Mosquitoes fauna diversity, Plasmodium falciparum infection and insecticide resistance status in malaria vectors in a lagoon area in Southern Benin, West Africa

Abstract

Lagoon areas maintain ideal water conditions for mosquito breeding habitats and are thus environments with high risk of malaria transmission. In Benin, several administrative units, among which the Sô‐Ava District, are located in lagoon areas. We conducted entomological surveys in this lagoon district from July 2014 to June 2015, in order to update existing information on biodiversity of mosquitoes, Plasmodium falciparum infection, and insecticide resistance status in malaria vectors. Our survey found that Culex quinquefasciatus and Mansonia africana were the most abundant species, and that Anopheles coluzzii represented the main malaria vector in this area, followed by Anopheles melas. Only Anopheles coluzzii was positive to Plasmudium falcimarum circum sporozoitic protein (4.2 %). An. gambiae s.l. were susceptible to chlorpyrifos‐methyl and bendiocarb but resistant to all pyrethroids tested and to pyrimiphos‐methyl. The average of kdr allelic frequency from July 2014 to June 2015 was 77.4% and that of ace1 gene was less than 1%. We conclude that Anopheles coluzzii is the main malaria vector in the lagoon area we studied, somewhat contrary to our expectations. However, this malaria vector was resistant to insecticides used for bed net impregnation, even if the resistance level was lower than observed in other parts of Benin.