RESUMO
Yersinia enterocolitica is an unusual cause of septicaemia, usually occurring in immunocompromised hosts. Endocardial involvement is rare and generally presents as acute endocarditis. We describe the case of a 73-y-old woman, apparently without risk factors for endocarditis, admitted to hospital for persistent fever of unknown origin, arthralgia, and weight loss. Y. enterocolitica was isolated from blood and urine cultures, and echocardiography showed a pedunculated vegetation attached to the non-coronary cusp of the aortic valve. Symptoms and fever resolved after 3 days of intravenous cefotaxime plus amikacin, which were continued for the 2 weeks of her hospital stay; this treatment was followed by intravenous ceftriaxone after discharge. We hypothesized that a chemotherapy course administered 2 months previously for breast cancer might have been a predisposing factor for the Y. enterocolitica valvular infection and that immune system recovery contributed to mitigate the clinical presentation as subacute endocarditis.