Key Points

• Since January 1, 2025, 868 cases of measles have occurred and been reported (an increase of 2 new cases in November). The decline in the number of cases observed since May continued through September and persisted through November, consistent with the known seasonal pattern of measles.

• Of these cases, 305 (35%) were hospitalized (including 12 in intensive care), and 121 cases (14%) developed complications (including 70 cases of pneumonia and 2 cases of encephalitis). Four deaths attributable to measles were reported, all in immunocompromised patients.

• The median age of cases is 16.7 years. The four age groups most affected are children aged 1–4 years (15%), adults aged 40 and older (14%), and adolescents aged 10–14 years (12%) and 15–19 years (12%).

• Among the target population for vaccination (those over 1 year of age and born since 1980), for whom vaccination status was known (n=614), 406 (66%) were unvaccinated or incompletely vaccinated, 191 (31%) had received two doses, and 17 (3%) had been vaccinated but the number of doses received was not specified.

• 72 departments in France (71%) reported at least one case during the period, including 4 cases reported in the Overseas Territories (Réunion). The five departments with the highest number of reported cases are: Nord (15%), Bouches-du-Rhône (6%), Aude (6%), Haute-Savoie (5%), and Isère (5%).

• During the period, 113 clusters of cases (groups of epidemiologically linked cases) were reported to the Regional Health Agencies (ARS) (provisional, unconsolidated data) for a total of 523 cases. Among these, 31 clusters involved 5 or more cases, and only one cluster (of imported origin) is still active.