Disseminated Bartonellosis Involving the Kidney and Heart.

Blood culture-negative infective endocarditis poses considerable clinical and diagnostic challenges because of its atypical manifestations and the difficulty in identifying the responsible pathogens. The involvement of Bartonella henselae, a rare etiologic agent of blood culture-negative infective endocarditis, further complicates diagnosis and management. Dissemination of Bartonella across multiple organ systems is a recognized feature of the disease. A 73-year-old female with a one-year history of prosthetic mitral valve replacement for mitral valve stenosis secondary to rheumatic fever presented with a one-year history of self-remitting fevers and worsening anemia. In the months preceding admission, she also experienced a cerebrovascular accident involving the left frontal lobe. She was known to care for feral cats, coming into close contact with them through feeding and combing their fur for fleas. CT (computed tomography) imaging on admission was concerning for a left renal infarction, prompting an embolic workup. The transesophageal echocardiogram was notable for irregular thickening of the bioprosthetic mitral valve and mobile, filamentous densities, suggestive of a vegetation. Bartonella henselae IgG titers were markedly elevated at 1:32,768, raising concerns for infective endocarditis secondary to Bartonella henselae with dissemination to the bone marrow and left kidney. This report emphasizes the need for increased awareness, thorough diagnostic imaging, and thoughtful treatment approaches for a patient with widespread bartonellosis. Early identification of Bartonella henselae should be considered in blood culture-negative endocarditis cases, especially in patients with relevant epidemiological exposure.