MAP 1 E 718' F 8I2' G 86° H K 1 L 6 2° 90 94 98° 02° DISTRIBUTION OF FILARIAL INFECTION ,(based on examination of thick blood smears) Areas with filarial infection After Megaw & Gupta 1927. ASH4iR ± revised Acton & Rao 1931. `i I R ,-H 11 M. M U 9 MAP of INDIA UDHAMRUR 32 32 ( SHOWING PROVINCES AND DISTRICTS ). REFERENCE. Boundanes- International demarcated, undemarcated ZHOB I , - Do, Province or State Do, Do Do,. -- ..District and minor State LaRALAi1 'GARNWAL S,q N CNAGAI E ALMO. BUNOR.I= NAINIT/L-,1, a maputra R 28 TRACT 0 LARN'NA A I TRACT BALIPAM FRONTIER BRITT ÂN L MTITLYINA RIGA MILLS - C.HAaiP HYDERABAD; 24 AR RAINA i ÓI o CuTCH 6HWEB0; r' ¢! HIL i1 LOWENCNINOWIÑI ,. NO wLITNwAIfN AHAN SNAN STf P TRACTS., HANDESN ABTAB 2 EpHANDESH Ml"BU ,) YAM ETNINi MADWE 11 DAMAN YAURPTM (POPTUGLI ESE REFERENCES THAT ORISSA (0.) COORG (C.) ANOLN', A I tlAu \) v 1 ANGUL 1 NORTH GOORO YjJ dávarl-ßL PUNJAB STATES (P. S.) 2 SOUTH COORG 1 RAPL,RTHALA BOMBAY (Bo.) AMABAO( NARiMNAGAR 2 NABHA MEHWAS A ] MALEP NOTLA 2 BROACH R RANCH NAHALB LOHARu ] OAMAN (Po,tuµw) èI 6 BILASPUR BOMBAY SUBURBAN S PATIALA O F 5 AHMAONAGAR U) T JiND SHOLAPUR 16 1 PUNJAB 0,1 T AHMADABAD I DUJANA A L 8 SURAT N (I 2 PATAUDI GWALIOR (G.) B ) FEROZEPORE 1 GIRO GWALIOR HISSAR REFERENCES UNITED PROVINCES 5 LUDHIANA (U. P) 6 ...LEM BENARES STATE EASTERN STATES (E. S.) BARODA (Be.) CENTRAL INDIA (C. I.) I SAMINELA 8NNARSAWAN 15 NHANDPARA AMRELI 151TAMAU 2 NAWARDHA NIMBI 16 NAYAGARN 2 NAVSARI 2 INDORE ) SANTI 10 ATHGARH 17 NAHPUR 3 BHOPAL AGENCY 6ARAHGARN 11 TIOIRIA 18 ATNMALLIN RfLJPUTANA (R.) AEI- RAJPUR 5 RHAIHAGARN 1) BARAMBA Iv TALCHER I NISHANOARH S SAMTHAB 6 NANOGAON 1) HiNOOL a0 PAL Lama. HHm, AN I. N RNNOL 2 TONTIBGARN T PAR. LINDA STATES OF WESTERN INDIA (S.W. I.) A N D BANTA 5 JASO weSTERN RITNIAWAR AGENCY 6 wADNwAN kMAN NATN11w1R DECCAN STATES (D. S.) 9 CHAR.:RI E Ew6TERN AGENCY a PAL1TANA BABAR BARTHA AGENCY N D B GUJARAT STATES (G. S.) LIMBDI 1 ANALNOT ISL RAOMANPUR 9 BNAUNDAR 2 SANGEI 1 SURGANA L ONRANOUNRA f0 VIJAYAMADAR 2 JAWNAR A C C A D ) JATN I V E BENGAL (B.) BOLHAPIJR d HowRAH MADRAS(M.) ] JAMNNANDI PONDICHERRY NISTNA S (FRENCH) 6 MODHOL I L A N D S MA)1E MADRAS STATES (M. S.) (FRENC W NUMNDVAD C SAVANOR fl YNGANPALLE 9 RAMBLING liARIKAL PUBURNOTTA1 (PRENCN) ,0 6AVANTVA01 1 = 160 Miles. BOGN,N Scale Inch 11 MIRY (UAW Juni°,/ Miles BURMA (Bu.) 100 320 480 12 AUNOH mike 100 120 80 40 1] !MALIAN NANTHAWADOY BAL)JCHIST/LN (B.) 1BOLAN PASS 15 BHOR 0 94 98' 8 2H 8 6° 9 o' G 6° 7 0 74 HELIOZINCOGRAPHED AT THE SURVEY OF INDIA OFFICES. CALCUTTA. RES No 1966. D 3,750 -- 500 -2, 000'29 -2,000 -400- 1,000'30- 1,500'34 -150 -400'38. 15.--1,000 -6,250'26 G. B 9tard, K.C.S.I., R.E., F.R.S., Surueyor General of India. Published under the direction of Colonel Sir S. COPYRIGHT RESERVED. (dawn 1915; 2nd 1930, 3rd 1934: 41h 1936. 1. III Copies of this map Can be obtained from the Map RecorO a Issue 011150. 13 Wood Street. Calcutta. Price: -Eight Anna.: with boundaries coloured One Rupee. Thesis for degree of Doctor of Medicine, University of Edinburgh :- FILARIASIS IN ASSA(, WITH SPECIAL REFERENCE TO THAT ASSOCIATED WITH MICROFILARIA MALAYI (BRUG). By G. Fraser, M.B., Ch.B., (Ellin). INTRODUCTION. Most of the more important diseases that are to be found in Assam have been very thoroughly investi- gated, and the part they play and their distribution have been well assessed. Notable examples have been Kala -Azar, Malaria, Cholera, Hookworm disease, Yaws, and, of late Nutritional diseases, the Anaemias and Tropical Ulcer. A disease which has received very scant attention, and the degree and distribution of which has not been studied is Filariasis. Filariasis itself in India as elsewhere has become more complex on account of the comparatively recent recognition of Mf.malayi, Brug. It is probable that when its recognition and differentiation from Mf. bancrofti becomes better established it will be found to have a much wider incidence than at present supposed. It is proposed in this paper to discuss the incidence of filarial infection in general in the province of Assam, and in particular the occurrence of Mf. malayi Brug; the mosquitoes which play the part of 2 vector of M Zf.malayi and the biological factors which operate in the case of these vectors. The results of the author's own investigation are given, and the discussion is based mainly on these findings. ASSAM. - Geography, physiography, climatology