A member of the World Health Organization investigative team says wildlife farms in southern China are the most likely source of the COVID-19 pandemic.
China shut down those wildlife farms in February 2020, says Peter Daszak, a disease ecologist with EcoHealth Alliance and a member of the WHO delegation that traveled to China this year. During that trip, Daszak says, the WHO team found new evidence that these wildlife farms were supplying vendors at the Huanan Seafood Wholesale Market in Wuhan with animals.
Daszak told NPR that the government response was a strong signal that the Chinese government thought those farms were the most probable pathway for a coronavirus in bats in southern China to reach humans in Wuhan.
Those wildlife farms, including ones in the Yunnan region, are part of a unique project that the Chinese government has been promoting for 20 years now.
"They take exotic animals, like civets, porcupines, pangolins, raccoon dogs and bamboo rats, and they breed them in captivity," says Daszak.
The agency is expected to release the team's investigative findings in the next two weeks. In the meantime, Daszak gave NPR a highlight of what the team figured out.
"China promoted the farming of wildlife as a way to alleviate rural populations out of poverty," Daszak says. The farms helped the government meet ambitious goals of closing the rural-urban divide, as NPR reported last year.
"It was very successful," Daszak says. "In 2016, they had 14 million people employed in wildlife farms, and it was a $70 billion industry."
Then on Feb. 24, 2020, right when the outbreak in Wuhan was winding down, the Chinese government made a complete about-face about the farms.
"What China did then was very important," Daszak says. "They put out a declaration saying that they were going to stop the farming of wildlife for food."
The government shut down the farms. "They sent out instructions to the farmers about how to safely dispose of the animals — to bury, kill or burn them — in a way that didn't spread disease."
Why would the government do this? Because, Daszak thinks, these farms could be the spot of spillover, where the coronavirus jumped from a bat into another animal and then into people. "I do think that SARS-CoV-2 first got into people in South China. It's looking that way."
First off, many farms are located in or around a southern province, Yunnan, where virologists found a bat virus that's genetically 96% similar to SARS-CoV-2, the coronavirus that causes the disease COVID-19. Second, the farms breed animals that are known to carry coronaviruses, such as civet cats and pangolins.
Finally, during the WHO's mission to China, Daszak said the team found new evidence that these farms were supplying vendors at the Huanan Seafood Wholesale Market in Wuhan, where an early outbreak of COVID-19 occurred.
The market was shut down overnight on Dec. 31, 2019, after it was linked to cases of what was then described as a mysterious pneumonia-like illness.
"There was massive transmission going on at that market for sure," says Linfa Wang, a virologist who studies bat viruses at Duke-NUS Medical School in Singapore. He's also part of the WHO investigative team. Wang says that after the outbreak at the Huanan market, Chinese scientists went there and looked for the virus.
"In the live animal section, they had many positive samples," Wang says. "They even have two samples from which they could isolate live virus."
And so Daszak and others on the WHO team believe that the wildlife farms provided a perfect conduit between a coronavirus-infected bat in Yunnan (or neighboring Myanmar) and a Wuhan animal market.
"China closes that pathway down for a reason," Daszak says. "The reason was, back in February 2020, they believed this was the most likely pathway [for the coronavirus to spread to Wuhan]. And when the WHO report comes out ... we believe it's the most likely pathway too."
The next step, says Daszak, is to figure out specifically which animal carried the virus and at which of the many wildlife farms.