Re-Emergence of Malaria in Armenia and Vector Control Interventions
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Journal of Health Sciences Management and Public Health RE-EMERGENCE OF MALARIA IN ARMENIA AND VECTOR CONTROL INTERVENTIONS Lilit M. Avetisyan1 Abstract Malaria was highly endemic in Armenia from ancient times. Malaria control from 1945 was directed towards the elimination of the disease, and when this was achieved in 1963, towards the maintenance of this status. Since then, no autochthonous malaria cases occurred and therefore, the control operations were sharply reduced in 1991. After 1991, following the collapse of the Soviet Union, the situation became critical in terms of maintaining a malaria - free status (Armenia- country update- January, 2001). Several factors placed Armenia at risk for the re- emergence of malaria. Recent severe financial constraints contributed to reduction of vector control activities and for non-full-fledged epidemiological control new malaria cases may have not been diagnosed, treated and reported properly. In 1994 the first indigenous case occurred since malaria eradication. In the following years a straight rise of both imported and indigenous malaria cases was recorded, reaching a peak of 567 locally transmitted cases in 1997. All cases were due to P. vivax. In 1998, a Roll Back Malaria program was developed to eliminate the recently established foci of malaria infection and to prevent the resurgence of malaria in Armenia. The objectives of this program were: early detection and radical treatment of all malaria cases, availability of anti-malarial drugs and improved accessibility to the health services, indoor residual spraying in malaria foci with cyfluthrin 0.05 gr/m2, mosquito source reduction. Since 1998, the epidemic has been successfully contained and the number of indigenous cases has dramatically dropped down in 1999-2002, reaching the 56 cases in 2000, 32: in 2001 and 13: in 2002. INTRODUCTION a rudimentary network of health Malaria was known to be highly institutions. After the establishment, endemic in Armenia from ancient in Yerevan, of the Tropical Medicine times. In the period 1920s-30s, Institute in 1923 and of a network of thousands of people were affected by anti-malaria stations in the 1920s- malaria and in 7 regions of the 1930s, the malaria situation greatly country (out of 11) and 3 cities improved; however, in 1934, still (Yerevan, Gumry, Diligan) were some 200,000 malaria cases were considered as malarious. Until 1923, registered in the country (4). From malaria control activities were the 1940s to the 1950s, with the rapid carried out on a very limited scale by development of health services, specialized malaria control institutions and social-economic 1 National Institute of Health, Department of Epidemiology, Yerevan, Armenia 138 Journal of Health Sciences Management and Public Health conditions, the malaria situation in were displaced from war strike the country improved further. By zones. In that year, 196 imported 1946, the number of malaria cases cases of malaria, all due to P. vivax. was reduced to 60,000, by 1950 to were recorded and the first 14,500 (6). During the malaria indigenous case of malaria was eradication period (1950s-1960s) detected in Masis Region (4). In 1994, comprehensive measures were the majority of imported cases undertaken (including indoor (91.8%) occurred in displaced spraying with residual insecticides, persons returning from conflict wide-scale hydro-technical areas. No patients received the environmental management). The appropriate radical treatment anopheline breeding places were because of the unavailability of dramatically reduced in number and primaquine in the country at that size as well as mosquito densities. time. Plasmodium falciparum and P. vivax were eradicated from the country by A further worsening of the malaria 1953 and by 1963 respectively. situation was observed in 1995, when 502 imported cases were recorded, After malaria eradication, due to the both among military and civilian progressive reduction of the vector people, but no indigenous cases control measures, anopheline were detected that year. In 1996, the populations started to reappear in epidemiological situation changed breeding places and the densities of dramatically: 149 indigenous cases potential vectors grew. In 1990, all were recorded out of a total of 347. vector control activities were sharply In 1997 a total of 841 cases was reduced due to the difficult reported, of which 567 (67.4%) were economical situation and, from 1991, indigenous (4). Most of these cases insecticides were not available (over 90%) occurred in the city of anymore in Armenia. Systematic Masis and in the close village of entomological investigations were Marmaraschen. All the remaining also reduced due to the lack of cases occurred in towns and rural transport and fuel facilities. villages of Ararat, Artashat and Echmiadzin districts, all located in In spite of sporadic malaria cases the Ararat valley. imported from abroad, until 1993 the malaria-free status was maintained In 1998, the Ministry of Health of