II. Epidemiology
- UTI Incidence
- Newborns
- Overall: 0.14%
- Febrile newborns: 7%
- Most common serious Bacterial Infection in children <3 months old
- Symptomatic UTI under age 6 years
- Girls: 7%
- Boys: 2%
- Recurrence rate: 30%
- School aged children: 1-2%
- Ages 7 to 11 year old females: 2.5%
- Newborns
- Vesicoureteral Reflux (VUR) Incidence
- School aged children with UTI: 25-40%
- Preschool sibling of child with VUR: 25-33%
- Child of parent with VUR: 65%
III. Causes (single organism in most cases)
-
Bacteria
- Escherichia coli (up to 85% of UTIs in children)
- Klebsiella
- Proteus (boys and associated with Nephrolithiasis)
- Enterobacter
- Citrobacter
- Enterococcus
- Pseudomonas
- Staphylococcus saprophyticus
- Coagulase negative Staphylococcus
- Viral
- Adenovirus (hemorrhagic cystitis)
- Atypical causes
IV. Risk Factors: Decision to evaluate for UTI
- Infants under age 2 months
- Age under 2 months is excluded from this guideline
- See Neonatal Sepsis guidelines
- Infants and children age 2 to 24 months (with fever >38 C)
- Urinary Tract Infection is responsible for 7-15% of fever in infants
- Risk factors for girls (<2 is reassuring and indicates a risk <1%)
- Risk Factors for circumcised boys (<3 is reassuring and indicates a risk <1%)
- Risk Factor for uncircumcised boys
- Uncircumcised boys have a risk >1% even in absence of other risk factors
- Male uncircumsized infants have a higher risk of Urinary Tract Infection than girls
- References
- Children over age 2 years
- Typical Urinary Tract Infection symptoms
- Constipation
- Encopresis
- Bladder instability
- Infrequent voiding
- Koff (1998) J Urol 160:1019-22 [PubMed]
V. Findings: Signs and Symptoms
- Newborn
- Infant or toddler
- Failure to Thrive
- Fever
- Weight Loss
- Nausea or Vomiting
- Irritability
- Jaundice
- Strong smelling urine
- Hematuria
- Abdominal Pain or Flank Pain
- Child
- Same as for adult Urinary Tract Infection
- Dysuria
- Urinary Frequency or urgency
- Urine hesitancy
- Lower Abdominal Pain
- New onset Urinary Incontinence
- Urine Odor does not predict Urinary Tract Infection
VI. Diagnosis
-
General
- Urinalysis dipstick can be used to rule-out UTI
- High Negative Predictive Value if normal
- Exception: Not sensitive in dilute urine (SG<1.005)
- However, Urinalysis may still have a 6-10% False Negative Rate
- Initial criteria for empirically starting UTI treatment
- High Negative Predictive Value if normal
- Urine Culture is required for UTI diagnosis
- Urinalysis dipstick testing is not diagnostic (use only for empiric initial therapy)
- Urine Culture is mandatory when a Urinary Tract Infection is suspected
- Urine sample for culture must be via catheter or SPA in children under 24 months
- Diagnosis requires pyuria and a catheterized specimen with >50,000 colonies of a single organism
- Urinalysis dipstick can be used to rule-out UTI
- Urine Sample Techniques
- Urine catheter specimen
- Recommended if child under age 2 years
- Consider Bladder Ultrasound first (one third of infants have a dry catheterization)
- Suprapubic Aspirate (SPA, rarely done in U.S. practice)
- Consider for child under age 6 months old
- Clean catch Urine (especially first morning void)
- See Noninvasive Urine Collection (includes Quick-Wee Method, Bladder stimulation technique)
- Possible in young children, but requires patience
- Urine Bag Collection (Not recommended)
- High Incidence of contamination
- May only be used to rule out UTI when risk of UTI is low (<1%, see above)
