. tlij. tec. Biyo. Derg,i 44:53-6I IIn Turkish with English sunrnaryl. Kasap, l'1. & Kasap, H. (1985) see reference list of VOL. I under z.L.L, p. 209. lGsap, tt. et al. (1981) Researches on the nosquito and oalaria in pukurova and its vicinity. Doga Bilin Dergisi 5:141-149. IIn Turkish with English suumary.l. I(asap, ti. et al. (1987) Developnent of Plasnodium vivax ln Anopheles superpictus under experinental conditions. eo. J. Tr6.F....ffi3241ffi l(asap, tt. et al. (1988) Sporogonic developnent of Plasroodiuu vivax in Anopheles sacharovi under experimental conditions. Tropical Bionedicine 5:33- 36. vbc/ 90.2 t4AL/90.2 Page 22L Kasap, M. et a1. (1990) Feeding and physiological age in Anopheles sacharovi. Acta Parasitologica Turcica (in press) (rn Turkish with Engrish s"troary). Kasap, H. et al. (1990?) Residual efficacy of piriniphos-net,hy1 (ActelJ.ic) on Anophel.es -sacharovi in fukurova, Turkey. (subnitted to Medical & VeEerinary Entonology). Lassen, K. (1982) Malaria control i.n Cukurova-Amikovasi. An Integrated-t'lultidiscipllnary-PHC Approach. I,lorking paper presented to the Seminar of Health Servtces and Traj-nlng Institutes in the Control of Vectors anrl Reservoirs of Diseases. Baltchik (Varna), Bulgaria, 4-11 october 19E2. - t{IHo EM/sEM.Rot. Ins. cTR.vcT.Rsv.DsS./6. TUR. Livadas, G.A. & Sphangos, G.C. (f941) - see under GREECEabove. l"Iacdonald,c. (1957)1 llinio!1u, M.M., Kasap, l'1. & lksap, H. (1988) Relations between density of breeding season populations of sacharovi and malari.a cases in Chukurova. Tijr. fti j. Den. Bio. Derg. 45:195-199.1G-ffiish wich English sum'naryl. c Moshkovsky, S.D. (1946) - see under GENERALabove. l'luench, H. (1959) - see under GENBML above. onori, E. & l'Iuir, D. (1987) Report on a vlsit to Turkey to assist in the llalaria Programne. 1 M,ay-9 June 1978. unpubllshed reporr to wlto/EuRo. rcpl}lpD 005. Restrlcted. onori, E. & Grab, B. (f980) Quantitative estimates of the evolutlon of a malaria epidenic in Turkey if renedial measures had not been applied. Bull.. I.I1d Hlth Org. 58:32L-326. Postiglione, l'1., Tabanli, S. & Raosdale, C.D. (L972) Anopheles claviger in Turkey. Riv. Parassit. 33:219-230. Postiglion€, M., Tabanli, S. & Ramsdale, C.D. (1973) The Anopheles of Turkey. Riv. Parassit. 34:L27-L59. c Ransdale, c.D. (1975) - see reference list of vol. r, under 2.6.2, p. 2L3. Ramsdale, C.D. & Haas, E. (1978) Someaspects of epiderniology of resurgent nalaria in Turkey. Trans. R. Soc. Trop. Med. Hve. 72:570-580. * c Terinel, O. et af. (1975) Ground water status in the Lower Seyhan Plain Irrigation Proiect Area and anticipated problens. $ukurova Univ. Ziraat Faak, Yilligi. 9:L79-L94. world Health organizarlon (1978) Malarla: Turkey. wkly. Epiden. Rec. No. 43, 27 October 1978. USSR Arteoiev' M.M. (1980) Anopheles mosqulto - I'Lain nalaria vectors ln USSR. In: .Inler{ratioqa} Sclentific lFojgqi on Ecologically Safe I'lethods f or Control of ltalariq and its Vectors. The USSRState Conmittee for Science ana fEEtrnotogy (GKi\T)/United Nations Environment Programne (UNEp). . I"Ioscow, USSR, 19E0. Collected Lectures ?:45-7L, Bandin, A. I. (1983) Changes of ecologic condltions, density and fauna of Anopheles nosquitoes under the influence of human economic activity. I"loscow,USSR, 1980. Collected Lectures 2:45-7L. vBc/90.2 MAL/90.2 Page 222 Detinova, T.S. (1962)1 Shunakov, I"I.A. (1980) Biological nethod of malarla vector control in conditions of intensive development of the irrigated agriculture. ibid. Collected Lecrures 2:227-249. Tinofeeva, L.V. (1980) Inpact of hydraullc engineering projects and irrigation