Key Points

Chikungunya, dengue, Zika

9 episodes of local transmission detected

• Seven outbreaks of local transmission of chikungunya have been identified in the region as of November 4, 2025, accounting for 52 cases. A new outbreak involving a locally acquired case of chikungunya, detected retrospectively and already resolved, has been identified in Meyzieu, Rhône. The latest active outbreak is in Varces (38) with 4 reported cases.

• Two episodes of local dengue transmission, totaling 4 cases.

Summary of imported cases

• From May 1 to November 4, 2025: 163 imported cases of chikungunya, 154 imported cases of dengue, and two imported cases of Zika;

• Most of these individuals were returning from a trip to the French overseas territories.

West Nile

• As of November 4, 2025, two human cases of West Nile virus infection, likely acquired through a vector, were identified in Puy-de-Dôme and Ardèche.