chikungunya

Chikungunya virus (CHIKV) is a single-stranded, positive-sense RNA alphavirus transmitted primarily by Aedes mosquitoes, with endemic transmission in Africa, Asia, and increasingly the Americas. The name derives from a Makonde word meaning 'to become contorted,' reflecting the stooped posture caused by severe joint pain. Clinical presentation includes sudden onset high fever, severe symmetric polyarthralgia/arthritis (often in hands, wrists, ankles), maculopapular rash, myalgia, headache, and conjunctivitis. Unlike dengue, hemorrhagic manifestations are rare, and unlike Zika, there is no established link to congenital microcephaly, though vertical transmission can occur. A hallmark feature is chronic, debilitating polyarthralgia that can persist for months to years after acute infection, mimicking rheumatoid arthritis and significantly impacting quality of life. Diagnosis is made via RT-PCR during the acute viremic phase (first 7 days) or serology (IgM/IgG) afterward. Differentiating chikungunya from dengue and Zika is a classic board question—dengue is associated with thrombocytopenia and hemorrhagic risk, Zika with congenital anomalies, and chikungunya with severe, persistent arthralgia. Treatment is supportive (NSAIDs, analgesics, hydration) as no specific antiviral therapy exists. Prevention focuses on mosquito control and avoidance; a vaccine has recently been approved in some regions. The virus is a reportable disease in many countries due to outbreak potential.