A new study has bolstered the theory that the coronavirus emerged from the wild.

Two new studies provide further evidence that the coronavirus pandemic originated in a market in Wuhan, China, where live animals were sold – further bolstering the theory that the virus emerged in the wild rather than escaping from a Chinese lab. .

Research published online Tuesday by the journal Science suggests that the Huanan seafood wholesale market was likely the initial epicenter of the scourge that has now killed about 6.4 million people worldwide. The scientists concluded that the virus that causes COVID-19, SARS-CoV-2, likely spread from animals to humans at two separate times.

“All this evidence tells us the same thing: It points to this particular market in the middle of Wuhan,” said Christian Anderson, a professor in the Department of Immunology and Microbiology at Scripps Research and a study author. “I was pretty convinced the lab itself was leaking until we looked at it very carefully and looked at it very closely.”

In one the studyIncorporating data collected by Chinese scientists, evolutionary biologist Michael Woroby of the University of Arizona and his colleagues mapped the locations of more than 150 of the first reported COVID-19 cases since December 2019. Used tools. 2020 using data from a social media app that created a channel for people with COVID-19 to get help.

“Of all the places where the initial cases could have been, where did they live? And it turned out when we were able to look at it, it was an unusual pattern where the highest density of cases was in that market,” he asked. Very close and very focused,” Wrooby said at a press briefing. “The important thing is that this applies to all cases in December and also to cases that have nothing to do with the market … and this is an indication that the virus began to spread among people who worked in the market. But then it started spreading in the local community.”

Andersen said they also found clusters of cases within the market, “and the clustering is very, very specific in certain parts of the market” where they now know people are selling wildlife, such as raccoons. Dogs, which are susceptible to corona virus infection. .

I Other studies, the scientists analyzed the genomic diversity of the virus inside and outside of China starting with the genome of the initial sample in December 2019 and extending through mid-February 2020. They found that two lineages — A and B — marked the start of the pandemic in Wuhan. Study author Joel Wertheim, an expert in viral evolution at the University of California, San Diego, pointed out that lineage A is genetically more similar to the bat coronavirus, but lineage B appears to be more common in humans, particularly in the market. I have already started to spread.

“Now I realize it seems like I just said that a once-in-a-generation event happened twice in a short space of time,” Wertheim said. But certain conditions were in place – such as people and animals living in close proximity and a virus that can spread from animals to humans and from person to person. So “barriers to spillover have been reduced to such an extent that we believe that, in fact, multiple introductions should be expected,” he said.

Many scientists believe in viruses. Jumped from bats to humans.either directly or through another animal. But in June, the World Health Organization recommended a thorough investigation into whether the laboratory could be responsible for the accident. Critics said the WHO was too quick to reject the lab leak theory.

“Have we disproved the lab leak theory? No, we haven’t,” Anderson said. “But I think what’s really important here is that there are possible scenarios and there are plausible scenarios and it’s really important to understand that possible doesn’t necessarily mean unlikely.”

The origins of the pandemic are controversial. Some scientists believe that a lab leak is more likely and others are open to both possibilities. But Matthew Aliotta, a researcher at the University of Minnesota’s College of Veterinary Medicine, opined that the pair of studies “is kind of a comfortable, hopefully, leaky hypothesis in the lab.”

“These two studies really provide compelling evidence for the natural-origin hypothesis,” said Aliotta, who was not involved in either study. Since it’s impossible to sample an animal on the market, “it’s probably as close to a smoking gun as you can get.”


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