A new genetic analysis of animals in the Wuhan market in 2019 may help find COVID-19’s origin

Scientists narrow down potential animal sources of COVID-19, aiming to trace the outbreak back to its origin.

Scientists searching for the origins of COVID-19 have zeroed in on a short list of animals that possibly helped spread it to people, an effort they hope could allow them to trace the outbreak back to its source.

Researchers analysed genetic material gathered from the Chinese market where the first outbreak was detected and found that the most likely animals were racoon dogs, civet cats and bamboo rats. The scientists suspect infected animals were first brought to the Wuhan market in late November 2019, which then triggered the pandemic.

Michael Worobey, one of the new study’s authors, said they found which sub-populations of animals might have transmitted the coronavirus to humans. That may help researchers pinpoint where the virus commonly circulates in animals, known as its natural reservoir.

“For example, with the racoon dogs, we can show that the racoon dogs that were (at the market) … were from a sub-species that circulates more in southern parts of China,” said Worobey, an evolutionary biologist at the University of Arizona. Knowing that might help researchers understand where those animals came from and where they were sold. Scientists might then start sampling bats in the area, which are known to be the natural reservoirs of related coronaviruses like SARS.

While the research bolsters the case that COVID-19 emerged from animals, it does not resolve the polarized and political debate over whether the virus instead emerged from a research lab in China.

Mark Woolhouse, a professor of infectious diseases at the University of Edinburgh, said the new genetic analysis suggested that the pandemic “had its evolutionary roots in the market” and that it was very unlikely COVID-19 was infecting people before it was identified at the Huanan market.

“It’s a significant finding and this does shift the dial more in favor of an animal origin," Woolhouse, who was not connected to the research, said. “But it is not conclusive.”