New genetic analysis of animals farmed at the 2019 Wuhan market may help shed light on origins of COVID-19

An elderly patient receives an intravenous drip while on a ventilator in a hallway at an emergency ward in Beijing, Thursday, Jan. 5, 2023. Credit: AP Photo/Andy Wong, File
Scientists investigating the origins of COVID-19 are zeroing in on a list of animals that may have played a role in the disease’s spread to humans, in the hope that the effort will pinpoint the source of the infection.
Researchers analyzed genetic material from the Chinese market where the first cases were identified and identified raccoon dogs, civet cats, and bamboo rats as the most likely animals. Scientists believe that infected animals were first brought into the Wuhan market in late November 2019, which sparked the pandemic.
Michael Worobey, one of the authors of the new study, said they found out which animal variants may have transmitted the coronavirus to humans, which could help pinpoint where the virus commonly circulates among animals – its natural hosts.
“In the case of the raccoon dogs, for example, we can prove that they were a subspecies that are common in southern China,” says Worobey, an evolutionary biologist at the University of Arizona. Knowing that could help researchers figure out where the animals came from and where they were sold. Scientists might then start sampling bats in the area, which are known natural hosts for SARS and other related coronaviruses.


Nurse Rachel Chamberlin, right, of Cornish, New Hampshire, comes out of an isolation room where Fred Rutherford, left, of Claremont, New Hampshire, is recovering from COVID-19, Monday, Jan. 3, 2022, at Dartmouth-Hitchcock Medical Center in Lebanon, New Hampshire. Credit: AP Photo/Steven Senne, File
The study supports the idea that COVID-19 originated in animals, but does not resolve the polarized political debate over whether the virus emerged in a Chinese lab.
Mark Woolhouse, professor of infectious diseases at the University of Edinburgh, said the new genetic analysis suggested the pandemic’s “evolutionary roots lie in the marketplace” and that it was highly unlikely that COVID-19 was infecting people before it was identified at the South China market.
“This is an important finding and it does turn the tide in favor of the animal origin hypothesis,” said Woolhouse, who was not involved in the study, “but it’s not conclusive.”
A group of experts led by the World Health Organization concluded in 2021 that the virus likely spread from animals to humans and that a laboratory leak was “highly unlikely.” WHO Director-General Tedros Adhanom Ghebreyesus later said it was “premature” to rule out a lab leak.


People check their rapid COVID-19 test results outside a testing site on Manhattan’s Lower East Side in New York, Dec. 21, 2021. Credit: AP Photo/Brittainy Newman, File
An Associated Press investigation in April found that the investigation into the origins of the new coronavirus in China has been hampered by political disputes and missed opportunities by local and global health officials to narrow the possibilities.
Scientists say we may never know where exactly the virus came from.
In a new study published Thursday in the journal Cell, scientists from Europe, the United States and Australia analyzed data previously released by experts from the Chinese Center for Disease Control and Prevention, including 800 samples of genetic material collected by Chinese workers at the Huanan Seafood Market on Jan. 1, 2020, the day after Wuhan city authorities first issued a warning about the unknown respiratory virus.
Chinese scientists published the genetic sequence they found last year but were unable to identify which animals may have infected the new coronavirus. In the new analysis, the researchers used a technique that can identify specific organisms from any mixture of genetic material collected from the environment.


A mall employee receives a swab test for COVID-19 during the opening of Paragon shopping mall in Bangkok, Thailand, Wednesday, Sept. 1, 2021. Credit: AP Photo/Sakchai Lalit, File
Worobey said the information provides a “snapshot of what was in the market before the pandemic began,” and genetic analyses such as theirs “help fill in the blanks about how the virus first began to spread.”
Woolhouse said the new research was significant but left some important questions unanswered.
“There’s no question that COVID-19 was circulating in that market where there were a lot of animals,” he said. “It leaves open the question of how it got there in the first place.”
Further information: Genetic Tracking of Wildlife and Viruses in Markets at the Epicenter of the COVID-19 Pandemic, Cell (2024). DOI: 10.1016/j.cell.2024.08.010. www.cell.com/cell/fulltext/S0092-8674(24)00901-2
Journal information: Cell
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