Key Points

Chikungunya, Dengue, and Zika 

• Since May 1, 2026, 67 imported cases of dengue, 12 imported cases of chikungunya, and 2 imported cases of Zika have been identified and investigated in the Île-de-France region (compared with a cumulative total of 124 imported cases of dengue and 145 imported cases of chikungunya during the same period in 2025).

Smallpox B (mpox)

• The weekly number of smallpox B cases in the Île-de-France region increased during April, followed by a decrease in May and a gradual decline that continued into July. 
• The year 2026 is characterized by an early surge in the circulation of the smallpox B virus, with the total number of cases already exceeding that of 2025.