Aligning climate and health: assessing zoonotic arboviral risks in agroforestry as a climate mitigation strategy - Recent outbreaks of arboviral diseases such as Zika and West Nile have their roots in tropical forests. Their spread coincides with significant land conversion for agriculture, impacting arthropod vectors and reservoirs of zoonotic diseases. Our decade-long epidemiological studies in Panama's Darien region indicate high incidence of zoonotic alphaviruses in humans, wildlife and more recently, in livestock. In Darien, open pasture ranching and crop farming coexist with agroforestry, an important climate change mitigation strategy that integrates crops, livestock and forest. Despite the rising global adoption of agroforestry, its impact on infectious disease risk is understudied. Our research aims to fill this knowledge gap by investigating zoonotic arboviral transmission in Darien in relation to its agricultural practices, including agroforestry. Various factors, from biodiversity shifts to land tenure benefits and irrigation schemes, likely influence disease transmission. We hypothesize that landscapes that merge forest, agriculture and human dwellings potentially enhance the spread of zoonotic arboviruses due to increased overlap of vectors, vertebrate reservoirs including livestock, and humans. Our first aim in this study is to assess agroforestry's impact on zoonotic arboviral risk among the agrarian population and livestock in Darien, Panama, by conducting serosurveys and acute febrile studies to inform habitat suitability modeling. Interviews with participants will provide data on health and social determinants influencing agriculture and zoonoses interactions. Our second aim is to characterize vector ecology, infection rates, and host use across an agricultural gradient. We will study immature vector breeding preferences and water quality, and employ a variety of vector trapping methods to assess viral transmission rates and blood meal origins to shed light on shifts is host usage within agroforestry environments. Our third aim is to map zoonotic arboviral risk using geospatial and field data. We will also analyze natural selection and gene flow of the predominant zoonotic arbovirus in the region, Venezuelan equine encephalitis virus, across the agricultural gradient. We will use genomes derived from field isolates (mosquito, animal and human), along with regional historical isolates, to test the hypothesis that increased host diversity at the forest/agriculture ecotone fosters greater VEEV genetic diversification, leading to the emergence of new variants capable of causing epizootics. The research outcomes will be instrumental in defining transmission dynamics and health burden of significant zoonotic arboviruses and informing preventive measures. This understanding will guide land use and health policies in Darien, serve as a blueprint for interventions, and help ensure alignment of climate and health objectives within the context of agroforestry. Our methodologies and findings will have broad applicability across regions with similar ecologies.
