For several days, WHO researchers have been dispatched to Wuhan, China, to identify the origins of Covid-19. Based on their findings, leakage of the coronavirus from a lab is deemed "highly unlikely".
This mission on the origins of the transmission of the new coronavirus has struggled to establish itself, China seeming very reluctant to let international specialists come to investigate. Finally, after twelve days of field work in Wuhan , a team of researchers – made up of ten international scientists and five WHO experts – has just delivered its conclusions on the origin of the SARS-CoV-2 virus .
While many questions still remain unanswered, this new report dismisses one of the most talked about leads:that of the leak of the virus from a laboratory P4 of the city, deemed “extremely unlikely” by researchers.
The team reached this conclusion after conducting an objective and standardized assessment, based on the scientific literature, interviews with local researchers and a visit to local laboratories, including including that of the Wuhan Institute of Virology. This conclusion agrees with those of many international geneticists, pointing out that there were no telltale signs of "human tinkering" in the SARS-CoV-2 genome.
On the other hand, the results of this investigation support the idea that the virus was transmitted to humans via an animal intermediate host , still elusive. He himself would therefore have been initially infected by a "reservoir species" (probably horseshoe bats).
Although Chinese researchers have already investigated more than 11,000 animals across the country, all have so far tested negative for SARS-CoV-2. Also, the identification of this intermediate host “will require more specific and targeted research” , underlines Ben Embarek, head of the international team of the WHO.
The team also provided some intriguing new details on the beginnings of the pandemic. After speaking with doctors from the hospital where the first patients were treated, and after going to the Huanan market – which mainly sold frozen food (seafood), but also wild animals – the researchers said been able to collect epidemiological data. In this way, they were able to map the times and locations of the first known cases in the city.
According to them, cases of Covid-19 – which had no clear link to this market – were recorded earlier in December. This suggests that the markets could have just been places where the virus spread more easily. On the other hand, this is not necessarily where it appeared.
The WHO team is now keenly interested in further studies of animals commonly transported to and from Wuhan, including frozen products . The latter are now considered by the WHO as the preferred route.
