Acute Post-infectious Glomerulonephritis Associated with Escherichia coli Urinary Tract Infection in an Adolescent: A Case Report and Review of the Literature

Abstract

Background: Acute post-infectious glomerulonephritis (APIGN) is one of the most common causes of acute nephritic syndrome in children and is classically associated with Group A β-haemolytic Streptococcus infection. However, non-streptococcal pathogens may also trigger immune-mediated glomerular injury. Escherichia coli-associated APIGN remains exceptionally rare in paediatric patients. Case Presentation: A previously healthy 14-year-old boy presented with fever and gross haematuria. Laboratory investigations revealed acute kidney injury (serum creatinine 22 mg/L), proteinuria (45 mg/kg/day), haematuria (3000 red blood cells/mm³), leucocyturia (30 white blood cells/mm³), low serum C3 (0.4 g/L) with normal C4 levels, and a urine culture positive for Escherichia coli (>10⁵ CFU/mL). Antistreptolysin O antibodies were negative, and autoimmune screening was unremarkable. The patient received intravenous ceftriaxone and gentamicin followed by oral cefixime. Renal function, proteinuria, and urinary abnormalities progressively improved. Serum C3 normalised after nine weeks of follow-up. Conclusion: This case highlights Escherichia coli urinary tract infection as a rare potential trigger of APIGN and emphasises the importance of considering non-streptococcal aetiologies in children presenting with acute nephritic syndrome.