As of September 20, 2022, 47 autochthonous cases of dengue fever have been reported in mainland France since July, divided into five clusters. These numbers mark an increase in autochthonous transmission at multiple levels.
A record number of cases have been identified. The previous peak number of reported cases was 14 in 2020.
The clusters are larger than before. A cluster in a town in the Alpes-Maritimes was particularly large, with 29 cases, and two other cases were also identified nearby. The highest transmission to date involved eight people in Nîmes in 2015.
The risk has spread to previously unaffected departments, including Pyrénées-Orientales, Hautes-Pyrénées and Haute-Garonne. Previous cases had mainly occurred in the Var, Alpes-Maritimes, Hérault and Gard departments.
As a reminder, dengue fever is an infectious disease caused by and transmitted by an arbovirus aedes genus of mosquitoes: Aedes aegypti and Aedes albopictus (Asian tiger mosquito). It most commonly manifests as flu-like symptoms, which may be combined with a skin rash within 3 to 14 days after a bite from an infected mosquito. Dengue fever is usually benign but can be complicated by visceral failure and hemorrhagic forms of the disease that require hospitalization and critical care. The disease is notifiable.
Treatment is symptomatic (analgesics and antipyretics), but aspirin and nonsteroidal anti-inflammatory drugs are contraindicated due to the risk of bleeding.
Why the increase?
There are several factors contributing to this increase in autochthonous transmission in mainland France, including the following:
The territorial extent and high densities of the vector Aedes albopictus Mosquito.
The resumption of travel and the return of travelers from endemic areas.
Climatic conditions of increased heat and rain, both of which contribute to the spread of mosquitoes.
Global warming, drought, heavy rainfall and flooding all contribute to the spread of mosquitoes. This makes arboviruses one of the infectious diseases most closely associated with climate change. Similarly, the massive scale of global trade and movement of people around the world, deforestation, and urbanization all contribute to this spread.
Is prevention possible?
Prevention must be carried out individually and collectively according to the following principles:
Control of mosquito breeding grounds at home and in public places.
Wearing clothing that covers the body and using mosquito nets and repellents (sprays or creams, coils, electric diffusers), especially when traveling to endemic areas and returning from travel, to avoid mosquito infection. It should be mentioned that aedes Vector mosquitoes bite mainly during the day.
Implementation of a mosquito control program by the regional health authorities (ARS) as soon as an imported or autochthonous case is reported.
Vaccine development: The first dengue fever vaccine has been launched, but is not recommended for people living in mainland France.
At the first appearance of symptoms, especially if they appear within 15 days of returning from a trip to a tropical region, consult a healthcare professional for help and recommendations on how to avoid spreading the disease to others (Avoidance of mosquito bites during the trip). contagious time).
A global, multidisciplinary response that engages all societies and communities is essential.
This article has been translated by Univadis France.