The importance of Indigenous Lands and landscape structure in shaping the zoonotic disease risk—Insights from the Brazilian Atlantic Forest

Indigenous Peoples hold traditional knowledge rooted in their ancestral ties to the land, contributing to lower deforestation and higher biodiversity. These ecological benefits may also support public health, as intact ecosystems help reduce the risk of zoonotic diseases linked to habitat loss and human encroachment. However, the role of Indigenous Lands (ILs) in mitigating such disease risks remains poorly understood. Here, we examined how the extent of ILs, along with the landscape composition (forest and agriculture cover) and configuration (forest edge density) of the municipalities where they are inserted, affect the incidence of Chagas disease, hantavirus, cutaneous and visceral leishmaniasis and Brazilian spotted fever across the Brazilian Atlantic Forest. We modelled each disease incidence based on annual data collected at the municipality level between 2001 and 2022. Using Generalised Additive Models, the relative effects of ILs, forest and agriculture covers and forest edge density were first analysed considering the entire Atlantic Forest. We secondly repeated the modelling for each of four classes defined according to the ILs extent: 0 %, <10 %, 10 % to 40 %, and > 40 %. Overall, ILs cover negatively affected the incidence of all but Chagas disease; forest cover negatively affected four diseases but had a positive effect on cutaneous leishmaniasis, which was also positively affected by the amount of agriculture areas; forest edge density exerted unexpected negative effects on cutaneous leishmaniasis and on the Brazilian spotted fever. In summary, our results showed a protective effect of forest cover on disease risk, which was exacerbated as the ILs cover increased in the municipality. Likely due to a more sustainable resource management and lower levels of exposure within ILs, these Lands seemly play a protective role on human health as their extent increases in the municipalities of the Brazilian Atlantic Forest. Our findings contribute to greater recognition of these areas for the provision of ecosystem services.