Urinary tract infection in children: AAP 2026 and EAU
Confirm a UTI promptly and correctly, choose the route and duration of antibiotic treatment, and know which children need ultrasound and which need a VCUG under the two main guidelines.
Step 1 of 16
Objectives
After this topic you will be able to
- Know when a child with suspected UTI should be evaluated.
- Collect a urine sample appropriately for age and apply the AAP 2026 diagnostic criteria.
- Distinguish febrile UTI, cystitis and atypical UTI.
- Choose the route (oral or parenteral) and duration of antibiotic treatment according to age and risk.
- Know the indications for ultrasound, VCUG and DMSA after a first febrile UTI.
- Know where the AAP 2026 and EAU recommendations agree and where they differ.
The two guidelines agree on the essentials: the diagnosis rests on urinalysis and culture of a properly collected sample, bag specimens are not used for culture, febrile UTI is treated with short courses, and BBD is looked for and treated. They differ mainly on the age from which oral treatment can be started and on the indications for VCUG.
Basics
UTI in numbers
- ~7% of febrile infants have a UTI (AAP 2026)
- ~8% / ~2% of girls / boys by age 7
- ~80% caused by E. coli
- ~15% renal scarring after a first febrile UTI
Risk factors (from the AAP 2026 systematic review): younger age; female sex; uncircumcised young boys (the risk is lower in circumcised boys, while in uncircumcised boys it is even higher than in girls); fever without a source; previous UTI; BBD and constipation; daytime wetting; abnormal imaging; preterm birth; continuous antibiotic prophylaxis discontinued after less than 1 year. Breastfeeding lowers the risk.
In infants, a UTI often presents with fever alone, sometimes with irritability, poor feeding, jaundice, vomiting or diarrhea. Severe cases can present with sepsis. Symptoms such as painful or frequent voiding and urgency can usually be reported only by children older than 2 years.
Basics
Two guidelines: AAP 2026 and EAU
| AAP 2026 | EAU (Paediatric Urology, 2026) | |
|---|---|---|
| Population | Children aged 8 days to 5 years who are not medically complex | No age limit |
| Excluded | Neurogenic bladder, immunodeficiency, extreme prematurity, known congenital anomalies of the kidney and urinary tract (CAKUT), multisystem or severe chronic disease | A chapter of the EAU Paediatric Urology Guidelines; VUR, obstruction and neurogenic bladder are covered in separate chapters |
| Intended users | Pediatricians, family physicians, emergency physicians | Urologists and pediatric urologists |
| Structure | 8 key recommendations (2 strong, 6 conditional; low or very low certainty of evidence) and 4 good practice statements, developed with the GRADE method | Recommendations graded strong or weak |
The urologist and nephrologist members of the AAP panel did not support all of the recommendations; final decisions were reached by majority vote. The recommendation on VUR management in particular is presented as an initial approach until the child is seen by a pediatric urologist.
The AAP 2026 guideline replaces the 2011 guideline, which is no longer in effect: the age range has been widened from 2–24 months to 8 days to 5 years, and race has been removed from the risk assessment.
Diagnosis
When to evaluate: 72 hours
AAP 2026 (conditional, low certainty of evidence): a child aged 2–24 months with fever without a source, and a child aged 2–5 years with symptoms suggesting UTI (painful voiding, new-onset urgency or frequency), should be evaluated for UTI within 72 hours of symptom onset; prolonged observation alone is not recommended.
- In a pooled analysis of six studies, evaluation within 72 hours reduced renal scarring (relative risk 0.68).
- Children at higher risk of pyelonephritis or renal injury should be evaluated sooner: known anomaly (hydronephrosis, VUR), previous febrile UTI, signs suggesting pyelonephritis (for example, flank pain).
- Fever: above 38 °C measured rectally.
- The evaluation can be done in the family physician's or pediatrician's office; the child does not need to be sent to the emergency department.
EAU: starting treatment more than 48–72 hours after the onset of fever increases the risk of renal scarring. Both guidelines stress that treatment should not be delayed.
