Key points

Dengue, Chikungunya, Zika

• Following the outbreak in La Crau in the Var department, a second locally transmitted chikungunya outbreak has been identified in the region in the municipality of Salon-de-Provence (Bouches-du-Rhône). The number and early onset of outbreaks across France confirm the very high risk of numerous areas with local transmission of chikungunya by 2025.

• Since the start of enhanced surveillance (May 1), 108 imported cases (+18 since the last update) have been identified in the region: 58 cases of chikungunya, 49 cases of dengue, and 1 case of Zika.

Heatwave

• No heat wave currently underway. Temperatures rising toward the end of the week.

• Emergency service activity related to the heat remains stable at a level typical for this time of year. Activity among SOS Médecins associations in S25 is rising to a level higher than expected for this time of year.

Pollen exposure, which may pose an allergy 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 high level, primarily due to grass pollen. Allergy-related activity at SOS Médecins associations is stable.

Monthly report on notifiable diseases

• Update on reports of Legionnaires’ disease, hepatitis A, invasive meningococcal disease (IMD), measles, and foodborne illness outbreaks (FBO) in PACA: 58 reports in May 2025, including 10 cases of Legionnaires’ disease, 13 cases of hepatitis A, 4 cases of IIM, 29 cases of measles, and 2 outbreaks of foodborne illness.

• The number of measles cases reported in the first 5 months of 2025 (98) exceeds the total number of cases reported in 2024 (63).