Study Links Duration in Wildlife Trade to Increased Pathogen Sharing with Humans

A new study published on Thursday in the journal Science examined the relationship between wildlife trade and pathogen sharing between animals and humans. The analysis reviewed 40 years of global trade records and pathogen data. It determined that traded mammal species are more likely to carry diseases that can infect humans.

4% of species not involved in trade. Researchers observed that the number of shared pathogens increases with the duration of a species' involvement in trade. On average, a species acquires one additional human-infecting pathogen for every decade it remains in the global wildlife trade.

Pathogen Risks in Trade Activities Wildlife trade encompasses activities such as hunting, breeding, transport, storage, and sale.

During these stages, animals are handled, confined, and often placed in close proximity to humans and other species. Such conditions can enable the spread of viruses, bacteria, and parasites, potentially leading to spillover into human populations. The research noted that repeated and prolonged contact creates more opportunities for pathogens to adapt and transfer between species.

One key finding was the correlation between time in trade and pathogen sharing. This pattern suggests that trade contributes to the emergence of new diseases alongside factors like deforestation, agriculture, and climate change.

Variations in Trade Risks The study identified differences in risks based on trade forms.

Species sold in live-animal markets showed higher rates of pathogen sharing with humans than those sold as meat or products. Illegally traded species were also associated with elevated disease risks, though the researchers stated that risks extend to both legal and illegal markets.

International frameworks, such as the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), primarily address species overexploitation.

The study pointed out opportunities to incorporate zoonotic disease risk into these regulations. Pathogen transmission arises from various human uses of wildlife, including both legal and illegal trade.

Global Coordination and Surveillance Needs The global scope of wildlife trade complicates risk management, as animals and pathogens cross political borders.

The researchers emphasized the importance of coordinated efforts across conservation, public health, and trade policy to address trade as a driver of health risks. Current disease surveillance systems often fail to detect pathogens in wildlife before human spillover occurs. Few countries systematically track traded species at borders or conduct routine pathogen screening.

The study suggested expanding surveillance, especially for known zoonotic carriers, to identify threats earlier. This could involve monitoring at fur farms, hunting communities, and import checkpoints. " — Colin Carlson, epidemiologist at the Yale School of Public Health and co-author of the study (Los Angeles Times) The findings build on prior links between wildlife trade and outbreaks like HIV, Ebola, and COVID-19.

By analyzing long-term data, the research provides a broader assessment of trade's role in disease emergence. Implementing enhanced monitoring and policy integration could help mitigate accumulating risks in undetected trade networks.