in Armenia by a well-developed Armenia, with the technical network of public health oriented assistance of the World Health institutions (8). In 1994, the situation Organization (WHO) and financial changed in relation with the conflict contributions of the Governments of over Mountainous-Karabakh in Norway and Italy, resumed malaria which several thousands of people control activities. With WHO, 139 Journal of Health Sciences Management and Public Health UNICEF and the International Change in may 1993, is necessary to Federation of Red Cross and say, that Armenia, a mountainous Crescent Societies assistance, a Roll country with vulnerable ecosystems, Back Malaria (RBM) program was especially perceptible displays of implemented to eliminate the unfavorable consequences of global recently established foci of malaria climate change are to be expected. infection and to prevent further During the implementing the project spread of the disease in the country “Armenia- Country Study on Climate (8). The four elements of the Program Change”, were studied and the are as follows: changing of malaria situations in that - Disease Prevention: to plan and condition. The expansions of the implement selective and areas of the vectors and the sustainable preventive measures; aggravation of epidemic situation of - Disease Management: to provide malaria can be expected, because of early diagnosis and prompt the optimization of a temperature treatment; mode in the foothill, –upland zone - Epidemic Control: to detect early and time. The possibility of outbreaks and prevent further alleviation of malaria danger in the spread of malaria epidemic; semi-desert zone related to the - Program Management: to expected parching of swamps and strengthen institutional capacities reservoirs of this belt is observed (5). of the National Program and The aim of this paper is to provide surveillance mechanism (3). relevant historical and detailed recent epidemiological information The main strategic directions were: on malaria situation in Armenia and 1) early detection and radical to evaluate the impact of the first four treatment of all malaria cases; 2) years of the vector control availability of 3 antimalarial drags operations. (include primaquine for radical treatment, never available before MATERIALS AND METHODS 1998; 3) improved accessibility to the health services; 4) indoor residual Geographic background spraying in malaria foci; 5) mosquito Armenia is a country of 3.3 million source reduction; 6) health education persons and one of the 13 Newly and information; 7) strengthening of Independent States born after surveillance. Follow up of malaria dissolution of the Soviet Union. The cases for P. vivax relapses up to 12 capital city is Yerevan. Armenia months was also implemented. borders Azerbaijan, Turkey, and the Republic of Georgia (Table 1). This Considering, that the Republic of country is mainly mountainous with Armenia ratified United Nations a long, narrow valley, the Ararat Framework Convention on Climate valley follows the course of the river. 140 Journal of Health Sciences Management and Public Health Indigenous malaria cases in Armenia by regions and districts, 1998-2003 Year Indigenous Cases by region Cases by district malaria cases (total cases) 1998 542 (1,156) Ararat 507 (93.5%) Artashat 47 Vedi 97 Masis 358 Ararat city 4 Yerevan city 1 Armavir 35 (6.5%) Echmiadzin 35 1999 329 (616) Ararat 299 (91%) Artashat 34 Vedi 65 Masis 200 Armavir 25 (7.6%) Echmiadzin 25 Tavush 5 (1.4%) Idjevan 5 2000 56 (141) Ararat 18 (32%) Artashat 3 Vedi 15 Armavir 38 (68%) Armavir 27 Echmiadzin 6 Metsamor 4 Baghramyan 1 2001 32 (79) Ararat 15 (46,9%) Ararat city 3 Vedi 9 Masis 3 Armavir 17 (53,1%) Armavir 6 Echmiadzin 2 Metsamor 9 2002 13 (48) Ararat 10 (90,9%) Vedi 6 C.Ararat 3 Masis 1 Armavir 3 (9,1) Armavir 1 2003 8 (29) Ararat 8 (90,9%) Vedi 5 C.Ararat 1 Masis 2 Araks is where most of the and 39 districts (called Rayon). population is concentrated. The Between the years, 1998 and 2000, country is divided into 11 locally contracted malaria cases administrative regions (called Marz) occurred in 3 regions which included 141 Journal of Health Sciences Management and Public Health Ararat, Armavir, Tavush. Also VECTOR CONTROL included were 7 districts, as follows: ACTIVITIES Masis, Artashat, Vedi -Armavir, A round of indoor residual spraying Echmiadzin, Metsamor, and Idjevan. was carried out yearly in the malaria The first 6 of which are located in the foci of Armenia in 1998-2000. Houses, Ararat valley (Ararat and Armavir animal sheds and any other kind of regions) and the last one in the hilly premise of all villages and city areas region of Tavush (Table 1). where malaria cases had occurred, were sprayed with cyfluthrin (Solfac MALARIA TRANSMISSION 10 WP) at 0.05 gr/m2. Spraying CONDITIONS AND VECTORS operations were made at the In the most favorable conditions, that beginning of the transmission season are present in the Ararat valley, the (May-June). The residual activity was sporogonic cycle of P. vivax can take long enough to cover the place from the ending of May up to transmission period (4-5 months).