Mosquito crackdown amid outbreak of Chikungunya in south-west France

Mosquito control operations are under way across parts of south-west France following an outbreak of more than 20 locally acquired chikungunya cases in the region.

The disease is usually associated with tropical and subtropical regions but the spread of the Asian tiger mosquito across mainland France means that people can now contract chikungunya without travelling abroad. 

Since May 1, 105 imported cases of chikungunya, 295 of dengue and 10 of Zika have been recorded, according to Santé publique France. 

By August 10, 17 locally-contracted cases of chikungunya had been reported, including two recently in Tarn. Johanna Fite, a vector-control expert at ANSES, described the situation as “a ticking time bomb of public health,” reports Franceinfo.

In 2026, Santé publique France (the French national public health agency) said the tiger mosquito was now established in 83 mainland departments, although its numbers vary from one department to another. 

Since the publication of its figures, further cases of chikungunya have been identified, bringing the reported number of locally-contracted cases to more than 20.

At the moment the outbreaks are mainly concentrated in Gironde and the Tarn, with cases also reported around Toulouse, north of Bordeaux.

16 cases in one Gironde village 

Sixteen of the cases are concentrated in the commune of Prignac-et-Marcamps, north of Bordeaux. One case is in Saint-Médard-en-Jalles.

Prignac-et-Marcamps has around 1,500 residents and sits on the right bank of the Dordogne river, with the Moron stream running through its western side. The commune also includes many wetland areas. 

This strong presence of water could provide more opportunities for stagnant water to collect, where tiger mosquitoes breed, although it is not clear whether the local geography is the only factor contributing to the unusually high number of cases. 

Since then, mosquito control operations have been carried out. In Prignac-et-Marcamps, outdoor sports activities in the town’s grounds, including the stadium, football pitch and tennis court have also been banned by municipal order. 

The mayor also asked residents to cooperate with mosquito control teams. He said that, following the detection of several chikungunya cases, “surveillance and treatment operations” were being carried out to limit the spread of the tiger mosquito.

Two treatment operations had already taken place in areas identified by the regional health authority but further interventions across the commune were considered necessary “to limit the risk of spread as much as possible”.

From August 17, mosquito control specialists working with health officials were due to carry out door-to-door visits. Their work includes identifying potential mosquito breeding sites and preparing or carrying out appropriate treatment.

Residents have also been asked to remove standing water where mosquitoes can breed. The municipality advises putting buckets, watering cans, children's toys and other objects that can collect water under cover, emptying plant saucers and other small containers at least once a week, and covering rainwater collectors.

Additionally, Aulnay-sous-Bois, in the Paris region announced and carried out another mosquito control operation on August 18 after the appearance of tiger mosquito breeding sites potentially carrying vector-borne diseases. 

Residents in the affected streets were asked to protect garden furniture, toys and clothes before treatment, stay indoors and keep windows closed during the operation. 

The municipality has advised residents to wait three days before eating fruit and vegetables from their gardens after the treatment and to clean garden furniture. 

The treatment usually involves spraying a fine mist of insecticide around areas where infected people have been and within a limited radius to kill adult tiger mosquitoes and reduce the risk of further transmission. 

Mosquito-control operations have also been carried out in Saint-Christoly-de-Blaye, Cavignac and Blaye in Gironde. In the Tarn, operations have also taken place in Mazamet, Lisle-sur-Tarn and Labastide-Rouairoux, following the detection of cases. Three communes near Toulouse: Cugnaux, Seysses and Brax have also been treated.

Fewer cases so far but the risk is not over

The number of locally acquired chikungunya cases is currently much lower than last year. By mid-August 2025, 154 cases had been recorded, compared with 25 by August 17 this year.

However, last year's unusually high figures were largely linked to an outbreak in Réunion, which led to the spread of the virus in mainland France.

The risk though has not gone away. Hot, dry weather appears to have reduced tiger mosquito activity so far this year but numbers could increase again when rain returns in September, potentially leading to more cases.

How serious is chikungunya?

The disease is usually not life-threatening, but it can cause severe symptoms such as a sudden fever, severe joint pain, muscle pain, headaches, fatigue and sometimes a skin rash.

Even though most people recover, joint pain can sometimes persist for weeks or months, making older people, newborns and people with certain underlying health problems more vulnerable to it. 

How can you protect yourself? 

Health authorities recommend several simple measures, particularly in areas where local transmission has been detected: 

• Wear loose, long clothing that covers the arms and legs

• Use an appropriate mosquito repellent on exposed skin (look for the ones where these three molecules are present: DEET, IR3535 and icaridin)

• Use mosquito nets, particularly for babies 

• Use a fan or air circulator to make it harder for mosquitoes to land

• Empty containers holding water at least once a week

• Store buckets, watering cans, toys and other objects under cover

• Cover rainwater tanks and other water containers

• Keep gutters and drains clear

“For mosquitoes, especially tiger mosquitoes, fans can be very effective because they do not fly very well. If you have one or two reasonably-sized fans blowing air towards your legs or your body, the mosquito will have difficulty reaching you. After a while, it gives up and goes elsewhere,” Grégory L’Ambert, head of the preventive tiger mosquito control and public health unit at EID Méditerranée previously told The Connexion. 

The tiger mosquito is particularly active during the day, especially in the morning and towards the end of the day.

If you develop any of the symptoms listed above, you should contact a doctor promptly, especially if you have travelled to an area where the disease is circulating. 

Finally, if diagnosed, cases must be reported to health authorities.