Key Points 

• Since January 1, 2026, 77 cases of measles have been reported, including 32 new cases in April. The number of cases reported during the first four months of the year remains well below that of 2025 for the same period (530 cases).
• Of these cases, 24 (31%) were hospitalized (including 1 in intensive care), and 14 cases (18%) developed complications (including 6 cases of pneumonia). No deaths have been reported.
• The median age of cases is 21 years. The three most affected age groups are children aged 1–4 years (16%), adults aged 20–24 years (16%), and adults aged 40 years and older (16%).
• Among the individuals targeted for vaccination (aged over one year and born since 1980) for whom vaccination status was known (n=52), 28 (54%) were not up to date on their vaccinations, while 24 (46%) had received two doses.
• 24 departments (24%) reported at least one case during the period. The departments with the highest number of reported cases are: Yvelines (10%), Moselle (9%), Hauts-de-Seine (9%), Meurthe-et-Moselle (8%), Paris (8%), and Essonne (8%). No cases were reported in the overseas territories.
• During the period, 12 outbreaks (clusters of epidemiologically linked cases) were reported to the Regional Health Agencies (ARS) with a total of 48 cases (provisional, unconsolidated data). Among these, 4 outbreaks accounted for 5 or more cases. Three outbreaks are still active.