Entomological characteristics of mosquitoes breeding sites in two areas of the town of Douala, Cameroon

Abstract

Many infectious diseases including malaria, lymphatic filariasis, chikungunya and dengue are transmitted by mosquitoes. Understanding the entomological diversity in a given area is critical for defining health risks, but also to design and evaluate control measures. Our study aimed to establish an entomological database of the Culicidae fauna in two clusters (Nyalla and Kambo) in the city of Douala in Cameroon. A longitudinal study was conducted from August to December in the Nyalla and Kambo neighbourhoods in the city of Douala. Culicidae larvae were weekly collected and reared until adult emergence. Adults were then morphologically identified using reference identification keys. A total of 20 breeding sites were productive out of an approximately 90 sites prospected. Water collections, pits, swamps and cinder blocks were main categories of larval habitats. In total, 2125 mosquito larvae were collected and reared during the survey. A total of 1790 mosquito adults emerged and were further identified and distributed among three genera: Culex (73.3%); Anopheles (22.6%) and Aedes (4.1%). Eleven Culicidae species were identified: Culex duttoni, Cx. descens, Cx. poicilipes, Cx. univittatus, Cx tigripes, Cx. antennatus, Cx. simpsoni, Cx. pipiens, Anopheles gambiae sl, Aedes aegypti and Ae. albopictus. Culex duttoni (39%) and An. gambiae s.l. (22.6%) were the main species recorded. The equitability, species richness and abundance of these genera was influenced by the nature of breeding sites and physical parameters including rainfall and temperature. The present study provides insights on the entomological diversity of the Culicidae fauna in the study area. Such information will help to orientate the fight against mosquito vectors in conjunction with the species and the types of breeding sites.