Data Links COVID to Wuhan Market Raccoon Dogs

Genetic data found in a Wuhan, China seafood market shortly after it was shut down in early January 2020 has linked the coronavirus with raccoon dogs, a fox-related animal that was being sold there at the time, according to a new report from a team of international virus experts.

The swabs were taken around the Huanan Seafood Wholesale Market after authorities in China ordered it closed because they suspected it was connected to the then-new coronavirus outbreak, reports The New York Times.

The animals had already been removed from the market when the tests were taken but their cages were tested, as were walls, floors, and the carts that were used to transport the cages.

In the samples that came back positive for the coronavirus, the research team also found genetic material that belonged to animals.

Scientists involved in the analysis, first reported by The Atlantic, said large amounts of that data matched the raccoon dogs.

They stressed that as the genetic material from the coronavirus and the animals were jumbled, it doesn't prove conclusively that a raccoon dog was infected, and even if it was, that it spread the virus to people, as another animal could have spread the disease to people, who then gave it to the raccoon dog.

But raccoon dogs are known to be able to transmit the coronavirus and as they deposited genetic signatures in the same places where the virus material was left, it shows consistencies with what would be a scenario in which humans were infected by wild animals, the report said.

The new evidence is being released just weeks after an intelligence assessment from the U.S. Department of Energy pointed to the theory that the COVID-19 pandemic originated from a leak at the Wuhan Institute of Virology.

However, it is also being considered as the first tangible evidence concerning how the virus could have spread to people through wild animals, and suggest that scientists in China may have not given a complete accounting of evidence about how the virus spread at the seafood market, The Times noted.

In 2022, Chinese scientists released a study that looked at the same market samples and reported they were positive for coronavirus but suggested that the traces came from humans who were infected and had been at the market, rather than from the animals that had been sold there.

The same researchers, who included some from the Chinese Center for Disease Control and Prevention, posted the raw data from the market swabs to GISAID, an international repository of genetic sequences of viruses.

On March 4, Florence Débarre, an evolutionary biologist at the French National Center for Scientific Research was searching the database for information on the Huanan seafood market when she noticed new data sequences. She logged in again last week and found raw sequence data that virus experts had been seeking since the Chinese 2022 report.

She said she alerted other scientists and the international team, also 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 working with the data last week.

One sample, taken from a cart linked to a specific stall at the market, Holmes found, had contained caged raccoon dogs that were sitting on top of a separate cage holding birds.

"We were able to figure out relatively quickly that at least in one of these samples, there was a lot of raccoon dog nucleic acid, along with virus nucleic acid," said Dr. Stephen Goldstein, a University of Utah virologist who worked on the new analysis.

The scientists reached out to the Chinese researchers who had uploaded the files, and after that, the sequences disappeared from GISAID. It's not clear who removed them or why.

Scientists who were involved with the analysis, meanwhile, said some samples contained genetic material from other animals and humans, which was to be expected.

Goldstein further cautioned that as researchers don't have an infected animal and can't prove definitely there was one at that stall, genetic material is stable enough for a determination, even if it's not clear when it was left behind at the market.

He added that the team is still analyzing the available data and had not intended for it to become public before an official report is released.