S5048 Beyond Borders: A Severe Case of Amebic Liver Abscesses and Colitis in a US Patient Without Travel History

Introduction: Entamoeba histolytica is a significant global health concern. In developing nations, it is responsible for 40-50 million symptomatic infections and approximately 100,000 deaths annually worldwide. While 90% of cases are asymptomatic, invasive amebiasis can involve severe and fatal invasion of multiple organ systems, including colitis/dysentery and extraintestinal manifestations, most commonly amebic liver abscesses. In developed countries, E. histolytica infections are rare and typically occur in immigrant populations, returning travelers from endemic regions, or specific risk groups such as immunocompromised individuals and men who have sex with men. Risk factors for severe disease and increased mortality include young age, pregnancy, corticosteroid use, malignancy, malnutrition, and alcoholism. We report a complex case of invasive amebiasis in a patient from the Southeastern United States with no identifiable source or risk factors for severe infection other than chronic alcoholism, underscoring the diagnostic challenges and management complexities. Case Description/Methods: A 55-year-old heterosexual man presented with a 5-month history of diarrhea, which became bloody, progressive abdominal pain and significant weight loss. Imaging revealed hepatomegaly with multiple liver lesions, the largest measuring 15.3 × 7.8 × 15.6 cm). Delayed diagnosis led to an initial surgical, rather than the recommended primary medical, approach. This deviation contributed to a protracted 2.5-month hospital course involving multiple surgical abscess drainages, a right partial hepatectomy, and management of severe complications like septic shock and disseminated intravascular coagulation. He received an extended 42-day course of metronidazole, followed by 7-days of paromomycin. Discussion: This case highlights the critical importance of considering E. histolytica in the differential diagnosis of dysentery and/or liver abscesses, even when common risk factors are absent. Alcoholism was the patient's only significant risk factor for severe disease. The substantial morbidity experienced by this patient underscores the potential catastrophic outcomes when diagnosis is delayed, and surgical intervention precedes appropriate antimicrobial therapy. Early detection, prompt initiation of targeted antimicrobial treatment, and judicious use of surgical intervention (reserved for specific indications like impending rupture or failure of medical therapy) are imperative to reduce mortality and prevent severe complications.