‘Beyond reasonable doubt’ Covid-19 came from wet market

Researchers from the US and France have conducted the most thorough genetic analysis yet of hundreds of samples collected in Wuhan.

Ground zero: The closed Huanan wholesale seafood market in the Chinese city of Wuhan in January 2020. Picture: AFP

Scientists have said it is now “far beyond reasonable doubt” that Covid-19 originated in an animal market rather than from a laboratory leak, following fresh analysis.

Researchers from the US and France have conducted the most thorough genetic analysis yet of hundreds of samples collected in Wuhan, China, in the early days of the pandemic in January 2020.

Swabs were used to gather samples from stalls, cages and equipment at the Huanan Seafood Wholesale Market after it was suggested that the virus may have been first transmitted to ­humans from an animal on sale at the market.

The samples were analysed to look for fragments of genetic code in order to ascertain which animals and viruses were present in the market at that time.

The study has found that one stall in particular was a hotspot for coronavirus and a shortlist has been compiled of animals that may have passed the virus on to humans – in a transmission known as zoonosis – and caused the global pandemic. Raccoons dogs, masked palm civets, hoary bamboo rats and Malayan porcupines were on the list.

The analysis, published in the journal Cell, does not constitute definitive proof that the virus was first present in an animal at the market before the outbreak as it cannot prove that any of the ­animals were infected.

However, the researchers behind the analysis say they are convinced.

“It’s far beyond reasonable doubt that this is how it happened,” Professor Michael Worobey at the University of Arizona told the BBC.

Professor Worobey said other theories involved some “really quite fanciful absurd scenarios”.

“We find a very consistent story in terms of this pointing – even at the level of a single stall – to the market as being the very likely origin of this particular pandemic,” said Kristian Andersen from Scripps Research in the US.

James Wood, an infectious disease epidemiologist at the University of Cambridge, who was not involved in the study, said that the “evidence is entirely consistent with a wildlife market origin for the pandemic emergence”, but said the samples were taken after the virus had already begun to spread between humans making it hard to say definitively.

He warned that, since the pandemic, “little or nothing has been done to limit the live trade in wildlife”, which could lead to future outbreaks.

Professor Worobey said: “Not much has been done to decrease the chance of a zoonotic scenario like this happening again.”

THE TIMES