(CN) — A team of Chinese and international scientists convened by the World Health Organization to investigate the origins of the novel coronavirus said Tuesday it remains a mystery where the virus came from, but they dismissed as “extremely unlikely” the theory that it escaped from a laboratory in Wuhan.
A team of international experts arrived in China on Jan. 14 and have spent four weeks investigating the origins of the virus causing a pandemic that's brought the world to its knees and killed more than 2.3 million people globally.
At a briefing at a hotel in Wuhan, the team of experts and their Chinese counterparts laid out their initial findings. They said they were no closer to knowing where the virus came from and that further research is needed in China and elsewhere to track down what animals are carrying the virus.
One conclusion the team agreed on was that it was “extremely unlikely” the virus somehow escaped from a high-tech virology laboratory in Wuhan that specializes in coronaviruses. That theory was pushed by the Trump administration and has led to much speculation.
The findings were hardly a surprise as scientists and the WHO have been saying for months that figuring out how the virus began infecting humans will be extremely complex and that the mystery may never be fully understood.
Shortly after the novel coronavirus was first identified circulating in the industrial Chinese city of Wuhan in December, scientists began worrying this new virus had spilled over from animals into humans just like the previous SARS and MERS coronaviruses had done and caused major outbreaks. Viruses found in wild animals can jump into other animals that are then consumed by humans. This remains the most likely hypothesis, the WHO team said.
“Our initial findings suggest that the introduction through an intermediary host species is the most likely pathway and one that will require more studies and more specific targeted research,” said Peter Ben Embarek, the lead WHO scientist on the team.
The scientists said extensive sampling of wild and farmed animals in Hubei province, where Wuhan is located, and other Chinese provinces found no trace of the novel coronavirus, which has been classified as SARS-CoV-2.
Extensive sampling and clinical reviews of patient data from hospitals in Wuhan and the rest of Hubei also found no evidence the virus was circulating in humans prior to December, when the first cases were detected. Many of those first cases were connected with the Huanan Seafood Market in Wuhan where wild animals were sold for human consumption.
“There is no indication of the transmission of SARS-CoV-2 in the population in the period before December 2019,” said Liang Wannian, the head of an expert panel on Covid-19 at China's National Health Commission. He spoke for the Chinese side of the team.
Embarek agreed and said there was no “evidence of large outbreaks that could be related to cases prior to December.”
This finding undermines allegations made by the Trump administration and others that China was somehow hiding the outbreak. There is, though, plenty of evidence that Chinese authorities took drastic measures to silence scientists and doctors warning about an alarming number of pneumonia-like cases in Wuhan. China officially notified the WHO about the outbreak on Dec. 31.
In Hubei, prior to December there was no uptick in pneumonia and influenza cases, no surge in deaths linked to respiratory problems and no surge in the purchase of cold and influenza medicine, Liang said. All this backs up an assumption that the virus was not widely circulating before December, he said. He said testing on blood samples from before December stored at blood banks also found no trace of antibodies to the virus, which would have indicated that people were being infected with the virus.