Journal Article

Diversity of larval habitats of Anopheles mosquitoes in urban areas of Benin and influence of their physicochemical and bacteriological characteristics on larval density

Cornelie, Sylvie, Akogbeto, Martin, Djouaka, Rousseau, Tchigossou, Geneviève, Nonfodji, Odilon M., Djogbenou, Luc, Hessou-Djossou, Donald, Chandre, Fabrice, Djègbè, Innocent, Ahadji-Dabla, Koffi Mensah

2022

Overview

Background The implementation of anti-larval strategies in the fight against malaria vectors requires fundamental knowledge of their oviposition sites. The aim of this study was to assess the spatial and temporal distribution of Anopheles breeding sites as well as the influence of abiotic and biotic factors on the proliferation of larvae in urban and non-urban areas of Benin. Methods Sampling of Anopheles larvae was carried out during the rainy and dry seasons in urbanized and non-urbanized areas of the cities of Cotonou, Bohicon, Parakou, and Natitingou in Benin. The Anopheles larval breeding sites were georeferenced and characterized by their nature, type, physicochemical (pH, temperature, dissolved oxygen, conductivity, turbidity, salinity) and biological attributes (larval density and coliform density). Results A total of 198 positive breeding sites for Anopheles larvae were identified, comprising 163 (82.3%) in the rainy season and 35 (17.7%) in the dry season. Out of these larval habitats, 61.9% were located in urbanized areas, and were predominantly puddles. Principal component analysis revealed a high positive correlation of larval density with temperature and dissolved oxygen, and with salinity in the coastal zone. In addition, cross-sectional analysis of the microbiological results with larval density showed a significant negative correlation between larval productivity and faecal coliform load. Conclusions This study indicated the presence of multiple larval habitats of Anopheles in the urban areas which were created through human activities, and associations between larval density and intrinsic factors of the habitats such as temperature, dissolved oxygen and faecal coliform load. This type of information may be useful for the implementation of appropriate control strategies in urban areas, including regulation of the human activities that lead to the creation of breeding sites, proper environmental management and targeted larvicidal use. Graphical abstract

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Animal biology / Anopheles / Aquatic insects / Benin / Biodiversity and Ecology / Biomedical and Life Sciences / Biomedicine / Biotic factors / Breeding sites / Cities / Coastal zone / Coastal zones / coasts / coliform bacteria / Coliforms / Correlation / cross-sectional studies / Density / Dipteran vectors and associated diseases / Dissolved oxygen / Distribution / Dry season / Ecology / Economic activity / Entomology / Environmental aspects / Environmental management / Environmental Sciences / Evaluation / Faecal coliforms / georeferencing / Habitats / Health aspects / Human diseases / humans / Infectious Diseases / Insecticides / Invertebrate Zoology / Larvae / Larval density / larvicides / Life Sciences / Malaria / Mosquitoes / Oviposition / Oxygen / Parasitology / Physicochemical parameters / Population / Prevention / principal component analysis / Principal components analysis / Proliferation / Puddles / Rainy season / Salinity / Salinity effects / Santé publique et épidémiologie / Sea level / Seasons / Temperature / Temporal distribution / Tropical Medicine / Turbidity / Urban areas / Urbanization / Vector control / Vector-borne diseases / Vectors / Veterinary Medicine/Veterinary Science / Virology / Virus-vector relationships / Wet season