Tiger mosquito expansion reaches 81 French departments

The tiger mosquito (Aedes albopictus) has expanded significantly across France, occupying 81 departments in metropolitan France as of early 2025. This represents approximately 84% of the national territory. Since its arrival in Menton in 2004, the insect has spread at a rate of two to three departments per year, moving north toward regions like Seine-Maritime.

Health authorities have confirmed an autochthonous case of chikungunya in Nogent-sur-Marne, near Paris. This marks the first local transmission of the virus identified in the Île-de-France region for 2026. The infected individual did not travel to an endemic area, indicating the virus was transmitted locally.

In response, Santé publique France has launched a sanitary investigation, including door-to-door searches for symptomatic residents and mosquito control operations. Experts note that mild winters and climate change are accelerating the mosquito's expansion and lengthening its period of activity.