Table 3

 Value of routine urine cultures in asymptomatic children with a previous history of UTI

CitationStudy groupStudy type (level of evidence)OutcomeKey resultsComments
*In view of study design (prospective cohort), risk reduction and NNT could not be calculated.
Wettergren et al (1990)Unselected population of 50 patients (14 girls) under 1 year of age with bacteriuria on screening, verified by suprapubic aspiration and untreated. Follow up for up to 6 yearsProspective cohort (level 4)1. Subsequent periodical urine cultures during the follow up period 2. Measurement of renal parenchymal thickness and renal surface area on IVU at 3 years1. Two infants developed pyelonephritis within 2 weeks of diagnosis of ABU. ABU recurred in 10 children* 2. No child (0/36) developed new renal damage. IR = 0 (95% CI = 0 to 0.09)*Unselected population of well infants (not after acute UTI) Screening of bacteriuria primarily detected innocent bacteriuria and was not recommended.
Randolph et al (1975)25 girls under 6 months of age with bacteriuria, followed up with cultures up to 6 years of age. No chemoprophylaxis but treatment of individual episodesProspective cohort (level 4)Development of UTI and renal scarring (IVU) during the follow up period1. Although described as ABU, initial episodes were always symptomatic (lower tract symptoms). No scars on initial IVU 2. Recurrences in 9 infants, always aymptomatic (lower tract symptoms) 3. New scarring developed in 3 children, all of whom had recurrences (symptomatic) and evidence of reflux, bladder trabeculation and urethral stricture. No recurrences after 3 years of age and no new scars at 6 yearsStudy exclusively in girls, natural history in boys may be different Even in ABU, signs of lower UTI were evident to the “instructed parents”