Chikungunya, Dengue, and Zika in the Pays de la Loire region. 2025 Report.

Published on 7 May 2026

Key Points

Between May 1 and November 30, 2025, 120 cases of arbovirus diseases were reported in the region, all of which were imported:
- 69 cases of chikungunya
- 50 cases of dengue
- 1 case of Zika
These cases were mainly returning from Réunion (chikungunya) and the French Antilles (dengue), where epidemics were raging during that same period.
A record number of locally acquired cases (nearly 800) were reported in mainland France in 2025.
No locally acquired cases were reported in the region.
Nearly 1.4 million people in the region were exposed to the tiger mosquito in 2025, representing 37% of the regional population (2% in 2020).

Chikungunya

thematic dossier

22 April 2026

Chikungunya is a viral disease transmitted by mosquitoes of the genus Aedes. The most common symptoms are fever and joint pain.

Dengue

thematic dossier

22 April 2026

Dengue fever is a viral disease transmitted by mosquitoes of the genus Aedes. The most common symptoms are fever and joint pain. Its complications can be severe.

Zika

thematic dossier

22 April 2026

Zika is a viral disease transmitted primarily by mosquitoes but also through sexual contact. Symptoms are usually mild, but the virus can cause birth defects if a woman becomes infected during...