Chikungunya

Chikungunya is an infection caused by the chikungunya virus (CHIKV).^[8][9][6] The disease was first identified in 1952 in Tanzania and named based on the Kimakonde words for "to become contorted".^[6] Chikungunya has become a global health concern due to its rapid geographic expansion, recurrent outbreaks, the lack of effective antiviral treatments, and potential to cause high morbidity.^[10] Chikungunya virus is closely related to O'nyong'nyong virus (ONNV), which shares similar genetic and clinical characteristics.^[11]

Symptoms include fever and joint pain.^[5] These typically occur two to twelve days after exposure.^[6] Other symptoms may include headache, muscle pain, joint swelling, and a rash.^[5] Symptoms usually improve within a week; however, occasionally the joint pain may last for months or years.^[5][12] The risk of death is around 1 in 1,000.^[7] The very young, old, and those with other health problems are at risk of more severe disease.^[5]

The virus is spread between people by two species of mosquitos in the Aedes genus: Aedes albopictus and Aedes aegypti,^[6] which mainly bite during the day,^[13][14] particularly around dawn and in the late afternoon.^[15] The virus may circulate within a number of animals, including birds and rodents.^[6] Diagnosis is done by either testing the blood for viral RNA or antibodies to the virus.^[6] The symptoms can be mistaken for those of dengue fever and Zika fever, which are spread by the same mosquitoes.^[6] It is believed most people become immune after a single infection.^[5]

The best means of prevention are overall mosquito control and the avoidance of bites in areas where the disease is common.^[7] This may be partly achieved by decreasing mosquitoes' access to water, as well as the use of insect repellent and mosquito nets. Chikungunya vaccines have been approved for use in the United States^[16] and in the European Union.^[17][18][19]

The Chikungunya virus is widespread in tropical and subtropical regions where warm climates and abundant populations of its mosquito vectors (A. aegypti and A. albopictus) facilitate its transmission.^[20] In 2014, more than a million suspected cases occurred globally.^[6] While the disease is endemic in Africa and Asia, outbreaks have been reported in Europe and the Americas since the 2000s;^[6] in 2014, an outbreak was reported in Florida in the continental United States. At the end of March, a severe outbreak of the Chikungunya virus (alongside dengue) was reported in Sri Lanka.^[21] As of the second week of March 2025, there are 173 documented cases. Additionally, there have been 340 hospital admissions and 12 deaths linked to Chikungunya in 2025.^[22]