The holidays are over, the start of the school year has begun but vigilance against the tiger mosquito must not drop, alert Public Health France (SPF). This reminder comes in the context of the appearance of so-called dengue outbreaks “indigenous“in metropolitan France, that is to say cases that do not come from people who have traveled abroad or overseas. Since 2010, the France public health agency has recorded barely more than one ten autochthonous cases in its heaviest annual assessments. But this year the cases are soaring, with a new assessment raised to 41 cases. Each time an autochthonous case is discovered, mosquito control operations are set up by the Regional Authority of health (ARS).
“The months of September and October are particularly conducive to the proliferation of dengue cases. Mosquitoes were able to breed all summer. The temperatures of this period are still very pleasant and adequate for them. Finally, we are in a holiday return period, during which travelers can return infected“, explains Marie-Claire Paty, director of infectious diseases at Public Health France (SPF), who explains that vigilance remains in order until the end of October, when the temperatures will be cooler.
67 departments concerned in 12 years
Dengue fever is an infectious disease that is transmitted from person to person through the bite of an infected tiger mosquito. The virus circulates regularly in the French departments of the Antilles, as well as in the French islands of the Pacific and the Indian Ocean. In mainland France, the mosquito Aedes albopictus or tiger mosquito, potential vector of dengue fever, is currently permanently established in 67 departments, with a total of five identified outbreaks in the Provence-Alpes Cote d’Azur (PACA) region and also in the suburbs of Toulouse. Last year, six outbreaks were identified but all were smaller.
The tiger mosquito has been monitored since the end of the 1990s on French territory. “It was established for the first time in 2004 in the gardens of Menton [dans les Alpes-Maritimes, ndlr]before having spread in 67 departments up to the North of France in 2022. The territory covered by the mosquito extends and the densities of mosquitoes on the spot are also increasingly important“, warns Marie-Claire Paty.
“This threat is only growing“
Dengue fever cases are likely to increase in the coming years. “This threat is only growing. Deforestation, urbanization, hot temperatures, drought and rainfall contribute to this. Just like the movements of people who travel. All this contributes to the increase in cases.“Public Health France thus recommends protecting oneself from mosquitoes also when returning from a trip and combating the proliferation of larvae in breeding sites, places with stagnant water where mosquitoes can multiply. Thus, the ministry de la Santé advises to store anything that may contain water away from the rain, to wear covering and loose clothing, to use a skin repellent, or even, if necessary, mosquito nets on the doors and windows.
It is also recommended to immediately consult your doctor in the presence of symptoms such as a high fever that appeared suddenly, muscle or joint pain, eye pain, fatigue, or headaches. The “symptomatic” treatment consists of managing fatigue and fever.