Key Points

• Since January 1, 2025, 873 cases of measles have occurred and been reported (an increase of 7 new cases in December). The decline in the number of cases observed since May continued through September, after which the number of cases remained at a very low level until the end of December, consistent with the known seasonal pattern of measles.

• Of these cases, 314 (36%) 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=620), 416 (67%) were unvaccinated or incompletely vaccinated, 194 (31%) had received two doses, and 9 (1%) had been vaccinated but the number of doses received was not specified.

• 71 departments in France (70%) 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, 114 clusters of cases (groups of epidemiologically linked cases) were reported to the Regional Health Agencies (ARS) (provisional, unconsolidated data), totaling 530 cases. Among these, 31 clusters involved 5 or more cases, and none are currently active.