Winter 2026 Newsletter III: Urinary Tract Infections

Overview

Urinary tract infections (UTIs) are common in children; females account for 80–90% of pediatric UTIs. Uncircumcised males are more susceptible than circumcised males
Uropathogenic Escherichia coli (UPEC) is the most common pathogen, accounting for approximately 80% of UTIs in children

Preverbal children: fever, poor feeding, vomiting, decreased urine output, lethargy, irritability, jaundice
Verbal children
- Lower urinary tract symptoms: dysuria, suprapubic or nonlocalized abdominal pain, urinary frequency, urgency, enuresis, hematuria
- Upper urinary tract symptoms: fever, vomiting, flank pain

Clean catch urine sample or catheterization for children who are not toilet trained
- In non-toilet trained children, the AAP allows non-invasive collection (urine bag) for urinalysis only. If results show pyuria, nitrite, or bacteriuria, a second sample must be obtained via catheterization. Do not use urine bag samples for culture
- Do not collect in a urine hat or use cotton balls in neonates as this is not sterile; it is acceptable to place sterile urine cups in the hat
Dipstick analysis with or without microscopy
Culture: send for all children not toilet trained (catheter sample). For toilet trained children, send if considering treatment

Hallmarks of UTI are pyuria, urinary nitrite, and bacteriuria
- Pyuria: at least 5 WBC per HPF on urine microscopy or detection of leukocyte esterase on urine dipstick
- Pyuria alone can be caused by other conditions such as urethritis, vulvovaginitis, STIs, crystalluria, or nephrolithiasis
- Blood in urine is not a specific finding for UTI
Diagnosing UTI can be difficult due to non-specific symptoms and uncertainty when only pyuria is present
In febrile children aged 2 to 24 months, AAP guidelines define UTI as urinalysis suggesting infection (pyuria or bacteriuria) plus a urine culture with at least 50,000 CFU/mL of a uropathogen
In toilet-trained children, diagnosis requres urinary symptoms, urinalysis suggesting infection, and a positive urine culture with 50,000–100,000 CFU/mL

Always treat empirically if the patient has fever; if well-appearing, afebrile, and without systemic findings, it is reasonable to wait for culture results
If no fever, it is reasonable to wait for culture and susceptibility data before starting antibiotics
Empiric antibiotic treatment
- Cephalexin (children) and Nitrofurantoin (adolescents)
- Simple cystitis: 3–4 day course
- Febrile UTI/pyelonephritis: 7 day course
- Amoxicillin is not recommended due to high resistance rates in E. coli

AAP guidelines recommend all infants aged 2–24 months with febrile UTI undergo kidney and bladder ultrasound (KBUS)
- If abnormal, AAP guidelines recommend voiding cystourethrogram (VCUG)

Antibiotics are not recommended for UTI prevention outside of urology consultation in cases of Grade 4/5 reflux
Consider and address contributing factors
- Bowel and bladder dysfunction
  - Dysfunctional Voiding Scoring System, Vancouver Symptom Score
  - Behavioral modifications and treatment of constipation
- Male circumcision
- Sexual hygiene
- Wiping hygiene