Multiple Liver Abscesses From Fusobacterium Infection

Abstract

Introduction: An 18-year-old white male with no significant past medical history presented with right upper quadrant pain associated with fever, vomiting, and loss of appetite for 4 days. He had a recent history of upper respiratory tract infection that resolved spontaneously and had dental cleaning done a month prior. On examination, he was febrile with a temperature of 102.8 F and had mild right upper quadrant tenderness. Labs from admission showed WBC of 25,000; Tbili 0.8, AST 28, ALT 50, ALP 161 and INR 1.41. Ultrasound of abdomen showed multiple complex hepatic lesions consistent with hepatic abscesses. US guided aspiration from one of the liver lesions revealed purulent material and gram staining showed abundant WBCs, moderate gram negative rods and some gram negative Coccobacilli. He was started on zosyn® and flagyl®. Transthoracic echo showed no vegetations. CT abdomen/pelvis showed no evidence of abnormal bowel, diverticulosis, or appendicitis. On hospital day 4, F. necrophorum was isolated from liver aspirate. Blood cultures were negative. Patient continued to spike fevers with further elevation in WBC. Under ultrasound guidance, each of these 9 abscesses was drained completely with no residual collection. After aspiration, the patient was sent home on ertapenem for 6 weeks. Follow-up labs after the antibiotic course showed WBC of 6.6, ALP 80, ALT 20, AST 20, ESR and PT/INR had normalized. MRI abdomen performed 3 months later showed complete resolution of abscesses. Discussion: The major bacteriology of pyogenic liver abscess have been reported to be, Escherichia coli, Klebsiella species and the Enterococcus species. Fusobacterium are filamentous gram-negative, anaerobic bacteria commensally inhabiting the oropharynx, gastrointestinal, and genital tracts. Anaerobic oropharyngeal infections comprise 1-5% of all anaerobic bacteremias, with <F. necrophorum</> the most common anaerobe in sepsis, originating from the oropharynx. F necrophorum has also been associated with meningitis, endocarditis, sinusitis, abscesses, septic arthritis, peritonsillar abscess, and appendicitis. Rare cases of F. necrophorum hepatic abscess have been described. The pathogenesis of liver infection remains unknown, although the proposed mechanisms include hematogenous spread from dental caries/peritonsillar abscess or spread through the portal circulation in the setting of diverticular disease. Oropharyngeal disease is demonstrable in about one-half of patients. The primary site of infection remains undiagnosed in about 50% and blood culture is positive in only 22.8% of cases.