Context
On June 16, 2025, the ARS Auvergne-Rhône-Alpes received the report for the suspicion of an Aboriginal chikungunya case.
This person would have been infected locally by a mosquito-tiger having bitten another person returning from a trip to the tropical zone.
The first analyzes received on June 18 tend towards this hypothesis. The final results of the levy will be confirmed by The National Reference Center for Arbovirus earlier this week.
If the case is confirmed, it would be the third episode of Aboriginal transmission observed in the Drôme department, after the cases of Dengue de Bourg-lès-Valence in September 2023 and Montélimar in August 2024.
On June 19, the ARS mandated the Rhône-Alpes interdepartmental agreement of Demoustication (EIRAD) to carry out an entomological survey, to confirm the presence of tiger mosquitoes in the sector frequented by the person.
The EIRAD teams have carried out door-to-door in order to inform the inhabitants of the sector concerned (around fifty dwellings) of the realization of an adulticide treatment on the night of June 23 to 24.
Health monitoring and actions implemented
Area concerned
The actions carried out and programmed are only planned in a limited sector, frequented by the Aboriginal case, residing in the town of Montoison.
Demonstrate the sector
A demoustication operation, led by Eirad The night of June 23 to 24, 2025 will take place to limit the risks of transmission to other people. The objective is to quickly eliminate larval lodges and adult mosquitoes, vectors of the virus.
Residents of the sector concerned (around fifty dwellings) have been informed by a flyer placed in their mailbox. If the inhabitants have not received information in their mailbox, it is because their accommodation is not affected by these operations.
Check if other people have been contaminated
This demoustication action will be completed by a Epidemiological survey, in door to door scheduled for Wednesday, June 25. It will be led by ARS and Public Health Agents France, to residents of the district where the person concerned resides.
The objective is to ensure that people living in the sector have not been contaminated by a tiger mosquito bite, to make them aware of the symptoms of chikungunya and to indicate the driving to be followed in the event of symptoms. All the inhabitants of the sector concerned are informed.
On the other hand, the mayor of the commune of Montoison, the Drôme prefecture, the Valence and Crest hospital centers as well as health professionals (Samu 26members of the Professional Territorial Health Community) have been informed.
New actions can be implemented according to the evolution of the situation.
Recommendations to the population
Monitor your health
People returning from travel to tropical zone must be particularly vigilant et :
People living in a sector where tiger mosquitoes are present must also remain attentive and consult a doctor in case of doubt.
Symptoms evocative of chikungunya are, in the absence of other established diagnosis: high fever (> 38.5 ° C), associated with at least another clinical sign such as :
- muscle, joint or lumbar pain, which can last over time,
- rashes,
- headaches,
Protect yourself from mosquito bites
To protect yourself from mosquito bites, it is advisable to use a skin repellent and wear covering and loose clothing.
Limit the proliferation of tigers mosquitoes
The best way to avoid tiger mosquito bites is to prevent them from setting home!
Find all the information on the tiger mosquito in Our dedicated section.
