Edwardsiella tarda Native Valve Infective Endocarditis in a Young and Non-Immunocompromised Host: A Case Report

BACKGROUND Infective endocarditis (IE) is an infectious disease that occurs in valves, centered on the endocardium and ventricular septal defects. It is a serious disease that is easily misdiagnosed and has a high mortality rate if left untreated. Edwardsiella tarda is an extremely rare cause of IE, especially in young and non-immunocompromised hosts. CASE REPORT A woman in her 20s presented to our hospital with fever of unknown cause and liver dysfunction. She was admitted to the Department of Gastroenterological Medicine owing to suspicion of gastrointestinal infection. Gastrointestinal examination, including contrast-enhanced computer tomography and endoscopic ultrasonography, was performed; however, there were no significant findings. Liver dysfunction improved spontaneously, but her fever did not improve with antibiotic treatment. Transthoracic echocardiography was performed on day 9 of hospitalization because E. tarda was detected in a blood culture test, revealing vegetation at the mitral valve. Asymptomatic cerebral infarction was shown by brain magnetic resonance imaging, and mitral valvuloplasty was performed on day 14. After surgery, transthoracic echocardiography was performed on day 22, showing no vegetation or mitral regurgitation. However, postoperative transesophageal ultrasonography performed on day 29 revealed severe mitral regurgitation. Redo mitral valvuloplasty was performed on day 38. She clinically improved and was discharged on day 67. CONCLUSIONS This is the first case in which E. tarda was diagnosed as the causative agent of IE on a native valve in a young and non-immunocompromised host. Aggressive source control resulted in a good clinical outcome.