Key Points

Chikungunya, Dengue, and Zika

Indigenous Cases

As of October 26, 2026, 34 outbreaks (+7 new outbreaks compared to the previous week) of locally transmitted vector-borne disease were identified in mainland France:

• 29 episodes of chikungunya (+7 new episodes compared to the previous week), totaling 205 cases (1 to 36 cases per episode) in the Tarn, Lot, and Gard departments (Occitanie), in Gironde, the Landes, and the Pyrénées-Atlantiques (Nouvelle-Aquitaine), in Val-de-Marne and Seine-Saint-Denis (Île-de-France), and in the Var (Provence-Alpes-Côte d'Azur);
• 5 dengue outbreaks (no new outbreaks compared to the previous week) totaling 8 cases (1 to 2 cases per outbreak) in the Tarn, the Hérault (Occitanie), the Bouches-du-Rhône, the Var (Provence-Alpes-Côte d'Azur), and the Dordogne (Nouvelle-Aquitaine).

Investigations and prevention and control measures are underway for the various outbreaks that are still active.

Imported Cases

From May 1, when enhanced surveillance began, through October 25, 2026, the following were identified:

• 162 imported cases of chikungunya
• 467 imported cases of dengue
• 17 imported cases of Zika

West Nile virus infections

Locally acquired cases

• As of October 26, 2026, 201 locally acquired cases of West Nile virus infection (+6 compared to the previous week) had been identified in mainland France. They are located in the Provence-Alpes-Côte d'Azur region (3 departments), Occitanie (7 departments), Île-de-France (7 departments), Auvergne-Rhône-Alpes (5 departments), Nouvelle-Aquitaine (2 departments), Pays de la Loire (4 departments), Centre-Val de Loire (Loiret department), and Corsica (2 departments). For 20 cases, no specific site of infection could be identified. For one of these cases, it could not be determined whether the infection was locally acquired or imported.