Apr 10, 2026
3 min read
Decades of data show that animals involved in the wildlife trade — from hog sales to meat markets to illegal hunting — are more likely to carry pathogens that can infect humans.
Wildlife trade is huge.Legal or not, it also includes the sale of pets, meat markets, fur and medicine.About 25 percent of mammal species are involved in some part of the trade, and scientists warn that it can lead to zoonotic diseases — diseases caused by pathogens that are transmitted from animals to humans, similar to the virus that causes COVID.But it is not always clear how and how often these diseases are transmitted from animals to humans.
A new study published today in the journal Science reveals a close relationship between species found in the wildlife trade and animals known to transmit pathogens to humans.
“There is a strong link,” said Jérôme Gippet, an ecologist at the University of Friborg in Switzerland.“What we could calculate is that for every 10 years the species is in the wild, it shares an additional pathogen with humans.”
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For more than 40 years researchers have combed through data on which animal species are involved in the illegal or illegal wildlife trade.This information is then compared to a dataset called CLOVER, which shows the pathogens found in different species.The team's analysis found that, of 2,079 commercial mammals, 41 percent shared at least one human-transmissible pathogen.In comparison, only 6.4 percent of non-commercial animals were exposed to the same pathogen.
Researchers had hoped that humans might find microbes from animals that are more closely related.However, Gippet said, the research highlights the need to monitor the disease and prepare for outbreaks.
"Before [the study], my idea of the risk of disease transmission in wildlife was like, 'Oh, there's some kind of dirt,'" he says."But what we're showing here is: it's not really about species, it's about people."
Not all zoonotic pathogens encountered by humans cause outbreaks or epidemics on the scale of COVID.Few are not destructive to our species or capable of human-to-human transmission.However, any increase in exposure and transmission comes with the risk of viruses or bacteria becoming more of a concern.
The study "underscores the importance of better monitoring and regulation of the wildlife trade," said Wayne Getz, an ecologist at the University of California, Berkeley, who was not involved in the new work.
Preparing for potential disease outbreaks involves increasing global disease surveillance, using predictive models to determine which pathogens should be a research priority, and creating action plans for when potential outbreaks are detected.The study authors hope their research inspires more preparation.
"There is no such thing as a safe business," says Gippett."Trade itself creates an opportunity for transmission of pathogens."
