Pangolins harboring coronavirus underscored risk of wildlife markets

Pangolins impounded by police en route to Vietnam wildlife markets have been found to harbor forms of the coronavirus — highlighting the risk that the scaly anteaters could serve as a viral rest stop on the next pandemic’s pathway between wild animals and humans.

The study in Frontiers in Public Health comes out as international public health and biodiversity experts push for a global treaty banning wildlife markets. They also want a more unified approach to “zoonotic diseases,” which rise in animals and jump to humans.

“It’s so amazing we allow these uncontrolled experiments to go on and in the middle of urban centers with millions of inhabitants,” Chris Walzer, veterinarian and executive director of health at the Wildlife Conservation Society, said in an interview.

Following the coronavirus outbreak, China moved to close its wildlife markets — including one in the city of Wuhan where cases of the coronavirus were first spotted — first temporarily and then permanently.  

Several studies have identified the Wuhan market as the epicenter of the pandemic’s start, according to the journal Nature.   

“The next one’s not going to happen in China,” Susan Lieberman, a vice president for international policy at the Wildlife Conservation Society, told The Hill, noting the steps China has taken recently. “If every government did what China did, you know, we’d be in better shape.”   

But such markets are still open in cities across Africa — where they serve as sources of everyday protein — and in Southeast Asian countries like Indonesia, Cambodia and Vietnam, Lieberman said.

There is some risk of contagion by new viruses whenever people go into forests or come into contact with wildlife.

An Ebola outbreak in three West African nations that began in 2013 happened after a 2-year old child came into contact with a bat or bat guano; different flu strains have emerged from pig farms in China; Middle East respiratory syndrome, or MERS, caused by another coronavirus that infects humans first identified in 2012, appeared to move between camels and workers who came into close contact with them on the Arabian Peninsula.

Yet urban markets with live animals represent a particularly dangerous risk, Lieberman said.

“Take local people: if they live in a village around the forest, they’re going to come in contact with a few animals that they go into the forest and kill and eat,” she said.

“They’re not bringing out hundreds and hundreds of animals in cages into markets so they can mix bodily fluids and see what happens.”

A key first step to prevent the next pandemic, she said, is therefore to focus on urban markets — where large numbers of live animals crowd together with each other and with crowds of people — rather than village markets, or the consumption of wild game more generally.

“People need to have other sources of protein than wildlife, or if they eat wild animals that they shouldn’t be in markets while alive,” Lieberman said. “To be blunt, if it’s something that’s cooked, it’s not a danger.”  

That’s why last April, the World Health Organization joined with the United Nations Environment Program and the World Organization for Animal Health to call for an end to the sale of live wild animals — and particularly mammals — in traditional food markets.  

And on Monday, the three organizations called for a global monitoring program of wildlife species to prevent the formation of “animal reservoirs” where the coronavirus pandemic could continue circulating and reinfecting humans.

“In addition to domestic animals, free-ranging, captive or farmed wild animals such as big cats, minks, ferrets, North American white-tailed deer and great apes have thus far been observed to be infected with [coronavirus],” the WHO wrote.  

This approach is a valuable example in the principle of One Health, an emerging public health approach that treats the health of “people, animals, plants, and their shared environment” as necessarily interconnected, according to the U.S. Center for Disease Control.   

That’s in contrast to what has traditionally been a largely siloed approach, Lieberman said. “Every agency — whether it’s a UN agency or a government agency, has their own turf, their own responsibility,” Lieberman said. “Livestock people will say ‘Sorry, wildlife? It’s not my agency.’   

“And the wildlife agencies say ‘Well, I’m sorry. We don’t do livestock,’” she added — even though new diseases typically require a jump from wild animals to livestock.  

A similar blind spot characterizes the idea that preparedness measures — like vaccine research — can substitute for the biosecurity hazard of urban wildlife markets, Lieberman said.  

“It’s both, but it can’t just be preparedness. It’s a lot cheaper to prevent something than to them to eradicate,” she said. “We know that vaccines need to be produced quickly, right? But it’s a lot cheaper not to have to need the vaccine in the first place.