The virologists at the Pasteur Institute in Paris have sequenced the genomes from samples taken from 97 French and three Algerian coronavirus patients between January 24 and March 24.
What they found is that the dominant types of Covid-19 viral strains in France differed from those that arrived from China or Italy, and belonged to another group, or ‘clade.’
The earliest sample in the French clade dated from February 19 and came from an infected person who hadn’t traveled abroad recently and had no contacts with possible carriers of the disease.
“We can infer that the virus was silently circulating in France in February” prior to the wave of Covid-19 cases in the country, the virologists said in a paper, published on bioRxiv website but not yet peer-reviewed.
The origins of this third strain were unknown to the scientists. They also pointed out that their sampling was insufficient to reliably establish the time of its introduction in France.
The first coronavirus-related fatality was registered in the country in mid-February, with 129,859 people confirmed as infected and 23,660 dying from complications related to the highly contagious disease since then.