Raccoon dog DNA from Wuhan market supports the idea that COVID came from animals

photo shows a common raccoon dog, which looks like a super fluffy raccoon, peering out from behind a fallen log in the woods

The common raccoon dog is an animal related to foxes. (Image credit: Edwin_Butter via Getty Images)

Scientists found the strongest evidence yet that the coronavirus SARS-CoV-2 leapt from animals to humans at a market in China, fueling the first reported outbreak of COVID-19. The genetic data was uploaded to a public database and then promptly removed at the request of the Chinese team that first shared it.

An international team of scientists reported that swab samples taken in and around the stalls at Huanan Seafood Wholesale Market in early 2020 contained SARS-CoV-2 genetic sequences commingled with the DNA of common raccoon dogs (Nyctereutes procyonoides). The Atlantic (opens in new tab) first reported the findings on Friday (March 17). Raccoon dogs, a fox relative with dark blotches around their eyes, are known to be able to carry and transmit the coronavirus, The New York Times reported (opens in new tab).

Given when and how the swab samples were collected, and the fact that the virus can't persist indefinitely in the environment without a host, the analysis suggests that raccoon dogs infected with SARS-CoV-2 may have shedding infectious virus while they were being illegally traded at the market in December 2019, the team concluded.

The analysis, which is not yet complete and has not yet been published, cannot definitely prove that infected raccoon dogs were present at the market. And if the animals were infected, the research cannot show how they caught the virus or how the virus spread from there.

However, the presence of SARS-CoV-2 and raccoon dog genetic material in the exact same swab samples at least suggests that infected wild animals were at the market, and thus, had the potential to spread the virus, the scientists said.

"This is a really strong indication that animals at the market were infected," Angela Rasmussen (opens in new tab), a virologist involved in the research, told The Atlantic. "There's really no other explanation that makes any sense."

The newly-analyzed genetic sequences were uploaded earlier this month to GISAID, an open-access genomic database, by researchers affiliated with China's Center for Disease Control and Prevention (CDC), according to The Atlantic. Evolutionary biologist Florence Débarre (opens in new tab) spotted that the raw sequence data had been shared and alerted other researchers.

Just hours after downloading the data from GISAID, scientists led by Kristian Andersen (opens in new tab), Edward Holmes (opens in new tab), and Michael Worobey (opens in new tab) uncovered the raccoon dog DNA commingled with SARS-CoV-2 genetic material. The team presented their findings Tuesday (March 14) to the World Health Organization's (WHO) Scientific Advisory Group for the Origins of Novel Pathogens, The Atlantic reported.

—Wuhan lab says there's no way coronavirus originated there. Here's the science.

—These viruses are the most likely to trigger the next pandemic, according to scientists

Back in February 2020, the Chinese CDC researchers had analyzed the same data but published only part of it, making no mention of raccoon dog DNA. In a preprint, they reported finding an "abundance" of Homo sapien DNA (opens in new tab) associated with SARS-CoV-2, which they said suggested infected humans carried the virus into the market. They couldn't find any evidence pointing to an animal host in that data, they wrote. But graphs in the same preprint contradicted that claim, showing animal DNA had been found mixed up with SARS-CoV-2 (opens in new tab), Science first reported in 2022.

Shortly after Tuesday's WHO meeting, the Chinese research group's 2020 preprint went into review at a peer-reviewed Nature Research journal, suggesting a new version will soon be published.

The team that presented their findings to the WHO initially reached out to the Chinese researchers to collaborate on the research, but shortly after they made contact, the genetic sequences were removed from GISAID, The New York Times reported.

GISAID noted that the sequences were removed at the request of the submitter, Science reported (opens in new tab). When asked why the sequences weren't shared sooner, the former head of the China CDC George Gao told Science that the data was "[n]othing new. It had been known there was illegal animal dealing and this is why the market was immediately shut down." When asked why GISAID took down the sequence data, Gao did not reply, but indicated that the data did not resolve the question of SARS-CoV-2's origin, which he said is "still scientific and open."

Critics of the widely-supported spillover hypothesis — that SARS-CoV-2 jumped from animals to humans — may ultimately want more conclusive evidence than research can offer, Joel Wertheim (opens in new tab), an evolutionary biologist involved in the analysis, told Science.

"You can't observe the zoonotic transmission of a novel virus from animals to humans," he said. "We're just never going to get that level of data."

