On March 15, the Directorate General of Health (DGS) sent a note to health professionals concerning a new variant of Covid-19, called "20C" and nicknamed "Breton variant". This strain was detected in the Lannion hospital center (Côtes-d'Armor) where 79 cases of coronavirus were identified, including 8 carriers of the variant. These results were confirmed by sequencing. The patients showed symptoms of the infection, but their nasopharyngeal screening tests were negative.
The Brittany Regional Health Agency (ARS) and the Prefect of Côtes-d'Armor announced Tuesday, March 16 at a press conference, that the eight patients affected by this mutation had died. For the time being there is "no causal link established between these deaths and the new variant ".
Investigations to assess the severity of the Breton variant
"The molecular analysis carried out by the CNR de Pasteur reveals a new variant carrying nine mutations in the region encoding the S protein but also in other viral regions", can we read in the document of the DGS. She also said that an assessment is underway to determine "the possible impact of these genetic modifications on a lack of recognition by virological tests leading to an underdiagnosis ".
Health authorities have also started investigations to assess the severity and spread of the Breton variant. "The first analyzes of this new variant do not allow to conclude either an increased severity or transmissibility compared to the historical virus ", however specified the DGS.
An opinion shared by Professor Bruno Lina, virologist and member of the Scientific Council: "It is a virus which today does not present any dangerous character, it is not more severe, it does not give longer infections and it seems to spread in a relatively restricted way (…). realizes that we probably do not have a very important spread of this virus ", he explained on RTL.
Breton variant: are other screening tests reliable to detect it?
Asked by BFMTV, Pierre Tattevin, head of the infectious diseases department at Rennes University Hospital (Ille-et-Vilaine) explained why PCR tests in patients affected by the Breton variant were negative. "Most often, it is related to the fact that the patient does not excrete through the nose ", he explains. "Our colleagues performed serological tests or lung samples. They then found traces coronavirus, but different from the one we knew ", underlined the specialist.
According to Pierre Tattevin, it is possible to use serological tests to detect the coronavirus, but the diagnosis is later. It occurs 7 to 10 days after infection. Health professionals can also perform more technical examinations. "Patients can be made to spit by irritating the airways a bit. We can obtain deeper samples without the need for overly invasive tests ", he detailed.
The head of the infectious diseases department at Rennes University Hospital, however, admitted that it is more complicated to identify cases of coronavirus. "Due to diagnostic difficulties, we do not have exact figures on the number of patients affected by the new variant, but several dozen cases have been recorded in recent weeks ", said Pierre Tattevin. According to him, it is too early to estimate the virulence of this new strain, but some patients have developed severe forms.
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