Kenya: Media report that Mombasa County has confirmed a chikungunya outbreak, with 25 of 45 suspected cases testing positive at Kenya Medical Research Institute (KEMRI). The outbreak follows heavy rains that likely boosted mosquito breeding.
Madagascar: At least 13 confirmed travel-associated cases have been imported to European countries: Four cases were confirmed in Florence, Italy, all linked to recent travel to Madagascar. The patients, part of a group of six adults, developed symptoms (arthralgia and fever, one had a rash) between 23–30 May 2025 and tested PCR-positive on 3 June 2025. In addition, chikungunya case were recently confirmed in travelers returning from Madagascar in France (n=6), Brescia, Italy (n=1), Basel, Switzerland (n=1), Antwerp, Belgium (n=1). All of these cases were seen in late May or beginning of June.
Maurice: according to health authorities, in May 5 cases were imported from Maurice.
Mayotte: Mayotte has officially entered the epidemic phase for chikungunya, prompting the activation of Phase 3 of the ORSEC (Civil Security Response Organization) arbovirus response plan on 27 May 2025. From week 10 (3 March) to week 21, 560 cases were confirmed, including 204 in week 21—a 42% rise from the previous week. Imported cases to France have been reported among 5 returning travelers.
La Réunion: The chikungunya epidemic on Réunion Island is in a declining phase but the virus continues to circulate actively. Despite this trend, the outbreak remains significant, particularly among vulnerable groups such as infants, older adults, and those with comorbidities.
Of note: Chikungunya is endemic in most tropical and subtropical countries, even if not explicitly shown on this map.
Chikungunya virus disease case notification rate per 100 000 population between March to May 2025:
Optimal mosquito protection 24/7, also in cities (also against other mosquito-borne diseases such as Zika, dengue).
Two vaccination against chikungunya is licensed in Europe but not yet in Switzerland.
Of note: The European Medicines Agency (EMA), the French National Authority for Health (HAS), and the U.S. health authorities currently do not recommend Ixchiq® vaccination for individuals over 65 years of age, as a small number of possible adverse reactions in this age group are under investigation.
In case of fever:
- Ensure adequate hydration and take paracetamol products.
- Avoid taking medications containing acetylsalicylic acid (e.g., Aspirin®), as this can increase the risk of bleeding during certain viral infections. However, do not stop taking medications containing acetylsalicylic acid if it is already part of your regular treatment for an underlying condition.