- If abnormal, catheterized sample or suprapubic aspirate is required
- Avoid Urine Culture of a bag specimen (False Positive culture rate >88%)
- Urine catheter specimen
-
Urinalysis Individual Factors (Sensitivity, Specificity)
- Urine Leukocyte Esterase (small or greater)
- Test Sensitivity: 83%
- Test Specificity: 78%
- Probability of UTI when positive: 30%
- Urine Nitrite
- Requires 4 hours within the Bladder to form (young children do not hold their urine)
- Test Sensitivity: 53%
- Test Specificity: 98%
- Probability of UTI when positive: 75%
- Urine White Blood Cells (10 or greater; some criteria use 5 or greater) on microscopy (hpf)
- Test Sensitivity: 73%
- Test Specificity: 81%
- Probability of UTI when positive: 30%
- Urine Bacteria present on microscopy
- Test Sensitivity: 81%
- Test Specificity: 83%
- Probability of UTI when positive: 35%
- Urine Red Blood Cells on microscopy
- Test Sensitivity: 47%
- Test Specificity: 78%
- Probability of UTI when positive: 19%
- Urine Leukocyte Esterase (small or greater)
-
Urinalysis Combined Factors (Sensitivity, Specificity)
- Urine Leukocyte Esterase AND Urine Nitrite Combined
- Test Sensitivity: 93%
- Test Specificity: 72%
- Urine Leukocyte Esterase AND Urine Nitrite AND positive microscopy (Bacteria or WBC>5/hpf)
- Test Sensitivity: 99.8%
- Test Specificity: 70%
- Very high Negative Predictive Value
- Urine Leukocyte Esterase AND Urine Nitrite Combined
-
Urine Culture
- See Urine Culture for diagnostic criteria
- Positive if catheterized specimen with >50,000 colonies of a single organism
- Culture sample within 4 hours or refrigerate
- Obtain in all children <10 years old when Urinalysis is evaluated (Urinalysis can be unreliable)
- Resources
- UtiCalc Tool (University of Pittsburgh)
- https:..uticalc.pitt.edu
- Predicts likelihood of UTI (tool recommends Urinalysis if >2% risk)
- UtiCalc Tool (University of Pittsburgh)
VII. Labs
- Precautions
- Always obtain urine sample before Antibiotics are started (Antibiotics rapidly render sterile urine)
- Standard
- Suspected Pyelonephritis
- Complete Blood Count (CBC)
- Blood Culture
- Indicated for febrile hospitalized child
- UTI with bacteremia may necesitate earlier imaging
- Inflammation Markers (70-80 sensitive, not specific)
- Renal Function tests)
VIII. Imaging
-
General
- First UTI in age <5 years old no longer requires imaging (unless indicated as below)
- Imaging goals are to identify children with modifyable risk factors for Recurrent UTI (and renal scarring risk)
- Vesicoureteral Reflux
- Posterior uretheral valves (males)
- Does not appear to change management or outcome (significant VUR Incidence is low)
- Zamir (2004) Arch Dis Child 89:466-8 [PubMed]
- Imaging indications
- Renal and Bladder Ultrasound (RBUS)
- Indications
- First UTI with fever at least 101.3 F (38.5 C) age under 2 years
- Recurrent UTI ages 2 to 5 years
- Timing
- Within 48 hours for severe infection or prolonged course
- Otherwise wait until acute infection resolves, and obtain within 6 months of acute infection
- Indications
- VCUG
- Do not routinely obtain for first febrile UTI
- Do not obtain until infection has resolved (wait at least 3-6 weeks after infection)
- Indicated for abnormal Ultrasound showing renal scar, Hydronephrosis or other signs of high grade VUR
- May also be indicated for second febrile Urinary Tract Infection (discuss with pediatric urology)
- DMSA Renal Cortical Scan
