Crimean-Congo haemorrhagic fever — DTM&H MCQ

Correct answer: B — Crimean-Congo haemorrhagic fever

Crimean-Congo haemorrhagic fever (option E) is the correct answer because the combination of tick exposure through handling cattle, geographic setting in Turkey, and the triad of severe thrombocytopenia, marked transaminitis and bleeding at venepuncture sites is classic for this viral haemorrhagic fever. CCHF is transmitted by Hyalomma ticks endemic to livestock-rearing regions of Turkey, the Balkans, the Middle East and parts of Africa and Asia, and abattoir workers and those handling cattle or removing ticks are at highest occupational risk. The virus causes a haemorrhagic fever with a short incubation period progressing to a haemorrhagic phase with severe thrombocytopenia, hepatic dysfunction (raised AST/ALT) and disseminated bleeding, exactly as described. No other option combines tick-borne acquisition from livestock with severe haemorrhagic and hepatic derangement to this degree. Why the other options are wrong: E. Dengue without warning signs: dengue is mosquito-borne, not tick-borne, and by definition excludes warning signs such as severe bleeding and platelets this low; it is also not linked to abattoir or cattle tick exposure. A. Scrub typhus: transmitted by trombiculid mite (chigger) bites in scrub vegetation, not cattle ticks, and typically causes an eschar with rash rather than the profound bleeding diathesis described. D. Q fever: caused by Coxiella burnetii from inhaling aerosols from infected livestock (not tick bites), usually causes an atypical pneumonia or hepatitis without severe thrombocytopenia or haemorrhage. C. Leptospirosis: acquired through contact with water or soil contaminated by animal urine, not tick bites, and although it can cause thrombocytopenia and deranged liver function (Weil disease), profound bleeding at venepuncture sites is less characteristic than in CCHF. Key point: severe thrombocytopenia, transaminitis and bleeding in someone with tick exposure to livestock in a CCHF-endemic country (such as Turkey) should immediately raise suspicion of Crimean-Congo haemorrhagic fever, a notifiable viral haemorrhagic fever with nosocomial transmission risk requiring urgent isolation and infection control.

Reference: UKHSA, Crimean-Congo haemorrhagic fever: origins, reservoirs, transmission and guidelines, GOV.UK, https://www.gov.uk/guidance/crimean-congo-haemorrhagic-fever-origins-reservoirs-transmission-and-guidelines