The World Health Organization (WHO) on Tuesday issued an urgent plea for action to prevent a recurrence of the mosquito-borne chikungunya virus epidemic that ravaged the globe two decades ago. New outbreaks, linked to the Indian Ocean region, are now spreading into Europe and other continents.
Diana Rojas Alvarez, a medical officer at the WHO, informed reporters in Geneva that an estimated 5.6 billion people residing in 119 countries are at risk from the virus. Chikungunya can cause symptoms such as high fever, debilitating joint pain, and long-term disability.
“We are seeing history repeating itself,” she stated, drawing parallels to the 2004-2005 epidemic, which affected nearly half a million people, primarily in small island territories, before its global dissemination. The current surge commenced in early 2025, with major outbreaks observed in the same Indian Ocean islands previously impacted, including La Reunion, Mayotte, and Mauritius.
Rojas Alvarez revealed that an estimated one-third of La Reunion’s population has already been infected. The virus is now spreading to countries such as Madagascar, Somalia, and Kenya, and has demonstrated epidemic transmission in Southeast Asia, including India. Of particular concern is the increasing number of imported cases and recent local transmission detected within Europe.
Approximately 800 imported chikungunya cases have been reported in continental France since May 1, according to Rojas Alvarez. Furthermore, twelve local transmission episodes have been identified in several southern French regions, indicating that individuals were infected by local mosquitoes without having traveled to endemic areas. A case was also detected last week in Italy.
Chikungunya, for which there is no specific treatment, is primarily spread by Aedes mosquito species, including the “tiger mosquito,” which also transmits dengue and Zika. This virus has the potential to cause rapid and widespread outbreaks. As these mosquitoes are active during the daytime, prevention is crucial through the use of insect repellent and long-sleeved clothing.
