Santé publique France.
Surveillance of tick-borne encephalitis (TBE) virus infections in France, 2021-2025. FLASH-INFO Infectious Diseases. No. 39. Published April 2026.
During the last decades, awareness of tick-borne encephalitis (TBE) in France remained limited. Only a few cases were reported annually, mainly in the Alsace region bordering the German federal state of Baden-Württemberg, a well-recognized high-risk area for TBE.
Awareness increased markedly following a food-borne outbreak in eastern France in April 2020 that affected more than 50 individuals (see Newsletter, May 2022).
In 2021, TBE virus infection was added to the list of notifiable diseases (maladies à déclaration obligatoire). Between 2021 and 2023, an average of 35 TBE cases were reported annually in France.
A substantial increase in the number of reported cases was observed in 2024 (n=64). The highest number ever recorded in France was reported in 2025 (n=98). Among these, 81 patients acquired the infection within France. Notably, one patient was infected in the Lozère department in southern France, representing the first documented autochthonous case in this department.
Cases occurred in individuals aged 8–83 years and were reported between April and December, with a peak in July.
Interpretation of epidemiological trends related to TBE virus infections in France remains challenging. The observed increase in reported cases may partly reflect improved awareness among healthcare professionals and increased diagnostic testing. A similar pattern—rising numbers of reported TBE cases associated with greater awareness and expanded diagnostic activity—has also been observed in other western European countries, including Belgium, the Netherlands, and the United Kingdom.