Evaluation of lambdacyhalothrin-impregnated bednets in a malaria endemic area of India. Part 2. Impact on malaria vectors

In malaria endemic villages of the Indian State of Orissa, the impact of be dnets treated with lambdacyhalothrin at 25 mg/m(2) on malaria vectors was a ssessed during a 3-year intervention trial beginning in May 1990. The main malaria vector was Anopheles culicifacies with a small contribution from An opheles fluviatilis. The impregnated bednets caused a significant reduction in vector density as assessed by morning indoor resting catches, man-bitin g rate, light trapping, the proportion of females engorged with human blood , and the parity rate as compared with villages with untreated or no nets. No statistically significant difference was observed in these parameters be tween the villages with untreated nets or no nets. The trial demonstrated t hat the lambdacyhalothrin-treated nets were highly effective against the ma laria vectors.