The findings of a World Health Organization draft report says that the an animal was the probable mode of transfer of the novel coronavirus that causes Covid-19 and its spread had possibly started not more than a month or two prior to the first cases were noticed in December 2019 in Wuhan city of China.
According to reports, the WHO report failed to find enough evidence of the virus spreading much earlier than the very end of 2019. Four possible sources for the virus are mentioned in the WHO report while it says that the most likely scenario of jumping of the virus was from an intermediate animal host – which possibly was a wild animal captured and then raised on a farm.
WHO has also not managed to find whether there were other animals that were infected with the virus from a bat – which has been identified as the most likely original source of the virus. “The possible intermediate host of SARS-CoV-2 remains elusive,” the WHO report says.
One of the animals that is known to carry a similar coronavirus, such as a bat or a pangolin, has been identified in the report to be the second most likely source of a direct transmission to humans. The report also noted the possibility, but not probability, of the virus being transmitted through frozen or chilled food while the least likely source was an accidental release of the virus form a virology laboratory.
His personal opinion was the virus was released from a lab, said former US Centers for Disease Control and Prevention Director Dr. Robert Redfield, in a television interview.
The WHO report however says that the chances of the virus escaping from a lab was “extremely unlikely.” “There is no record of viruses closely related to SARS-CoV-2 in any laboratory before December 2019, or genomes that in combination could provide a SARS-CoV-2 genome,” read the report. “In view of the above, a laboratory origin of the pandemic was considered to be extremely unlikely.”
This has been stressed by independent researchers for quite some time as they have argued that genomic testing of the virus have given indications that it was not engineered in a lab but was transferred naturally from animals – in the same way that the SARS virus was transferred and which infected 8,000 people globally in 2002-2004.
The report also ruled out the possibility a transmission from frozen food. “There is no conclusive evidence for foodborne transmission of SARS-CoV-2 and the probability of a cold-chain contamination with the virus from a reservoir is very low,” it says.
The report does not provide a clear conclusion on the role of the Huanan seafood market in Wuhan. The report stated that the market was potentially not the original source of the outbreak but it may have amplified the spread of the virus because of the denseness of the market which has a roof and open sewers.
“Many of the early cases were associated with the Huanan market, but a similar number of cases were associated with other markets and some were not associated with any markets. Transmission within the wider community in December could account for cases not associated with the Huanan market which, together with the presence of early cases not associated with that market, could suggest that the Huanan market was not the original source of the outbreak,” the report added.
“No firm conclusion therefore about the role of the Huanan market in the origin of the outbreak, or how the infection was introduced into the market, can currently be drawn,” the report concludes.
(Adapted from CNN.com)