The tiger mosquito is now present in 84% of mainland departments

Introduced to mainland France in 2004, the tiger mosquito (Aedes albopictus) continues its rapid expansion. As of January 1, 2025, it is established in 81 departments, representing 84% of mainland departments. The departments newly colonized in 2024 are Marne, Haute-Marne, and Haute-Saône.

This mosquito transmits not only the dengue virus but also the chikungunya and Zika viruses.

In 2024, mainland France recorded a record number of dengue cases, both imported (contracted during a stay in a tropical region) and locally acquired (contracted within France). Since early 2025, Santé publique France has already recorded more than 1,100 imported cases of dengue and more than 900 imported cases of chikungunya. Beyond the risk of dengue transmission, the start of 2025 is indeed marked by a particularly heightened risk of the importation and circulation of the chikungunya virus in mainland France due to ongoing outbreaks in Réunion and Mayotte. This situation raises concerns about the potential for local transmission of these diseases in the coming weeks.

All of these factors underscore the importance of taking the right precautions to protect against bites, combat the proliferation of mosquitoes, and limit the transmission of diseases.

Health authorities, healthcare professionals, and vector control stakeholders are fully mobilized

Throughout the year, government agencies, national and regional health agencies, local authorities, and vector control operators are fully mobilized to limit the risk of outbreaks of mosquito-borne diseases.

Surveillance is stepped up during the tiger mosquito’s active season (May 1 to November 30) in mainland France, thanks in particular to efforts to raise awareness among healthcare professionals regarding the diagnosis and reporting of cases from the start of the season, enabling regional health agencies to implement vector control measures around infected individuals to limit the risk of local transmission.

The fight against these so-called vector-borne diseases is a public health priority for the Ministry of Health and Access to Healthcare.

Fighting mosquitoes is everyone’s responsibility!

Fighting mosquito bites means fighting the transmission of potentially serious diseases. While no single measure is 100% effective, it is the combination of individual and collective actions that helps reduce the transmission of these diseases.

Simple steps to prevent mosquito proliferation

To limit the risk of mosquito proliferation and establishment, everyone must take steps to eliminate breeding sites that are conducive to mosquito development. To do this, it is important to remove standing water inside and around homes (under plant pots, tarps, trash, gutters, etc.).

Avoiding mosquito bites means protecting yourself and also preventing the spread of disease

There are ways to protect yourself, such as wearing long, loose-fitting clothing, using repellents, and installing mosquito nets.

An infected mosquito can, a few days later, bite other people who will in turn be infected with the virus, leading to the emergence of the first local cases that could trigger an epidemic: it is therefore essential to protect yourself and others.

Follow the advice for people staying in high-risk areas

For people traveling to and returning from areas where mosquito-borne diseases are circulating (including Réunion, Mayotte, Martinique, Guadeloupe, and French Guiana, as well as many tropical countries), it is strongly recommended that you:

• Find out before departure about the diseases circulating in your destination areas;

• Protect yourself against mosquitoes during your stay in these high-risk areas and for up to three weeks after returning, to avoid transmitting a disease to your loved ones via mosquitoes.

Be vigilant for the onset of symptoms after a mosquito bite

If symptoms (joint or muscle pain, headache, rash, conjunctivitis, with or without fever) develop after a bite, it is important to consult a doctor immediately, specifying that you have been in an area where the chikungunya, dengue, or Zika viruses are circulating.