Bloodfeeding behavior of Anopheles gambiae s.l. and Anopheles funestus in Kilifi District, Kenya.

Blood meal samples were tested by ELISA for 534 Anopheles gambiae s.l. and 76 Anopheles funestus collected from 25 sites in Kilifi District, Kenya. Human IgG was detected in 94.4% of the An. gambiae s.l. and in 90.8% of the An. funestus. No samples were positive for cow and only a few were positive for goat. Both species fed predominantly on humans irrespective of host availability. At these sites on the Kenyan coast, the high degree of human-feeding by malaria vectors contributes to the efficiency of malaria parasite transmission and the high incidence of severe malaria.

Plasmodium falciparum infection rates in malaria vectors at two ecologically district sites in Kilifi Districts; Kenya

Transmission of Plasmodium falciparum was studied for one year at two ecologically different sites in Kilifi district. Anopheline mosquitoes were collected by three sampling methods and tested for P.falciparum sporozoites by ELISA. Anopheles gambiae s.l. was the predominant vector. Plasmodium falciparum sporozoite rates were 4.07 (20/491) and 2.17 (3/138) for An.gambiae s.l. at Sokoke and Kilifi town respectively. No sporozoite infections were detected in An.funestus or An.coustani. Transmission was year-round with highest levels occurring after the long rains (June to September). Entomological inoculation rates indicated taht each person could receive 8 infcetive bites per year at Sokoke; compared with 1.3 infective bites per year at Kilifi town. Our studies indicate taht the public health problem of malaria in Kilifi district is associated with extremely low levels of P.falciparum transmission by vector populations