The location of the first coronavirus infections in late 2019 in Wuhan, China, suggests the virus likely spread to humans from a market where wild and farm animals were sold and slaughtered, a committee says reading item published Thursday in the journal Science which is the latest round of the debate on the start of the pandemic.
The article, by University of Arizona evolutionary virologist Michael Worobey – an expert on the origins of viral epidemics – does not purport to answer all questions about the origins of the pandemic, nor is it likely to stifle speculation that the virus may have somehow emerged from a risky lab. research.
Worobey was open to the theory of a lab leak. He was one of 18 scientists who wrote a high-profile letter to Science in May calling for an investigation into all possible sources of the virus, including a lab accident. But he now maintains that the geographic configuration of the early cases strongly supports the hypothesis that the virus originated from an infected animal at the Huanan seafood market – an argument that will likely reignite the wider debate over the virus’s origins.
Worobey notes that more than half of the virus’s first documented illnesses were in people with a direct connection to the market, and he argues that this was not simply the result of the early attention to the market as a potential source of the virus. ‘epidemic. It concludes that the first patient known to fall ill with the virus was a market seafood vendor who became symptomatic on December 11, 2019.
This contradicts a report released earlier this year by investigators from the World Health Organization and China, who concluded that the first patient was a 41-year-old accountant unrelated to the market and fell ill on December 8. But Worobey said the accountant’s medical records reveal he visited the dentist that day to treat preserved baby teeth that needed to be extracted, but only showed symptoms of the coronavirus on December 16 and has was hospitalized six days after that.
The stealthy nature of the virus, which can spread asymptomatically, makes it very likely that the pathogen had started to spread several weeks before one of the identified cases. But Worobey said the locations and occupations of the first known patients indicate a market origin, with the virus radiating out into the city of 11 million people.
“It becomes almost impossible to explain this pattern if this epidemic didn’t start there,” Worobey said in an interview.
Geography has been at the heart of the theories about the origin of the virus. Wuhan is home to the Wuhan Institute of Virology, where researchers study and conduct experiments on coronaviruses that circulate abundantly in bats in central and southern China. The institute has been at the center of those who argue that an accidental leak from one of its research labs is the most likely explanation for the virus’s spread in humans.
Huanan Seafood Market is several kilometers from the Institute of Virology and across the Yangtze River. Few of the first documented cases were near the laboratory. A second coronavirus lab at the Wuhan CDC, which oversaw the city’s coronavirus response, moved in late 2019 to a location close to the market.
Worobey’s article immediately drew skeptical responses from two prominent scientists who, like Worobey, have been deeply engaged in the debate over the most likely scenario for the start of the pandemic.
“It is based on fragmentary information and to a large extent hearsay,” David Relman, professor of microbiology at Stanford University, said in an email after reading an embargoed copy. “In general, there is no way to verify much of what he describes and then come to a conclusion.”
Jesse Bloom, a computer biologist at the Fred Hutchinson Cancer Research Center in Seattle, said the quality of Chinese data on early coronavirus infections is too poor to support a conclusion.
“I don’t think anything can be concluded with high or even very modest confidence as to the exact origin of SARS-CoV-2 in Wuhan, simply because the underlying data is so limited,” said Bloom said. He argues that genetic evidence from the first virus samples indicates the market is a super-spreading event, but not like the location of the first round of infections.
Bloom is among those sounding the alarm over what he considers too risky research being conducted at the Wuhan Institute of Virology. This research sparked huge controversy, with some Republican lawmakers and conservative media figures focusing on funding some of the experiments, channeled through a nonprofit group, EcoHealth Alliance, of the National Institute of Allergy and Infectious Diseases, led by President Joe Biden. Chief Pandemic Medical Advisor Anthony Fauci.
Worobey’s article garnered much praise from proponents of the natural zoonosis theory.
“Mike’s article shows without a shadow of a doubt that in fact the Huanan market was the epicenter of the outbreak,” said Robert Garry, a virologist at Tulane University and one of the most vocal supporters of the zoonosis hypothesis.