- Less commonly used now (defer to local pediatric urology consultants)
- May be preferred in girls as spares some ovarian radiation seen in VCUG
- Renal and Bladder Ultrasound (RBUS)
IX. Evaluation: Decision Protocols to treat empirically while awaiting Urine Culture
- University of Pittsburgh UTI Calculator
X. Management: Overall protocol for a febrile child between ages 2 months and 24 months
- Step 1: Child requires immediate empiric antimicrobial therapy
- Go to Step 4
- Step 2: Likelihood of Urinary Tract Infection is <1% (see Decision to evaluate for UTI as above)
- No urine testing required
- Complete additional evaluation of a febrile child
- Follow-up in 1-2 days for re-evaluation
- Step 3: Negative Urinalysis (LE, Nitrite, micro) by any method
- No further urine testing required
- Complete additional evaluation of a febrile child
- Follow-up in 1-2 days for re-evaluation
- Step 4: Urine Culture by catheter, clean catch or suprapubic aspirate only
- Determine disposition based on inpatient criteria below
- Start Antibiotics as described below
- Step 5: Negative Urine Culture
- Stop Antibiotics
- Complete additional evaluation of a febrile child
- Follow-up for Recurrent Fever
- Step 6: Positive Urine Culture
- Treat for 7-14 days adjusted for Urine Culture sensitivities
- Step 7: Renal and Bladder Ultrasound
- Obtain at any time after Urinary Tract Infection is confirmed
- Positive Ultrasound for anatomic abnormalities (e.g. Hydronephrosis)
- Obtain VCUG to evaluate for Grade IV to IV vesicoureteral reflux
- References
XI. Management: Inpatient criteria
- Ill appearing or toxic children
- Children unable to maintain oral hydration
- Risk of renal scar
- Febrile children under age 6 months to 1 year old
XII. Management: Antibiotics
- Precautions
- Initiate early empiric Antibiotics after urine sample when UTI is suspected in young children
- Delaying treatment for Urine Culture results (48 hours) increases renal scarring risk
- Oral Antibiotics are as effective as intravenous Antibiotics for UTI in Children >2 months of age
- When IV Antibiotics are used, short course (2-4 days) followed by oral Antibiotics is effective
- Strohmeier (2014) Cochrane Database Syst Rev (7):CD003772 [PubMed]
- Desai (2019) Pediatrics 144(3):e20183844 [PubMed]
- Initiate early empiric Antibiotics after urine sample when UTI is suspected in young children
- Oral Antibiotics
- Duration
- Typical course: 7 to 14 days
- Febrile UTI is treated for 10 days or more
- Five day course may be sufficient in otherwise uncomplicated febrile UTI age 3 months to 5 years
- Amoxicillin-clavulonate (Augmentin) 45 mg/kg/day divided twice daily
- E coli resistance to Amoxicillin is increasing (>50% in some regions as of 2016)
- Trimethoprim Sulfamethoxazole (Septra, Bactrim)
- Dosing: 6-12 mg/kg/day TMP,30-60 mg/kg/day SMZ divided bid
- Avoid under age 2 months
- Poor renal penetration
- E coli resistance to TMP-SMZ is also increasing (25% in some regions as of 2016)
- Second generation or Third Generation Cephalosporins
- Cefixime (Suprax)
- Expensive
- Day one: 16 mg/kg for the first day
- Next: 8 mg/kg/day in single dose or divided every 12 hours
- Cefpodoxime (Vantin) 10 mg/kg/day divided every 12 hours
- Cefprozil (Cefzil) 30 mg/kg/day divided every 12 hours
- Cephalexin (Keflex) 25-50 mg/kg/day orally divided three to four times daily
- Good renal parenchymal penetration and Pyelonephritis coverage
- Cefixime (Suprax)
- Duration
- Intravenous Antibiotics for hospitalized children
