An internal story of how one scientist completed a covid began with a spillover at the Wuhan wet market

Zhou Zhaomin, a specialist in Chinese wildlife marketing at China West Normal University in Nanchong, states: “Punishment for offenders is harsh. Entrepreneurs of protected species can spend up to 15 years in prison, and smuggling them in or out of China in large quantities could result in life imprisonment.

But the enactment of the rules was bad. Several researchers have told MIT Technology Review that it is “a secret” that wildlife trade is rampant in China.

Of course, Zhou and his colleagues did research between 2017 and 2019 it found that four markets in Wuhan, including Huanan, sold about 48,000 wild animals of 38 species, almost all of which were sold live, confined, and stored in cramped, unhygienic conditions suitable for transmitting the virus. The animals, whether caught in the wild or domesticated by pets, also include species that can be caught by SARS-CoV-1 and SARS-CoV-2, such as civets, mink, dogs, and raccoon dogs.

The study, published in June in Scientific Reports, found that all wildlife trade surveyed by researchers was illegal. Many retailers sell protected varieties; no one set out the necessary documents to show where the animals came from or whether they were free of disease.

This means that as soon as Huanan is affected by the original Covid-19 lawsuits, sellers who sell live mammals, perhaps illegally, run away from arrest, while law enforcement agencies cannot accept that this has ever happened. Given this, it was not surprising that Chinese authorities did not find ways to sell live animals in the Huanan market, says Harvard’s Hanage.

Restrictions on wildlife trade were relatively low after SARS, which gave scientists the opportunity to find animals and traders in Guangdong wetlands – but even that was not enough to help them reduce the SARS source. When they quickly got infected with viruses in civets, seals, and raccoon dogs that were more than 99% similar to SARS-CoV-1, subsequent research has not found the spread of the virus, either in the wild or in agricultural fields. The main idea is this civets contracted the virus during commercialization, most likely from bats that were purchased and sold at the same time.

Now, 18 years later, the situation is remarkably similar. It seems to exist there is no spread of SARS-CoV-2 in animals. No more than 80,000 specimens or more have been tested by the Chinese World Health Organization to investigate the source of the epidemic, including suspects such as pangolins, civets, badgers and bamboo rats infected with the virus.

However, many scientists still rely heavily on the theory that wet markets played a major role in the development of Covid-19. Although all eyes are on Yunnan and other parts of Southeast Asia as the place where the plague originated, Hanage says it is “not crazy” to say that Hubei’s Wuhan district would be where SARS-CoV-2 originated naturally.

Indeed, scientists at the Wuhan Institute of Virology have discovered Coronaviruses like SARS in bats in Hubei. Although not systematically detecting coronavirus animals throughout the region, in less well-known research which took place after SARS, found that the seven civets that tested on a farm in the region in 2004 all had relatives of SARS-CoV-1. Several research groups in China and the US are trying to determine where animals have been infected, whether coronavirus infection among civets is more common than previously thought, and how it could affect our understanding of the origins of Covid-19.

Regular spillover

But without evidence of an animal with more than 99% of corona viruses similar to SARS-CoV-2, some scientists have continued to challenge the environment.

One such critic is Alina Chan, a biochemist at the Broad Institute of MIT and Harvard (the book is MIT’s, but independent). The big question, he said in a recent webinars produced by Science magazine, and how the virus spread to Wuhan from caves more than a thousand miles from China or other parts of Southeast Asia. “There is a very strong path for the scientists in Wuhan to go to this place where they go [knew] found SARS viruses, bringing them to the city of Wuhan, about thousands of miles away, “he said.

Such ambiguity also undermines SARS sources, says Linfa Wang, director of Duke-National University’s Singapore Infectious Diseases Program. The cave that provided the closest relative of SARS-CoV-1 is located about 1,000 kilometers from Guangdong market where the first SARS cases were discovered – similar to the distance between Wuhan and the location of one of SARS-CoV’s closest relatives. -2 found.

And it is clear that people who are in close contact with wildlife are infected with coronaviruses more often than previously thought.

“[Huanan] “It is much more difficult than other events from what we now know.”

Michael Worobey

Studies show that up to 4% of people who live near bats and work with wildlife southern China has contracted an animal-borne virus, including coronaviruses. Laotian and French group, which found close relatives of SARS-CoV-2, he found One in five working in Laos had antibodies against coronaviruses.

Most spillover infections can go away on their own, researchers say. In a study published in Science in April, Worobey and colleagues point out in computer simulations that in order for the SARS-CoV-2 outbreak to cause major epidemics, urban areas are very important – without this, they can disappear very quickly.

“By the hundreds, or even thousands, of many times” that a wildlife dealer who came in contact with the parent of SARS-CoV-2 – either from bats or other animals – brought the disease to Huanan more than the researcher went. to take samples from bats he returned to Wuhan with pathogens and brought them to Huanan, says Wang.

Worobey agrees. Based on many evidence, they now believe that the outbreak of the epidemic in the Huanan market is true, but that is when the parent of SARS-CoV-2 jumped from animals to humans. He said: “This is more likely to happen than any other event at present.

Preliminary results from the ongoing work of his organization and others will help to further strengthen the case, he adds: “All are pointing in the same direction.”

The report was supported by a donation from the Pulitzer Center.

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