It has been a constant in recent years, the number of cases of dengue fever is increasing in Europe and in France. Last October, in Île-de-France, a first indigenous case of dengue had been detected, according to the Regional Health Agency. An unprecedented situation at the time. At the European level, the European Center for Disease Prevention and Control (ECDC) notes in its bulletin of June 11, 2024 “a significant increase compared to the ten year period 2010-2021”.
Indeed, according to the latest figures for 2023, 130 locally contracted cases of dengue fever were reported in the EU/EEA, while 71 cases were reported in 2022. Over the last 10 years, only 73 cases were locally contracted. So how can we explain this increase? We take stock.
Dengue fever: how is the “tropical flu” transmitted?
In France, 2,166 cases of imported dengue fever have been recorded in mainland France between January 1 and April 30, compared to 131 cases over the same period in 2023. These alarming figures pushed the Directorate General of Health and Public Health France to sound the alarm during a press conference on April 23, 2024, in order to take stock of the situation epidemiology in France and good practices to adoptas the start of the activity period approaches tiger mosquito. Indeed, the number of dengue cases is particularly monitored between May 1 and November 30, the period of activity of the tiger mosquito, vector of the virus.
As a reminder, the virus the dengue is transmitted by the bite of an Aedes mosquito (such as the tiger mosquito) carrying one of the four dengue viruses, present in mainland France for several years, but especially in overseas regions such as Guadeloupe, Guyana, and Martinique. Dengue fever most often causes flu-like symptoms such as fever, headache, or body aches, within 3 to 14 days after being bitten by a carrier tiger mosquito.
How can we explain the increase in cases in France and Europe?
Faced with the increase in cases, the European Center for Disease Prevention and Control believes that global warming has a role to play. “Europe is already seeing how climate change is creating more favorable conditions for invasive mosquitoes to spread to previously untouched areas and transmit diseases such as dengue fever to more people,” explains Andrea Ammon, director of the ECDC in a press release published on June 11, 2024.
The latter specifies that travel can also impact the number of cases in Europe. “Increased international travel from countries where dengue is endemic will also increase the risk of imported cases, and inevitably also the risk of local outbreaks,” she emphasizes. In France, 82% of imported cases come from the French West Indies (Guadeloupe and Martinique), where an epidemic is underway since September-October 2023. However, this epidemic does not equal the levels of that of 2010, but has many more cases imported to the mainland. However, this increase does not only concern the French West Indies, but the entire area of Latin America and the Caribbean.
Dengue: “reinforced surveillance” of tiger mosquitoes as the Olympics approach
The Directorate General of Health noted in its press briefing on April 23 that “the Olympic Games are not an additional risk factor, what is is the increased flow of travelers”, the Ile-de-France Regional Health Agency reaffirmed that “vector control is one of the Agency’s priorities and the actions carried out are reinforced within the framework of the Paris 2024 Olympic and Paralympic Games”.
Indeed, according to the Mosquito Vigilance site, because of the Olympics, “expected tourist flows will increase the risk of appearance of imported cases of dengue, chikungunya or Zika”, or, when they appear “in departments in red or purple, the risk of developing outbreaks of indigenous cases increases with it”.
In anticipation of these risks, the ARS of Ile-de-France affirmed that “the actions of public authorities have been reinforced, in particular in terms of awareness and prevention for travelers departing from or arriving in endemic areas of these pathologies, as well as identification and reduction of areas conducive to the proliferation of mosquitoes near places of large gatherings”.
Good reflexes to fight against the tiger mosquito
Among the good reflexes to adopt to stem the proliferation tiger mosquitothe General Directorate of Health recalled the importance ofeliminate stagnant water indoors or near homes. She also recommended that people traveling to risk areas such as Guadeloupe, Martinique, or Guyana protect yourself from mosquito bitesin order to avoid contracting the disease.
For those returning from risk areas, it is advisable to continue protecting yourself from mosquito bites for three weeks, in order to prevent a tiger mosquito from possibly being contaminated and in turn transmitting the virus, but also to consult your doctor as soon as possible if you experience symptoms.
Sources :
- Upsurge in imported cases of dengue fever in mainland France: call for vigilance as the tiger mosquito activity season approaches – Public Health France – April 23, 2024
- Upsurge in cases of dengue fever imported into mainland France: health authorities call for vigilance as the period of tiger mosquito activity approaches – Directorate General of Health – April 23, 2024
- Vector control: strengthening surveillance of the tiger mosquito from May to November 2024 – Ile-de-France Regional Health Agency – May 16, 2024
- Mosquito Vigilance
- Mosquito-borne diseases: an emerging threat – European Center for Disease Prevention and Control (06/11/2024)
