Pauchard JY, et al. – The experts aimed to figure out whether the presence of Escherichia coli versus non–E. coli bacteria and/or normal or abnormal renal ultrasound (US) could avoid the use of voiding cystourethrography (VCUG) in infants aged 0–3 months. Investigations approved that the presence of E. coli and normal renal US findings safely avoid VCUG in infants. They concluded that performing VCUG only in infants with urinary tract infection (UTI) secondary to non–E. coli bacteria and/or abnormal US would save many unnecessary invasive procedures, limit radiation exposure, with a very low risk (<1%) of missing a high–grade vesicoureteral reflux (VUR).

Methods

• This study selected 122 infants with a first febrile UTI.
• By the presence of VUR grade ≥III, high–grade VUR was defined.
• The presence of high–grade VUR was recorded using VCUG, and correlated with the presence of E. coli/non–E. coli UTI and with the presence of normal/abnormal renal US.
• To calculate pretest and post–test probability, the Bayes theorem was used.

Results

• In the presence of urinary E. coli infection, the probability of high–grade VUR was 3%.
• Adding a normal renal US finding decreased this probability to 1%.
• However, in the presence of non–E. coli bacteria, the probability of high–grade VUR was 26%, and adding an abnormal US finding increased further this probability to 55%.