Exploring the impacts of wildlife trade on zoonotic spillover and disease outbreaks: A multiple-perspective study

The emergence of zoonotic pathogens from wildlife poses a major global health threat, contributing to frequent and impactful disease outbreaks. While wildlife trade is recognized as a key driver of zoonotic spillover, no studies have quantitatively assessed how trade volume relates to the occurrence and frequency of emerging infectious diseases (EIDs) at a global scale, especially regarding the impact of extreme volumes. This study addresses this gap by conducting a multiple-perspective analysis on country-level yearly zoonotic EID data from 1975 to 2013 using a Bayesian zero-inflated negative binomial spatiotemporal model combined with extreme value theory to evaluate the influence of wildlife trade on EID occurrence, frequency and extreme events. After adjusting for reporting bias and conducting rigorous sensitivity analyses, we find that wildlife import volume significantly increases the probability of zoonotic EID occurrence and extreme outbreaks, but does not affect the frequency. In contrast, wildlife export volume shows no significant impact on either EID occurrence or frequency, and a much weaker effect on extreme events. Beyond wildlife trade, mammalian richness and socioeconomic indicators exhibit complex associations with EID patterns mediated by the varying effectiveness of national disease surveillance systems. This integrated methodology advances understanding of zoonotic disease drivers and underscores a critical import-driven risk profile, suggesting that pandemic prevention strategies should prioritize biosecurity and regulation at wildlife importation points.