Spatial Distribution and Biodiversity of Anopheles Mosquito Species Across Climatic Zone in Burkina Faso: Implications for Malaria Vector Control

Malaria transmission in sub-Saharan Africa is dominated by the Anopheles gambiae complex and Anopheles funestus group, whose distribution varies across ecological settings. Secondary species occur at lower densities, but their role in transmission may differ with local conditions. Assessing Anopheles biodiversity using ecological indices is therefore essential to characterise their diversity and relative abundance. This study investigated the biodiversity and spatial distribution of Anopheles species across the three climatic zones of Burkina Faso to guide effective vector control strategies. Indoor resting mosquitoes were collected from 67 health districts across 13 regions between September and December 2022 using pyrethroid spray catches. A total of 30,521 Anopheles mosquitoes were identified, with Anopheles gambiae s.l. dominating (94.4%). The Sudano-Sahelian zone recorded the highest abundance, followed by the Soudanian and Sahelian zones. Biodiversity decreased from humid southern to arid northern areas, with the Soudanian zone showing the highest diversity. Molecular analysis of 2,026 An. gambiae s.l. specimens revealed marked heterogeneity: Anopheles coluzzii predominated in Sahelian (74.9%) and Sudano-Sahelian (71.2%) zones, while An. gambiae s.s. was most frequent in the Soudanian zone (53.8%). These results highlight spatial and ecological differences in Anopheles composition across Burkina Faso and emphasize the need for locally adapted malaria vector control strategies.