High malaria transmission intensity due to Anopheles funestus (Diptera: Culicidae) in a village of savannah-forest transition area in Cameroon

Abstract

An entomological survey was conducted on vectors of malaria in a village of the forest-savannah transition area in Cameroon from February 1999 to October 2000. A total of 2,050 anopheline mosquitoes belonging to eight species were caught 1) after landing on human volunteers, 2) by using pyrethrum spray collections in human dwellings, and 3) in resting sites outdoors. Anopheles funestus Giles was the most abundant species (accounting for 91% of anophelines caught) followed by Anopheles gambiae Giles (7%). Applying polymerase chain reaction led to the identification of all specimens of the An. funestus group as An. funestus sensu stricto and mosquitoes from the An. gambiae complex were mostly An. gambiae sensu stricto of the S molecular form. Malaria transmission was perennial with an entomological inoculation rate estimated at 172 infective bites per person during the period of study. An. funestus was responsible for 88% of the total malaria transmission, with a Plasmodium falciparum circumsporozoíte rate of 6.8% and an anthropophilic rate of 99.3%. These results confirm that in high agricultural activity areas, An. funestus can be, by far, the major malaria vector.