In this photo from January 31, 2021, a security guard signals to reporters to clear the road after a convoy carrying the World Health Organization team entered the Huanan Seafood Market. New research has found that the Huanan Food Market in Wuhan, China, served as the epicenter of the SARS-CoV-2 outbreak in late 2019, according to a study co-authored by a researcher from the University of China. ‘Utah. (Ng Han Guan, Associated Press)
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SALT LAKE CITY – New research shows that the Huanan Seafood Market in Wuhan, China, served as the epicenter of the SARS-CoV-2 outbreak in late 2019, despite previous beliefs that the pandemic had started elsewhere.
“This article…clearly shows that the first place where this virus was circulating was the area immediately surrounding Huanan Market. Within Huanan Market, the virus clearly emanated from the section of the market that sold live animals,” said said Stephen Goldstein. , a virologist and postdoctoral researcher at the University of Utah School of Medicine, said Tuesday.
Goldstein was co-author of the international study published Tuesday in Scientific journal.
While early reports indicated the virus originated in the market, later reports speculated that it escaped from a Chinese lab.
Goldstein and other researchers found that two versions of SARS-CoV-2, the virus that causes COVID-19, were geographically associated with the market. Previously, only one variant was supposed to have been associated with the market.
The researchers estimate that a total of eight variants have been introduced to humans on the market, but only two – called variants A and B – have caused human infections.
Goldstein said the research disproves the idea that the virus came from a Chinese lab. As of December 2019, the virus was only circulating in the area immediately surrounding the market, which is “fairly far” from the Wuhan Institute of Virology which was suspected to be the source, according to Goldstein.
“So the idea that the virus was quietly circulating all over Wuhan and then had just been introduced to the market, where there was a super spread event – we are able to refute that possibility,” he said. declared.
Animals susceptible to SARS-CoV-2 have been sold in the Wuhan market, “including in November 2019, when the accompanying document estimates that the first human infections occurred,” Goldstein said.
These animals included raccoon dogs, badgers, hares, rabbits and foxes, all of which are known to be susceptible to infection. But researchers believe these animals served as intermediate hosts for the virus and likely picked it up from infected bats.
“Humans don’t have particularly intense contact with bats. We have much more intense contact with these potential intermediate hosts in places like live animal markets,” he said.
But little is known about how bats infected other animals – or about the “upstream” origins of the virus. Further research is needed to understand how to limit the ability of viruses to cross between species.
Researchers were able to reconstruct the market using information from a Chinese report, data from the World Health Organization’s Origins Mission, and market company records. They identified 10 to 15 stalls in the market that sold live animals, according to Goldstein.
Five virus-positive environmental samples from the market were from a stall, items associated with the live animal trade, including cages, carts and a drain grid under the stall. Those samples were clustered in the southwest corner of the market, and the closer a sample was to a live animal stall, the more likely it was to test positive for the virus, Goldstein said.
While the results of this paper and a companion study provide a “high degree of confidence” that the first human infections occurred in the animal market, Goldstein said, the events that led to the market outbreak have not yet been understood.
Researchers don’t know if there were early infections among animal dealers or people who worked on cattle farms. These clues could lead to insights into the kinds of regulations in the animal trade that could reduce the risk of future spreads of animal viruses to humans, Goldstein said.
“As for the type of measures that could be taken (…) to minimize the fallout, I would leave that mainly to experts in public health and animal ecology, experts in the live animal trade, the live animal trade in the world, especially in China and Southeast Asia, to prescribe certain measures that could do these things,” he said.
Some potential solutions include surveillance testing of animals on farms and farm workers who might be exposed to viruses; removing infected animals from the supply chain; and, any kind of regulation of live animal sales in cities, according to Goldstein.