Native case of dengue fever reported in Marseille
Health authorities conducting anti-mosquito operations in the city
The first native case of dengue fever in the Provence-Alpes-Côte d’Azur region this year has been declared by regional health authorities.
The case was recorded in Marseille’s 12th arrondissement (Bouches-du-Rhône department) and was probably caused by a tiger mosquito, said the Agence régionale de santé (ARS, regional health authorities) in a press release on Tuesday.
Tiger mosquitoes are responsible for spreading several tropical diseases in France including dengue fever, Zika virus, and chikungunya, and are considered to be ‘established’ in 83 of mainland France’s 96 departments.
West Nile virus is spread by culex mosquitoes native to France.
A native case of any of these tropical diseases occurs when a person falls ill despite not having left mainland France in the previous 15 days.
Mosquitoes can spread these viruses by feeding on those infected with the illness who have returned to France – typically from tropical overseas regions – and then biting other humans to infect them.
This means that the virus can quickly spread in built-up areas.
The ARS is now conducting anti-mosquito operations in Marseille where the case was confirmed. Read more about how these eradication efforts work in our article here.
Symptoms of dengue fever include:
High fever
Nausea and vomiting
Aches and pains
Blotchy skin
Aching or swollen lymph nodes
If you have any of these symptoms and passed through an area where a case has been reported, you should immediately contact your GP or a healthcare professional.
Reduction in diseases reported this summer
French health authorities track the progression of tropical diseases on the mainland until November 30, covering all cases across the summer.
Outbreaks this year are significantly lower than in previous years.
In its most recent bulletin published on August 26, national health body Santé publique France recorded seven outbreak clusters of chikungunya.
A total of 33 cases have been reported across Tarn, Lot (both Occitanie), Gironde (Nouvelle-Aquitaine), and the Val-de-Marne (Île-de-France).
Similarly, there have been five outbreaks of dengue fever this summer, with one to two cases per outbreak.
Incidents have been recorded in Tarn, Hérault (both Occitanie), Dordogne (Nouvelle-Aquitaine), alongside the case in Bouches-du-Rhône mentioned above.
In comparison, there were 809 native cases of chikungunya recorded across 2025, and 30 native cases of dengue fever. In 2024, 83 native cases of dengue fever were reported.
Healthcare professionals are required to report suspected or confirmed cases of these diseases to regional health bodies, so eradication efforts can take place.
There have also been 117 imported cases of chikungunya and 328 imported cases of dengue fever, alongside 11 imported cases of Zika virus so far in 2026, significantly lower than in 2025 (although the summer season is not yet over).
These ‘imported cases’ occur when people have been infected when in tropical locations and return to mainland France.
