Adult Mosquito Populations and Their Health Impact around and far from Dams in Tigray Region, Ethiopia
Keywords:
Anopheles, Culex, Dam, Intervention, MalariaAbstract
Malaria control program in Ethiopia has a history of more than 40 years, but still now, malaria is a major cause of morbidity and mortality in Ethiopia. The objective of this study is to assess the impact of dam construction in the distribution of mosquito in intervention (dam nearby villages) and controlled (villages far from dam). Indoor adult mosquitoes were collected using 144 CDC light traps from 12 villages (6 from the intervention and 6 from the control villages) Community- based malaria parasitology was also done. Sampling was done in November 2005, December 2005, May 2006 and September 2006). A total of 1713 adult indoor mosquitoes were collected, of these, 1182 (69%) were Anopheles and 531 (31%) Culex. The prevalence of Anopheles was 45.77% in the intervention villages and 23.23% in the controlled villages (F p = 0.012). The prevalence of Anopheles increased twice in the intervention compared to the controlled villages. A total of 1436 children, 888 from intervention and 548 from control villages were examined for malaria parasitology. Only 57 children were found infected by Plasmodium species. Malaria prevalence rate was 3.97% (4.17% and 3.65% in intervention and control village, respectively)(x2 = 0.11, p= 0.7399). Among the 57 malaria positive cases in 32 (56.14%) we found P. vivax and in the 25 (43.86%) P. falciparum. We can tentatively conclude that the dams situated at 2000m and above do resulted two fold adult indoor mosquito, but do not seem to have resulted in a markedly higher incidence of malaria in the region. The study concludes that concerned authorities should take appropriate measures to improve health-care facilities for local communities when planning new irrigation schemes wherever they occur.