Diagnosis
How is a urine sample collected?
| Child | Method | Note |
|---|---|---|
| Toilet-trained child | Midstream sample after cleansing | EAU 2026, strong |
| Child not toilet-trained | Catheter or suprapubic aspiration | For urinalysis and culture (EAU 2026, strong) |
| Child not toilet-trained, stable | Clean-catch sample with stimulation | Acceptable for screening (EAU, weak). Under AAP 2026, the culture threshold for clean-catch urine is higher (see below) |
| Any age | Urine bag | Not used for culture (EAU, strong). Only a negative result is useful |
For febrile infants aged 8–60 days (the 2021 AAP guideline, to which AAP 2026 defers on this point) there are two options. In the first, urine is obtained by catheter or suprapubic aspiration and sent for urinalysis, with culture if the urinalysis is positive. In the second, urine for urinalysis is collected by bag or from a spontaneous or stimulated void; if the urinalysis is positive, a new sample is obtained by catheter or suprapubic aspiration for culture (strong recommendation).
AAP 2026 advises that the choice of method should depend more on the likelihood of obtaining a sample successfully than on the child's age.
Whenever possible, urine is collected before the first dose of antibiotic: even a single dose can make the culture falsely negative. If the child is seriously ill and a sample cannot be obtained quickly, treatment is not delayed.
Diagnosis
Diagnostic criteria: AAP 2026
AAP 2026 defines a high-probability UTI by age in children who are not medically complex. The diagnosis requires both evidence of inflammation (pyuria or leukocyte esterase) and a positive culture.
| Age | Presumed UTI while culture is pending | After culture: evidence of inflammation | After culture: culture and collection method |
|---|---|---|---|
| 0–2 months | ≥ 5 WBC/HPF or leukocyte esterase trace or greater | ≥ 5 WBC/HPF or leukocyte esterase trace or greater (any method) | ≥ 10,000 CFU/mL of a pathogen; catheter or suprapubic aspiration |
| 2 months to 5 years | ≥ 10 WBC/HPF or leukocyte esterase ≥ 2+ | ≥ 5 WBC/HPF or leukocyte esterase ≥ 1+ (any method) | Catheter: ≥ 10,000 CFU/mL; clean-catch urine: ≥ 100,000 CFU/mL |
- In the 2011 guideline the threshold for a catheter sample was 50,000 CFU/mL. Newer evidence shows that a threshold of 10,000 CFU/mL for a single organism increases sensitivity without a clinically meaningful loss of specificity. Because contamination is common in clean-catch urine, its threshold remains 100,000 CFU/mL.
- Urinalysis thresholds support the decision; they are not rigid rules. In a child who is seriously ill, a culture can be sent and empirical treatment started even if the urinalysis is equivocal. In a well-appearing child without focal signs, an equivocal urinalysis points more toward the absence of UTI, and if there are no additional risk factors, empirical treatment is usually not needed.
- Nitrite is specific but has low sensitivity and does not indicate inflammation: it does not distinguish asymptomatic bacteriuria from UTI.
- Typical uropathogens: E. coli, Proteus, Klebsiella and other gram-negative bacteria, Enterococcus. Growth of several organisms, or of bacteria that are not uropathogens, usually indicates contamination.
- DMSA can show pyelonephritis in the acute phase but is not used routinely for diagnosis.
Diagnosis
Diagnostic criteria: EAU and the differences
- Pyuria (EAU): more than 5 WBC/HPF in centrifuged urine (25/µL) or more than 10 WBC/µL in uncentrifuged urine. In children younger than 2 years, nitrite alone is not sensitive enough.
- Culture (EAU 2026): ≥ 100,000 CFU/mL is expected in febrile UTI, but clean-catch, midstream and catheter samples can be considered positive at 1,000–10,000 CFU/mL of a single organism. Any growth on suprapubic aspiration is significant. In febrile infants younger than 4 months, 1,000 CFU/mL can be accepted as the threshold when clinical and laboratory findings are consistent and the sample was collected correctly.
- Procalcitonin above 1.0 ng/mL (EAU) predicts pyelonephritis in young children. It is a supporting marker and does not make the diagnosis on its own.
| AAP 2026 | EAU 2026 | |
|---|---|---|
| Catheter sample | ≥ 10,000 CFU/mL | Growth of 1,000–10,000 CFU/mL can be considered positive |
| Clean-catch urine | ≥ 100,000 CFU/mL | Growth of 1,000–10,000 CFU/mL can be considered positive |
| Suprapubic aspiration | ≥ 10,000 CFU/mL | Any growth |
| Pyuria | Required for the diagnosis | Urinalysis and culture are interpreted together |
In practice: growth of a single uropathogen at ≥ 10,000 CFU/mL in a catheter sample, together with pyuria, is a UTI under both guidelines. Lower colony counts, especially without pyuria, are interpreted in the light of the clinical picture. Bacteriuria without pyuria is often asymptomatic bacteriuria or contamination.
