A rare case of extraintestinal infection caused by nontyphoidal Salmonella

Abstract

Introduction. Nontyphoidal Salmonella is one of the leading bacterial causes of diarrhea. Commonly identified serotypes include S.Enteritidis, S.Newport, and S.Typhimurium. While primarily an intestinal pathogen, Salmonella can occasionally cause extraintestinal infections, especially in immunocompromised patients. These cases are rare in immunocompetent individuals, posing diagnostic and treatment challenges. Case Description. A 28-year-old woman presented with acute left-sided abdominal pain (VAS 6) and fever (38.8°C) without any other gastrointestinal symptoms. She reported no chronic illnesses, allergies, prior surgeries, or regular medication use. An abdominal ultrasound identified two cystic lesions in the left upper quadrant: a larger (11.8×10.6 cm) with dense, heterogeneous content and a smaller one (4.2×3.6 cm) surrounded by a 0.6 cm layer of free fluid near the spleen, with no evident connection to surrounding structures. No changes were observed in the abdominal organs. CT and MRI scans did not reveal any new information about the origin of the masses. Serological tests for echinococcal infection were negative. Empirical antibiotic therapy with cefuroxime and metronidazole was started. Persistent fever and poor response to initial antibiotics led to abscess drainage under ultrasound and CT guidance, yielding 1500 mL of purulent fluid, and culture confirmed Salmonella Enteritidis infection. Targeted antibiotic therapy with ciprofloxacin was initiated. Followup imaging showed significant improvement, and the patient was discharged with a referral to a surgeon to remove abscess. Summary. This case highlights a rare instance of extraintestinal infection caused by nontyphoidal Salmonella within an intra-abdominal abscess, occurring without diarrhea in an immunocompetent individual. Although uncommon, such infections emphasize the importance of comprehensive diagnostic evaluation. Conclusions. Nontyphoidal Salmonella can cause extraintestinal infection even in immunocompetent patients. A combination of precise imaging, microbiological identification, and surgical intervention ensures optimal management and recovery in such cases.