Raccoon canine DNA from Wuhan market helps the concept COVID got here from animals

Scientists discovered the strongest proof but that the coronavirus SARS-CoV-2 leapt from animals to people at a market in China, fueling the first reported outbreak of COVID-19. The genetic information was uploaded to a public database after which promptly eliminated on the request of the Chinese language crew that first shared it. 

A world crew of scientists reported that swab samples taken in and across the stalls at Huanan Seafood Wholesale Market in early 2020 contained SARS-CoV-2 genetic sequences commingled with the DNA of widespread raccoon canines (Nyctereutes procyonoides). The Atlantic (opens in new tab) first reported the findings on Friday (March 17). Raccoon canines, a fox relative with darkish blotches round their eyes, are recognized to have the ability to carry and transmit the coronavirus, The New York Times reported (opens in new tab)

Given when and the way the swab samples have been collected, and the truth that the virus cannot persist indefinitely within the surroundings and not using a host, the evaluation means that raccoon canines contaminated with SARS-CoV-2 might have shedding infectious virus whereas they have been being illegally traded on the market in December 2019, the crew concluded. 

The evaluation, which isn’t but full and has not but been revealed, can not positively show that contaminated raccoon canines have been current on the market. And if the animals have been contaminated, the analysis can not present how they caught the virus or how the virus unfold from there.

Associated: Will we ever find COVID-19’s ‘Patient Zero?’ 

Nevertheless, the presence of SARS-CoV-2 and raccoon canine genetic materials in the very same swab samples not less than means that contaminated wild animals have been on the market, and thus, had the potential to unfold the virus, the scientists mentioned. 

“This can be a actually sturdy indication that animals on the market have been contaminated,” Angela Rasmussen (opens in new tab), a  virologist concerned within the analysis, informed The Atlantic. “There’s actually no different clarification that makes any sense.”

The newly-analyzed genetic sequences have been uploaded earlier this month to GISAID, an open-access genomic database, by researchers affiliated with China’s Middle for Illness Management and Prevention (CDC), based on The Atlantic. Evolutionary biologist Florence Débarre (opens in new tab) noticed that the uncooked sequence information had been shared and alerted different researchers.

Simply hours after downloading the information 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 canine DNA commingled with SARS-CoV-2 genetic materials. The crew introduced their findings Tuesday (March 14) to the World Well being Group’s (WHO) Scientific Advisory Group for the Origins of Novel Pathogens, The Atlantic reported. 


Again in February 2020, the Chinese language CDC researchers had analyzed the identical information however revealed solely a part of it, making no point out of raccoon canine DNA. In a preprint, they reported finding an “abundance” of Homo sapien DNA (opens in new tab) related to SARS-CoV-2, which they mentioned steered contaminated people carried the virus into the market. They could not discover any proof pointing to an animal host in that information, they wrote. However graphs in the identical preprint contradicted that declare, displaying 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 assembly, the Chinese language analysis group’s 2020 preprint went into evaluate at a peer-reviewed Nature Analysis journal, suggesting a brand new model will quickly be revealed. 

The crew that introduced their findings to the WHO initially reached out to the Chinese language researchers to collaborate on the analysis, however shortly after they made contact, the genetic sequences have been faraway from GISAID, The New York Instances reported.  

GISAID famous that the sequences have been eliminated on the request of the submitter, Science reported (opens in new tab). When requested why the sequences weren’t shared sooner, the previous head of the China CDC George Gao informed Science that the information was “[n]othing new. It had been recognized there was unlawful animal dealing and because of this the market was instantly shut down.” When requested why GISAID took down the sequence information, Gao didn’t reply, however indicated that the information didn’t resolve the question of SARS-CoV-2’s origin, which he mentioned is “nonetheless scientific and open.”

Critics of the widely-supported spillover speculation — that SARS-CoV-2 jumped from animals to people — might in the end need extra conclusive proof than analysis can supply, Joel Wertheim (opens in new tab), an evolutionary biologist concerned within the evaluation, informed Science.

“You may’t observe the zoonotic transmission of a novel virus from animals to people,” he mentioned. “We’re simply by no means going to get that degree of information.”


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