Nicoletta Lanese is the health channel editor at Live Science and was previously a news editor and staff writer at the site. She holds a graduate certificate in science communication from UC Santa Cruz and degrees in neuroscience and dance from the University of Florida. Her work has appeared in The Scientist, Science News, the Mercury News, Mongabay and Stanford Medicine Magazine, among other outlets. Based in NYC, she also remains heavily involved in dance and performs in local choreographers' work.

6 Comments Comment from the forums

7%solution

Clearly, the Chinese government covered up any covid virus DNA evidence that emerged early during the pandemic. They wanted to preserve the theory that the virus developed elsewhere, possibly not even in China. Well, that backfired when several scientists put pressure on the Chinese government by claiming the virus could have escaped the infamous virology lab in Wuhan. It was even suggested the virus could've been engineered. Now the Chinese government has an incentive to re-release all the data they tried to bury 3 years ago. It's better for China's image if the wet market theory prevails than standing accused of a lab leak. Funny how that works.
Reply
Debed

What if a chinese scientist, working in the Wuhan lab, got infected, went to the wet market to get some chow, sneezed, then went their merry way.
And that made the poor little fella infected and that was that.
Reply
7%solution

Unlikely. Scientists working in virology labs are super extra careful not to contaminate the outside world. Of course, that doesn't exclude the lab leak theory. However, earlier studies concluded it's very unlikely the virus originated in a lab, because there's nothing in the pathogen's DNA that suggests tampering. The animal source theory has lots of precedent with other pandemics, and is therefore the most likely scenario.
Reply
Debed

7%solution said:
Unlikely. Scientists working in virology labs are super extra careful not to contaminate the outside world. Of course, that doesn't exclude the lab leak theory. However, earlier studies concluded it's very unlikely the virus originated in a lab, because there's nothing in the pathogen's DNA that suggests tampering. The animal source theory has lots of precedent with other pandemics, and is therefore the most likely scenario.

And yet, the lab in question had already gotten remarks on its lax security.
Another peculiar aspect was the existence of 4 positive molecules after one another, which should not appear. Positive attracts negative.
There are viruses that has 2 positive molecules after one another, but we haven’t seen anyone with 3, and much less 4.
Reply
leninsballs123

Mystery respiratory illnesses were already becoming a problem in the USA in the summer of 2019. Covid could have been released from a lab—possibly Fort Detrick in Maryland, which is a short drive from the nursing home outbreak I've linked to, and which was shut down right after the events I've mentioned here—all several months before the pandemic officially began. The Chinese have one of the best health care systems on Earth, which is probably why they were the first ones to identify covid as a serious problem. As Che said: "It's not my fault reality has a Marxist bias."
Reply
7%solution

Debed said:
And yet, the lab in question had already gotten remarks on its lax security.
Another peculiar aspect was the existence of 4 positive molecules after one another, which should not appear. Positive attracts negative.
There are viruses that has 2 positive molecules after one another, but we haven’t seen anyone with 3, and much less 4.
No doubt, the lab leak theory is still alive. However, the quick and merciless conclusion by many westerners that the Chinese are not running a tight ship when it comes to protecting the population from disasters, is rooted in some politically, and possibly ethnically based ill will. There's a lot of China bashing going on right now. The lab leak theory fits perfectly into this trend. As tantalizing as the lab leak idea may be, I have not seen hard evidence that it has legs. It's possible, but so is the jump from animals. Judging by what we know from past pandemics, animals are suspects #1. Lab leaks have happened in the past, but statistically to a much lesser degree. That means, until the animal theory has been thoroughly discounted, the potential lab leak is in the backseat. Granted, the Chinese have potentially incriminated themselves by seemingly playing games with early SARS 2 research data. However, that's what the Chinese government typically does. They're excessively image conscious. They avoid getting caught with their pants down at almost any cost. In itself this doesn't prove anything. It could point to a cover up within a cover up. However, this is only assumption potentially combined with a dose of prejudice. That doesn't mean we should forget about the lab leak theory. Nevertheless, in absence of conclusive evidence it seems prudent to focus on the biggest target first. It took nearly 2 decades to source the SARS 1 virus with any kind of certainty. What's the rush to pin the SARS 2 virus on anyone or anything? That's the question I always come up with.
Reply

Show more comments