Swiss consensus recommendations on urinary tract infections in children

Key points

• A urinary tract infection (UTI) should be considered in every child with fever without a source; in children under 2 years, pyelonephritis should be assumed in case of doubt.
• Diagnosis requires urine analysis and urine culture; a dipstick or microscopy alone is not enough to confirm UTI.
• In children under 60 days, starting with parenteral treatment should always be considered; after 60 days, an oral or parenteral start is equally efficacious in children in good general condition, and upper UTI is treated for 7 to 10 days in total.
• All children should have a urinary tract ultrasound after a first pyelonephritis, while a micturition cystourethrogram (MCUG) is reserved for specific situations.
• In general, antibiotic prophylaxis is not recommended; bladder-bowel dysfunction is a relevant risk factor for recurrent UTI.

Overview

These consensus recommendations from the Swiss paediatric nephrology, infectious diseases and urology groups update the 2013 Swiss guidance on diagnosing and treating UTI in children. The main message is that management depends on age and clinical presentation: careful urine sampling and culture, age-appropriate antibiotics adjusted to susceptibility testing, ultrasound after pyelonephritis, more restrictive invasive imaging and, in general, no prophylaxis. They cover neonates to adolescents up to 16 years, but not children with known immunodeficiency or hospital-acquired UTI.

Suspicion and upper versus lower UTI

Risk factors include congenital anomalies of the kidney and urinary tract (CAKUT), a family history of vesicoureteric reflux (VUR) or renal disease, uncircumcised male infants, abnormal urine flow or dysfunctional voiding, constipation and previous or recurrent UTI. A child with bacteriuria and fever should be considered to have acute pyelonephritis rather than cystitis. No inflammatory marker reliably rules pyelonephritis in or out, but repeatedly low C-reactive protein (below 20 mg/l) or procalcitonin (below 0.5 μg/l) makes it less likely; ultrasound can neither prove nor exclude it.

Urine collection and culture

In infants and toddlers, bladder catheterization and suprapubic aspiration are the gold standard; midstream urine is preferred in cooperative children with bladder control, and a clean catch sample is a valid alternative in younger children. Collection bags should only be used to exclude UTI, attached for 15 to 30 minutes, and their urine should not be sent for culture. Growth of a single uropathogen of at least 10,000 CFU/ml in catheter urine, or at least 100,000 CFU/ml in midstream urine, is highly suggestive of UTI; growth of 2 or more species generally suggests contamination. Asymptomatic bacteriuria should not be screened for or treated.

Antibiotic treatment

The choice of drug and route depends on age, clinical presentation and risk factors, and the initial treatment is adjusted to antimicrobial susceptibility testing. Parenteral therapy is advised in children under 60 days and in those who are septic, vomiting or feeding poorly. In Switzerland, empiric oral options are amoxicillin-clavulanate or a 3rd generation cephalosporin. Children should be reviewed on days 3 to 5; if the culture shows no significant growth, antibiotics are stopped and another diagnosis is considered. Multidrug-resistant pathogens should be discussed with a paediatric infectious disease specialist.

Imaging after pyelonephritis

Ultrasound in the acute phase is advised for atypical infection (for example sepsis, poor urine flow, an abdominal or bladder mass, raised creatinine or no response to suitable antibiotics within 48 h) and for recurrent UTI; otherwise it can be done later. MCUG is recommended only for CAKUT or urinary tract dilatation on ultrasound (an isolated mild renal pelvis dilatation of 10 mm or less is not an indication), poor urine flow, non-E. coli infection, no response within 48 h, raised creatinine, abnormal electrolytes or arterial hypertension, and 2 or more episodes of pyelonephritis. Early MCUG, within 8 days of starting antibiotics, does not affect VUR detection; contrast-enhanced ultrasound is an alternative mainly in girls.

Prophylaxis, bladder-bowel dysfunction and surgery

Prophylaxis may be indicated in complex CAKUT or bladder dysfunction after interdisciplinary review, in high-grade VUR (WHO grades IV and V) and until an indicated MCUG; in grade III it is discussed individually. 5500 antibiotic doses are needed to prevent one UTI, and prophylaxis has not been shown to reduce renal scarring; the indication is reviewed after 6 to 12 months. Trimethoprim is a suitable option in neonates and amoxicillin is accepted in newborns; otherwise beta-lactams and quinolones should be avoided. Bladder-bowel dysfunction, including constipation, is assessed with diaries, questionnaires and, if needed, uroflowmetry. Surgical or endoscopic treatment may be considered in selected children with high-grade VUR.

Frequently asked questions

Can urine from a collection bag be sent for culture?

No. It is usually contaminated with perineal flora and should only be used to exclude UTI; if results are abnormal, a second sample is taken by catheterization, clean catch or suprapubic aspiration before antibiotics are started.

How long should an upper UTI be treated?

The recommended total duration is 7 to 10 days, which is considered safe even in young infants; longer treatment may be considered in a severe course with underlying comorbidities.

Is an MCUG needed after every first UTI?

No. It should not be done routinely after a first UTI in a neonate or young infant without the listed indications, and it is mainly indicated up to the age of 3 years.

Source

Buettcher M, Trueck J, Niederer-Loher A, Heininger U, Agyeman P, Asner S, et al. Swiss consensus recommendations on urinary tract infections in children. European Journal of Pediatrics 2021;180(3):663-674. DOI: 10.1007/s00431-020-03714-4. Open access; published online 3 July 2020, with a correction published later. This page is a summary prepared by Medpresso from the original publication and is not a substitute for the full text or for medical advice.