- Preferred agents
- Cefotaxime 50 mg/kg IV every 8 hours
- Ceftriaxone (Rocephin) 75-100 mg/kg every 24 hours
- Ceftazidime 50 mg/kg every 8 hours
- Other Antibiotic options
- Gentamicin
- Neonates <8 days: 4 mg/kg/day divided every 8 hours OR once daily
- Neonates 8 to 60 days: 5 mg/kg/day divided every 8 hours OR once daily
- Children >60 days: 7.5 mg/kg/day divided every 8 hours OR once daily
- Tobramycin 5 mg/kg/day divided every 8 hours
- Piperacillin 300 mg/kg/day divided every 6-8 hours
- Gentamicin
- Preferred agents
XIII. Management: UTI Prophylaxis
- Indications
- Prophylaxis is no longer routinely recommended prior to completion of evaluation
- Discuss with local pediatric urology consultants
- Medications (at bedtime if toilet trained)
- Nitrofurantoin (Furadantin, Macrodantin, Macrobid)
- Dosing: 1-2 mg/kg once daily
- Preferred UTI prophylaxis agent
- Associated with less Antibiotic Resistance than other prophylaxis agents
- Adverse effects
- May be associated with greater gastrointestinal side effects (Nausea, Vomiting, Abdominal Pain)
- Trimethoprim Sulfamethoxazole (Septra, Bactrim)
- Avoid under 2 months
- Dosing
- Nightly: 2 mg TMP/10 mg SMZ per kg at bedtime
- Bi-weekly: 5 mg TMP/25 mg SMZ per kg twice weekly
- Nalidixic Acid (NegGram)
- Dosing: 30 mg/kg/day divided bid
- Methenamine mandelate 75 mg/kg/day divided bid
- Sulfisoxazole (Gantrisin) 10-20 mg/kg/day divided bid
- Nitrofurantoin (Furadantin, Macrodantin, Macrobid)
- Other prevention
- Circumcision in uncircumsized boys
- Treat comorbid Constipation
XIV. Management: Evaluation for secondary urologic anomaly
- Indications
- See Imaging above
- Family History may dictate screening despite no prior personal UTI history
- Preschool siblings of child with urologic anomaly
- Preschool child of parent with vesicoureteral reflux
- Protocol
- See Imaging above
XV. Complications
- Acute
- Sepsis
- Renal Abscess
- Acute Kidney Injury
- Chronic
- Renal scarring
- Retrospective population study of UTI in first 5 years of life shows low risk for renal scarring (1.25%)
- Hughes (2024) Br J Gen Pract 74(743): e371-8 [PubMed]
- Recurrent Urinary Tract Infection
- Chronic Kidney Disease (including End Stage Renal Disease)
- Hypertension
- Preeclampsia
- Renal scarring
XVI. Prognosis: Vesicoureteral Reflux
- Risk End-stage renal disease if renal scarring occurs
- Responsible for 20% of end-stage renal disease
- Spontaneous Resolution Rates for Ureteral Reflux
- Grade I: 70-80%
- Grade II: 70-80%
- Grade III: 50%
- Grade IV: 15%
- Grade V: <15%
XVII. Prevention: Prevent renal scars in high risk children
- Children under age 2 years
- Recurrent Pyelonephritis
- Pyelonephritis with urinary anatomic abnormality
- Pyelonephritis untreated for more than 3 days
XVIII. References
- (2019) Sanford Guide, accessed on IOS 9/24/2019
- Orman and Horeczko in Herbert (2018) EM:Rap 18(3): 17-8
- (2016) Presc Lett 23(6): 33-4
- (2011) Pediatrics 128(3):595-610 [PubMed]
- Alper (2005) Am Fam Physician 72:2483-8 [PubMed]
- Bulloch (2000) Pediatrics 106:e60 [PubMed]
- Fisher (1999) Pediatrics 104:109-11 [PubMed]
- Hoberman (1999) Pediatr Infect Dis J 18:1020-1 [PubMed]
- Hoberman (1999) Pediatrics 104:79-86 [PubMed]
- Honkinen (2000) Pediatr Infect Dis 19:630-4 [PubMed]
- Roberts (2012) Am Fam Physician 86(10): 940-6 [PubMed]
- Roberts (2000) Am Fam Physician 62(8): 1815-22 [PubMed]
- Ross (1999) Am Fam Physician 59(6): 1472-8 [PubMed]
- Veauthier (2020) Am Fam Physician 102(5): 278-85 [PubMed]