The World Health Organization (WHO) warned on Tuesday that the world could face a repeat of the 2005 chikungunya epidemic unless swift measures are taken to curb the virus’ spread.
Diana Rojas Alvarez, WHO’s arbovirus lead, told a UN briefing that chikungunya, though not widely known, is already circulating in 119 countries, putting 5.6 billion people at risk.
The mosquito-borne disease causes fever, rash and severe joint pain, with up to 40% of patients suffering long-term disabilities.
Since early 2025, major outbreaks have hit Indian Ocean islands including La Reunion, Mayotte and Mauritius, where a third of La Reunion’s population is estimated to have been infected. The virus is spreading further into Madagascar, Somalia and Kenya, while South Asia continues to see outbreaks after India’s 2024 epidemic. Sri Lanka and Bangladesh report rising cases, and imported infections have been detected in Europe, with local transmission in France and suspected cases in Italy.
“This pattern mirrors what we saw in 2004–2005,” Rojas warned. “We must act now to avoid history repeating itself.”
She urged countries with Aedes mosquitoes to strengthen surveillance and mosquito control. Although cases are declining with winter in the Indian Ocean, early detection and rapid response are crucial to limit infections and prevent long-term health and economic impacts.
WHO is deploying experts, training health workers and supporting vector-control measures to help affected countries.
