Covid-19 may have started in raccoon dogs, new DNA evidence shows

The long-running debate over the origins of covid-19 took one other flip this week, after a French scientist noticed that genetic sequences placed on a database by Chinese language researchers recommend that the coronavirus accountable may need come from animals reminiscent of raccoon canines on the Huanan Seafood Market in Wuhan.

Inside just a few days, the sequences had been eliminated by the identical researchers – though another scientists managed to obtain them beforehand and are investigating additional.

“It’s actually important that any and all knowledge that pertains to how this pandemic started be made obtainable instantly,” Maria Van Kerkhove on the World Well being Group (WHO) mentioned at a press convention on 17 March.

“There are a number of hypotheses that must be examined, together with how the virus entered the human inhabitants, both from a bat, via an intermediate host or via a breach in biosecurity from a lab. And we don’t have a definitive reply.”

The Huanan market has lengthy been seen as a possible origin for the SARS-CoV-2 coronavirus, as most of the first instances of covid-19, in December 2019, had been in individuals with a connection to it and the stalls offered a spread of reside and lifeless animals, not simply seafood.

SARS-CoV-2’s authentic host is considered bats, as they carry many coronaviruses, though they haven’t but been discovered with SARS-CoV-2. The ancestor of this virus might have jumped from bats to an intermediate host offered on the market, after which to individuals.

Another clarification is that the virus escaped from the Wuhan Institute of Virology, the place researchers had been identified to be learning bat coronaviruses, however not SARS-CoV-2. Whereas it is a less-favoured thought amongst scientists, in February, the US Division of Power mentioned it was the most likely explanation, however didn’t launch supporting proof.

Now, genetic sequences uploaded onto a world virology database referred to as GISAID by the Chinese language Heart for Illness Management and Prevention might have shed extra mild on SARS-CoV-2’s origin. These sequences had been derived from swabs taken from numerous surfaces on the market in early 2020 after it had been shut down.

They had been seen by Florence Débarre on the French Nationwide Centre for Scientific Analysis, who shared her findings with the WHO on 14 March. “I used to be specializing in market sequences after I logged in, however I used to be not anticipating to seek out the information I discovered,” says Débarre.

Débarre declined to say any extra till her evaluation is full, however Van Kerkhove mentioned on the press convention: “Amongst the samples that had been constructive for SARS-CoV-2, they noticed proof of DNA of animals. A few of these animals embody raccoon canines.”

Raccoon canines (Nyctereutes procyonoides) have beforehand been discovered to be prone to SARS-CoV-2 and to be able to spreading it. “We all know they’re good at carrying it,” says Alice Hughes on the College of Hong Kong.

This doesn’t show that raccoon canines or any of the opposite animals on the market had been contaminated with the virus in December 2019 and such proof is now inconceivable to supply, says Hughes.

Jonathan Stoye on the Francis Crick Institute in London says: “The information would seem to offer convincing proof that raccoon canines and different animals had been current on the market at a important time. That is one other hyperlink within the chain that you’d anticipate to see if the pandemic began that approach.”

Off the again of the data Débarre shared, Van Kerkhove mentioned that the WHO has requested the Chinese language Heart for Illness Management and Prevention to rerelease the genetic knowledge. “The massive difficulty is that this knowledge exists and that it’s not available to the worldwide neighborhood, to not point out that it ought to have been made obtainable years earlier.”