House-scale Evaluation of Bifenthrin Indoor Residual Spraying for Malaria Vector Control in India

Abstract In an area of India where the main rural malaria vector, Anopheles culicifacies Giles, has developed triple resistance to DDT, HCH, and malathion sprayed indoors in antimalaria program, bifenthrin (10% wettable powder) was evaluated in a randomized house-scale trial between July 1999 and March 2000. Entomological impact of four serial doses of bifenthrin (25, 50, 100, and 200 mg/m2) sprayed in rooms in five villages was compared with malathion (2 g/m2) and unsprayed control. An. culicifacies was 100% susceptible to bifenthrin (0.1%), but only 57% to malathion (5%) test papers. Contact bioassays were carried out on sprayed surfaces for 24 wk, and 24 h mortality in An. culicifacies was recorded. Bifenthrin 100- and 200-mg doses caused ≥80% mortality until 24 wk. The 50-mg dose caused ≥80% mortality on tin, wood, and mud surfaces for 24 wk, and on brick walls for 16 wk. Bifenthrin 25-mg dose produced ≥80% mortality for 24 wk on tin, 20 wk on mud walls, 16 wk on brick walls, and 8 wk on wood surfaces...