France chikungunya: Local cases reported in new regions

As of July 1, 2025, the number of indigenous chikungunya transmission that have been identified in mainland France now is 14.

For the first time, an episode of indigenous chikungunya transmission has been identified in the Grand Est region, north of the Lyon region.

The occurrence of a first episode of indigenous transmission in the Grand Est region, combined with the precocity and number of episodes already detected, confirms the significant risk of indigenous transmission of chikungunya in mainland France, including in regions that have been free of the disease until now. This is facilitated by the well-adapted nature of the strain of the virus circulating in Réunion and the Indian Ocean to the Aedes albopictus mosquito vector.

Public Health France reiterates the importance of reporting cases, which allows for rapid intervention to limit indigenous transmission, as well as the importance of protective measures against mosquito bites and the control of larval breeding sites.