and population. The administered area of Assam is nearly 70,000 square miles, as large as England & '.,Tales and a third of Scotland. The population is a little over 9 raillions. It is situated in north east India bordered on the "`est by Bengal, in the South by Tripura State and the Chittagong Hill Tracts, on the East by the Lushai Hills, Manipur State and Naga Hills contiguous lith Burma, on the North by Bhutan, and the lower eastern end of the Himalaya range. Except on the T','est, then, where it borders Bengal,it is surrounded by hills and mountains.It is divided into two valleys,separated by the North Cachar Hills, and the Khasia & Jaintia Hills running practically East and Test,the upper being the Assam or Brahmaputra Valley, and the lower the Surma Valley. In the Assam Valley the main river is the great Brahmaputra winding from the north east corner along the northern part of the Valley to the north estern corner where it abruptly turns South and then South East through Eastern Bengal to empty into the Bay of Bengal, in a delta on which stands the port of 3 - Chittagong. The plains districts of the Surma Valley are two, Cachar in the Fast, Sylhet in the West bordering East Bengal; the main river is the Barak or "urina rising in Manipur State, pursuing a very tortuous course from East to Test through Cachar and Sylhet, finally emptying into the Brahmaputra in East Bengal. In both valleys there are innumerable smaller rivers, in the hilly districts shift and moderately straight, in the plains slow and tortuous except at flood time. The plains occupying the central part of each Valley, are very lot°: -lying - from about 300 ft. above sea level in the upper part of the Assam Valley to 70 ft. in the Surma Valley at rice -land level. They form an alluvial tract of clay, sand and vegetable matter,and are freely cultivated for rice. In the Upper Valley there are large stretches of low flat plateau on which tea is cultivated, but the Surma Valley is more broken up by isolated hillocks and small plateaus on which the tea is grown. In both valleys swamps and stagnant water areas abound. The annual rainfall in the Upper Valley varies from 80 inches in certain districts to 125 inches in others. In Lakhimpur it is 120 inches. In the Surma Valley it averages 130 inches, Sylhet being a little more than Cachar. 7inor floods are common \+ith occasional major floods in both valleys. The range of temperature is from 80° to 95 °F. or higher 4 - in the hot weather and rains, and 45° to 60 °F. in the cold weather, and the higher range continues roughly from April to October. The humidity in the plains of both valleys is from 70 to 100 per cent for about 7 months of the year. Finally, Cachar and Sylhet are about 180 miles distant from the sea (Chittagong), Tezpur 300, and Dibrugarh in Lakhimpur is 400 miles distant (Map 2). PRESENT VIEWS ON THE INCIDENCE OF FILAHIASIS IN AbSAM. It is generally agreed filarial infection seldom to any degree occurs above 2000 ft., so that the hilly area of Assam is ruled out of consideration. But the plains, apart from their low -lying situation, fulfill the requirements generally postulated for the occurrence of the infection : those are a range of temp. between 75° and 90 °F., and a humidity of over 60 per cent, for. 6. or 7 months of the year, the appro- priate carrier mosquitoes, and the infective human reservoirs. At the same time, in India, endemic areas are generally found either along the sea coast or in the neighbourhood of rivers. In this respect the plains of Assam are very similar to Bengal, especially Fast Bengal,except that Assam has got no sea -board although on the other hand it has got a very large system of rivers. Bengal as a whole is one of the most MAP 2 O SAUn A ñIeKUlA DIBRU G ARA A. N U `` P " JORIIAT:1 N KAMRUP OWGONGr''' NOWGONG P PUT R A o KORIMAi¡ GARO HILLS;' $HILLONG .. TURA KHASI &JAINTOA HILLS Q- Ir G MANIPUR 7 STATE `J SILCHAR O SYLHET 1MPHAL O SYLHET MYMENSINGH SRIMANGAL 'T O AIJAL DACCA LUSHP,I HILLS 0 9 o P P 92 tr" 2^^ O BARISAL Z O CHITTAGONG r BAY I EIAL MAP OF ASSAM SCALE 50 mYL ES TO ONE /NCH 5 heavily infected provinces of India, but Fast Bengal lying adjacent to Assam, mainly the Sylhet district of Assam, has an infection rate of less than 5; (Rao 1937). Rao explains this as being due to the efficient drainage by the river system of Fast Bengal preventing water- logging.