Key Points

• Since January 1, 2025, 828 cases of measles have occurred and been reported (an increase of 23 new cases in August). The surge in cases observed since January has been declining since May.

• Of these cases, 289 (35%) were hospitalized (including 12 in intensive care), and 111 (13%) developed complications (including 65 cases of pneumonia and 1 case of encephalitis); 2 deaths were reported.

• The median age of cases is 16.6 years. The three age groups most affected are children aged 1–4 years (15%), adults aged 40 and older (14%), and adolescents aged 15–19 years (12%).

• Among the individuals targeted for vaccination (aged over 1 year and born since 1980), for whom vaccination status was known (n=578), 376 (65%) were unvaccinated or incompletely vaccinated, 186 (32%) had received two doses, and 16 (3%) had been vaccinated without the number of doses received being specified.

• 70 departments in France (69%) reported at least one case during the period, including 3 cases reported in the Overseas Territories (Réunion). The five departments with the highest number of reported cases are: Nord (16%), Bouches-du-Rhône (7%), Aude (6%), Haute-Savoie (5%), and Isère (5%).

• During the period, 108 clusters of cases (groups of epidemiologically linked cases) were reported to the Regional Health Agencies (ARS) (provisional, unconsolidated data), totaling 502 cases. Among these, 30 clusters involved 5 or more cases, and 3 are still active.