Bio-efficacy and operational feasibility of alphacypermethrin (Fendona) impregnated mosquito nets to control rural malaria in northern India.

Bio-efficacy and operational feasibility of alphacypermethrin treated nets was evaluated in certain villages of District Ghaziabad (U.P.). Results revealed that poly-filament nylon nets treated with alphacypermethrin suspension concentrate (g/l) formulation @ 25 mg/m2 has shown repellent action (26.5 +/- 8.1), excito repellent action (93.7 +/- 8.1) and killing action (100%) against An. culicifacies landed on treated nets. Significant reduction in indoor resting density of An. culicifacies in human dwellings was also observed in treated nets village (p < 0.05). Instant killing action of treated nets did provide complete protection to inhabitants sleeping inside the net from An. culicifacies bites. The persistent use of nets by the inhabitants has also resulted significant reduction in malaria cases (p < 0.05). It was interesting to note that not even a single case of falciparum malaria was observed after distribution of treated nets in spite of the fact that at no point of time cent per cent compliance of net usage was observed during the study period. Bio-assay tests revealed that treated nets can produce up to 70% mortality in An. culicifacies for about 22 weeks and as such only one treatment with insecticide is required in a year in seasonal transmission area to protect from malaria. The study also revealed that treated nets can be stored at room temperature for about 10 months without loosing their efficacy suggesting thereby that malaria outbreaks can be tackled by the nets if adequate treated nets are stored in core problem districts. It was also revealed that An. culicifacies is a late night biter and as such treated nets can be used successfully against this species.