Does climate change influence the spread of malaria in Benin? Insights from ecological niche modeling for surveillance efforts.

Background: Malaria is a severe and endemic disease, remaining one of the most prevalent tropical illnesses and a leading cause of death among children aged <5 y. Anopheles gambiae, the primary vector of malaria in Benin, plays a critical role in its transmission. This study aims to contribute to the health protection of populations in Benin by assessing the risk of vector-borne diseases, particularly malaria, in the context of climate change.

Methods: Using the Maxent algorithm for ecological niche modeling, we mapped the distribution of A. gambiae, a highly effective vector of Plasmodium parasites.

Results: Our findings revealed that high-risk areas for malaria cover nearly all departments of Benin, with the majority of southern departments-Mono, Littoral, Couffo, Ouémé, Plateau and Zou-identified as high-risk zones. Projections for 2055 under Representative Concentration Pathway (RCP) 4.5 and RCP 8.5 climate scenarios indicate a significant expansion of high-risk areas, extending to Collines and parts of Donga, Borgou and Atacora.

Conclusions: Climate change is expected to exacerbate the spread of A. gambiae, increasing the disease risk across the country. These results are crucial for guiding policymakers in Benin to mitigate the current impact of malaria and implement preventative measures to address future risks.