Chikungunya: epidemic confirms its decline in Reunion, many cases imported into mainland France

The chikungunya epidemic in Réunion continues to decline, but remains "significant".

After several weeks of a particularly intense epidemic, the number of chikungunya cases continues to fall in Réunion. More than 50,000 cases have been reported on the island since the beginning of the year. Since the end of April, a decline in epidemic indicators has been observed, particularly in hospitals, although activity remains "significant," according to the latest report from Public Health France published on May 21.

In total, 2,750 emergency room visits, including 391 hospitalizations, have been recorded since the epidemic began in January. According to Public Health France, almost all of those hospitalized had a "risk factor for severe forms," ​​such as diabetes, chronic kidney failure, obesity, or pregnancy. Age is also a major risk factor, as those over 65 and infants under 6 months old account for the majority of hospitalizations and serious cases. The chikungunya epidemic has caused the deaths of 12 people: all were over 70 years old and had comorbidities.

Even though the chikungunya epidemic is subsiding in Réunion, Public Health France recently warned that "importation pressure has been very high in mainland France for several weeks and is not expected to subside for several weeks. The current period in mainland France is considered to be the period at risk of local transmission."

Due to the epidemic in Réunion, many cases of chikungunya have been imported into mainland France. Since the beginning of the year, more than 950 cases have been reported, compared to only around thirty in 2024 or 2023. Between May 1 and 20 alone, 225 imported cases were reported in mainland France.

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 watch for symptoms (fever, joint and muscle pain, nausea and vomiting, fatigue, eye pain, red spots on the skin, etc.).

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. Since the beginning of 2025, nearly 50,000 cases have been confirmed in Réunion.