Key Points

Local cases

As of July 22, 2025, fifteen outbreaks of local transmission have been identified in mainland France:

• 12 chikungunya outbreaks (1 to 13 cases per outbreak)

• 3 dengue outbreaks (1 to 2 cases)

These total 42 cases and are located in the Provence-Alpes-Côte d'Azur, Corsica, Occitanie, and Auvergne-Rhône-Alpes regions—which were already affected in previous years—and, for the first time, in Grand Est and Nouvelle-Aquitaine.

The number of transmission clusters highlights the significant risk of local transmission of these viruses in mainland France. Additional cases are likely to be identified, including outside the usual transmission zones.

Santé publique France reiterates the importance of reporting cases, which enables rapid intervention to limit transmission, as well as the importance of protective measures against mosquito bites and efforts to control larval breeding sites.

Imported cases

From May 1, the start of enhanced surveillance, through July 22, 2025, the following were identified:

• 833 imported cases of chikungunya

• 624 imported cases of dengue

• 2 imported cases of Zika