Newly available COVID-19 origins data could point to raccoon dogs in Wuhan market, study says

Genetic material collected at a Chinese market near where the first case of COVID-19 was identified showed raccoon dog DNA mixed with the virus, suggesting the pandemic originated in animals, not laboratories, according to an international group of scientists.

Other experts have not verified the analysis, which has not yet appeared in a peer-reviewed journal. How the coronavirus began to sicken people remains uncertain. The sequence must be matched with the genetic record of the virus’s evolution, to see which came first.

“These data do not provide a definitive answer about how the pandemic started, but every piece of data is important to get closer to that answer,” said Director-General of the World Health Organization (WHO) Tedros Adhanom Ghebreyesus on Friday, when asked for comment. .

He criticized China for not sharing genetic information earlier, telling a press briefing that “this data could have been shared three years ago.”

Samples were collected in early 2020

The sample was collected from the surface of the Huanan seafood market in early 2020 in Wuhan, where the first case of COVID-19 was found in late 2019.

Tedros said the genetic sequence was recently uploaded to the world’s largest database of common viruses by scientists at China’s Centers for Disease Control and Prevention.

They were later removed, but not before a French biologist discovered the information by chance and shared it with a group of scientists outside of China studying the origins of the coronavirus.

The data showed that some of the COVID-positive samples collected from stalls known to be involved in the wildlife trade also contained the raccoon dog gene, indicating the animals were infected with the virus, according to the scientists. The analysis was first reported in The Atlantic.

After international scientists discovered the data and contacted China’s CDC, he said, the sequences were removed from the global virus database.

The researchers said they were baffled as to why data on samples collected more than three years ago had not been made public. Tedros asked China to share more COVID-19 research data.

Possible ‘zoonotic spill event’

“There’s a good chance that the animal that deposited the DNA also harbored the virus,” said Stephen Goldstein, a virologist at the University of Utah who was involved in the analysis of the data. “If you go and do environmental sampling after a zoonotic spillover event – this is basically exactly what you would expect to find.”

Ray Yip, an epidemiologist and founding member of the US Centers for Disease Control (CDC) office in China, said the findings are important, although not definitive.

“Market environmental sampling data published by the China CDC is the strongest evidence to support animal origin,” Yip told the AP in an email. They are not connected to the new analysis.

The virus has not been found in any animals

The WHO’s technical lead for COVID-19, Maria Van Kerkhove, warned that the analysis did not find the virus in any animals, nor did it find strong evidence that any animals had infected humans.

“What this gives us is a clue to help us understand what’s going on,” he said. An international group of scientists also told the WHO that they found DNA from other animals as well as raccoon dogs in samples from seafood markets, he added.

“There is molecular evidence that animals were sold in the Huanan market and this is new information,” Van Kerkhove said.

Efforts to determine the origins of the COVID-19 pandemic have been complicated by factors including a surge in human infections in the first two years of the pandemic and increasingly bitter political disputes.

It took virus experts more than a dozen years to determine the animal origin of SARS, the related virus.

It is possible that humans carry the virus to animals

Goldstein and his colleagues say the analysis is the first strong indication that there are wild animals infected with the coronavirus in the market. But it is possible that humans brought the virus to market and infected raccoon dogs, or that infected humans simply left traces of the virus near the animals.

Gao Fu, the former head of China’s CDC and lead author of the China paper, did not immediately respond to an Associated Press email seeking comment. But he told Science magazine that the sequence was “nothing new. It’s already known that there are illegal animal transactions and that’s why the market was immediately closed.”

Goldstein said his group presented its findings this week to an advisory panel appointed by the WHO to investigate the origins of COVID-19.

Mark Woolhouse, an infectious disease expert at the University of Edinburgh, said it would be important to see how the genetic sequence of raccoon dogs fits with what is known about the historical evolution of the COVID-19 virus. If the dog is shown to have COVID-19 and the virus proves to have an earlier origin than the one that infected people, “Perhaps this is evidence that we can expect that this is a spillover event in the market.”

After visiting China for several weeks to study the origins of the pandemic, the WHO published a report in 2021 that concluded that COVID-19 likely jumped to humans from animals, rejecting the possibility of laboratory origin as “unlikely”.

But the UN health body backtracked the following year, saying “crucial pieces of data” were still missing. And Tedros said all hypotheses remain on the table.

Chinese CDC scientists who previously analyzed Huanan market samples published a paper as a preprint in February showing that humans brought the virus to the market, not animals, suggesting that the virus came from somewhere else. The paper did not say whether animal genes were found in samples that tested positive.

Wuhan, the Chinese city where COVID-19 was first detected, is home to several laboratories involved in collecting and studying the coronavirus, giving rise to theories that the virus leaked from one.

In February, the Wall Street Journal reported that the US Department of Energy had assessed “with low confidence” that the virus had leaked from a laboratory. But others in the US intelligence community disagree, believing it came first from animals. Experts say the true origins of the pandemic may not be known for years — if ever.