scheares on change of nalariogenic situation and measures to preven! its decerioration. ibid. Collected Lectures 2:72-93. Schlnava, Sh.G., Stegni, V.N. & Sapovich, N.G. (1983) The prevalence and biology of naggJiegr-rgis.M:ig:t AnoPhgle.s 'tL2: f818 in Western Georgia. Soobschcheniya Akad. Nauk Gruizinskoi SSR. 4L7-42O. IIn Russian wirh English sunnaryJ. YUGOSLAVIA Adauovid, Z.R. (1975a) A preliminary survey of the rnosquitoes (Diptera, Culicidae) of Cbedska Bara, Serbia. Bu11. Mus€un Histoire Naturelle (Belgrade) 30:75-80. Adanovid, Z.R. (1975b) Distrlbution of Anophellne mosquiroes (Dlprera, Culicldae) in Negoti.nska Krajina, Serbla. Acta Veterinaria (Beograd) 25:307-313. AdanoviC, Z.R. (L975c) Anopheline mosguitoes (Diptera, Culicidae) recorded in potisje of che Pannonian Plain. proce. Parasitology, Troglr 399:m Adanovid, Z. (L977) Distrlbution and relative abundance of Anopheline mosquitoes (Diptera, Culicidae) ln South Banat, Yugoslavia. Acta Veterlnaria (rieograd) 27zL-7. AdanoviC, Z. (1978) Anophellne nosquito species (Diptera, Culicidae) in Wesr 8aeka, Yugoslavia. Acta Veterlnaria (Beograd) 28:243-249. Adanovid, Z. (I979a) Slbllng specles of the Anopheles naculipennls complex (Diptera, Culicidae) ln Macva and Pocerlna. Acta Parasitologica Jugoslavia LQ..2L-26. AdanoviC, Z. (1979b) Anopheline mosquitoes (Diptera, Cullcldae) of southeast Serbla. Acta Veterlnaria (Beograd) 29:105-111. AdauoviC, Z. (f980) Anopheles messeae Falleronl in Serbia and l"lacedonia. Acta Veterinaria (Beograd) 3O:2I7-23A. AdanoviC, Z.R. (1981) Anopheline populations (Diptera, Culicidae) In east Macedonla, Yugoslavia. Bulletin de frAcad6rnie Serbe des Sciences et des Arts. Classe des Sciences Naturelles et Math€naqiques, Sciences Naturelles 75:81-91. AoarnoviC, Z. (tggZ) Anopheline populations (Dlptera, Culicidae) in Sren, Serbia. Acra Veterlnaria (Beograd) 32:131-138. AdanoviC, Z. (1983a) Anopheline mosquitoes (Dlptera, Culicidae) in rhe Nererva Delra, Yugoslavia. Acta Veterinaria 33:1I5- 122. AdanoviC, Z. (1983b) Distrlbution and abundance of anophelines (Diptera, Cullcidae) in southeast l'lontenegro. Glasnik Republickog Zavod,aZa Zasritu Prirode i Prirodnjackog Muzeja u Titogradu No. 16:ll7-L28 [seen in an abstract]. AdanoviC, Z. (1984) Vertical. dlstrlbutlon of the anopheline nosqultoes in lrlontenegro, Yugoslavia. Acta Veterinerla (tseograd) 34:287-293. AdanoviC, Z.R. (1985) A conparison of two anophellne populations examined in Ravni Kotari Livanjsko Polje, Yugoslavta. Acta Veterinaria (Beograd) 35:347-352. AdamoviC, Z. (Jgg6) Anophelines (Diptera, Cullcidae) in Gruza, Levac and Teonlc, Serbia. Acta Veterinaria 39:39-44. AdanoviC, Z. 6 Pau1us, R. (1983) Anopheline mosguitoes (Dlptera, Cullcidae) in Podravina, Croatia. Acta ent.omologica Jugoslavica (Zagreb) 19:9-17. vBc/90.2 t4ALl90.2 Page 223 Maoovic, Z, & Paulus, R. (1984) A survey of the anopheline mosquiEoes (Diptera, Culicldae) in Srednja Pasovlna, Yugoslavla. Acta Veterinaria (Beograd) 34:L99-2O4. Adanovid, Z. & Paulus, R. (1986) A new survey of the anopheline (Diptera, Culicidae) in NE Slovenia, Yugoslavia. Acta Veterinaria (Beograd) 36 :l-41-l-46. Guelnino, D.J. (1951) The physiology of Anopheles naculipennis during hibernation. An aEtenpt to interpret the phenomenonof gonotrophic dissociation. Ann. Trop. Med. Parasir. 45:161-169. Lepes, T.R. & Vitanovic, R. (1962) The appearance of Anopheles sacharovi ln the Republic of llacedonia, Yugoslavia. 8u11. Wld Hlth Org. 26:L26-128. Paulus, R. & AdamoviC, Z. (1983) Anopheline nosquitoes (Diptera, Culicidae) i.n Spacva and Senberija, Yugoslavia. Acta Veterinaria (Beograd) 33:2LL-22L. 1. See reference llst of PREFACE1n VOL. I, pp. 11-12. 