Key Points

Chikungunya, Dengue, and Zika

Indigenous cases:

As of October 13, 2025, 90 outbreaks of locally transmitted chikungunya and dengue and a total of 770 cases have been identified in mainland France:

• 729 cases of chikungunya spread across 78 outbreaks (1 to 134 cases per outbreak; 33 of these outbreaks have been contained)

• 28 cases of dengue spread across 12 outbreaks (1 to 8 cases per outbreak; 9 of these outbreaks have been resolved)

• 13 isolated cases of chikungunya for which the exact site of infection could not be identified

Imported cases

From May 1, the start of enhanced surveillance, through October 13, 2025, the following were identified:

• 1,014 imported cases of chikungunya

• 987 imported cases of dengue

• 11 imported cases of Zika

West Nile virus infections

Indigenous cases

As of October 13, 2025, 48 human cases of vector-borne West Nile virus infection have been identified in 15 departments of mainland France. The affected regions are Provence-Alpes-Côte d'Azur, Occitanie, Nouvelle-Aquitaine, and, for the first time, Île-de-France and Auvergne-Rhône-Alpes.