An exploration of the protective effect of rodent species richness on the geographical expansion of lassa fever in West Africa

Abstract

Background Lassa fever (LF) is one of the most devastating rodent-borne diseases in West Africa, caus-ing thousands of deaths annually. The geographical expansion of LF is also a concern; cases were recently identified in Ghana and Benin. Previous ecological studies have suggested that high natural-host biodiversity reduces the likelihood of spillover transmission of rodent-borne diseases, by suppressing the activities of reservoir species. However, the association of biodiversity with the geographical expansion of LF has not been the subject of epidemiological studies. Methodology/Principal findings We conducted a spatial analysis based on sociodemographic, geographical, and ecological data, and found that higher rodent species richness was significantly associated with a lower risk of LF emergence in West Africa from 2008 to 2017 (Odds Ratio = 0.852, 95% Credible Interval = 0.745–0.971). Conclusions/Significance The results reinforce the importance of the ‘One Health’ approach by demonstrating that a high level of biodiversity could benefit human health.