Key Points

Chikungunya, Dengue, and Zika

Since the start of enhanced surveillance (May 1), 33 imported cases (+9 since the last update) have been identified in the region: 20 cases of chikungunya, 12 cases of dengue, and 1 case of Zika.

The chikungunya outbreaks in Réunion (and more broadly in the Indian Ocean) and the dengue outbreaks in Guadeloupe are having a significant impact on surveillance in mainland France.

Measles

• In April 2025, measles circulation remained high in the region. The vast majority of cases were among under-vaccinated individuals.

Pollen exposure, which may pose an allergic risk

• In the Provence-Alpes-Côte d’Azur region, the pollen index—established by Atmo France and accredited air quality monitoring associations—is at a moderate to high level, primarily due to grass pollen.