Chikungunya is a virus that spread by the same kinds of mosquitoes that spread dengue and Zika virus. Rarely, it can spread from mother to new-born around the time of birth. It may also possibly spread through infected blood. There have been outbreaks of chikungunya virus in Africa, Asia, Europe, the Indian and Pacific Oceans, the Caribbean, and Central and South America.

Chikungunya has caused numerous epidemics in Africa and Asia. In 2005-2006 a major outbreak occurred in the Indian Ocean. Imported cases were found in Asia, Australia, USA, Canada and continental Europe. In 2007, an outbreak of autochthonous chikungunya virus infections took place for the first time in Europe (Italy). In 2010 and 2014, autochthonous cases were reported in France. In December 2013, chikungunya emerged in the Caribbean and quickly spread in the Americas. Now the virus has spread to the whole (sub) tropical regions of America, Africa and Asia.

The risk of chikungunya spreading in EU is high due to importation through infected travellers, presence of competent vectors in many countries (particularly around the Mediterranean coast) and population susceptibility.

In 2015, nearly 1.2 million suspected and confirmed cases of chikungunya virus infection have been reported in the Caribbean and other regions of the Americas.