Key Points

Dengue, Chikungunya, and Zika

• Nearly 350 locally acquired cases of chikungunya in the region.

• Since the last bulletin, a new episode of local transmission of chikungunya has been identified in the Bouches-du-Rhône department. Several isolated cases with undetermined exposure have also been identified.

• The Paca region is the most affected by local chikungunya transmission, with a total of 28 local transmission outbreaks and 347 cases linked to these outbreaks (+35 since the last update). Four dengue outbreaks totaling 14 cases (+2) have also been identified.

West Nile virus infections

• The Paca region has recorded 25 cases of WNV infection (+3 since the last update, all in the Bouches-du-Rhône department).

Asthma at the Start of the School Year

• In Week 39, three weeks after the start of the school year, asthma-related visits among children under 15 continued to rise at SOS Médecins clinics (47 medical procedures vs. 40 in Week 38), while they declined in hospital emergency departments: 244 emergency room visits vs. 298 in S38, of which 31% were followed by hospitalization (75 vs. 121 in S38).

Acute Respiratory Infections

• Epidemiological surveillance of acute respiratory infections for the 2025–2026 winter season began on September 29, 2025. The first indicators will be published in the weekly bulletin on October 8.