The AP received a copy on Monday from a Geneva-based diplomat from a WHO member country. It was not clear whether the report could be changed before it was published, although the diplomat said it was the final version. A second diplomat confirmed that he had also received the report. Both refused to be identified as they were not authorized to release it before it was released.
WHO did not immediately respond to emails and phone calls for comment.
The researchers listed four scenarios in order of likelihood for the occurrence of the coronavirus called SARS-CoV-2. Topping the list was bats transmission from another animal that they said was very likely. They rated the direct spread of bats to humans as likely, saying that spread through “cold chain” foods is possible but not likely.
Bats are known to carry coronaviruses, and in fact, the closest relative of the virus that causes Covid-19 has been found in bats. However, the report states that “the evolutionary gap between these bat viruses and SARS-CoV-2 is estimated to be several decades, suggesting a missing link.”
It is said that very similar viruses have been found in pangolins, which are a different species of mammals, but mink and cats have also been found to be susceptible to the Covid-19 virus, suggesting that they could also be carriers .
The report is largely based on a visit by a WHO international team of experts to Wuhan, the Chinese city where Covid-19 was first discovered, from mid-January to mid-February.
Peter Ben Embarek, the WHO expert who led the Wuhan mission, said Friday that the report had been finalized and was being reviewed and translated.
“I assume that the whole process will be completed in the next few days and that we can publish it publicly,” he said.
The draft report is inconclusive as to whether the outbreak began in a Wuhan fish market, which had the earliest case groups in December 2019.
The discovery of other cases prior to the Huanan market eruption suggests that it may have started elsewhere. However, the report notes that there could have been milder cases that went undetected and that this could be a link between the market and previous cases.
“As such, no firm conclusion can be drawn at this time about the role of the Huanan market in causing the outbreak or how the infection was brought to the market,” the report said.
The market was an early suspect because some stalls were selling a number of animals – and some wondered if they had brought the new virus to Wuhan. The report found that a range of animal products – from bamboo rats to deer, often frozen – were sold in the market, as were live crocodiles.
As the pandemic spread around the world, China found samples of the virus on the packaging of frozen food entering the country and, in some cases, tracked localized outbreaks.
The report said the cold chain, as it is called, may be a driver of the spread of remote virus, but was skeptical that it could have triggered the outbreak. The report says the risk is lower than human-to-human respiratory infections, and most experts do agree.
“While there has been some evidence of a possible reintroduction of SARS-CoV-2 through handling of imported contaminated frozen products in China since the first wave of pandemics, this would be exceptional in 2019 if the virus was not widespread,” the study said.
Several reasons were cited in the report, but the possibility that the virus escaped from a laboratory in Wuhan was ruled out. This speculative theory was proposed and promoted by former US President Donald Trump, among others.
Such laboratory accidents are rare and the laboratories in Wuhan working on coronaviruses and vaccines are well run. It was also found that there were no records of viruses closely related to SARS-CoV-2 in any laboratory until December 2019 and that the risk of the virus accidentally growing was extremely low.