Bartonella henselae Infective Endocarditis Detected by a Prolonged Blood Culture

A 65-year-old Japanese man was admitted with a 4-month history of fatigue and exertional dyspnea. Transthoracic echocardiography revealed a vegetation on the aortic valve and severe aortic regurgitation. Accordingly, infective endocarditis and heart failure were diagnosed. Although a blood culture was negative on day 7 after admission, a prolonged blood culture with subculture was performed according to the patient's history of contact with cats. Consequently, Bartonella henselae was isolated. Bartonella species are fastidious bacteria that cause blood culture-negative infective endocarditis. This case demonstrates that B. henselae may be detected by prolonged incubation of blood cultures.