France's Next Chikungunya Outbreak

The Mayotte Regional Health Agency announced today that it has detected its first case of imported Chikungunya on the main island off the east coast of Africa.

On March 5, 2025, a Mamoudzou resident returned from visiting La Reunion Island, another of France's overseas departments. These departments are separated by the island of Madagascar and the Mozambique Channel. 

Following this identification, the ARS of Mayotte immediately implemented vector control actions to identify larval breeding sites around the person's home. Local health professionals and emergency services have been informed of the situation.

No indigenous case has been reported in Mayotte to date. 

Generally, a single, travel-related Chikungunya case does not generate significant actions.

However, since late August 2024, La Reunion has been facing a Chikungunya epidemic, with 3,390 cases recorded.

Furthermore, an apparent Chikungunya epidemic has increased in late February and early March 2025. During one week, 1,300 new cases of Chikungunya were confirmed.

In mainland France, 25 travel-related cases were reported in 2024. And, for the first time, Ile de France (Paris) reported a locally acquired Chikungunya case.

The World Health Organization says Chikungunya transmissions have occurred frequently in about 110 countries.

So far this year, 49,491 Chikungunya cases and two related fatalities have been confirmed in the Region of the Americas. In 2024, over 400,000 cases were confirmed.

Most people infected with the Chikungunya virus develop some symptoms 3–7 days after a bite by an infected mosquito. People at risk for more severe disease include newborns infected around the time of birth, older adults, and people with medical conditions.

Chikungunya has recently become a vaccine-preventable disease.

Since late 2023, an innovative vaccine has been available in various countries, including the United States. The U.S. CDC recommends Valneva SE's IXCHIQ® vaccine for certain international travelers in 2025. This vaccine is often offered at travel clinics and pharmacies,