- Victoria Gill
- BBC science correspondent
image source,Reuters
Scientists said the initial outbreak of the new coronavirus was “very closely related” to the sale of live animals at the Huanan Seafood Market in Wuhan.
Scientists say there is “compelling evidence” that the Huanan seafood and wildlife market in Wuhan is the epicenter of the coronavirus outbreak.
Two scientifically peer-reviewed studies published July 26 on the website of the journal Science re-examined information on the initial outbreak of the new coronavirus in the Chinese city of Wuhan.
It suggests that two variants were introduced to humans in November or early December 2019.
Together, the evidence paints a picture of the emergence of the new coronavirus in live mammals sold in the South China market in late 2019, the researchers said. In two separate “spillover events,” they said, the virus was transmitted to people working or shopping at the market, where people contracted the virus from animals.
One of the researchers involved, Prof David Robertson, a virologist at the University of Glasgow, told the BBC he hoped the studies would “correct the erroneous record that the virus came from the laboratory”.
Epidemic epicenter
Two years of scientific efforts to learn more about the various aspects of the new coronavirus have provided these researchers with a more solid foundation.
This allowed them to solve a key conundrum in the earliest patient data: Of the hundreds of people hospitalized with the virus in Wuhan, only about 50 had direct, traceable links to the market.
Professor Robertson said: “It’s really puzzling that most cases can’t be linked to the market. However, based on what we know now about the virus, it’s in line with what we’d expect because many people have mild symptoms, so they will Communities spread the virus to others, and severe cases have difficulty finding links to each other.”
The Covid-19 case-location study found that a large percentage of early patients had no known connection to the market, where they neither worked nor shopped, but ended up living near the market.
The study’s lead author, biologist Prof Michael Worobey of the University of Arizona, said this lends credence to the idea that the market was the epicentre of the virus outbreak: wildlife traders were the first to be infected, and “chain infection” has been caused among the residents of the community.
Professor Worobey said: “In a city of more than 3,000 square miles (about 7,770 square kilometers), the places with the highest probability of the world‘s earliest cases of infection are concentrated in areas composed of several city blocks, and the South China market It’s in it.”
The study also focused particularly on the market itself. Scientists drew fluid samples from drains and market stalls to map the locations of those who tested positive for the virus.
Professor Robertson explained: “Most positive samples are concentrated on the south-west side of the market. This is where we report the sale of animals such as raccoons.”
“So we’ve confirmed that we now know that animals that are vulnerable (to the coronavirus) were sold there in late 2019.”
lab leak says
WHO’s new crown epidemic envoy talks about the crisis of WHO’s credibility under the epidemic
Over the past two years, the search for the origin of the deadly coronavirus has gone from a scientific investigation to a toxic political debate.
There has been a heated international debate over who is responsible for the outbreak, especially among politicians in the United States and China. One of the topics was the laboratory virus leak theory, that the virus may have leaked from the Wuhan Institute of Virology.
However, Professor Stuart Neil from King’s College said this hypothesis “doesn’t explain the data”.
“Based on the sporadic evidence we have, we can now determine that this is a virus spillover event in this market.”
Many scientists agree that crowded live animal markets provide an ideal transmission hotspot for new diseases to “spill” from animals. In the year and a half before the coronavirus started, a separate study showed that nearly 50,000 animals of 38 different species were sold at the Huanan Seafood Market in Wuhan.
Professor Neal said the virus epidemic was likely the result of “unhealthy, cruel and unsanitary practices” that Chinese authorities had been warned about.
He added that focusing on finding someone in the lab to be responsible for it all is a distraction, and the big risk is that “we risk letting this happen again because we’re focusing on on the wrong question.”