Controversial hunt for Covid’s starting points for China’s animal trade

Photographer: Hector Retamal / AFP / Getty Images

Scientists are discovering the the origins of the Covid-19 pandemic are believed to have identified a source of transmission: China’s thriving wildlife trade.

The highly expected results from experts called by the World Health Organization and the Chinese government are expected to show a parallel parallel to the 2002 outbreak of severe respiratory syndrome, or SARS, a bat-infected coronavirus. spread by civets that killed 800 people. The pathfinder with SARS-CoV-2 – the so-called new coronavirus – before it appeared in central China in December 2019 remains a mystery, although it says researchers are able to solve it.

In Wuhan, where the first group of cases occurred, scientists involved in the hunt identified four hypotheses to explain the genesis of the virus, including two that were controversy even as they were perceived as unlikely. The idea that the virus was introduced through contaminated food or packaging is one that has been introduced in Beijing, and the Trump administration said it may be a result of laboratory accident. But the most plausible theory, say experts involved in the mission, applies to China’s wildlife trade for food, fur and traditional medicine, a worthwhile business 520 billion Yuan ($ 80 billion) in 2016.

Read more: Where are we in the hunt for the origin of the coronavirus?

Live animals susceptible to coronavirus disease were present at the Huanan food market in central Wuhan, the city where the first major Covid-19 mutation was discovered. It is possible that they were the link for the virus, carrying it from bats – perhaps the main source – to humans, say Peter Daszak, an ophthalmologist who was part of the joint research effort, saw international experts visit Wuhan earlier this year after months of stonework by the Chinese government.

“The main conclusion from this phase of the work – and it is not yet over without a doubt – was that the very path by which SARS appeared alive and well for Covid was emerging,” said Daszak, who is also as president of it EcoHealth Alliance, a New York-based nonprofit organization that works to prevent viral outbreaks worldwide.

Scientists report, slate to be released the following week delays due to political breakdown are likely to be far from certain. Further studies, including outside China, are being planned with the Covid-19 creation story crucial to understanding how best to prevent its recovery, and to help similar accidents in the future.

China is making it harder to solve a mystery where Covid has started

While the hunt for the origin of the virus has become a political football for the world’s superpowers, Daszak says he believes the scientific process will have an impact. Important data will be obtained on the origins of SARS-CoV-2 and how it emerged over the next few years, he said during March 10 webinar organized by Chatham House.

SARS Distribution

Farming and wild capture Civets, a small nocturnal mammal eaten in China, have been blamed for spreading the SARS virus in a market in the southern Guangdong province in 2003. Scientists later discovered that the disease had entered cattle-bats, a natural reservoir of coronaviruses.

Both species appear to have hit markets where they were animals live in a cage crowded conditions, which may be exposed to the bat-bat virus change and increase before it has poured over people, first among all workers and those who handle the animals.

Scientists working on the original hunt say a similar situation may have played out with Covid-19. A study of the first 99 patients treated at an infectious diseases hospital in Wuhan found half of which were linked to the Huanan seafood market, which was also reportedly selling live animals, some illegally captured in the country and killed in front of buyers.

It is possible that the virus was introduced through an infectious animal sold at a Huanan market or elsewhere in Wuhan, said Dominic Dwyer, a Sydney microbiologist who was part of the team called up. by WHO who traveled to the Chinese city in February.

However, there are still questions about the ultimate role of the market.

Tests failed after the closure in December 2019 of any infected animals had failed. Surface contamination was widespread, consistent with the introduction of the virus through infected people or thin animal products. Confirming the controversy, the first known Covid-19 patient developed four days before the earliest cases were market-related.

Looking back at other Huanan and Wuhan markets (Video)

A study of SARS-CoV-2 samples collected in mid-December found subtle genetic differences between them. The variant indicates that the virus may have been circulating positively for weeks in the community before doctors were notified through a handful of patients who were critically ill. viral pneumonia.

The initial outbreak of the coronavirus to humans appears to have been followed by a rapid mutation of the virus, said Joel O. Wertheim, associate professor of medicine at the University of California, San Diego. It is possible that the virus has been infected several times and disappearing when infected people did not pass on the virus to anyone, Wertheim and colleagues said in a paper published March 18 in the journal Science. Eventually, the virus caught someone who transmitted it to several people, who also passed it on to others, possibly in a very widespread event.

That may have happened on the Huanan market, Wertheim said in an interview. “The market may have played an important role in the virus introducing itself into humans.”

Current evidence indicates that it is the market where SARS-CoV-2 has been upgraded, and this may not be the birthplace, Dwyer said.

‘Perfect place’

“When you visit the market, you’ll realize that it’s a great place for a revolution to take place because it’s packed, there are lots of stalls, lots of animal products, and a little suboptimal ventilation and drainage,” he said in an interview. “No wonder we had an explosion through there.”

The WHO research team found evidence that wildlife farms in southern China provided vendors at the Huanan market, Daszak told U.S. National Public Radio. He also found a way from southern areas like Yunnan – where the the closest coronavirus to SARS-CoV-2 was found in equine bats in 2013 – to Wuhan, he said at a Chatham House webinar.

“It provides a link and a way for a virus to spread from wildlife to people or animals that can be farmed in the area, and then introduced to the market in a meaningful way. somehow, ”Daszak said. “That’s a very important idea. An understanding of a path needs to start very quickly. ”