Just over 90 imported cases of chikungunya, dengue and Zika, three diseases transmitted by tiger mosquitoes, have been recorded in mainland France since the beginning of May and the start of enhanced surveillance of arboviruses, according to a report published Wednesday by Public Health France.
The tiger mosquito is active from May to November.
From May 1st, the start of this enhanced surveillance, until May 25th, 12 imported cases of chikungunya79 of dengue and one case of Zika have been identified, the health agency specifies. At this stage, no locally acquired cases of these diseases, which are transmitted by the tiger mosquito, have been detected.Aedes albopictus), now established in 83 departments and active between May and November.
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During this period of mosquito activity, the detection of a case of dengue, chikungunya, or Zika (imported or locally acquired) triggers epidemiological and entomological investigations to rapidly implement vector control measures and thus limit the risk of local transmission of these viruses. The Ministry of Health sent a " call for increased vigilance » on these arboviruses in France, in an urgent message issued by the Directorate General of Health.
Prevent the emergence of locally acquired cases
“ The start of the 2026 season is marked by a significant number of imported cases of dengue and chikungunya in metropolitan France (approximately 500 confirmed cases of dengue and 50 confirmed cases of chikungunya imported into mainland France since the beginning of 2026), increasing the risk of the emergence of autochthonous cases in the territory during this period of vector activity.", this points out document of six pages.
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Also, " Faced with a suggestive clinical picture, such as sudden-onset fever, in the absence of other signs of infection, and without any other diagnosis, it is essential to consider these diagnoses and order the recommended laboratory tests, even in the absence of travel to a risk area."The ministry writes. Because the occurrence of autochthonous cases is very often linked to a lack of diagnosis, underreporting, or late reporting of cases, notes the DGS. These three diseases are part of the list "Diseases that must be reported".
Healthcare workers are also encouraged to be vigilant about the presence of mosquitoes in and around (their) premises", in particular by removing stagnant water that is conducive to the development of these insects in larval habitats.
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After a record year in 2025 in mainland France for locally acquired cases of mosquito-borne diseases, with chikungunya at the top (more than 800 cases), health authorities urged people in early May to remain " all vigilant "to limit the risks of importation and spread."
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