An international team of virus experts said Friday the 17th they had found genetic data from a market Wuhanin China, call the origin of the Covid19 pandemic Raccoon dogs for sale on site.
They explained that the evidence indicates that the Coronavirusthe worst in a century could have been triggered by an infected animal trafficked through the illegal wildlife trade.
The genetic data was extracted from samples taken in and around the Huanan Seafood Wholesale Market in Wuham in January 2020, shortly after Chinese authorities closed the market on suspicion it was linked to an outbreak of a new virus .
The Huanan Seafood Wholesale Market in Wuham: where the coronavirus spread Photo: Dake Kang/AP Photo
By that time, the animals had already been removed, but researchers cleaned walls, floors, metal cages, and carts that were often used to transport animal cages.
In samples that tested positive for the coronavirus, the international team of researchers found genetic material from animals, including large amounts, that was compatible with the raccoon dog, three scientists involved in the analysis told The New York Times.
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Mixing genetic material from the virus and the animal does not prove that a raccoon dog itself was infected. And even if a raccoon dog were infected, it would not be clear whether the animal transmitted the virus to humans. Another animal could have transmitted the virus to humans, or someone infected with the virus could have transmitted the virus to a raccoon dog.
The analysis found that raccoon dogs friendly foxlike animals known to be able to transmit the coronavirus deposited genetic signatures in the same place where genetic material of the virus was left, the three scientists said. That evidence, they said, was consistent with a scenario in which the virus had spread from a wild animal to humans.
A report with the full details of the international research team’s findings has yet to be released. His analysis was first published by The Atlantic magazine.
Security guards stand at the entrance of the Wuhan Institute of Virology during a visit by a World Health Organization (WHO) team in February 2020 Photo: Thomas Peter/Portal
In recent weeks, the lab leak theory, which suggests the coronavirus emerged from a research lab in Wuhan, has gained traction thanks to a new intelligence assessment by the US Department of Energy and hearings led by the new Republican leadership in the House of Representatives.
However, market genetic data offers some of the most tangible evidence of how the virus may have spread from wild animals to humans outside of a laboratory. It also suggests that Chinese scientists have presented an incomplete account of the evidence that could provide details on how the virus is spreading in the Huanan market.
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Jeremy Kamil, a virologist at Louisiana State University’s Shreveport Center for Health Sciences who was not involved in the study, said the results showed that “market samples containing early Covid strains were contaminated with DNA readouts from wildlife.” .
Kamil said there was no conclusive evidence that an infected animal caused the pandemic. But, he said, “it really paints a vivid picture of the risks of the illegal pet trade.”
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Chinese scientists published a study in February 2022 analyzing the same market samples. That study reported that the samples were positive for the coronavirus, but suggested the virus came from infected people who shopped or worked at the market, rather than animals being sold there.
At one point, the same researchers, including some associated with the Chinese Center for Disease Control and Prevention, published the raw data of material collected across the market in GISAID, an international archive of viral genetic sequences.
On March 4, Florence Débarre, an evolutionary biologist at France’s National Center for Scientific Research, was searching this database for information about the Huanan market when, as she said in an interview, she noticed that more sequences than usual were popping up. Initially confused as to whether they contained new data, Débarre put them aside, only to log back in last week to find that they contained a treasure trove of raw data.
Virus experts have been waiting for the raw market sequence data since learning of its existence in the February 2022 Chinese report of origin.
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As the WHO traveled to China to investigate the origins of Covid19, Peter Ben Embarek said he was concerned about biosafety standards at a lab near the market where the first human cases were discovered. Photo by Ng Han Guan/AP Photo
An international team including Michael Worobey, an evolutionary biologist at the University of Arizona; Kristian Andersen, a virologist at the Scripps Research Institute in California; and Edward Holmes, a biologist at the University of Sydney began researching the new genetic data last week.
One sample in particular caught his eye. It was taken from a cart attached to a specific stall at the Huanan market that Holmes visited in 2014, scientists involved in the analysis said. Holmes discovered that this pen contained caged raccoon dogs on top of a separate cage with birds, just the kind of environment conducive to the transmission of new viruses.
The research team found that the swab taken from a car in early 2020 contained genetic material from the virus and a raccoon dog.
“We were able to determine relatively quickly that at least one of these samples contained a lot of raccoon dog nucleic acid in addition to the virus nucleic acid,” says Stephen Goldstein, a virologist at the University of Utah who worked on the study. new analysis. (Nucleic acids are the chemical building blocks that carry genetic information.)
After coming across the new data, the international team approached the Chinese researchers who uploaded the files to the internet with an offer to collaborate while respecting the rules of the online repository, scientists involved in the new analysis said. After that, the sequences from GISAID disappeared.
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It is unclear who removed them or why they were removed. Débarre said the research team is looking for more data, including some from market samples that have never been released. “What’s important is that there’s more data,” she said.
Scientists involved in the analysis said some of the samples also contained genetic material from other animals and humans. Angela Rasmussen, a virologist at the Vaccines and Infectious Diseases Organization at the University of Saskatchewan in Canada who worked on the analysis, said human genetic material is expected as people shop and work there and that the cases of Covid are in humans increase the market.
Goldstein also warned that “we do not have an infected animal and cannot definitively prove that there was an infected animal at this location.” The genetic material of the virus is stable enough, he said, and it’s not clear when exactly it was launched. He said the team was still analyzing the data and that he did not intend to release his analysis until a report was released.
“But,” he said, “as the animals on the market have not been sampled at this time, this is the best we can hope for.”