Overview
A global resurgence of chikungunya virus (CHIKV) disease was observed in 2025. Major outbreaks have been documented across multiple World Health Organization (WHO) regions, including the African, South-East Asia, and the Region of the Americas. For the first time, sustained local transmission has been reported in countries within the European region, as well as in China, in the Western Pacific region.
Approximately 502,264 CHIKV disease cases (suspected and laboratory-confirmed) and 186 deaths were reported globally from 41 countries and territories between 1 January to 10 December 2025. The most severely affected region was the region of the Americas, accounting for the highest number of reported cases and deaths, while substantial outbreaks were also reported in the European region, driven largely by transmission in French overseas territories, particularly La Réunion Island.
Chikungunya virus disease
Chikungunya is a vector-borne viral disease caused by CHIKV, a ribonucleic acid (RNA) virus in the genus Alphavirus, and the Togaviridae family. The natural reservoir of the CHIKV includes mosquito vectors Aedes aegypti and Aedes albopictus, which can carry the virus and transmit it to humans. Human infection occurs through the bite of infected female mosquitoes, which bite predominantly during daylight hours. Once a human is infected, the virus can be transmitted to other mosquitoes that bite the infected individual during the viremic period, perpetuating transmission cycles. These same mosquito species also transmit dengue and Zika viruses.
The illness begins after an incubation period of 3-7 days (range 2-12 days), with early symptoms such as sudden high fever (often above 38.5 °C), severe polyarthralgia affecting multiple joints bilaterally and symmetrically, headache, myalgia, and maculopapular rash. In severe cases, patients may experience persistent arthralgia for months to years. Case fatality rates remain low overall, but deaths can occur particularly in vulnerable populations, including neonates exposed during the peripartum period, adults over 65 years, and persons with underlying medical conditions such as hypertension, diabetes, or cardiovascular disease.
Currently, there is no specific antiviral treatment. Clinical case management is supportive and includes rest, adequate hydration and analgesic therapy with paracetamol for fever and pain relief.
Current risk assessment and travel advice
As of 17 December 2025, the WHO conducted a risk assessment based on available information on the chikungunya outbreaks globally. The risk assessment considered the public health risk to be high at the national level (within affected countries) due to factors such as the reported number of deaths; large immunologically-naive populations in newly affected temperate regions, which pose a greater risk of community transmission; as well as widespread presence of Aedes mosquito vectors and conducive environmental conditions. Global risk is assessed as moderate given the unprecedented scale and geographic distribution of the 2025 outbreaks and potential for infected travelers to introduce the virus into receptive areas.
No travel or trade restrictions have been recommended. Travelers are advised to take precautions such as using insect repellent, wearing long-sleeved clothing, staying in accommodations with air conditioning or screens, and avoiding outdoor activity during peak mosquito hours. Travelers should monitor themselves for symptoms for 12 days following any potential exposure. Anyone who develops symptoms such as sudden high fever, severe joint pain, headache, muscle pain, rash, or conjunctivitis should seek medical care, inform healthcare providers of travel history, and avoid further mosquito bites for at least one week to prevent local transmission.
Situation in South Africa
In South Africa, no autochthonous transmission has been documented in association with the current global outbreaks. The presence of Aedes aegypti mosquitoes in South Africa’s urban areas creates potential for local transmission should there be an imported case during periods of high vector density. These mosquitoes are particularly abundant along the eastern seaboard, with established populations documented in the coastal provinces such as KwaZulu-Natal and the Eastern Cape, as well as in the inland Gauteng province.
The risk of importation of chikungunya cases into South Africa exists due to international travel networks (direct flights) between South Africa and affected regions, particularly the Indian Ocean Islands. Vigilance is vital given ongoing outbreaks in the region. Healthcare workers should consider chikungunya in any patient presenting with unexplained acute febrile illness accompanied by severe arthralgia who has recently traveled to an affected area or had potential mosquito exposure. Rapid action is essential, which includes isolation of suspected cases, safe specimen collection and immediate reporting to the relevant public health authority to initiate rapid response and to the National Institute for Communicable Diseases (NICD) for laboratory testing.
Clinicians identifying a suspected case of chikungunya should contact the NICD Clinical Hotline (0800 212 552), a 24-hour service for healthcare professionals, to discuss the case’s risk assessment (based on clinical, travel, and exposure history), as well as laboratory testing. Chikungunya is classified as a Category III notifiable medical condition (NMC) in South Africa and must be notified within seven days of laboratory diagnosis through the NMC notification system.
