Chikungunya virus (CHIKV) causes an infection predominantly spread to humans through the bite of infected Aedes mosquitoes. These mosquitoes are typically active during the daytime (in particular after sunrise and at dusk). Chikungunya virus typically circulates in tropical and subtropical regions of the world, in areas of Asia, Africa, Latin America and the Caribbean where the Aedes mosquitoes have a wide distribution. In recent years, these mosquitoes have also been found in parts of Europe (France, Italy and Spain) and the United States.
In recent decades, following international spread of disease, large outbreaks have occurred in:
- the Indian Ocean islands
- India
- the Pacific islands
- the Caribbean
- Central America
- South America
A notable outbreak occurred in La Réunion in 2025. Smaller outbreaks have occurred in France and Italy. The presence of Aedes mosquitoes in European countries, and importations from infected travellers returning from endemic countries, means that the likelihood of CHIKV spreading in mainland Europe is high.
Chikungunya symptoms include:
- fever of abrupt onset
- severe joint pains (known as arthralgia)
- muscle pains (known as myalgia)
- headaches
- sensitivity to light (known as photophobia)
- skin rashes
The illness is usually self-limiting and symptoms usually improve within one to 2 weeks, but joint pains can be severe and may persist for months or years. Chikungunya is an unpleasant disease which only rarely results in death. However, chronic disability rates can be high[footnote 1].
Individuals at risk of more severe disease include those over the age of 65 years, individuals with immunosuppression, and newborn babies.
There is currently no chikungunya transmission in the UK, with all identified cases being related to travel and having been imported into the UK.
