Chikungunya: What do we know about the new case detected in eastern France, and what is the status of the epidemic?

In mainland France, numerous cases have been detected since the beginning of the year, including eight local cases. While the majority of cases affect the South of France, the East has not been spared.

No region is spared. A case of chikungunya has been detected in the Grand Est region, according to a press release from the Regional Health Agency (ARS) . It did not specify whether it was an imported or indigenous case. The ARS noted that the reported case "frequented neighborhoods in the municipalities of Lipsheim and Fegersheim (Alsace) during its viremic period," during which the virus can be transmitted to a tiger mosquito, which can then infect another person. Around twenty cases of chikungunya were detected in the region between early May and late June.

In total, approximately 650 cases of chikungunya have been detected in metropolitan France since May 1st, according to the latest report from Public Health France published on June 25th, and more than 1,560 cases since the beginning of the year. The three most affected regions are: Auvergne-Rhône-Alpes, Île-de-France, and Nouvelle-Aquitaine. In the previous two years, only about thirty cases had been reported, with zero or one indigenous case.

Since the beginning of the year, eight indigenous cases have already been reported in France. "Such an early start to the mosquito's activity season and such a high number of outbreaks have never been observed before," according to Public Health France.

Where were previous cases detected this year?

All cases were detected in four regions: Provence-Alpes-Côte-d'Azur, Corsica, Occitanie, and Auvergne-Rhône-Alpes. Four cases had already been reported, and the other four developed symptoms between June 11 and 17 in Bouches-du-Rhône (Salon de Provence), Drôme (Montoison), and Gard (Nîmes and Bernis). "Investigations and prevention and control measures are underway," the institute said.

The two cases detected in Corsica on the weekend of June 20 were announced by the Corsican Regional Health Agency on June 25. They concern two people from the same family living in the commune of Grossetto-Prugna. "The evolution of their health is not considered worrying," reassures the ARS. It also specifies that "vector control actions were immediately launched" in the places "frequented by the sick people."

The second indigenous case of chikungunya this year in mainland France was detected in mid-June in Hérault, in the commune of Prades-le-Lez. Fortunately, "the health of the sick person does not give rise to concern," according to a press release from the Occitanie Regional Health Agency (ARS) published on June 16, 2025.

The Agency asked "people who have been to the town of Prades-le-Lez and who have shown signs suggestive of chikungunya since the beginning of May, are invited to consult their doctor." These symptoms can include various factors: fever, joint and muscle pain, nausea and vomiting, fatigue, eye pain, red spots on the skin... The first indigenous case in metropolitan France dates back to June 11, 2025, in the Var, according to the Regional Health Agency (ARS) of Provence-Alpes-Côte-d'Azur.

What are the latest figures for the epidemic in Réunion and Mayotte?

The chikungunya epidemic is ending in Réunion, but it began in Mayotte. The territory entered the epidemic phase on May 27, 2025, according to Public Health France. The institute reports that "chikungunya circulation remains active with high intensity" in Mayotte. Nearly 1,000 cases have been detected so far, and no deaths have been reported.

In Réunion, a decline in epidemic indicators has been observed since the end of April. The epidemic is now "of low intensity," even though the virus is still circulating and "cases are still being confirmed," according to the latest report from Public Health France published on June 18. Nearly 54,000 cases have been reported on the island since the beginning of the year. The chikungunya epidemic has caused the deaths of a total of 27 people, who were "mainly" over 65 years old and had comorbidities.

How to protect yourself from chikungunya?

There is a vaccine against chikungunya. But while a vaccination campaign against chikungunya was launched in early April in Réunion, it was halted barely a month later for a portion of the population. Health authorities made this decision on April 26 following "serious adverse events" in three people over the age of 80 after being vaccinated. One of them died. Health authorities therefore removed "people aged 65 and over, with or without comorbidities, from the vaccination target," and did so "without delay." Those aged 18 to 64 who have comorbidities can still be vaccinated.

Aside from vaccination, the only way to protect yourself from the disease is to avoid mosquito bites by using repellents, mosquito nets, and wearing long, loose-fitting clothing. It is recommended that people living in, visiting, or returning from Reunion Island monitor themselves for symptoms.

Vulnerable people should be particularly vigilant, especially those suffering from chronic illnesses, but also pregnant women and immunocompromised people, and now those over 65, for whom vaccination is not recommended. The disease can indeed be serious in these people. There is currently no specific treatment for chikungunya. The only available treatments are symptomatic, notably paracetamol. A portion of the population is already immune to chikungunya following the last epidemic in 2005-2006, which affected approximately 260,000 people.