The global wildlife trade – especially in illegal and live-animal markets – is fueling the spread of diseases from animals to humans, according to a new study. The findings show that traded mammals are more than 40% more likely to harbor human-infecting pathogens, with species accumulating more shared pathogens the longer they remain in the trade. Close interactions between humans and wild animals create pathways for the spread of parasites and pathogens, sometimes triggering epidemics and pandemics. The global wildlife trade, which encompasses hunting, breeding, transport, retail, and pet ownership, poses particularly high risks of animal-to-human pathogen spillover. This trade has been linked to outbreaks ranging from HIV and Ebola to COVID-19 and mpox. While research has explored environmental and ecological factors that influence pathogen transmission, the dynamics of disease spread specifically within the wildlife trade and between humans and traded animals remain poorly understood.
Jérôme Gippet and colleagues analyzed 40 years of global wildlife trade data drawn from the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), the Law Enforcement Management Information System (LEMIS), and the Dataset of Seized Wildlife and their intended uses (DSW) datasets. They then linked this to the CLOVER database, which catalogs over 190,000 mammal-pathogen associations, to identify which species are known to share pathogens with humans. Gippet et al. found that among the 2,079 mammal species involved in global trade, 41% were found to share at least one pathogen with humans, compared with only 6.4% of nontraded species, and that traded mammals are 1.5 times more likely to host pathogens transmissible to humans. According to the authors, this suggests that cross-species transmission is an inherent feature of wildlife trade. Species in live-animal markets and, to a lesser extent, those involved in illegal trade, host more pathogens than those traded solely as products or legally. What’s more, the findings show that the duration a species spends in trade further amplifies risk. Gippet et al. found that each decade a species is traded corresponds to one additional pathogen shared with humans, on average.
Science
Wildlife trade drives animal-to-human pathogen transmission over 40 years
9-Apr-2026