Climate Change Favors African Malaria Vector Mosquitoes

Malaria, a parasitic disease transmitted by mosquitoes of the genus Anopheles, causes half a million deaths annually, mostly among children in Africa. While climate change is expected to significantly alter malaria transmission, previous forecasts have largely overlooked the species-specific responses of mosquito vectors which may substantially impact the outcome of such forecasts. Here, we for the first time estimate the future human exposure to each of six dominant African malaria vector species. Using an extensive mosquito observation dataset, robust species distribution modeling, and climate and land-use data, we investigate the climatic niches of six dominant African malaria vector species and map out their differing responses to climate and land use change across sub-Saharan Africa. Projections of future vector suitability identify three species that are likely to experience a substantial expansion of suitable habitat: Anopheles gambiae, Anopheles coluzzii, and Anopheles nili s.l. By combining these projections with human population density data, we conservatively estimate that approximately 200 million additional people could be living in areas highly suitable for these three vector species by the end of the century, with new hotspots of human exposure emerging in Central and East Africa. Our results align with observed historical range shifts of Anopheles species but stand in contrast to earlier studies that have predicted climate change would have little effect on or even reduce malaria transmission. We find that climate change impacts on malaria vectors are highly species-specific, emphasizing the need for longitudinal field studies and integrated modeling approaches to address the ongoing redistribution of malaria vectors. As the world strives for malaria elimination amidst accelerating climate change, our study underscores the urgent need to adapt malaria control strategies to shifting vector distributions driven by environmental change.