France reports 1st local dengue case, chikungunya cases rise to 25
According to French health authorities, a total of 10 new episodes of arboviral transmission transmitted by Aedes albopictus have been identified in mainland France: 9 episodes of chikungunya and 1 of dengue fever. This was announced on July 8.
The cases were reported from the regions of Provence-Alpes-Côte d'Azur, Corsica, Occitanie, Auvergne-Rhône-Alpes, and, for the first time, Grand Est and Nouvelle-Aquitaine. This brings the total autochthonous arbovirus infections to 26 cases.
The first local transmission of dengue fever for 2025 was identified in Auvergne-Rhône-Alpes, with a symptom onset date of July 1, becoming the only case identified to date.
Nine episodes of autochthonous chikungunya transmission were identified, bringing the total for 2025 to 25 cases). The symptom onset dates vary between May 27 and July 1.
In Salon-de-Provence, 12 cases were identified, including 2 cases residing in the neighboring municipalities of Grans and Lambesc. This is the largest outbreak at this stage. Investigations are ongoing.
Despite a decrease in the number of imported chikungunya cases, particularly from Réunion Island and the Indian Ocean, their level contributes to the emergence of indigenous transmissions in mainland France.
The strain circulating in Réunion Island, well adapted to the Aedes albopictus mosquito, facilitates this transmission. To date, in at least four episodes, imported viremic cases from Réunion Island have been identified near the outbreaks and are likely the source of local transmission.
Concerning imported cases, since May 1st, the start of enhanced surveillance, until July 8, 2025, the following have been identified:
552 imported cases of dengue fever
761 imported cases of chikungunya
1 imported case of Zika
Public Health France reiterates the importance of reporting cases, which allows for rapid intervention to limit transmission, as well as the importance of protective measures against mosquito bites and the control of mosquito breeding sites.