Chikungunya Remains Prevalent in Mayotte With Weekly Cases and Hospitalizations

Health officials in Mayotte continue to monitor a persistent chikungunya outbreak that has seen widespread transmission across the French overseas department. Reports indicate that the virus remains present in the population, with ongoing weekly cases and hospitalizations.

The current situation follows a period of intense activity that began in 2025. According to health reports, Mayotte entered a chikungunya epidemic phase on May 27, 2025. By June 20, 2025, a total of 969 confirmed cases had been recorded since the start of that year.

Epidemic Trends and Geographic Spread

The transmission of the virus has been described as intense and widespread. While a declining trend was noted starting at the end of May 2025, the virus has circulated throughout the country.

Mamoudzou has been identified as the most affected municipality. Other areas showing high epidemic dynamics include the two municipalities of Petite-Terre, as well as Koungou, Mtsamboro, Chiconi, and Dembéni.

The spread of the virus has been comprehensive, with cases reported in all municipalities across the country. For example, in early June 2025, the municipality of Mamoudzou had recorded 210 cases, while Pamandzi and Dzaoudzi reported 102 and 95 cases respectively.

Demographics and Clinical Impact

The outbreak has primarily affected young and middle-aged adults. Data from week 24 of 2025 showed that people aged 25–34 were the most affected group with 214 cumulative cases. This was followed by those aged 45–54 with 162 cases and those aged 35–44 with 147 cases.

Other significantly represented groups include individuals aged 15–24, with 144 cases, and children aged 5–14, with 93 cases. Conversely, the virus has had a more limited impact on children under five and adults aged 65 and over.

Hospitalizations have been recorded as the virus circulated. By June 20, 2025, a total of 36 hospitalizations had been documented. Earlier in the epidemic, during week 21 of 2025, hospitalizations included five children under one year of age and eight pregnant women, the latter of whom were admitted as a precautionary measure due to specific infection risks.

Despite the number of hospitalizations, no deaths have been reported in Mayotte, and no patients have required intensive care.

Regional Context and Public Health Response

The situation in Mayotte is part of a broader regional trend in the Indian Ocean. Since August 2024, widespread transmission of the chikungunya virus has also been documented in La Réunion. In La Réunion, over 47,500 cases and twelve deaths were reported as of May 4, 2025.

The resurgence is notable because the Indian Ocean islands had not experienced major outbreaks for nearly two decades. In Mayotte, the detection of locally transmitted cases marked the first such occurrences since 2005–2006.

To combat the spread, public health authorities have implemented several response measures:

• Enhanced surveillance of new cases.
• Vector control activities to reduce the population of mosquitoes that spread the virus.
• Novel targeted vaccination efforts.

More recent data from March 3, 2026, indicates that 219 chikungunya cases were reported in Mayotte, with rising test positivity. These findings suggest that favorable environmental conditions continue to support the widespread transmission of the virus.