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Culture-negative infective endocarditis — ABIM Board MCQ

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HardCardiovascularCulture-negative infective endocarditisABIM Board

A 46-year-old man experiencing homelessness has 3 weeks of fever, weight loss, and a new diastolic murmur. Three sets of blood cultures remain negative after 5 days. Transesophageal echocardiography shows a 1.2-cm aortic valve vegetation. He reports exposure to body lice. Which of the following is the most appropriate diagnostic study?

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Correct answer: B — Serologic testing for Bartonella species

Culture-negative endocarditis with homelessness and body lice exposure should prompt Bartonella testing. Coxiella, Tropheryma, and HACEK organisms are other considerations depending on epidemiology.

Reference: AHA Infective Endocarditis Scientific Statement; IDSA Guidance