A 34-year-old woman returns from Kerala with high fever and incapacitating symmetrical pain in the small joints of her hands and wrists. There is no rash or bleeding tendency, platelet count is normal, and joint symptoms persist beyond three months. Which statement best fits the causative agent?

• A A flavivirus transmitted by Culex mosquitoes causing self-limited arthropathy
• B An orthobunyavirus transmitted by sandflies causing recurrent polyarthritis
• C An alphavirus (Togaviridae) transmitted by Aedes aegypti causing chronic inflammatory arthritis ✓
• D A coltivirus transmitted by ticks causing relapsing arthralgia

Explanation

Chikungunya virus is an alphavirus of the family Togaviridae, transmitted by Aedes aegypti and Aedes albopictus. Unlike dengue, it causes severe arthralgia rather than myalgia, thrombocytopenia is absent, and joint disease can persist for months to years due to persistence of viral antigen in macrophages driving chronic synovial inflammation. Dengue, a flavivirus, is distinguished clinically by hemorrhagic manifestations and thrombocytopenia, which this patient conspicuously lacks.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.