Chikungunya fever usually lasts 3-7 days. It is rarely fatal. The etiologic agent, chikungunya virus, is arthropod-borne and has been placed in the family Togaviridae, genus [Alphavirus]. Human infections are acquired by the bite of infected [Anopheles aegypti] mosquitoes, and epidemics are sustained by human-mosquito-human transmission.
The word "chikungunya" is Swahili for "that which bends up," in reference to the stooped posture of patients afflicted with the severe joint pain associated with this disease. The disease was first recognized in epidemic form in East Africa in 1952-53.
Chikungunya virus has been isolated from humans and mosquitoes in eastern, southern, western, and central Africa and in southeastern Asia, where it has been responsible for illnesses in hundreds to thousands of individuals. The virus has been implicated as the cause of epidemics in Asian countries including the Philippines, Thailand, Cambodia, Vietnam, India, Myanmar (Burma) and Sri Lanka. Similarities between clinical appearances of chikungunya and dengue fever probably account for misclassification and under-reporting of chikungunya fever in areas with endemic dengue.