The inside story of a scientist concluding covid began with a spill in the wet market in Wuhan.

“Penalties for criminals can be harsh,” says Zhou Zhaomin, a policy expert on Chinese wildlife trader at China West Normal University in Nanchong. Those who sell protected species can face up to 15 years in prison, and smuggling into or out of China in large enough quantities could lead to a life sentence.

But the implementation of the laws was poor. Several researchers have told the MIT Technology Review that it is “an open secret” that illegal wildlife trade is widespread in China.

In fact, it was directed by Zhou and his colleagues a survey Between 2017 and 2019, a total of 38,000 wild animals of 38 species were sold in four markets in Wuhan, including Huanan, almost all of them alive, caged and stacked in tight and unhygienic conditions, perfect for transmitting viruses. Animals — species that are caught in the wild or are not farmed — include species that suffer from SARS-CoV-1 and SARS-CoV-2, such as civets, minks, badgers, and raccoon dogs.

this study was published in June Scientific reports, found that all wildlife trade surveyed by the researchers was illegal. Many vendors sold protected species; no one put up the necessary certificates stating that they were of animal origin or without disease.

This means that as soon as Huanan is involved in the initial covid-19 cases, vendors selling live mammals would probably escape illegally to face imprisonment, and law enforcement agencies are unlikely to accept that such activities ever existed before. Seeing this, it was not surprising that Chinese authorities found information on the sale of live animals in the Huanan market, says Harvard’s Harage.

Restrictions on animal trade were minimal after SARS, giving scientists almost unlimited access to animals and traders in Guangdong’s wetlands, but even that was not enough to help determine the source of SARS. While civets, badgers and raccoon dogs quickly got into viruses More than 99% is the same as SARS-CoV-1, subsequent research found no widespread circulation of the virus in either wild or grown conditions. One of the main points of view is this civets took the virus to trade, which were probably bought and sold at the same time from bats.

Now, 18 years later, the situation is incredibly similar. It seems there is no widespread circulation of SARS-CoV-2 in animals. None of the 80,000 samples tested by the Chinese team at the World Health Organization mission contained the virus.

However, many scientists still lean heavily into the theory that the wet market played an important role in launching covid-19. Even if all eyes are placed on Yunnan and other parts of Southeast Asia as the safest places of origin for the pandemic, Hanage says “it’s not crazy” to suggest that SARS-CoV-2 in Wuhan’s Hubei province could be created naturally.

In fact, it was discovered by scientists at the Wuhan Institute of Virology SARS-like coronaviruses in bats in Hubei. Although farmed animals have not been systematically tested for coronavirus infection throughout the province, little known study Made after SARS, seven civets tested on a farm in the province in 2004 found that they were infected with relatives of SARS-CoV-1. Several research groups in China and the United States have identified where the virus came from, which is more common than expected among coronetavirus infections, and what effect this may have on the origin of covid-19.

Continuous discharge

But without evidence of an animal infected with coronavirus that is more than 99% identical to SARS-CoV-2, some scientists have continued to argue against its natural origin.

One such critic is Alina Chan, a molecular biologist at MIT and the Harvard Broad Institute (this publication is owned by MIT but independent of the publisher). The central question, he said a The latest webinar organized by the journal Science, so the virus reached Wuhan from caves more than a thousand kilometers from China or other parts of Southeast Asia. “There is a very strong path for scientists in Wuhan to go down to these places [knew] They would find SARS viruses, taking them to the city of Wuhan, like thousands of kilometers away, ”he said.

This lack of clarity also affects the origins of SARS, says Linfa Wang, director of Duke-National University’s emerging infectious disease program in Singapore. The cave that gave rise to the closest relative of SARS-CoV-1 bats is similar to the site of one of the closest relatives of SARS-CoV bats in Wuhan and one of the closest relatives of SARS-CoV bats is located nearly 1,000 kilometers from Guangdong market, where SARS cases since they were created. -2 found.

And it is becoming increasingly clear that coronaviruses are transmitted more often than people who are in close contact with wildlife.

“[Huanan] as far as we know now it is more likely than other scenarios. “

Michael Worobey

Studies show that up to 4% people living next to bats and work closely with wildlife They have been infected by deadly viruses transmitted by animals in southern China, including coronaviruses. A group from Laos and France, which he discovered Closest relatives of SARS-CoV-2, he found that One in five bat managers in Laos had antibodies against these coronaviruses.

Most of these spilled infections go away on their own, the researchers say. In a study published in the journal Science in April, Worobey and colleagues show in a computer simulation that SARS-CoV-2 emissions trigger major epidemics that make the urban environment essential; without it, it would disappear very quickly.

“Hundreds, thousands of times, it is likely” that a wildlife trader (of a bat or other animal species) who was under the influence of a pioneer SARS-CoV-2 carried the contamination to Huanan, rather than a former researcher. he returned to Wuhan to collect samples of bats with the pathogen and then was taken to Huanan, Wang says.

Worobey agrees. Based on many lines of evidence, it is now believed that the pandemic’s connection to the Huanan market is real, rather that a SARS-CoV-2 progenitor has jumped from an animal to a human. “That’s more likely than any other scenario we know now,” he says.

Preliminary results of the work being done by his team and others will help further strengthen the case, he added: “Everyone is heading in the same direction.”

Reporting on this article was supported by a grant from the Pulitzer Center.