Bartonella henselae endocarditis in an immunocompetent adult.

We describe a case of aggressive Bartonella henselae endocarditis in an immunocompetent man who owned a cat. Aortic valve replacement was required, and his infection was diagnosed by histology, serology, and polymerase chain reaction analysis. The manifestations of his disease included mediastinal lymphadenopathy, glomerulonephritis, myocarditis, and a petechial rash; the unusual finding of a positive titer of c-antineutrophil cytoplasmic antibodies was noted. Serological titers were markedly elevated for > 1 year despite clinical improvement.