COVID-19 researchers find clues to animal origin in Wuhan market, possibly linked to raccoon dogs

The World Health Organization on Friday called on Chinese health authorities to release genetic sequences of SARS-CoV-2 that recently disappeared from an international database after an analysis of the data revealed it offered new clues that could point to an animal origin for the COVID-19 pandemic.

The plea comes after a group of scientists outside China analyzed genetic sequences of SARS-CoV-2 viruses first posted late last month to the Global Initiative on Sharing Avian Influenza Data (GISAID) database by China’s Center for Disease Control and Prevention. The database is a site where scientists around the world can access and share genetic sequencing and other data.

The data comes from samples taken in early 2020 around the Huanan pet market in Wuhan, which investigations by US and Chinese authorities suggest may have been an early epicenter for the outbreak.

Analysis of those samples found “molecular evidence” of animals such as market raccoon dogs mixed with swabs from the same spots that marketed the shedding of the virus itself.

Raccoon dogs are a species susceptible to SARS-CoV-2 infection that could have potentially served as an intermediate host, transmitting the virus from bats or another source to humans. However, the samples only indicate that both raccoon dogs and the virus were present on the market; it is not direct evidence that the species was the carrier.

File photo of a raccoon dog

ARTERRA/Universal Images Group via Getty Images

“We need to make it clear that the virus has not been identified in any animal on the market or in animal samples from the market, nor have we actually found the animals infecting humans. What this does is provide clues. It gives clues to help we understand what may have happened,” the WHO’s Maria Van Kerkhove told reporters on Friday about the findings.

This new data prompted a meeting on Tuesday by the WHO’s Scientific Advisory Group on the Origin of Novel Pathogens for the international scientists to present their analysis, as well as with the Chinese CDC researchers who had initially posted the data.

It’s not clear why the data disappeared from the GISAID database after being posted last month, or why Chinese researchers waited three years to release the data.

The data was initially posted by the Chinese researchers as part of work on a paper originally released as a preprint last year.

Researchers at China’s CDC released a preprint last year, now “under review,” which concluded that the Huanan market “may have served as an amplifier” for the spread of the virus brought to humans by humans.

“We have been told by GISAID that China CDC data will be updated and expanded. But again, we have directly called on China CDC to make that data fully accessible. And so that remains absolutely fundamental,” said Van Kerkhove.

George Gao, the preprint’s lead author and former head of China’s CDC, downplayed the importance of the new analysis to the journal Science. Gao said it was “known that there was an illegal trade in animals and so the market was closed immediately.”

Gao declined to comment to CBS News about why the sequences were initially posted and then disappeared, deferring comment to GISAID.

GISAID denied in a statement that they are deleting records from their database. Data “may become temporarily invisible from time to time” when revisions are needed to improve or correct data, GISAID said.

“To continually improve the quality of data records, data contributors regularly update their records, such as when higher-resolution sequences or additional metadata become available, or when verification is required,” a GISAID representative said in an email.

Questions are also unanswered about the new analysis, which was first reported by The Atlantic. Van Kerkhove, for example, declined to provide additional details about how and what other animals were identified in the sequence analysis, deferring comment to the researchers.

French scientist Florence Débarre, named by The Atlantic as the researcher who initially saw the sequences, did not respond to a request for comment.

On Twitterwrote Débarre that they “had no intention of communicating results until our report was ready. Completing the report is my current priority.”

But even if Chinese health authorities republish the sequences they removed from GISAID, Van Kerkhove cautioned that much more research would be needed to understand whether the origins of COVID-19 could be definitively linked to animals on the planet. market are sold.

“We have repeatedly asked for studies to be done in other markets in Wuhan and Hubei and across China. We have repeatedly asked for studies to trace those animals back to their source farms so that we can go back in time and really look at to see where the animals came from and whether testing had been done,” says Van Kerkhove.

While scientists have discovered evidence suggesting COVID-19 likely had a zoonotic origin – that the virus originated from animals infecting humans, similar to previous viruses – some elements of the US intelligence community have concluded that it is plausible that the pandemic was caused by a laboratory accident.

“Based on my initial analysis of the data, I came to believe, and I still believe, that it indicates that COVID 19 was more likely the result of an accidental lab leak than the result of a natural spillover event,” the former government said. -Trump. CDC Director Dr. Robert Redfield told a hearing hosted by House Republicans earlier this month.

In an interview with CBS News on Thursday, Dr. Anthony Fauci, who helped lead the U.S. response to the pandemic, said we may never get a conclusive answer to the question of the origins of COVID.

“There’s really no definitive evidence,” he said. “We may never know exactly and definitively.”

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