An Infected Bicuspid Aortic Valve, an Anomalous Coronary Artery, and a Dog-Bitten Postman

Abstract

Risk factors for infective endocarditis (IE) include congenital heart defects, poor dentition, immunosuppression, or recent instrumentation. The occupational hazard of a dog bite, combined with bicuspid aortic valve (BAV) led to IE. 16S ribosomal DNA was able to pinpoint the causative organism. A healthy 33-year-old postman presented in profound heart failure and sepsis due to aortic regurgitation and an aortic root abscess. He underwent emergency aortic valve replacement and was found to have a BAV and anomalous right coronary artery. Blood cultures remained negative. 16S ribosomal DNA polymerase chain reaction (PCR) revealed the causative organism was Capnocytophaga canimorsus. On review, he recalled receiving a dog bite followed by a febrile illness a few days later. Congenital BAVs may become infected by seemingly innocuous injuries. 16S rDNA PCR is a more sensitive and specific diagnostic test than culture. This case demonstrates its utility in providing appropriate antimicrobial management for IE.