To what extent does the British variant of Covid-19 circulating on French territory? During his hearing in the Senate, the Minister of Health Olivier Véran revealed that “The virologist Bruno Lina had found approximately 1% of variant of English origin among the positive PCRs in France ”. This percentage is taken from the study called Flash and conducted from all the RT-PCR tests that came back positive on the days of January 7 and 8 in mainland France. The final results and the mapping of the mutation should be communicated this Thursday, January 14 in the weekly bulletin of Public Health France.
To detect the British variant, which is more contagious, the biologists first analyzed all the positive RT-PCR tests with a specific machine called Thermo Fisher. “With this technique, if the RT-PCR is positive for Covid-19, three signals turn green, explains Alain Le Meur, Director of Development at Biogroup. In the event of a mutation, two out of three lights come on: the target which detects the S protein, characteristic of the virus, does not react, which indicates an anomaly compared to the base strain ”. To be certain of this result, the RT-PCR test is then sent to the National Center for Research on Respiratory Viruses in Lyon for genome sequencing.
Eleven cases confirmed in Ile-de-France
Apart from the Flash study, the mutant virus has already been detected in the country and in particular in Ile-de-France: to date eleven cases have been confirmed and around forty others are “Probable” and awaiting sequencing results. In this territory, the hunt has intensified particularly since the discovery of a case on Friday January 8, in Bagneux in the Hauts-de-Seine department. The infected person had no connection with England, “We have therefore set up a massive screening campaign which is still ongoing for the population of Bagneux (just under 40,000 inhabitants) to find out if the virus mutation is circulating in the city ”, we told the Ile-de-France Regional Health Agency.
→ REPORTAGE. Bagneux in search of the English variant
“What worries me the most are all these sporadic cases, where the epidemiological link between England or Ireland cannot be made. This is a sign that the virus is already circulating in the metropolis ”, warns Professor Denis Malvy, infectious disease specialist at Bordeaux University Hospital and member of the scientific council.
“The strain will have become dominant in the spring in France”
Can the British variant spread to the point of overcoming the original strain? ” It seems inevitable ”, regrets the epidemiologist Renaud Piarroux. According to his prediction, the percentage of positive tests for the British variant “Will take about five weeks to go from 1 to 10% and the strain will have become dominant by early spring ».
A scenario to which Professor Malvy adheres: “This is what happened in the UK where the variant was detected at the end of September. Now, the epidemic is out of control at home. “
The urgency to set up “Difficult measures”
“Today 25,000 people are hospitalized because of Covid-19, against 32,000 during the peak of last April. A stationary but very high figure, describes Renaud Piarroux. We can still manage to slow down the epidemic, we still have levers, such as containment. “ Difficult measurements “Which nobody wants”, recognizes the epidemiologist, but according to him we must resolve “From the moment we have learned that the situation can only get worse because of the presence of the English variant”.
→ EXPLICATION. Covid-19: Are the new variants worrying?
In a note probably published Thursday January 14 in parallel with the government announcements, the Scientific Council should also plead for “Strong and emergency measures”. Professor Denis Malvy believes that we are now in a race against time between vaccination and the British variant: “We know that the Pfizer vaccine is effective against the British variant, so we need to vaccinate as many vulnerable people as quickly as possible to save lives and also to protect our hospitals that would not stand another assault.”