Scientists say there is “compelling evidence” that Wuhan’s Huanan seafood and wildlife market was at the centre of the Covid-19 outbreak.
Two peer-reviewed studies published on Tuesday re-examine information from the initial outbreak in the Chinese city. One of the studies shows that the earliest known cases were clustered around that market. The other uses genetic information to track the timing of the outbreak. It suggests there were two variants introduced into humans in November or early December 2019.
Together, the researchers say this evidence paints a picture that Sars-Cov-2 was present in live mammals that were sold at Huanan market in late 2019. They say it was transmitted into people who were working or shopping there in two separate “spillover events”, where a human contracted the virus from an animal.
Two years of scientific effort to understand the virus that causes Covid-19 have provided these researchers with a more informed perspective. This has enabled them to address a key conundrum in the earliest patient data: That out of hundreds of people who were hospitalised with Covid-19 in Wuhan, only about 50 had a direct, traceable link to the market.
“That was really puzzling that most cases could not be linked to the market,” said Prof Robertson. “But knowing what we know about the virus now, it’s exactly what we would expect - because many people only get very mildly ill, so they would be out in the community transmitting the virus to others and the severe cases would be hard to link to each other.”
This Covid-19 case-mapping research found that a large percentage of early patients - with no known connection to the market, meaning they neither worked nor shopped there - did turn out to live near it.
The lab leak theory
Over the last two years, the search for the origin of the deadly pandemic turned from a scientific investigation into a toxic political row.
One of the subjects of a fierce international blame game - primarily between politicians in the US and China - was a theory that the virus could have been leaked from a Wuhan laboratory, the Wuhan Institute of Virology. But that hypothesis, said Prof Stuart Neil from Kings College, “can’t explain the data”.
Crowded, live animal markets, many scientists agree, provide an ideal transmission hotspot for new diseases to “spill over” from animals. And in the 18 months up to the beginning of the pandemic, a separate study showed that nearly 50,000 animals - of 38 different species - were sold at markets in Wuhan.
Prof Neil said the pandemic was very likely to have been a consequence of an “unhealthy, cruel and unhygienic practice that Chinese authorities had been warned about”.
The major risk of being distracted by looking for someone in a laboratory to blame for all this, he added, “is that we run the risk of letting this happen again because we’ve focused on the wrong problem.”
Of course, there will be naysayers and conspiracy theorists who will refuse to accept what, IMO, is the plausible explanation for the start of the COVID-19 outbreak.
