Chikungunya: An urban disease resembling dengue fever, seen mainly in Africa, the Indian subcontinent, and Southeast Asia, caused by an arbovirus transmitted by Aedes mosquitoes. The most prominent frequent feature is severe arthritis. Chikungunya fever was first described in epidemic form in East Africa in 1952-1953. The virus is arthropod-borne (it is therefore an arbovirus) and belongs to the family Togaviridae, genus Alphavirus. Human infections are acquired by the bite of infected Aedes aegypti mosquitoes, and epidemics are sustained by human-mosquito-human transmission. This epidemic cycle is similar to that of dengue and urban yellow fever. Chikungunya fever is characterized by sudden onset, chills and fever, headache, nausea, vomiting, arthralgia, and rash. In contrast to dengue, chikungunya is characterized by a briefer febrile episode, by persistent arthralgia in some cases, and by the fortunate absence of fatalities. Chikungunya in Swahili means "that which bends up" referring to the stooped posture of patients afflicted with the severe joint pain of this disease. Pronounced chik-n-gunya with the accent on the first syllable.