Chikungunya

Chikungunya is an infection caused by the chikungunya virus. The most common symptoms are fever and joint pain, typically occurring four to eight days after the bite of an infected mosquito. The pain has been described as "excruciating"; however some people may be infected without showing any symptoms. Other symptoms may include headache, muscle pain, joint swelling, and a rash. Symptoms usually improve within a week; however, occasionally the joint pain may last for months or years. The very young, old, and those with other health problems are at risk of more severe disease.

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

The best means of prevention are overall mosquito control and the avoidance of bites in areas where the disease is common. 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 and in the European Union. No specific treatment for chikungunya is available.

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. The disease was first identified in 1952 in Tanzania and named based on the Makonde words for "to become contorted". The disease has spread widely since the 2000s with outbreaks reported in many tropical and some temperate areas. It is considered to be endemic in many parts of the world, affecting millions of people every year. 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 severe symptoms and death.