A case report of Nocardia spp. infective endocarditis in an injection drug user

BACKGROUND: Nocardia-related endocarditis is rare. Intravenous drug use with nonsterile injection practices is a potential risk factor for nocardia infection. Disseminated nocardiosis with endovascular involvement is rarely reported in immunocompetent individuals. CASE PRESENTATION: A 54-year-old male was diagnosed with infective endocarditis due to Nocardia asteroides with septic emboli in the brain and spleen. The use of a matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) rapid diagnostic system was beneficial in identifying the causative organism. He was empirically treated with combination therapy consisting of three antibiotics. Antimicrobial susceptibility testing indicated that all three antibiotics had favorable minimum inhibitory concentrations (MICs). Due to his clinical status, he was not a surgical candidate. Patient passed away after discharge to hospice. CONCLUSIONS: This case demonstrates unique challenges in the identification, diagnosis, and management of Nocardia-related infective endocarditis. A detailed history of injection practices should guide clinicians in assessing the risk for environmental pathogens. Valvular surgery and combination antibiotic therapy should be recommended for all eligible patients to improve the chances of survival.