Key Points

Chikungunya / Dengue / Zika

In Occitanie, from May 1 to October 21, 2025, the following cases were identified:

• 94 imported cases of dengue, 102 imported cases of chikungunya, and 1 imported case of Zika.

• 84 locally transmitted cases of chikungunya: 42 in Gard and 42 in Hérault.

• 6 locally acquired cases of dengue: 3 in Haute-Garonne, 1 in Lot, 1 in Pyrénées-Orientales, and 1 in Hérault.

To limit the risk of local transmission, 323 entomological surveys and 266 vector control treatments were carried out in the vicinity of the cases.

West Nile Virus

Episodes of local transmission:

• 8 confirmed human cases of West Nile Virus infection were identified in 2025.

• 5 cases in the Hérault department in the municipalities of Florensac, Agde (2), Pomerols, and Castelnau-le-Lez. The onset dates of symptoms ranged from July 18, 2025, to September 23, 2025. Among these cases, one person presented with a neuroinvasive form, and two were identified following screening conducted by the French Blood Establishment during blood donations.

• 1 case in Haute-Garonne who developed symptoms on 08/27 and was hospitalized for a neuroinvasive form on 08/31.

• Two probable cases of West Nile virus infection identified in Tarn-et-Garonne in Aucamville (onset of symptoms on 08/20/2025), the first identified in this department.

Measures to ensure the safety of human-derived products (blood donations and transplants) have been implemented in the affected departments.