A team of US researchers believes that Covid-19 appeared in China much earlier than we thought. This is a preliminary study indicating that the coronavirus emerged in China in the summer of last year!
At the beginning of May 2020, British researchers had examined 7,000 genome sequences in order to trace the history of the spread of SARS-CoV-2 (Covid-19). According to the results, patient zero appeared in Wuhanbetween October 6 and December 11, 2019 . The scientists reported that, despite the mutations and other evolutionary stages of the sequences studied, they were able to identify their Recent common ancestor (MRCA – most recent common ancestor).
A new report (PDF in English / 10 pages) published this early June 2020 by Harvard Medical School indicates that the coronavirus appeared at the earliest in August 2019 and no later than early fall. The document reports the filling of the parking lots of hospitals in Wuhan via the observation of satellite images. However, this filling began strongly in August and peaked in December. There's also been a significant increase in web searches for keywords 'cough' and 'diarrhea' . As part of their research, the authors examined Baidu, the Chinese Google.
Recall that officially, the Covid-19 appeared on a market in Wuhan in December 2019 and that China notified the UN only on the 31st of the month. However, the report in question here is formal. There has indeed been an upward trend in hospital traffic as well as search volume several months before. The document also states that by then the virus had emerged in southern China and may have already spread to other countries. It is also possible that the virus had already strongly adapted to humans at the time of its official detection in December 2019.
The authors also state that some reports linking the source of Covid-19 to a market in Wuhan are misguided. Indeed, the latter do not mention the fact that 14 of the first cases detected had no direct connection with this same market.
Finally, the study has not yet been published in a scientific journal but only through a posting on Harvard's Digital Access to Scholarship. It will therefore be necessary to be patient before obtaining certainties on this research or not.
