Deforestation and visceral leishmaniasis: linking landscape change and health in the Amazon

Visceral leishmaniasis (VL) is a neglected tropical disease whose transmission is shaped by environmental and social conditions. In the Brazilian Amazon, extensive landscape change has raised concerns about how deforestation may influence disease dynamics. This study investigated the spatiotemporal association between VL incidence and deforestation from 2001 to 2023 across all health regions of the Brazilian Amazon. Data on confirmed cases of VL and annual deforested areas were aggregated by health region and analyzed via temporal and spatial statistical models. We observed a statistical association between deforestation and VL incidence, with increases in reported cases between 2001 and 2010 and from 2015 onward. Spatial analysis revealed an association between areas of increased deforestation and increased disease incidence, particularly along the arc of deforestation. While this ecological design does not allow causal inference, the findings highlight correlations that can guide future studies on the ecological mechanisms linking land-use change, vectors, and reservoirs. Integrating environmental indicators into surveillance systems may enhance early detection, inform more effective control strategies, and support intersectoral public policies. These approaches, which are consistent with the One Health framework of the World Health Organization, are especially relevant in socially vulnerable Amazonian territories undergoing rapid landscape transformation.