Benjamin Neuman, a virologist at Texas A&M University who was one of the coronavirus experts to name SARS-CoV-2 in early 2020, called the report “detailed and compelling, in a way that Most detailed conspiracy schedules haven’t been … When evidence is presented in this way, the association with the market is strong long before anyone realizes it – from the start. “
Worobey and the critics Relman and Bloom have one thing in common: They signed the letter to the journal Science in May which called for further investigation into the origins of the virus, including the possibility of a laboratory leak.
Soon, opinion polls showed that more people were in favor of the lab leak theory than the origin of the market. And Biden ordered his intelligence agencies to review the case and report back within 90 days.
In the months following the signing of the Science letter, Worobey became more convinced that the pandemic began as a market spillover, where animals known to be able to harbor the virus – such as raccoon dogs – have been sold.
The Science letter had an influence by taking conjectures that had once been ridiculed as a conspiracy theory and propelling them into the mainstream of debates about the origin of viruses, even doing so, as Worobey puts it, “the main competitor “in the public mind for the origin of the pandemic.
“The pendulum has swung way too far to the other side,” he said.
It has been known since the start of the pandemic that the Huanan market was linked to many early cases, and early reports invariably cited it as the likely source of the viral fallout. But the joint WHO-China report this year presented a darker picture, noting that some cases in December 2019 were unrelated to the market: “So no firm conclusion on the role of the Huanan market in the origin of the epidemic, or how the infection was introduced to the market, can currently be learned.
The market was quickly closed, the animals slaughtered foremost were tested for SARS-CoV-2, and everything was cleaned and disinfected shortly after the outbreak began. Still, subsequent investigation showed traces of the virus were found on market surfaces, including drains, especially in the area where vendors sold animals.
Worobey acknowledged that grouping infections could be misleading, saying that early attention to the market might have skewed the data because epidemiologists could have looked for market-related infections and missed infections occurring in areas receiving less beware – a common trend in research known as “finding bias. But he concluded that the chronology and geography of early cases rule out such an error.”
Chinese officials have said the Huanan market was not the source of the pandemic. The Chinese government has pushed the idea that the coronavirus could have been introduced into China from abroad, notably from Fort Detrick in Maryland and via frozen food imports.
Worobey doesn’t claim to have definitively proven how the pandemic started. And his article is not a research study presenting new data, but is instead tagged as a “Perspective” article. Such articles generally consolidate and interpret information which, for the most part, has already fallen into the public domain.
Although the idea of the lab leak was first derided by many scientists and in the mainstream media as a conspiracy theory – a theory adopted by President Donald Trump and his allies as part of their attacks rhetoric against China and the “Chinese virus” – the failure to find an animal host for the immediate precursor to SARS-CoV-2 kept all assumptions on the table.
The 90-day investigation by US intelligence agencies at Biden’s request was inconclusive. Most agencies have promoted the theory of natural zoonosis. One was in favor of the lab leak. The only firm conclusion was that the virus was not a biological weapon.
Worobey said he was open to the possibility of a lab leak, simply because of the Wuhan Institute of Virology’s proximity to the first outbreak. But he took a closer look at the question of geography. If the virus came out of the lab, why did the first cases cluster in and around the market several miles away? And that market, he notes, had sold animals that were implicated in the first SARS outbreak of 2002-2003.
“It becomes almost absurd in my mind to imagine that this virus started at the Wuhan Institute of Virology, and almost immediately this person went to one of the few places that sell raccoon dogs and other animals involved in SARS-1, “he said.
His article does not mention the Wuhan CDC laboratory. Chinese officials have insisted that SARS-CoV-2 has never been in any of the country’s laboratories, and was not found in tests on wild or domesticated animals.
Supporters of the laboratory leak theory point to the lack of transparency from Chinese authorities and the removal of experimental data from a database at the Wuhan Institute of Virology several months before the pandemic. Worobey’s commercial origin theory suggests an alternate scenario, in which authorities were unwilling to find evidence that the spillover had occurred in a market with live animals that could have been illegally caught and sold.
Worobey also suggests that Chinese officials may have been embarrassed that the country’s system for quickly identifying and responding to new pneumonia-like illnesses – a system put in place after the original SARS outbreak – was slow. to detect the epidemic of diseases caused by the new coronavirus.
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Eva Dou of the Washington Post contributed to this report.