An asymptomatic 18 month old boy, undergoing radiological investigations after a urinary tract infection (UTI) diagnosed few months earlier, is reviewed at the clinic. According to departmental protocol, a three monthly urine culture should be submitted in infants and young children as, until the age of 4 years, they remain at risk of developing renal scars after UTIs. You wonder as to the value of this routine culture.

Structured clinical question

In an asymptomatic infant or preschool child with a history of UTI under 4 years of age [patient] does the detection and management of asymptomatic bacteriuria (ABU) on routine urine culture [intervention] decrease the incidence of symptomatic UTI or renal scarring [outcomes]?

Search strategy and outcome

Secondary sources—Cochrane Library (Issue 3, 2003): search words: (1) “urine culture” OR (2) “asymptomatic bacteriuria” OR (3) “urinary tract infection”. Database of systematic reviews: 32, 24, and 135 articles (for 1, 2, and 3 respectively), with 24, 14, and 101 complete reviews (for 1, 2, and 3 respectively). No relevant systematic review for under 4s.

PubMed (1975–2003): search words—(“urine culture” OR “asymptomatic bacteriuria” OR “urinary tract infection”) AND (“prognosis” OR “renal …