Erysipelothrix rhusiopathiae-associated bloodstream infection in a patient with systemic lupus erythematosus: a case report and literature review

Introduction: Systemic human infections caused by Erysipelothrix rhusiopathiae have been increasingly reported especially within immunocompromised hosts and those with significant occupational exposure to livestock and aquatic animals. We report a case of Erysipelothrix rhusiopathiae bacteremia in a patient with systemic lupus erythematosus (SLE) and present a literature review on clinical outcomes and microbiologic diagnosis for this organism. Case Presentation A 43-year-old female patient was reporting a 1-month history of intermittent fevers. She recently increased her immunosuppression medication for her underlying SLE on advice of her rheumatologist. The patient sustained a finger laceration from butchering cattle meat two weeks after onset of her initial symptoms, with worsening index finger swelling and increased febrile episodes. Two weeks post-injury, multiple blood cultures were drawn and each isolated Gram-positive bacilli. Given her recurrent intermittent fevers, there was concern for ongoing infection and therefore intravenous vancomycin was started with prompt referral to outpatient parenteral antibiotic therapy clinic. The Gram-positive bacillus was confirmed as Erysipelothrix rhusiopathiae via MALDI-TOF analysis. Given intrinsic resistance to vancomycin, vancomycin was switched to intravenous ceftriaxone as targeted antimicrobial therapy for two weeks. Reassuringly, there was no echocardiographic evidence of infective endocarditis warranting prolonged treatment course. Post-treatment, she remained symptom-free with resolution of joint symptoms and fevers. Conclusion Our report illustrates a case of Erysipelothrix rhusiopathiae bacteremia from a immunodeficient host, with prompt microbiologic diagnosis and intervention with appropriate antimicrobial coverage. Literature reflects the rarity of this infection, predilections to specific susceptible hosts and the importance for raising awareness of zoonotic infections.