Nature reports:

The quest to understand where the COVID-19 pandemic started has revealed fresh clues. Researchers have re-analysed data collected from a market in Wuhan, China, during the early days of the pandemic and found that animals there were infected with a virus – although they could not confirm what exactly caused the infection.

“The conclusion is convincing that there was infection in the animals,” says Spyros Lytras, an evolutionary virologist at the University of Tokyo. The results, which have not been peer reviewed, were presented at a conference, Preparing for the Next Pandemic: Evolution, Pathogenesis and Virology of Coronaviruses, in Awaji, Japan, on 3 December.

Many of the first COVID-19 cases to be identified were linked to Wuhan’s Huanan Seafood Wholesale Market. Some studies have reasoned that people brought the virus to the market, where they passed it on to others, whereas other studies have suggested that the market was the site of the first spillover events, in which animals with the virus first infected people. Although these earlier studies established the presence of animals susceptible to the virus that causes COVID-19, and the virus itself, at the market, they were not able to confirm that the animals were infected with the virus.

“The missing link in the whole zoonotic story has been the animal,” says Edward Holmes, a virologist at the University of Sydney in Australia. “If you can show there are infected animals at the market, then the story is complete,” he says, referring specifically to animals infected with a progenitor of SARS-CoV-2.

The latest analysis suggests that infected animals were at the market at the same time that early cases of COVID-19 emerged there. “This is one more piece of indirect evidence that suggests a connection of the origin of the SARS-CoV-2 pandemic with the Huanan market,” says Christian Drosten, a virologist at the Charité University Hospital in Berlin. [Continue reading…]