Dual-Valve Culture-Negative Endocarditis: A Case Report

Infective endocarditis (IE) is a rare but life-threatening condition that poses diagnostic and management challenges, particularly in cases involving atypical presentations or uncommon pathogens. This is a case of a 54-year-old male patient who presented with gastrointestinal (GI) and constitutional symptoms of one week duration, including abdominal pain, intermittent fever, and unintentional weight loss. He tested positive for <i>Helicobacter</i> <i>pylori</i> gastritis that did not improve with antibiotics and supportive management during admission. Further inpatient evaluation revealed new heart murmurs suggestive of aortic and mitral regurgitation. Due to persistent fever during admission, blood cultures were taken, and an echocardiogram was performed, revealing severe aortic valve endocarditis, anterior mitral valve leaflet perforation, and an aortic root abscess, supportive of IE. Blood culture results were initially positive for <i>Streptococcus</i> <i>paraberis</i>; however, the rest were negative since then, suggesting that the initial blood culture was a contaminant rather than a true positive culture, and likely attributed to the use of antibiotics prior to obtaining blood cultures. He was diagnosed with blood culture-negative endocarditis and managed by targeted intravenous antibiotics followed by surgical dual valve replacement. Valvular tissue biopsy cultures obtained from dual-valve replacement surgery were negative as well. This case highlights the importance of maintaining a high index of suspicion for IE in patients presenting with generalized symptoms and GI complaints, along with performing systemic physical examinations on all patients, as early recognition can lead to timely diagnosis and improved patient outcomes. Management includes antibiotics and surgical valve replacement if indicated.