France is witnessing a record surge in chikungunya, dengue, and West Nile virus cases in 2025, marking one of its most widespread mosquito-borne disease outbreaks.
Health officials attribute the rise to warmer temperatures and the expanding range of the tiger mosquito (Aedes albopictus), which now thrives in new regions.
The government has intensified vector-control operations and urged citizens to take precautions, as local transmission of these diseases becomes increasingly common.
Health authorities in France have warned of an unprecedented spread of mosquito-borne illnesses this year, with sharp increases in cases of chikungunya, dengue fever, and West Nile virus across both mainland and overseas territories.
The national public health agency reported that clusters of locally acquired chikungunya infections have appeared earlier than usual and in regions previously unaffected. By mid-summer, over a dozen confirmed cases were detected in several departments, including the Grand Est region — a sign, experts said, of “early and widespread” viral transmission.
Dengue fever has also been detected in mainland France, while West Nile virus infections have extended beyond their usual seasonal boundaries. Health officials attribute the spike to the spread of the tiger mosquito (Aedes albopictus) and the impact of climate change, which has expanded breeding habitats and lengthened transmission seasons.
Authorities have urged citizens to take preventive measures such as using insect repellent, covering exposed skin, and eliminating standing water near homes. Medical professionals are also advising vigilance for symptoms including fever, rashes, joint pain, and neurological complications.
France has ramped up mosquito control drives and surveillance operations across multiple departments as experts warn that local viral transmission is becoming the new normal in the country’s warmer climate zones.
