Climate Change Favors African Malaria Vector Mosquitoes

TL;DR

This study shows that climate change could expand the range of three key malaria mosquitoes in Africa, putting millions more people at risk.

Contribution

The study is the first to estimate future human exposure to six dominant African malaria vector species under climate and land-use changes.

Findings

Three mosquito species (Anopheles gambiae, Anopheles coluzzii, and Anopheles nili s.l.) are projected to expand their suitable habitats.

Approximately 200 million additional people could be at risk in Central and East Africa by the end of the century.

Climate change impacts on malaria vectors are highly species-specific, contradicting earlier predictions of reduced transmission.

Abstract

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.

Malaria is a deadly parasitic disease that is transmitted by mosquitoes. This study investigates occurrence patterns of malaria mosquito species to predict how climate change will affect their range in sub‐Saharan African, where most malaria deaths occur. It highlights three mosquito species that could expand their range throughout Africa because of climate change, potentially affecting hundreds of millions of people.

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