Researchers have determined that early Covid-19 cases are concentrated in the market among the vendors who sold these live animals and those who shopped there. They believe that two separate viruses spilled on humans were circulating in animals.
“All eight COVID-19 cases detected before December 20 were from the western part of the market where mammalian species were also sold,” the study said. The proximity to five stalls selling live or recently slaughtered animals was predictive of human cases.
“Clustering is very specific,” said research co-author Scripps Research’s Professor of Immunology and Microbiology, Christian Andersen, on Tuesday.
Another co-author, Michael Worobey, Dean of the University of Arizona’s Department of Ecology and Evolutionary Biology, said the “abnormal” patterns that emerged from the mapping of these cases were very clear.
Researchers mapped the earliest cases unrelated to the market, and Warobib said those people lived or worked in the immediate vicinity of the market.
“This started to spread to the people who worked in the market, but then the vendor went to local stores and infected the people who worked in those stores, so it started to spread to the surrounding community. It shows, “said Mr. Warobib.
According to this study, the earliest versions of the coronavirus probably came in various forms that scientists call A and B. The lineage was the result of at least two cross-species transmission events to humans.
Researchers suggest that the first animal-to-human transmission probably occurred around November 18, 2019, and that it came from strain B. They found strain B type only in people who are directly related to the South China market.
The authors believe that strain A was introduced from animals to humans within weeks or days of infection from strain B. Lineage A was found in a sample of humans who lived or stayed near the market.
“These findings suggest that it is unlikely that SARS-CoV-2 was widespread in humans before November 2019, and that SARS-CoV-2 was the first COVID-19 to infect humans. It shows that it defines a narrow time period for cases to be reported. “Studies show.” Like other coronaviruses, the appearance of SARS-CoV-2 is a common veterinary infection. May be due to. ”
Co-author Joel Wertheim, an associate professor of medicine at the University of California, San Diego, admits that such viruses are unlikely to originate from two different events.
“Now, it sounds like I said that the once-in-a-generation event happened twice in a short series. Pandemics are certainly rare, but when all the conditions are met, they become zoonotic viruses. Both human and close-to-human infections-we believe that the barriers to spillover will be lower and multiple deployments should actually be expected, “Wertheim said. increase.
Andersen said the study did not explicitly deny Labrique’s theory, but it was so convincing that it changed the mindset about the origin of the virus.
“Until we examined this very carefully and looked at it in more detail, I was convinced of the lab leak myself,” Andersen said. “Based on the data and analysis we have done on many other viruses over the last decade, we are convinced that the data actually points to this particular market.”
Mr. Warobib also thought that a lab leak was possible, but said the epidemiological predominance of market-related cases was “not a mirage.”
“It’s real,” he said. “It is not plausible that the virus was introduced by any means other than wildlife trade.”
To reduce the likelihood of a future pandemic, researchers want to be able to accurately determine which animals may have been infected first and how they were infected.
“The raw material for the zoonotic virus, which may be a pandemic, is still lurking in the wild,” Wertheim said. He believes the world needs to do a much better job to monitor and monitor potential threats to animal and other human health.
Andersen said the outbreak cannot be prevented, but cooperation among scientists around the world can be the key to the difference between a low-impact disease and one that kills millions.
“The big question we need to ask ourselves is how to detect it early and prevent it from becoming a pandemic, as it will happen the next time it happens. . “
Source: www.cnn.com
