TB or Not TB: Culture-Negative Aortic Valve Endocarditis

Bartonella quintana infection is commonly associated with alcohol abuse and homelessness and can be a cause of blood culture-negative infective endocarditis. Bartonella endocarditis has a subacute clinical course and can cause severe valvular disruption with potentially fatal outcomes. Its diagnosis requires a high index of suspicion in the clinical scenario of culture-negative endocarditis and may require serological testing, western blotting, or culture in specialized media. 16S RNA amplification sequencing analysis and histopathological examination may be helpful if a surgical specimen is available. We present a case of blood culture-negative infective endocarditis in the context of active pulmonary tuberculosis; endocarditis caused by Mycobacteria tuberculosis is extremely rare so another cause of the endocarditis was sought. Bartonella quintana was confirmed as the cause by molecular detection done on the vegetation.