Chikungunya is circulating at a level never seen before in mainland France this early in the year

Chikungunya is circulating at an unprecedented level this early in the year in mainland France, with eight indigenous cases detected so far, the public health agency reported on Wednesday, establishing a clear link with the epidemic that has been ongoing for several months in Réunion.

"These indigenous cases, whose first symptoms appeared between May 27 and June 19, are the earliest ever identified in mainland France," Public Health France emphasizes in a weekly report.

An indigenous case means that the infection occurred locally and not outside the country. This means that the chikungunya virus, which is transmitted through tiger mosquito bites, is actively circulating in France.

So far, eight indigenous cases have been detected, all in the south of the country: in Hérault, Var, Bouches-du-Rhône, Drôme, Gard and Corsica.

"Such an early start in the mosquito activity season and such a high number of episodes have never been observed until now," insists Public Health France.

The agency had already warned last week that the first cases were the earliest ever identified in mainland France, but, with this acceleration, it is this time even more assertive about the unprecedented nature of this year.

High temperatures contribute to the circulation of the tiger mosquito

Furthermore, Public Health France says it has established a clear link between several cases that have appeared in mainland France and the epidemic currently underway overseas in Réunion, where some 200,000 residents have been infected since March and around twenty deaths.

"For at least two indigenous cases, the identification of viremic cases from Reunion Island (is) probably the origin of local transmission," the agency emphasizes.

Although we cannot yet speak of an epidemic in mainland France, this observation fuels fears of epidemic transmission between Reunion Island and mainland France. This risk has been raised by health authorities for several weeks.

It is all the more heightened with the return of high temperatures in mainland France. High temperatures contribute to the circulation of the tiger mosquito, a phenomenon exacerbated by global warming.

In parallel with Réunion, where the epidemic is now clearly easing with the arrival of the southern winter, another chikungunya epidemic is also underway in Mayotte.

But its extent is difficult to determine, with authorities believing that the number of reported cases is probably lower than the actual number.