An Unusual Presentation of Native Valve Endocarditis Caused by Staphylococcus warneri

Staphylococcus warneri is a coagulase-negative staphylococcal (CoNS) bacterium. It is a common saprophyte on human skin, present in approximately 50% of the healthy adult population; it has emerged as a cause of serious infection in the past two decades. In most cases, there is a predisposing condition, such as a new implant or surgical procedure, before the identification of S warneri as the pathogen. It is believed that CoNS are mostly associated with prosthetic valve infections. S warneri can lead to a slow growing and an indolent course and late diagnosis. Cases of CoNS infective endocarditis are less likely to have a vascular or immunologic phenomenon and can lead to large vegetations requiring valve replacement if not detected in time. There are currently only two cases of native valve endocarditis from community-acquired S warneri in the literature. We report a case of native valve endocarditis in an immunocompetent patient without any of the usual predisposing risk factors. Our case illustrates the importance of CoNS bacteremia and the implications of delayed diagnosis of CoNS endocarditis in clinical practice.