Raccoon dogs sold in Wuhan thought to be the source of the COVID-19 pandemic | Coronavirus

A raccoon dog in a cage at the Xin Yuan Wild Animal Market in Guangzhou city, southern China. (File photo)

A new genetic analysis of samples collected from the surfaces of the Huanan market, in Wuhan, China, tends to corroborate the theory that raccoon dogs sold illegally on the spot would be the origin of the pandemic, and not a leak from a laboratory.

These data don't provide a definitive answer on where the pandemic started, but every piece of information is important to get us closer to that answer, the World Organization's director-general said. of Health (WHO), Tedros Adhanom Ghebreyesus, during a press conference held on Friday.

In work yet to be published in a peer-reviewed journal, a step that helps verify the value of a study, scientists analyzed previously inaccessible genetic data from samples collected at the nearby market of where the first human cases of COVID-19 were recorded.

WHO criticized China for not sharing genetic information sooner, adding that this data could and should have been shared three years ago.

Tedros Adhanom Ghebreyesus reported that the genetic sequences were uploaded to the world's largest public virus database at the end of January by scientists from the Chinese Center for Disease Control and Prevention. This crucial information has since been removed from the database.

A French biologist spotted the information by chance while going through the database and shared it with a group of scientists who are based outside of China and who are studying the origins of the coronavirus. Canadian virologist Angela Rasmussen, from the Vaccine and Infectious Disease Organization (VIDO) at the University of Saskatchewan, participated in this work.

The Associated Press (AP ) reports that genetic sequencing data shows that some of the samples, known to be positive for coronavirus, also contained genetic material from raccoon dogs, indicating that these animals may have been infected with the virus, the scientists say.

There's a strong chance that the animals that dropped that DNA also dropped the virus, said University of Utah virologist Stephen Goldstein, who helped analyze the data. .

“If environmental sampling was done following a zoonosis, it is exactly what one would expect to find.

—Stephen Goldstein, University of Utah

For Ray Yip, epidemiologist and founding member of the US Centers for Disease Control office in China, who was not involved in this work, these new results may not be definitive, but they are significant.

“The market environment sampling data released by China CDC is by far the evidence strongest supporting animal origin.

—Ray Yip, US Centers for Disease Control China

Scientists have been trying to find the origin of the COVID-19 pandemic since its onset, but this search has been complicated by factors such as the massive increase in human infections during the first two years of the pandemic and a opaque political reality.

However, it is possible that humans first brought the virus to market and infected the raccoon dogs or that infected humans left traces of the virus near animals.

Mark Woolhouse, an infectious disease specialist at the University of Edinburgh interviewed by the AP, who was not involved in the work, believes it will be essential to see how the genetic sequences of raccoon dogs match what is known about the historical evolution of the COVID-19 virus.

According to the expert, if analysis shows that animal viruses have older origins than those that have infected humans, that will probably be the best evidence we can hope to get that it is of a spillover event in the market.

In 2021, after a weeks-long visit to China to study the origins of the pandemic, the WHO published a report concluding that COVID was most likely passed from animals to humans.

The following year, the UN health agency backtracked, saying the investigation was still missing key elements.

In recent months, the director of the WHO, Mr. Ghebreyesus, even claimed that all the hypotheses remained under study and asked China to share more data.

Chinese CDC scientists also analyzed the samples collected from the surfaces of the Huanan market. They pulled a non-peer-reviewed paper from it and published it in February 2022. In it, they claim that it was humans who brought the virus to market, not animals.

< p class="e-p">However, they do not mention that animal genetic material had been found in the samples declared positive for COVID-19.

Last February, the United States Department de l'Énergie believed that a laboratory accident in China was probably the cause of the COVID-19 pandemic.

With information from Associated Press