Febrile UTI (with fever ≥ 38 °C) is regarded as pyelonephritis. A UTI without fever, with only frequent and painful voiding, is usually cystitis. In children older than 2 years, pyelonephritis may present with higher fever and costovertebral angle pain.
Diagnosis
Atypical UTI
| Typical UTI | Atypical UTI | |
|---|---|---|
| Organism | Common bacteria (E. coli) | Non-E. coli and/or multidrug-resistant organism |
| Response | Rapid response to oral antibiotics within 48 hours | No response to oral treatment, or the child cannot tolerate it |
| Setting | No admission needed | Admission may be needed |
NICE lists the same core features and adds: a seriously ill child or sepsis, poor urine flow, an abdominal or bladder mass, and raised creatinine. Any one of these makes the UTI atypical.
The AAP 2026 guideline identifies a similar group: age younger than 1 month, a non-E. coli organism, a circumcised boy, a severe course (septic shock, intensive care admission), and unreliable follow-up. In these children, VCUG after a first febrile UTI is considered on an individual basis (see "VCUG and DMSA: who needs them?").
Treatment
Oral or parenteral?
- Infants aged 8–28 days (AAP 2026, conditional, very low certainty of evidence): start with a parenteral antibiotic and switch to oral treatment soon after clinical improvement; parenteral-only treatment is not recommended.
- Children older than 28 days and younger than 5 years (AAP 2026, strong, very low certainty of evidence): oral antibiotics; parenteral or sequential (intravenous, then oral) treatment requiring admission is not routinely recommended. A child who can take oral medication and needs no admission for another reason is treated as an outpatient.
- According to the AAP, parenteral or sequential treatment may be appropriate in these situations: age younger than 28 days, bacteremia, critical illness, inability to take oral medication.
- If there is concern that the family will not be able to obtain the medication from a pharmacy in time, a single dose of a parenteral antibiotic can be given before oral treatment.
Why the recommendation is strong: renal scarring and short-term recurrence rates are the same with oral and parenteral treatment, whereas parenteral treatment brings admission, pain from intravenous line placement, infiltration, added cost, and the complications of peripherally inserted central catheters (PICC), such as infection and thrombosis.
| Age and condition | AAP 2026 | EAU 2026 |
|---|---|---|
| 8–28 days | Parenteral, then oral soon after | Parenteral |
| 1–2 months | Oral (in a stable infant) | Parenteral (younger than 2 months) |
| Older than 2 months, stable | Oral | Oral or parenteral (equally effective) |
| Seriously ill, sepsis, vomiting | Parenteral or sequential | Parenteral (strong) |
The main difference concerns infants aged 1–2 months: the AAP recommends oral treatment in a stable infant, while the EAU recommends parenteral treatment because of the risk of urosepsis. At this age the decision depends on the infant's condition and on local resources.
Treatment
Duration of treatment
AAP 2026 (conditional, low certainty of evidence): an antibiotic course of 7 days or less (no longer than 7 days) is recommended for UTI. In 10 randomized trials, recurrence rates were the same after short and long courses; recurrent UTI caused by resistant organisms was less frequent after a short course, but the difference was not statistically significant.
| Child | Clinical picture | Duration (AAP 2026) |
|---|---|---|
| Low risk, 2–5 years, no anomaly | Afebrile UTI, symptoms of cystitis | 3–5 days |
| Low risk, 2–24 months | Febrile UTI | 5–7 days |
| Low risk, older than 2 years, no anomaly | Febrile UTI, signs of pyelonephritis (for example, fever ≥ 39 °C) | 5–7 days |
| High risk, 8 days to 2 months | Febrile UTI | 7–14 days |
| High risk, older than 2 months | Known anomaly, bacteremia or poor response to treatment | 7–14 days |
EAU 2026: febrile UTI 4–7 days, oral or parenteral (strong); simple cystitis 3–5 days. In focal bacterial nephritis, the total duration is about 3 weeks.
If empirical treatment was started while awaiting culture and the culture is negative, the antibiotic is stopped. The exception is a sample taken after antibiotics had already been given.
Treatment
Choice of antibiotic
- AAP 2026: a narrow-spectrum agent whenever possible. In a child who is not seriously ill and not medically complex, cefazolin (parenteral) or cephalexin (oral) can be chosen if local susceptibility exceeds 80–85%. Alternatives (if resistance is high or in case of intolerance): ceftriaxone, cefixime, trimethoprim-sulfamethoxazole, ciprofloxacin; these are chosen with caution and according to local resistance.
