Wildlife Trade a Key Risk Factor in the Global Spread of Infectious Disease

As humanity continues to struggle to contain the COVID-19 pandemic, scientists from The Nature Conservancy and the Ashoka Trust for Research in Ecology and Environment (ATREE) in India, have conducted a first-of-its-kind analysis, published today in the journal Current Biology, which seeks to quantify the link between global wildlife trade and the risk of emerging zoonotic diseases – including pathogens such as SARS, MERS, HIV, and COVID-19, which transfer from animals to humans.

The research revealed that one-quarter of mammal species in wildlife trade host 75 percent of the known zoonotic viruses; and that the risk of disease transfer is much higher among those mammals commonly traded, as opposed to species that are not traded, or are domesticated.

In total, the study compared the association of 226 viruses known to cause zoonotic diseases across more than 800 mammal species, then categorized these animals into three distinct groups: traded mammals, non-traded mammals, and domesticated mammals.

“From our findings, it is conceivable that wildlife trade (legal and illegal) is the key risk factor driving the global spread of zoonotic and emerging infectious diseases,” said lead author Dr Shivaprakash Nagaraju, a senior scientist for The Nature Conservancy in India.

“Annually, it is estimated that international wildlife trade results in upwards of one billion direct and indirect contacts between wildlife, humans, and domestic animals,” Shivaprakash continued. “By pinpointing the species that pose the highest risk of passing zoonotic diseases to humans, we hope our research can help global health experts prioritize where to concentrate their efforts to prevent the next global pandemic.”

While previous scientific literature identified rodents and bats as groups of particular concern for disease transmission, this is the first study to present evidence that primates and even-toed ungulates (e.g. hoofed mammals like deer, antelope) in wildlife trade are an even greater risk to human health, due to the higher number of host species within their group, and the diversity of diseases they carry which can be transmitted to humans. 

“This study is particularly timely as the COVID-19 pandemic, and its suspected origins in a wildlife wet market, has brought the global health risks of wildlife trade to the urgent attention and concern of civil society, political leaders, and scientists,” said Dr Joe Kiesecker, a Lead Scientist for The Nature Conservancy and co-author of the study. “If we want to stop the next pandemic before it starts, our findings indicate that we should, among other measures, focus our efforts on keeping rodents, bats, primates, ungulates, and carnivores out of wildlife trade.”

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Notes for Editors

Shivaprakash, K.N., Sen, S., Paul, S., Kiesecker, J.M., Bawa, K.S. (2021)

Mammals, wildlife trade, and the next global pandemic. Current Biology.

DOI – 10.1016/j.cub.2021.06.006

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Ashoka Trust for Research in Ecology and the Environment (ATREE) focuses on research and education to engage and influence policy and practice in the conservation of nature, management of natural resources, and sustainable development. Established in 1996 as a non-profit organisation, ATREE works in the forests of the Western Ghats, the ecosystems of Northeast Himalayas, grasslands of Kutch, wetlands of Tamil Nadu and Kerala, the expanding urban cities of Karnataka and Tamil Nadu, and other parts of India.