Chikungunya returns: WHO warns of global risk from mosquito-borne virus epidemic

The World Health Organization (WHO) issued a stark warning on Tuesday, calling for urgent global action to contain the resurgence of the chikungunya virus, a mosquito-borne illness that caused a major international outbreak two decades ago.

The virus is now spreading rapidly again, with fresh cases reported across the Indian Ocean region, Southeast Asia, and Europe.

According to WHO medical officer Diana Rojas Alvarez, approximately 5.6 billion people living in 119 countries are currently at risk of chikungunya infection. The disease, which causes high fever, severe joint pain, and in some cases, long-term disability, has no approved treatment and can spread quickly through mosquito populations.


“We are seeing history repeating itself,” Rojas Alvarez said at a press briefing in Geneva, referencing the 2004–2005 chikungunya epidemic. That outbreak, which began in small island nations in the Indian Ocean, ultimately infected nearly half a million people and spread to several continents.

2025 outbreak mirrors 2005 epidemic

The current resurgence began in early 2025, with La Réunion, Mayotte, and Mauritius once again experiencing significant outbreaks. On La Réunion, an estimated one-third of the population has already been infected.

From these islands, the virus has spread to nearby regions including Madagascar, Somalia, and Kenya, and has now reached parts of Southeast Asia, with India seeing signs of epidemic-level transmission.

Rising threat in Europe

WHO is particularly concerned about the virus’s growing footprint in Europe. While chikungunya has traditionally been considered a tropical disease, changing climates and increased global travel have facilitated its spread.

Since May 1, France has reported around 800 imported cases of chikungunya.

More alarmingly, 12 local transmission episodes have been identified in southern French regions—meaning individuals contracted the virus from local mosquitoes, without having traveled to an infected area. A locally transmitted case was also confirmed in Italy last week.

About Chikungunya: Symptoms & transmission

Chikungunya is transmitted primarily by Aedes mosquitoes, especially Aedes aegypti and Aedes albopictus (commonly known as the tiger mosquito), which also spread dengue and Zika viruses.

Unlike many other mosquito-borne illnesses, these mosquitoes bite during the daytime, increasing the likelihood of infection.

While most patients recover, symptoms such as joint pain can persist for weeks or even months. The virus can also trigger complications in older adults and those with pre-existing health conditions.

Urgent need for prevention & public awareness

With no specific antiviral treatment or vaccine currently available, prevention remains the most effective defense. WHO has emphasized the importance of personal and community-level precautions, especially in at-risk regions.

Key prevention measures include:

• Using insect repellents regularly
  
• Wearing long-sleeved clothing and pants to avoid bites
  
• Installing mosquito nets and screens in living areas
  
• Eliminating stagnant water where mosquitoes breed
  
  

The WHO is urging health authorities worldwide to step up surveillance, public education, and vector control programs to limit further spread of the virus and avoid a repeat of the global crisis seen in the mid-2000s.

(With Reuters inputs)