Distribution and characterization of anopheline larval habitats in flooded areas of the Dakar suburbs (Senegal)

Abstract

Knowledge of mosquito ecology is a prerequisite for efficient implementation of vector control strategies. This one-year study was carried out during the 2013 rainy season and the 2014 dry season throughout the flooded areas of the suburbs of Dakar with the aim to characterize and map anopheline larval habitats. In both seasons, all water bodies that were encountered within the study departments were geo-located and their features (type of water body, size, turbidity and distance to human dwellings) recorded. The presence of anopheline and/or culicine larvae and predators was assessed. A total of 908 and 278 potential larval habitats were visited during the rainy season and the dry season, respectively. A significant positive association was found between the rainy season and the presence of anopheline larval sites, which consisted of ponds, puddles, ravines, drain channels, streams and canals. Anopheline larvae were more likely to be found in clear water bodies located within 10 m to human dwellings. During the dry season, only puddles were likely to host anopheline larvae. Anopheline larval habitats were significantly more frequent in the Department of Rufisque during the rainy season (univariate analysis, P = 0.006) and in the Department of Guediawaye during the dry season (multivariate analysis, P = 0.036). The malaria vector identified was Anopheles arabiensis. Data gathered in this study will guide larval control programmes in urban settings prone to flooding. Key words: Anopheline, larval habitat, flood, suburb of Dakar, Senegal.