A50-46 Salmonella Typhi Associated Splenic Abscess With Reactive Pleural Effusion in an Immunocompetent Host

Abstract Background Splenic abscess is an uncommon complication of systemic infection and is exceedingly rare in immunocompetent hosts. Salmonella typhi is an unusual pathogen in this setting and may extend beyond the abdominal cavity to involve thoracic structures through contiguous spread or inflammatory reaction. Early recognition is crucial to prevent rupture and avoid unnecessary splenectomy. Case Presentation A 24-year-old previously healthy male presented with a three-day history of high-grade fever (Tmax 105 °F) and progressive left upper-quadrant abdominal pain. On admission, he was tachycardic (HR 114) with leukocytosis (12.4 × 109/L) and elevated CRP (24.6 mg/L). CT abdomen revealed a 5.7 cm cystic lesion in the spleen, and MRI confirmed a complex subcapsular abscess with a small left pleural effusion. Empiric ceftriaxone and metronidazole were initiated. Within 24 hours, his condition deteriorated, prompting diagnostic laparotomy for suspected peritonitis. Four-quadrant purulent peritonitis was observed, but the spleen remained intact. Blood and intra-abdominal cultures yielded pan-sensitive Salmonella typhi. Further history revealed occupational exposure at a fishing bait shop and recent raw fish consumption. Despite intermittent fevers and mild transaminitis (AST 139 U/L, ALT 224 U/L), his inflammatory markers improved with continued antibiotic therapy. However, due to recurrent fevers and enlarging splenic collection, ultrasound-guided percutaneous drainage was performed, yielding Salmonella typhi-positive aspirate. The left pleural effusion was tapped and found to be sterile exudate. The patient completed a 21-day hospital course and was discharged on oral Bactrim, achieving full recovery without splenectomy. Discussion Splenic abscess secondary to Salmonella typhi is exceedingly rare in immunocompetent individuals, typically arising from transient bacteremia and hematogenous seeding. Extension of infection across the diaphragm can cause reactive pleural effusion, as observed here. Although splenectomy was once the preferred management, accumulating evidence supports conservative therapy with percutaneous drainage and targeted antibiotics to preserve splenic function. This case underscores the diagnostic value of early imaging, the role of minimally invasive intervention, and the importance of a multidisciplinary approach in managing thoraco-abdominal complications of enteric fever. This abstract is funded by: None