Rising Threat of Mosquito-Borne Diseases in France in 2026 as Tiger Mosquitoes Spread

France is facing an escalating risk from mosquito-borne diseases such as chikungunya, dengue, and West Nile virus in 2026 due to the widespread proliferation of tiger mosquitoes across its territory. In 2025, the country recorded an unprecedented 809 autochthonous cases of chikungunya along with 30 dengue cases, signaling a sharp increase in these infections. These diseases are expected to continue their expansion this year as conditions remain highly favorable for mosquitoes, particularly the tiger mosquito, which now inhabits 83 of the 96 departments in metropolitan France.

Public Health France has issued warnings that the likelihood of epidemics grows each year, driven by heat and humidity that facilitate mosquito population growth. Dr. Harold Noël, the director of infectious diseases at Public Health France, emphasized, “the conditions for the start of an epidemic are much simpler each year.” This rise in cases is linked to exceptional outbreaks in the Indian Ocean regions of Réunion and Mayotte, where over 50,000 chikungunya cases were reported. Travel between these territories and mainland France has contributed to the spread.

Authorities have activated their surveillance period for mosquito-borne infections starting early May 2026, maintaining vigilance to monitor and control outbreaks. The expanding range of the tiger mosquito, a primary vector for these diseases, presents a growing public health challenge for France.

As the surveillance continues, French health officials urge residents to remain cautious and take preventive measures against mosquito bites to mitigate the risk of infection. This situation highlights the increasing epidemic risks that climate conditions and mobility pose to metropolitan France’s public health landscape.