2. See reference list 1n ANNEX 1 ln the present issue. vBcl90.2 NtaL/90.2 Page 224 ANNEX 1 SELECTEDREFERENCES ON MALARIA QUANTITATIVEEPIDEMIOLOGY Bailey, N.T.J. (f982) The Bloroathernatics of llalaria. The Blonathematics of Diseases. Charles Grlffln & Bruce-ChwaLt, L.J. (1976) l.lathenatical oodels in the epideniology and control of nalarla. Trop. geog. Lled.28:1-8. Dietz, K., I"lolineaux, L. & Thonas, A. (1974) A nalaria nodel tested in the Afri.can savannah. 8u11. Wld Hlth Org. 5O:J47-357, Dutertre, J. (1976) Etude drun nodEle 6pid6niotogique appliqu6 au paludisme. Ann. Soc. belges I'I€d. trop. 56:L27-L4L. Fine, P.E.Il. (f975) Superlnfection - A problen in fornulatlng a problen (an historical cri.tique of I'lacdonaldrs theory). Trop. Dis. Bull.. 72:565-57L. Garrett-Jones, C. (1964) Progonsis for interruptlon of malaria transmj.ssion through assessment of the nosquitofs vectorial capacity. Nature., Lond. 204:1173-1175. Garrett-Jones, C. & Grab, B. (1964) The assessuent of insecticidal ltnpact on the rnalaria nosqultors vectori.al capacity, froo data on the proportion of parous females. Bull. Wld Hlth Org. 3l:71-86. l4acdonald, G. (1957) The Epldenlology and Control of Malariq. London, Oxford University Press. !{acdonald, G. (1973) Dynanics of Tropical Diseases. Bruce-Chnatt, L.J. & Glanville, V.J. (eds.) London, Oxford Unlverslty Press. Molineaux, L. & Granmicia, G. (f980) The Garkl Project. Research on the Epideniology and Control of Malaria ln the Sudan Savanna of West Africa. i.lld Hlth Org., Geneva. llolineaux, L., Dletz, K. & Thornas,A. (1978) A further epideniological evaluation of a malaria nodel. BulI. Wld Hlth Org. 56:565-220. l4oskovskij, S.D. (1950) The nain laws governlng the epldeniology of malaria. Moscow. [In Russian]. (Seen by title only). I"loskovskij, S.D. (1963) The dynaroics of oalarla eradication. In: Proc. 7th Int. Cong. Trop. !Ied. llalar. Rio de Janei.ro, Vol . 5, pp,2L9-220. MoskovskiS, S.D. (f967) A further contribution to the theory of nalaria eradication. 8u11. Wld Hlth Org. 36:992-996. Najera, J.A. (1974) A critical revlew of the field application of a mathematical model of nalari.a eradication. 8u11. W1d Hlth Org. 50:449-457. Onori, E. & Grab, E. (1980) Indicators for the forecasting of nalaria epldenics. Bull. I.I1dftlth Org. 58:9I-98. Pu1l, J.ll. (L976) La notion de risque dans les oaladies parasitaires avec r6f6rence particuliEre au paludisne. Rev. Epid6o1o1. Sant6 publ., Paris 24:22I'229. PuIl, J.H. & Grab, B. (1974) A siuple epldeniological nodel for evaluating the oalaria i.noculation rate and the rlsk of infectlon in infants. tsull . W1d H]..1[hiQrg. 5I: 507-516. vtsc/90.2 ttL}.I/90.2 Page 225 Rao, N.R. et al. (1976) Transmlssion dynanics of malaria. Part III. Quantitative studies - A conputer slnulation approach to measurerDent.J. Con. Dis. 8:246-254. Rlbeiro, H. (f981) Sobre a capacidade vectorial dos Anofeles (Insecta, Di.ptera, Culicidae) na transmissao de paludisno. Bo1. Soc. port. Ent. 16:1-6, IIn Portuguese j . Ross, R. (1911) The Prevention of l'laLaria. 2nd ed. London, John Murray. wc/90.2 ttAL/90.2 Page 226 AIINEX 2 AEBREVIATIONS Entonological PSC Pyrethrun spray collection ETC Exit-trap colleccion UF Unfed feuaLes Fed or fully engorged feroales HG Half-gravid fenales G Gravid fenales H8I Human blood lndex EIR Entornological lnoculatlon rate Parasitologlcal & others AEER Annual blood examination rate API Annual parasite incidence SPR Slide positivity rate PR Parasite rate PHC Prlnary Health Care RH Relatlve htroidlty