The World Health Organization (WHO) on Tuesday warned that the world could face a repeat of the 2005 chikungunya epidemic unless urgent action is taken to contain the virus' spread.

"Chikungunya is not a widely known disease, but it’s already circulating in 119 countries, placing 5.6 billion people at risk," Diana Rojas Alvarez, WHO's team lead on arboviruses, said during a UN briefing.

The mosquito-borne virus causes fever, rash, and severe joint pain that can last for weeks or lead to long-term disabilities in up to 40% of patients.

Since early 2025, major outbreaks have erupted across Indian Ocean islands, including La Reunion, Mayotte, and Mauritius, where one-third of La Reunion's population is estimated to have been infected, Rojas said.

According to her, the virus is now spreading further into Madagascar, Somalia, and Kenya, while South Asia is seeing continued outbreaks following India’s 2024 epidemic.

Limiting infections

Sri Lanka and Bangladesh have reported a rise in cases, and imported infections have been detected in Europe, including local transmission in France and suspected cases in Italy.

"The pattern mirrors what we saw in 2004–2005," Rojas warned. "We must act now to avoid history repeating itself."

She emphasised the urgency for countries where Aedes mosquitoes are present to boost surveillance and mosquito control efforts.

Although cases are now declining with the onset of winter in the Indian Ocean, she stressed that early detection and rapid response are key to limiting infections and preventing long-term health and economic burdens.

WHO is assisting countries by deploying experts, training health workers, and supporting vector control measures, she added.