Nearly 40 autochthonous cases of dengue fever have been detected in mainland France since July 2022. Proof of the strengthening of the presence of the tiger mosquito in a large number of departments, but also of the interest of reinforced surveillance by the public health authorities. Explanations.
Dengue fever, a disease under close surveillance in France
Dengue is a viral disease, transmitted in the vast majority of cases when bitten by a tiger mosquito. In more than half of cases, dengue causes no symptoms, but in 10% of cases it can lead to:
- A fever above 38.5°C;
- Unexplained fatigue;
- Headaches ;
- Nausea and vomiting;
- muscle and joint pain;
- As well as a rash, not systematic.
Exceptionally, symptomatic forms of dengue can progress to a severe, potentially fatal form in 24 to 48 hours.. This complication occurs more frequently in children, and during a second infection with the virus.
A reinforced monitoring system under the aegis of Santé Publique France
The existence of severe forms of dengue fever and the arrival of the tiger mosquito on metropolitan territory in recent years has justified the implementation of enhanced monitoring. This is Public Health France who ensures and coordinates this surveillance. This is the same type of device as for the Zika virus and chikungunya. Otherwise, Public Health France is related to the Regional Health Agencies (ARS). Together they collect dengue fever data in the metropolitan departments between 1er May and November 30 each year. The purpose of this monitoring is twofold. The first step is to collect epidemiological data on the evolution of the tiger mosquito and associated vector-borne diseases on the territory of metropolitan France. In a second step, it is necessary to promote an early diagnosis of cases of dengue fever. The aim is to optimize care and prevent serious complications.
Nearly 40 indigenous cases in the summer of 2022
In this year 2022, between 1er May and September 9, Public Health France identified 165 imported cases of dengue fever, of which 156 were diagnosed in departments where the tiger mosquito is documented. At the same time, they identified indigenous cases :
- In the Eastern Pyrenees, only one case;
- In the Hautes Pyrénées, an outbreak of 4 cases between mid-July and the end of August;
- In Haute-Garonne, another focus of 4 cases having affected the same family at the end of August;
- In the Var, an outbreak of 6 cases declared at the start of the summer;
- As well as in the Alpes Maritimes, with an outbreak of 21 cases identified at the end of summer.
The identification of these foci systematically leads to epidemiological and entomological research. A diagnosis of relatives can be put in place, while mosquito control actions can be launched to stop the development of transmission. While the tiger mosquito is now established in the majority of metropolitan departments, monitoring dengue fever cases is a essential means of combating vector-borne diseases transmitted by mosquitoes.
Estelle B., Doctor of Pharmacy