Chikungunya virus (CHIKV) is a mosquito-borne, single-stranded RNA virus classified within the genus Alphavirus and the family Togaviridae. It was first identified during an outbreak in 1952–1953 on the Makonde Plateau, located in southern Tanzania, where it was isolated from a febrile patient. The term "chikungunya" is derived from the Kimakonde language, meaning “to become contorted,” referring to the bent posture caused by intense joint pain, one of the hallmark symptoms of the disease.
The virus is primarily transmitted to humans through the bites of infected mosquitoes, chiefly Aedes aegypti and Aedes albopictus. These species are also responsible for the transmission of other arboviruses such as dengue and Zika, and their widespread geographic distribution has contributed significantly to the global expansion of chikungunya outbreaks.
Virology and Classification
CHIKV belongs to the Semliki Forest antigenic complex, a group of antigenically related alphaviruses. Other members of this complex include Ross River virus, Mayaro virus, O'nyong-nyong virus, Getah virus, Bebaru virus, and Semliki Forest virus itself. These viruses share antigenic determinants and are all capable of causing febrile illnesses in humans, with varying degrees of severity and geographic spread.
Clinical Presentation
Chikungunya fever typically manifests with sudden onset of high fever, severe polyarthralgia, myalgia, headache, fatigue, and maculopapular rash. While the acute phase of the illness often resolves within a week, joint pain can persist for months or even years in some individuals, leading to chronic arthritis-like symptoms. In severe cases, patients may assume a characteristic stooped posture due to debilitating joint inflammation. Although rare, complications such as myocarditis, meningoencephalitis, and hepatitis have been reported, particularly in the elderly or immunocompromised individuals.
Last update: Wednesday, June 4, 2025
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