An indigenous case of dengue, most likely transmitted locally by a mosquito, has been reported for the first time in Île-de-France, announced the health authorities on Tuesday. This is unprecedented for such a northern region in mainland France.
The regional health agency (ARS) confirmed in a statement that this is the “first indigenous case of dengue in Île-de-France.” The case was identified in Limeil-Brévannes (Val-de-Marne), about fifteen kilometers southeast of Paris.
Increase in indigenous cases
An “indigenous case” means that the person has not recently traveled to regions of the world, such as the French West Indies, where this virus is widely circulating and transmitted from person to person by tiger mosquitoes.
This means that the person was most likely infected locally after being bitten by one of these mosquitoes, whose presence has been increasing for nearly 20 years in mainland France, facilitated by climate change.
This logically results in an unprecedented increase in indigenous cases of dengue in mainland France: 66 in 2022, with already about thirty for the current year. These cases were previously observed in southern regions, which have a climate more favorable to tiger mosquitoes. The case mentioned by ARS Île-de-France is therefore the first in such a northern region.
“Exceptional” situation
In 2022, the epidemiological situation regarding dengue in mainland France was “exceptional,” according to a report published this summer by Santé publique France. Indigenous transmissions for just the last year exceeded the total number of cases identified from 2010 to 2021 (66 cases, compared to 48).
Dengue is a viral disease that is characterized by high fever and, in rare cases, can progress to a more severe form causing bleeding. However, deaths are very rare, accounting for approximately 0.01% of all cases.
In the Overseas, the French West Indies have been in an epidemic phase since mid-August, and health authorities are monitoring high-risk profiles for severe forms, particularly patients with sickle cell disease.
