Chikungunya fever — DTM&H MCQ

Correct answer: E — Chikungunya fever

The correct answer is E, Chikungunya fever. The abrupt onset of high fever with severe, often incapacitating small-joint polyarthralgia, plus a widespread maculopapular rash, is the classic triad of chikungunya, and the alphavirus name itself derives from a description of patients bent over by joint pain. Household and neighbourhood clustering with a high Aedes albopictus index strongly supports an Aedes-borne arboviral cause, and Ae. albopictus (alongside Ae. aegypti) is a recognised chikungunya vector, particularly in South and South East Asia including India, where major outbreaks have occurred since 2006. The combination of high fever and debilitating small-joint arthralgia is highly specific for chikungunya compared with other arboviral mimics. Why the other options are wrong: A. Rheumatoid arthritis: This is a chronic autoimmune polyarthritis with insidious onset and no association with fever, rash, or mosquito exposure; it would not explain simultaneous illness in multiple household members. D. Dengue fever: Dengue causes fever and myalgia but arthralgia is typically less prominent and less debilitating than in chikungunya, and dengue more characteristically produces thrombocytopenia, haemorrhagic tendency, and shock rather than dominant small-joint polyarthralgia. C. Zika virus infection: Zika typically causes a milder illness with conjunctivitis and a pruritic rash, but joint symptoms are usually mild, not severe and debilitating as described here. B. Reactive arthritis: This follows a preceding gastrointestinal or genitourinary infection by one to four weeks, is not an acute febrile mosquito-borne illness, and would not cluster among household contacts and neighbours simultaneously. Key point: Sudden high fever with severe, debilitating small-joint polyarthralgia and rash, occurring in clusters where the Aedes index is high, is the hallmark presentation of chikungunya fever.

Reference: GOV.UK (UK Health Security Agency), Chikungunya guidance, last updated 17 October 2025, https://www.gov.uk/guidance/chikungunya