Researchers in France have carried out genetic analysis and found that the dominant types of the viral strains in the country did not come from China or Italy.
The coronavirus outbreak in France was not caused by cases imported from China, but from a locally circulating strain of unknown origin, according to a new study by French scientists at the Institut Pasteur in Paris.
Genetic analysis showed that the dominant types of the viral strains in France belonged to a clade – or group with a common ancestor – that did not come from China or Italy, the earliest hotspot in Europe.
“The French outbreak has been mainly seeded by one or several variants of this clade … we can infer that the virus was silently circulating in France in February,” said researchers led by Dr Sylvie van der Werf and Etienne Simon-Loriere in a non-peer reviewed paper released on bioRxiv.org last week.
“Since the earliest European strains of [the coronavirus] Sars-CoV-2 seem to be associated with Belgium, the idea that the virus spread from Belgium to both Italy and France at around the same time seems plausible, as this paper contends,” he said.
France is the latest in a growing number of countries and areas where no direct link between China and local outbreaks could be established.
The dominant strains in Russia and Australia, for instance, came from Europe and the United States, respectively, according to some studies.
These findings have drawn fire from some politicians who have tried to deflect domestic anger over their handling of the crisis by blaming China.
US President Donald Trump lashed out on social media after two separate teams in the US found the strains devastating New York came from Europe.
“So now the Fake News *nytimes is tracing the CoronaVirus origins back to Europe, NOT China. This is a first!” he tweeted on April 11, referring to a story about the studies in the The New York Times’ science section.
The findings also highlight the difficulties governments face in tracing the source of coronavirus outbreaks.
According to some estimates, the ancestor of Sars-CoV-2, the virus causing Covid-19, might have left bats between 50 and 70 years ago.
A recent study by a team of geneticists in Oxford University estimated the first outbreak of the current pandemic could have occurred as early as September last year.
They found that the dominant strains circulating in China and Asia were genetically younger than some popular strains in the United States.