Pediatric UTI

Screen UTI

  • <3 years old, if fever with unclear source
  • >3 years old, consider testing if presence of dysuria, urinary frequency, hematuria, abdominal/back pain, daytime incontinence
    • Consider low risk UTI (<1%) if female and no more than one of following
      • <1 years old
      • White race
      • T>39° C
      • Fever >2d
      • Absence of source


  • Lower urinary tract (cystitis)
    • Dysuria, frequency, urgency, malodorous urine, enuresis, hematuria, suprapubic pain
  • Upper urinary tract (pyelonephritis)
    • Fever, chills, CVA pain/tenderness
    • Infants may have non-specific signs (poor appetite, failure to thrive, lethargy, irritability, vomiting, diarrhea)

Urinalysis and Urine Culture

  • Catheterization or mid-stream if toilet trained for culture
    • May consider 25 mins after feeding, holding baby upright, tap on bladder x30s then massage sacrum x30s (repeat maneuvers until micturition)
  • May consider bag urine to screen by microscopy (positive if >10-20 WBC/hpf, or LE, NT positive) then catheterization needed
  • Criteria for UTI
    • Positive urine specimen from suprapubic bladder puncture
    • >1000 cfu/mL from bladder catheterisation
    • >10^4 with symptoms or >10^5 without symptoms from midstream void
  • Sterile pyuria may be due to incomplete antibiotic treatment, urolithiasis, foreign body, infection by Mycobacterium tuberculosis, Chlamydia trachomatis
  • Negative nitrites not reliable if infant empties bladder frequently (requires 4h to convert)

Treatment (usually 7-14d)

  • Ampicillin 50 mg/kg/dose IV q6h + Gentamicin 7.5 mg/kg IV/IM once daily
  • Cefixime 8mg/kg PO daily (max 400mg/d)
  • TMP/SMX 6-12mg/kg/day divided q12h (max 320mg TMP daily), avoid in newborns
  • Amox/Clav 7:1 suspension, 45mg/kg/day of Amox divided q8h (max 3g Amox daily)
  • Alternatives
    • Amoxicillin 50 mg/kg/day divided q8h (max 3g daily)
    • Cephalexin 50 mg/kg/day divided q6h (max 500mg/dose)


  • Admit if <2 months old or complicated
  • Consider discharge if well and >2 months old with follow-up


  • Renal-Bladder Ultrasound if child
    • <2yo with first febrile UTI within 2w of acute illness
    • Recurrent UTIs
    • Pyelonephritis (Complicated)
    • Family/personal history of urologic/renal abnormalities
  • VCUG if
    • Hydronephrosis on ultrasound that suggests high grade (4-5) VUR, in addition consult urology or nephrology
    • <2yo with second febrile UTI


  • Prophylaxis not routinely recommended, but may consider in Grade IV/V VUR or significant urological anomaly