Effect of permethrin impregnated bednets in reducing population of malaria vector Anopheles culicifacies in a tribal village of Orissa state (India).

The role of permethrin impregnated bednets at the application rate of 0.5 g (ai)/m2 in reducing A. culicifacies population in a tribal village of Orissa, highly endemic for Plasmodium falciparum was studied. The per man-hour density was significantly reduced in the Kenduguda village for about three months where impregnated bednets were supplied to the villagers, while in the control village Deulaguda where unimpregnated nets were supplied, vector density remained high during the study period. Bioassay carried out on the treated nets showed that there was 100 per cent mortality in A. culicifacies for over three months with the unwashed nets as well as with bednets washed once or twice.