COVID-19 researchers find clues to animal origins in Wuhan market, possible link 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 they offered new clues that may point to an animal origin for the COVID-19 pandemic.

The call comes after a group of scientists outside China analyzed the genetic sequences of SARS-CoV-2 viruses that were originally published late last month in the Global Sharing Initiative database. data on avian influenza (GISAID) by the Chinese 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 animal market in Wuhan, which investigations by US and Chinese authorities had pointed to as a potential early epicenter of the outbreak.

Analysis of these samples found “molecular evidence” of animals like raccoon dogs in the market mixed with swabs from the same locations that revealed shedding of the virus itself in the market.

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

File photo of a raccoon dog

ARTERRA Group/Universal Images via Getty Images

“We must clarify that the virus has not been identified in any animal in the market or in samples from animals in the market, nor have we found the animals that have infected humans. This provides clues This provides clues to help understand what may have happened,” WHO’s Maria Van Kerkhove told reporters on Friday.

The new data prompted a meeting on Tuesday of the WHO’s Scientific Advisory Group on the Origins of New Pathogens for international scientists to present their analysis, as well as with the Chinese CDC researchers who originally published the data.

It’s unclear why the records disappeared from the GISAID database after they were released last month, or why Chinese researchers waited three years to release the data.

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

Researchers from China’s CDC published a preprint last year, which is now ‘under review’, which concluded that the Huanan market ‘may have acted as an amplifier’ for the spread of the virus introduced into the market. by humans.

“GISAID told us that China CDC data is updated and expanded. But again, we asked the Chinese CDC directly to make this data available in full. And so it remains absolutely fundamental,” Van Kerkhove said.

George Gao, the lead author of the preprint and former director of China’s CDC, played down the significance of the new analysis to Science magazine. Gao said it “was known that there was an illegal trade in animals and that’s why the market was immediately shut down.”

Gao declined to comment to CBS News on why the footage was originally posted and then disappeared, referring the comments to GISAID.

GISAID denied in a statement that it deleted records from its database. The data “may from time to time become temporarily invisible” when revisions to improve or correct the data are needed, GISAID said.

“To continuously improve the quality of data recordings, data contributors frequently update their recordings, for example, when higher resolution footage or additional metadata becomes available, or when verification is needed,” a said a GISAID representative in an email.

Questions are also unanswered about the new analysis, which was first reported by The Atlantic. For example, Van Kerkhove declined to elaborate on additional details about how and what other animals were identified in the sequencing analysis, deferring comments to the researchers.

French scientist Florence Débarre, named by The Atlantic as the researcher who originally spotted the footage, did not respond to a request for comment.

On TwitterDébarre wrote that they “do not plan to release the results until our report is complete. Completing the report is my current priority.”

But even if Chinese health authorities republish the footage they removed from GISAID, Van Kerkhove warned that much more research would be needed to understand whether the origins of COVID-19 could be conclusively linked to animals sold in the market. .

“We have repeatedly requested studies to be done in other markets in Wuhan and Hubei and throughout China. We have repeatedly requested studies to trace these animals back to their farms of origin so that we can go back in time and actually look to see where the animals came from and if any tests were done,” Van Kerkhove said.

While scientists have discovered evidence that suggests COVID-19 likely had zoonotic origins – that the virus emerged from animals that infected humans, like previous viruses – some elements of the US intelligence community concluded that it is plausible that the pandemic originated from a laboratory accident.

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

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

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

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