Key Points 

Smallpox B (mpox)

• As of May 19, 2026, there were 73 confirmed cases and 2 probable cases in Île-de-France.
• Of the 87 confirmed cases in 2026 as of June 2:
  • In April 2026, 36 cases were detected, a 300% increase compared to March 2026. In May 2026, the number of cases decreased to 28 according to data available at this time, a 22.2% drop compared to April.
  • 86% of cases were concentrated in the 15–44 age group.
  • 92% of cases were among males, with a median age of 32 years (range: 17–62 years). Among females, the median age was also 32 years, but for a younger population (range: 21–35 years).
  • 10 cases (11.4%) required hospitalization, including one case of ocular mpox. No deaths have been reported to date.
  • 43 cases (49.4%) were residents of Paris (75), and among the 79 cases with known vaccination status, 22 (28.6%) reported having been vaccinated ≥1 time since 2002.

Chikungunya, dengue, and Zika

• Imported cases: 30 of dengue, 2 of chikungunya

Extreme heat and heat waves 

• On 05/25/2026, four departments in the Île-de-France region (Paris, Hauts-de-Seine, Seine-Saint-Denis, Val-de-Marne) were placed under a yellow heatwave alert by Météo-France. On May 28, 2026, these same departments were upgraded to an orange heat wave alert, while Seine-et-Marne, Yvelines, Essonne, and Val-d’Oise were placed under a yellow heat wave alert. On Saturday, May 30, 2026, the departments of Paris, Hauts-de-Seine, Seine-Saint-Denis, and Val-de-Marne were downgraded from orange to yellow. On Sunday, May 31, 2026, at 6:00 a.m., all departments were downgraded to the green level.