Laboratoire des Milieux Naturels et Conservation de la Biodiversité de l’UFR Biosciences, Université Félix Houphouët-Boigny, 22 BP 582 Abidjan 22, Côte d’Ivoire
Malaria remains a public health concern in Côte d’Ivoire. The fight against transmission of this disease requires a good knowledge of the vector as well as their level of susceptibility to insecticides most commonly used in public health, in order to better select tools and guide vector control strategies. An entomological survey was conducted in Grand-Bassam from January 2015 to december 2015. Adult resting mosquitoes were collected using pyrethrum spraying catches methods. Susceptibility tests were performed with three pyrethroids (alphacypermethrin, deltamethrin, permethrin) and an organophosphate (chlorpyrifos-methyl) according to the standard WHO test cylinder method, on 2-to-4-days old female Anopheles gambiae s.l. emerged from larvae collected in breeding sites and reared in the insectary. Complex members, insecticide resistance genes and An. gambiae s.l. infection with Plasmodium were analyzed, using polymerase chain reaction (PCR) method. Four genera of culicidae (Aedes, Anopheles, Culex and Mansonia) divided into nine species were collected. Anopheles gambiae s.l. was the most abundant species (69.3%) with the highest size recorded in June (n=116). The parity rate of captured females An. gambiae was very high (94.1%). Susceptibility tests showed that An. gambiae s.l. were resistant to all insecticides tested. The PCR results demonstrated that An. coluzzii was the only species of An. gambiae s.l. found in the study area. The resistance mechanisms involved the Kdr-w and Ace-1 mutations, which were expressed at allelic frequencies of 0.54 and 0.29, respectively in the population. Plasmodium falciparum was the only malaria parasite found with an infestation rate of 4.3%. These outcomes are important for planning the national malaria vector control programs.