- EAU 2026: the choice is based on local resistance and previous cultures. A full course of an oral third-generation cephalosporin alone is as effective as 2–4 days of intravenous treatment followed by oral treatment.
- The antibiotic is adjusted according to the culture result.
- Dexamethasone does not reduce renal scarring and is not recommended for this purpose.
Nitrofurantoin does not reach adequate concentrations in renal tissue, so it is not used for febrile UTI. For simple cystitis, however, it is a good empirical oral choice.
Fever settles within 24–48 hours in 90% of children. If it persists despite appropriate treatment, the ultrasound is repeated to rule out abscess and obstruction.
Treatment
Imaging: kidney and bladder ultrasound
AAP 2026 (strong, low certainty of evidence): kidney and bladder ultrasound is performed in every child younger than 5 years after a first febrile UTI. The aim is to detect structural anomalies and findings associated with VUR, not VUR itself.
- Ultrasound is not reliable for detecting VUR: after a first febrile UTI its sensitivity for VUR is about 50% and its specificity 71%. A normal ultrasound does not exclude VUR, but it makes high-grade VUR less likely.
- After a febrile UTI, about 22% of children have some abnormality on ultrasound, but a finding that changes management is present in only about 3% (4.5% in children younger than 24 months).
- According to the AAP, the ultrasound does not have to be done in the acute phase; with a severe or atypical course, however, it is done in the acute phase.
EAU 2026 (strong): in infants with febrile UTI and in seriously ill children, ultrasound is done within 24 hours. In children who do not need admission it can be scheduled later. In toilet-trained children, the bladder is scanned before and after voiding, with measurement of the post-void residual.
Both guidelines call for ultrasound after a first febrile UTI. The difference is timing: the EAU recommends ultrasound within 24 hours in infants and seriously ill children, whereas the AAP accepts an outpatient ultrasound after treatment in children who are not seriously ill.
Treatment
VCUG and DMSA: who needs them?
AAP 2026 (conditional): routine VCUG is not recommended in a child younger than 5 years with a first febrile UTI and a normal ultrasound. VCUG is offered in the following situations:
- A clinically significant abnormality on ultrasound after a first febrile UTI.
- A second febrile UTI in a child younger than 2 years.
- A second febrile UTI in a child older than 2 years when no other risk factor explains it.
- On an individual basis after a first febrile UTI: age younger than 1 month, a non-E. coli organism, a circumcised boy, a severe course (septic shock, intensive care), unreliable follow-up. If the result is abnormal, the child is referred to a pediatric urologist.
EAU 2026 (weak): VCUG (or contrast-enhanced voiding urosonography) is done in selected cases and after the acute phase. Consider it for: a first febrile UTI before 12 months of age (with a typical infection and a normal ultrasound, waiting for a second infection is also reasonable); recurrent febrile UTI; an abnormal ultrasound or abnormal DMSA; atypical UTI at any age.
| Situation | AAP 2026 | EAU 2026 |
|---|---|---|
| First febrile UTI, normal ultrasound, younger than 12 months | No routine VCUG | VCUG is considered; with a typical UTI, waiting for a second infection is reasonable |
| First febrile UTI, normal ultrasound, older than 12 months | No routine VCUG | Usually not needed |
| Abnormal ultrasound | VCUG is offered | VCUG is considered |
| Second febrile UTI | VCUG is offered (in a child older than 2 years, if there is no other explanation) | VCUG is considered |
| Atypical UTI | On an individual basis | Considered at any age |
DMSA: shows pyelonephritis in the acute phase; to assess renal scarring it is done at least 6 months after the infection (EAU, weak). Some centers perform DMSA first and do a VCUG only if the DMSA is abnormal (the "top-down" approach). The AAP does not recommend DMSA routinely.
VCUG is usually done as an outpatient after treatment is completed. If there is serious concern that the family will not return for follow-up, it can be done during the initial admission (AAP). Management of VUR, once found, is covered in the "Vesicoureteral reflux" module.
Treatment
Preventing recurrent UTI
- BBD: in a child with UTI, bladder and bowel dysfunction, including constipation, is looked for and treated (AAP 2026, good practice statement; EAU 2026, strong: in every toilet-trained child with febrile and/or recurrent UTI). A history, physical examination and simple screening questionnaires are enough for this. Treating constipation lowers recurrence.
