France: Locally acquired chikungunya rises to 15 cases

Surveillance for dengue, chikungunya, Zika, and West Nile virus infections is based on mandatory reporting. During the active season of the *Aedes albopictus* vector mosquito (tiger mosquito) in mainland France—from May 1 to November 30—this is supplemented by a seasonal enhanced surveillance system

Santé publique France reports as of August 10, 2026, five episodes of autochthonous vector-borne transmission have been identified in mainland France:

• 3 chikungunya episodes totaling 15 cases (1 to 8 cases per episode) in the Tarn (Occitanie) and Gironde (Nouvelle-Aquitaine) departments.

• 2 dengue episodes (1 case per episode) in the Tarn and Hérault departments (Occitanie).

Bacterial vaginosis (BV) and the increased risk of sexually transmitted infection (STI) coinfections

Investigations and prevention and control measures are underway for these various events.

From May 1—the start of enhanced surveillance—through August 9, 2026, the following were identified:

• 105 imported cases of chikungunya

• 295 imported cases of dengue

• 10 imported cases of Zika

Concerning West Nile virus, as of August 10, 2026, six autochthonous cases of West Nile virus infection have been identified in mainland France. These cases are located in the Provence-Alpes-Côte d’Azur region (Bouches-du-Rhône and Vaucluse departments) and the Occitanie region (Pyrénées-Orientales and Aude departments).