Resting and feeding behaviour of malaria vectors, in two areas of high long-lasting insecticidal nets coverage in Côte d’Ivoire

The resting and feeding behaviour of the main malaria vectors was studied in rural areas of Côte d’Ivoire, after Long-Lasting Insecticidal Nets (LLINs) national coverage. Adult mosquitoes were sampled by Human Landing Catches (HLC) and Pyrethrum Spray Catches (PSC). The annual entomological inoculation rate (EIR) was calculated for each species. An. coluzzii, An. gambiae s.s. and An. funestus were the vector species identified in Toumbokro while An. coluzzii, An. funestus and An. nili were identified in Kassiapleu. These vectors feed preferentially on humans in the two villages. In Toumbokro, An. gambiae s.l. is exophagic while An. funestus is endophagic. In this village, the annual Entomological Inoculation Rate (EIR) average was high and estimated at 228.49 infectious bites per person per year (ib/p/y) with the contribution 80.81 ib/p/y either 35% for An. gambiae s.l. and 147.68 ib/p/y either 65% for An. funestus. An. funestus has become the main vector and provide its own more than half of this transmission. In Kassiapleu, this EIR was also high and estimated at 348.58 ib/p/y. An. gambiae s.l. and An. funestus have been responsible for 332.15 ib/p/y either 95% and 16.43 ib/p/y either 5%, respectively. An. gambiae s.l. is endophagic and has remained the main vector of malaria. This work shows that malaria transmission remains high and is assured by two main vectors (An. funestus and An. gambiae s.l.) in rural areas of Côte d’Ivoire. These vectors bite both inside and outside the house. Thus, effective malaria control requires combining indoor residual spraying and outdoor control tools at LLINs currently used against the vectors inside the home.