Chikungunya Outbreak Surpasses 27,000 Cases

When the U.S. Centers for Disease Control and Prevention (CDC) issued a Level 2 Travel Health Advisory regarding an outbreak of chikungunya in France's Réunion in February 2025, most public health experts did not expect an overwhelming epidemic.

As of April 12, 2025, Réunion Island has become the leading chikungunya outbreak in the world.

Since the beginning of 2025, 27,521 confirmed cases of this mosquito-transmitted disease have been reported.

More concerning is data from ARS Réunion last week. 

From March 24 to 30, 2025, there were 6,289 confirmed cases and 54 hospitalizations in Le Tampon (800 cases), Saint-Paul (900 cases), Saint-Denis (750 cases), and Saint-Pierre (600 cases). 

ARS Réunion says people can protect yourself by preventing mosquito bites, or participating in a free vaccination program.

The first phase of the 40,000 vaccination campaign has been launched with the single-dose IXCHIQ® vaccine. It is available for people aged 65 and over with comorbidities and who have not previously contracted chikungunya.

Over the last few years, most chikungunya cases in the U.S. have been related to returning international travelers from tropical and subtropical regions. Diagnosing chikungunya is challenging, as people may also have been infected with dengue or Zika.

According to the U.S. CDC, vaccination against chikungunya is recommended for adults and some adolescents traveling to a destination with a current chikungunya outbreak, such as Réunion.