Key Points

Chikungunya, Dengue, and Zika

• Since May 1, 2026, 120 imported cases of dengue, 33 imported cases of chikungunya, and 2 imported cases of Zika have been identified and investigated in the Île-de-France region.  
• These figures remained significantly lower than those observed in 2025.  

West Nile Virus Infections

• As of October 19, 206, 27 locally acquired human cases of West Nile virus (WNV) infection have been identified in the Île-de-France region, including 15 cases of neuroinvasive disease and 4 deaths.

Bronchiolitis 

• No outbreak at this time 

Influenza 

• No outbreak at this time