Key Points

Chikungunya, Dengue, and Zika

• Since May 1, 2026, 115 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.
• In the Île-de-France region, the first outbreak of locally transmitted chikungunya was identified in Nogent-sur-Marne in Val-de-Marne (94), with 6 cases identified to date. The onset dates of symptoms for these 6 cases range from August 16 to August 29.

West Nile Virus Infections

• As of October 4, 2026, 24 locally acquired human cases of West Nile virus (WNV) infection have been identified in the Île-de-France region.

COVID-19

• After five weeks of increases around the start of the school year, the number of emergency department visits for suspected COVID-19 decreased in week 40. This decline was observed among children under 15 and adults aged 65 and older.

Typhoid Fever

• Since the beginning of 2026, the number of typhoid fever cases among travelers returning from Senegal has risen sharply in the Île-de-France region, with 41 cases reported. Between 2022 and 2025, between 9 and 18 cases were reported each year.