Paris at the time of the Covid 19

“Was the virus present in France before 2020? “The difficulty with Covid-19 lies in its protean symptoms. Apart from the loss of taste and smell, which is not systematic, it is very complicated to distinguish it from other respiratory diseases. So some cases may have gone under the radar. Jean-Claude Manuguerra, head of the biological emergency response unit at the ’Institut Pasteur Officially, it all begins on December 12, 2019, in Wuhan, when health officials in China’s Hubei province investigate patients with viral pneumonia.

It was not until January 22, 2020 that the virus entered French territory, with the infection of Laurent Chu from Bordeaux.

“Officially, it all begins on December 12, 2019 in Wuhan, when health officials in the Chinese province of Hubei investigate patients with viral pneumonia. It was not until January 22, 2020, that the virus entered the French territory, with the contamination of the Bordelais Laurent Chu.

However, there are several indications that the virus was already circulating in the country. Indeed, many people have complained afterwards of symptoms similar to those of Covid-19 after travelling in Asia.

In March 2020, thanks to the South China Morning Post, which relies on Chinese government data, we learn that the first Chinese contagion dates back to November 17.

It is believed to have involved a 55-year-old man living in Hubei province. Since then, genetic sequencing of the virus has confirmed the plausibility of this case. The more time passes, the more mutations the viruses accumulate in relation to the genetic sequence of their common ancestor.

Once the frequency of occurrence of these mutations is known, it is possible to trace and calculate how long it took for them to appear.

“20,000 randomly selected volunteers. Antibodies to the virus were found in seven of the samples collected in November, three in December and three in January. Of the thirteen people who tested positive, five experienced typical Covid-19 symptoms.

Significantly, one of them had traveled to Spain in early November, where she had been with a family member with respiratory symptoms of unknown origin.

However, it seems unlikely that these cases were linked to the start of the epidemic, whether in France, Italy or Spain. Rather, they should be seen as false starts, which indicates that some cases that went unnoticed later, in February, may have been at the origin of the epidemic’s dynamics.

« Il It is very rare for an epidemic to start with a single infection,” says e Jean-Claude Manuguerra.. Most of the time, the first contagions escape everyone’s attention and stop by themselves, before the situation gets out of control.

One example: genome analysis of SARS-CoV-2 strains in Iceland concluded that forty-two separate introduction events occurred before the outbreak on the island.”

Passi di: Vincent Bordenave. “Covid-19 – Vérités et légendes”. Apple Books.