- If treatment of constipation and correction of voiding habits do not help, the child is referred to a pediatric urologist or pediatric nephrologist.
- Antibiotic prophylaxis: the EAU recommends offering it to children at risk of recurrent UTI (strong). The AAP does not recommend routine prophylaxis in low-risk VUR (grades I–II, no BBD); the decision is shared with the family. Details are in the "Vesicoureteral reflux" module.
- Non-antibiotic measures (EAU): cranberry products reduce recurrence (moderate evidence); probiotics are used only as an adjunct; vitamins are not prescribed routinely.
- Phimosis: in boys with phimosis and UTI, topical steroid cream reduces recurrence; circumcision is of greater benefit when posterior urethral valves or VUR are also present (EAU).
The family is told that if the child has a fever again, they should see a doctor promptly and have a urinalysis done.
Treatment
Referral to a pediatric urologist
- Atypical UTI or no response to treatment within 48 hours.
- A clinically significant abnormality on ultrasound (dilation, kidney or bladder anomaly).
- VUR or other abnormality on VCUG.
- Recurrent febrile UTI.
- BBD that does not respond to initial treatment.
- Medically complex children (neurogenic bladder, known anomaly, immunodeficiency): according to the AAP, these children are referred to a specialist.
The pediatrician's role: evaluation within 72 hours, a properly collected urine sample, oral or parenteral treatment appropriate for age, a short course, ultrasound after the first febrile UTI, treatment of BBD, and referral of at-risk children to a pediatric urologist.
Quiz
Quiz: Urinary tract infection
Test yourself: choose one answer.
A 10-month-old girl has a fever of 39 °C, and urinalysis of a bag specimen is nitrite-positive. What is the next step?
A positive bag result may reflect contamination, and bags are not used for culture. Culture of catheter urine obtained before antibiotics confirms the diagnosis.
A febrile 14-month-old has 12 WBC/HPF in a catheter sample, and the culture grows E. coli at 20,000 CFU/mL. Under AAP 2026, what does this indicate?
AAP 2026 lowered the threshold for catheter samples from 50,000 to 10,000 CFU/mL. Growth of a single uropathogen at 10,000 CFU/mL together with pyuria confirms a UTI.
A 6-week-old infant has a febrile UTI. The infant is stable, feeding well and not vomiting. How do AAP 2026 and the EAU differ on the route of treatment?
AAP 2026 strongly recommends oral treatment in children older than 28 days. The EAU recommends parenteral treatment in newborns and infants younger than 2 months because of the risk of urosepsis.
A 3-year-old girl with no urinary tract anomaly has a febrile UTI with a fever of 39.5 °C and costovertebral angle pain. She is stable. Which treatment is appropriate under AAP 2026?
For a child older than 2 years without an anomaly who has signs of pyelonephritis, the AAP recommends a 5–7-day oral course. Nitrofurantoin is not used for febrile UTI.
An 18-month-old boy has had a first typical febrile UTI, and his ultrasound is normal. Does he need a VCUG under AAP 2026?
The AAP does not recommend routine VCUG after a first febrile UTI with a normal ultrasound. A second febrile UTI in a child younger than 2 years is an indication for VCUG.
A child with a febrile UTI has a normal ultrasound. What does this result tell you?
The sensitivity of ultrasound for VUR is about 50%. A normal ultrasound excludes most structural anomalies but does not exclude VUR.
Related topics
Related articles for parents
Sources
- Alverson BK, Hains DS, Downs SM, et al. Clinical practice guideline for the diagnosis and treatment of urinary tract infection in children from 8 days to 5 years of age. Pediatrics. 2026;158(4):e2026078565.
- EAU Guidelines on Paediatric Urology, 2026: Urinary tract infections in children.
- Roberts KB; Subcommittee on Urinary Tract Infection. Urinary tract infection: clinical practice guideline for the diagnosis and management of the initial UTI in febrile infants and children 2 to 24 months. Pediatrics. 2011;128(3):595–610.
- Hoberman A, Wald ER, Hickey RW, et al. Oral versus initial intravenous therapy for urinary tract infections in young febrile children. Pediatrics. 1999;104(1 Pt 1):79–86.
- National Institute for Health and Care Excellence (NICE). Urinary tract infection in under 16s: diagnosis and management. NICE guideline NG224, 2022.
This material is intended for medical professionals and is based on current clinical guidelines. Decisions about an individual patient are made by the treating doctor.
Updated: