The World Health Organization has obtained information indicating the presence of raccoon dogs – the species some suspect of spreading COVID-19 to humans – in a Wuhan market linked to the start of the virus, officials said on Friday.
Raccoon dogs – which are known to be susceptible to COVID-19, and spread the virus to humans – are believed to have been illegally sold on the market. They could be the missing link in the chain of transmission from bats to humans, experts in the zoonotic transmission camp say.
But WHO officials on Friday cautioned against assumptions, saying that the information was an important piece of the proverbial jigsaw puzzle, “not determining what the picture shows” – and that laboratory leaks could not be ruled out.
“The more pieces that are in the right place, the more you see the picture,” said Dr. Michael Ryan, executive director of the organization’s emergency response, at a press conference, referring to the puzzle analogy.
“You’re never sure what you’re building until you make a piece in the context of all the other pieces,” he says. But “your confidence level increases as you integrate.”
There is no definitive answer
The WHO on Sunday was made aware of data from samples taken at the Huanan Seafood Market in Wuhan at the start of the pandemic, before the market was closed. The data was published to GISAID – an international research database that tracks changes in the COVID and flu virus – by officials with China’s Centers for Disease Control and Prevention in late January, but was recently retrieved, Dr. Tedros Adhanom Ghebreyesu, WHO director general, said at a news conference.
The knowledge prompted a meeting Tuesday of the WHO’s Scientific Advisory Group on the Origin of Novel Pathogens, which is investigating the origins of the virus. At the meeting, international scientists who had previously obtained the data removed and analyzed presented their findings. Chinese CDC officials also presented it, at the request of the WHO.
The new information does not provide a definitive answer about the origin of the pandemic, Ghebreyesu warned. “But every piece of data is important in moving us closer to the answer.”
All data related to studying the origin of novel viruses “must be shared with the international community,” he said. “The data could – and should – have been shared three years ago.”
The data only shows that raccoon dogs are on the market, in addition to other animals and the virus, said Maria Van Verkohove, technical lead for COVID-19 at the WHO.
While this is the first molecular evidence that animals are being sold illegally in the wet market, it is not proof that the animals – or any animals – are infected, he said. If they have, it doesn’t mean they brought the virus to the market. It may have been infected by humans, either in the market or elsewhere.
“It just tells us that more data is out there, and that data needs to be fully shared,” he said.
A February 2022 preprint article, not peer-reviewed, published by the Chinese Academy of Sciences George Gao, the former head of the country’s CDC, and a litany of other researchers from the country details 1,380 samples collected from the environment and animals at Huanan Seafood. Market in Wuhan in early 2020.
A total of 73 environmental samples were positive for COVID-19. The virus was not detected in 18 animal swabs collected there, according to the report.
‘smoking gun’
Dr. Georges Benjamin, executive director of the American Public Health Association, said fortune that the new information is “strong evidence” supporting the theory of virus transmission from animals to humans.
Evidence that “raccoon dogs, known transmitters of viruses to humans, are in the illegal wet market is the smoking gun,” Benjamin said.
Dr. Raj Rajnarayanan, assistant dean of research and associate professor at the New York Institute of Technology campus in Jonesboro, Ark., called the report a “key piece of the puzzle,” adding that it will allow virus trackers to “determine.” timeline” of evolution.
While the new information doesn’t solve the puzzle, it provides valuable hope that the puzzle can be solved, Benjamin said. “It takes research and hard science to do that. But now we have a path to finding out.”
However, not everyone agrees on the utility of such information – at least not yet. Dr. Amesh Adalja, an infectious disease specialist and senior scholar at the Johns Hopkins Center for Health Security, said fortune that the scientific community at large still does not have access to data recently pulled from international research databases by Chinese officials.
Thus, there is not “enough information to be able to say anything useful” about the raccoon dog DNA reports on the market, Adalja said. “You haven’t given any evidence yet.”
If the data is scientifically valid, “it will lend support to the consensus view that COVID-19 likely spilled from animals to humans without a laboratory accident or intentional release,” Dr. Jay Varma, chief medical officer. adviser at the New York-based think tank Kroll Institute, told fortune
But maybe the raccoon dog is nothing more than a red herring, when it comes to determining the origins of COVID, Varma cautions.
There have been anecdotal reports of “COVID or COVID-like illness” unrelated to the market occurring since November 2019—before the market’s super-spreading event in December.
These cases could signal that COVID-19 did not spread to humans from markets — or that the spill was not responsible for human COVID-1 cases.
Varma spent three years in China with the US Centers for Disease Control and Prevention, working on the problem of respiratory virus circulation in central China. He said he thinks there may have been multiple spill-overs from animals to humans in the area between October and December 2019.
Outbreaks are happening in the market, he said. But it may not start there.
Spillovers may have happened to “other people in and around Wuhan,” he said.