Viruses on the edge: Exploring zoonotic virus species richness at ecosystem edges

Keywords: Zoonoses, deforestation, planetary health
Abstract Type: Paper Abstract

Abstract

Landscape change transforms disease dynamics by impacting community composition and movement, bringing new species into contact with one another. This study explores the impact of “edge effects” on zoonotic disease spillover in tropical ecosystems using concepts from ecological theory and empirical data from one of the largest virus surveillance efforts to date. We utilized data from countries with ≥20% forest cover (n=14 countries) and sufficient sampling effort (n≥5 sites) from 2014-2020, wherein samples from wild animals were tested for known and novel coronaviruses, paramyxoviruses, flaviviruses, and influenzaviruses. We classified sampling sites by edge status (manmade or natural) and forest fragmentation using multiple metrics, including by employing an algorithm with ALOS-PALSAR data. We then utilized mixed-effect regression models to explore measures of viral richness at anthropogenic edges of ecosystems, accounting for distance from sampling site to nearest forest edge, degree of forest fragmentation at buffers of biological relevance, and primary and secondary land use types, among other variables. We hypothesize that there is greater virus diversity at ecosystem edges because of host generalism in these habitats, and that this generalism could translate to heightened virus host plasticity and increased risk of spillover to humans. Findings are highly dependent on spatial scale and stratification by virus and reservoir taxa. This work will support strategic emerging disease surveillance and forest conservation efforts more broadly.