On Tuesday, an investigative team from the World Health Organization (WHO) revealed the findings from their four-week visit to the Chinese city of Wuhan, where the novel coronavirus was first discovered, as reported by the Associated Press. The group of international and Chinese scientists concluded that the virus most likely spread to humans from an animal, with the leader of the WHO mission, Peter Ben Embarek, describing an alternate theory of it originating in a lab as "unlikely."
"The findings suggest that the laboratory incidents hypothesis is extremely unlikely to explain the introduction of the virus to the human population," he said.
He suggested that it was much more likely that the virus had spread from a bat to another animal before being found in humans, but further research would be required before that theory could be confirmed. He acknowledged that the early understanding of the virus had not been changed dramatically by the research, which was closely observed by the Chinese government, but said it allowed the team to "add details to that story."
A leak at the Wuhan Institute of Virology had been previously accused of being the source of the original outbreak due to its research and collection of many virus samples. The team of experts now consider that theory as improbable and it will no longer be pursued for investigation. China has long rejected the claim, as a team of scientists from the country worked alongside the WHO to investigate other explanations of how the virus entered humans and killed 2.3 million people worldwide.
Current theories suggest that the virus was transmitted by an animal such as a pangolin or bamboo rat, with potential direct transmission from bats to humans or through frozen food products. The team of experts from 10 countries visited the Huanan Seafood Market, the site of one of the earliest coronavirus clusters. The team identified the traders, suppliers and farms connected to the market. The head of the Chinese faction of the investigation team, Liang Wannian, pointed out that the virus may have originated elsewhere as it was found in other areas of the city.
"We haven't been able to fully do the research, but there is no indication there were clusters before what we saw happen in the later part of December in Wuhan," Liang said.
However, the WHO team claimed there was no evidence of widespread cases before the initial outbreak in December 2019.
The investigation has been a sensitive issue for the Chinese government due to concerns that it would be blamed for alleged missteps during the early stages of the outbreak. The government placed limits on the investigation and prevented scientists from speaking to reporters during their visit. Peter Daszak of the WHO team did say they were granted more openness than they had expected and had full access to all of the sites and personnel they requested.