PE20.1 | Urinary Tract Infection — Summary & Reflection

KEY TAKEAWAYS

Urinary tract infection in children is the commonest serious bacterial infection in infants and carries a real risk of permanent renal scarring if inadequately treated. E. coli (~80%) is the predominant organism, ascending via the periurethral route. Presentation is age-dependent: neonates and infants present with non-specific fever and systemic signs; older children develop classic dysuria, frequency, and loin pain. Diagnosis requires appropriate urine collection (SPA > catheter > midstream; avoid bag cultures for diagnosis) and a positive culture above the method-specific threshold. Imaging is risk-stratified: USG first-line for all, MCU to detect VUR, and DMSA 4–6 months later to define renal scarring. Neonates require IV antibiotics (ampicillin + gentamicin); older children with febrile UTI receive 10–14 days of parenteral-then-oral cephalosporins; afebrile cystitis needs only 3–5 days oral. Prophylaxis is recommended for VUR grades III–V and recurrent infections. Long-term complications — renal scarring, hypertension, CKD — can be prevented by early, definitive treatment and structured follow-up.

REFLECT

Think about the 9-month-old girl from the hook scenario. If her urine culture confirms a pure growth of E. coli at >10⁴ CFU/mL, and her ultrasound shows mild left pelviectasis suggesting possible VUR: (1) How would you communicate the need for MCU to her anxious parents in a way they can understand? (2) If the MCU shows grade III VUR, what is your plan for antibiotic prophylaxis and follow-up? (3) How does early identification and treatment of VUR in infancy change this child's trajectory compared with a child whose VUR is discovered only after multiple renal scars have formed?