'COVID-19 leak from Wuhan lab unlikely; wet market origin theory not probable either': WHO investigator to China

As coronavirus that emerged from Wuhan wreaked havoc across the world, fingers were pointed at China. Theories about the origin of the virus were abound, including one that stated the coronavirus was leaked from a lab in Wuhan. However, Dominic Dwyer, Director of Public Health Pathology, NSW Health Pathology at the Westmead Hospital and University of Sydney, who was part of the WHO team that visited Wuhan to determine the emergence of the virus has said it is unlikely the virus leaked from the Wuhan Institute of Virology. Dwyer also said that it is unlikely that the COVID-19 virus emerged from the wet markets of Wuhan.

In a piece on The Conversation, authored by Dwyer, he said that the team visited the Wuhan Institute of Virology and found it to be an "impressive research facility" that appeared to be "run well". He said that they spoke to the scientists there and heard that blood samples of the scientists were taken regularly and stored. "No evidence of antibodies to the coronavirus was found. We looked at their biosecurity audits. No evidence," he said.

Dwyer also said that they looked at the closest virus to SARS-CoV-2 -- the RaTG13 virus --  that was detected in caves in Southern China where some miners had died seven years ago. "But all the scientists had was a genetic sequence for this virus. They had not managed to grow it in culture. While viruses certainly do escape from laboratories, this is rare. So, we concluded it was extremely unlikely this had happened in Wuhan," he concluded.

Speaking about the Wuhan wet market, believed to be the origin of the virus, Dwyer said that they visited the now-closed market. Some of the stalls sold domesticated wildlife products including bamboo rats, civets and ferret badgers. He said that there is evidence to show that some of the domesticated wildlife could be susceptible to SARS-Cov-2 but none of the samples taken from animals in the market after its closure tested positive.

None of the initial 174 cases had visited the market, including patient zero. Dwyer said that the market could, however, have led to the spread of the virus considering its poor ventilation, drainage as well as daily footfall of 10,000. "The market in Wuhan, in the end, was more of an amplifying event rather than necessarily a true ground zero. So we need to look elsewhere for the viral origins," he wrote in the piece.

Speaking about the cold chain hypothesis that states that the virus might have originated elsewhere via farming, catching, processing, transporting, refrigeration or freezing of food, Dwyer wrote, "Was that food ice cream, fish, wildlife meat? We do not know. It is unproven that this triggered the origin of the virus itself. But to what extent did it contribute to its spread? Again, we do not know."

The team of investigators had 17 Chinese and 10 international experts along with seven other experts and support staff from various agencies. Dwyer said that their mission to China was only Phase One. The official report of the mission will be published in the coming weeks.

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