Urinary tract infections in infants and children: a comprehensive overview.

PURPOSE OF REVIEW Urinary tract infections are the most common serious bacterial infections in infants and young children. This review focuses on new additions to the literature for the period August 22, 2002, to August 21, 2003. RECENT FINDINGS There is still considerable interest in determining which test is best to predict the likelihood of a positive urine culture in children at risk for urinary tract infection. One new analysis and several older analyses suggest that the finding of pyuria, as measured by at least 10 leukocytes/mm3 on unspun urine is a very valuable cutoff for identifying infants for whom urine culture is warranted. Several new investigations have studied the value of various imaging studies in children with urinary tract infections. It has been shown that the finding of vesicoureteral reflux is variable and that single studies may underestimate or overestimate the degree of reflux. The natural history for lower grades of reflux (grades 1, 2, and 3) is spontaneous resolution at a rate of 13% per year. The rationale for the determination of the degree of reflux by voiding cystourethrogram is to guide the institution of antimicrobial prophylaxis or surgical intervention until the reflux resolves. This is based on the assumption, as yet unproven, that these interventions will prevent or decrease reinfection and thereby prevent the development of renal scarring. Data are presented indicating that there is still no evidence that this assumption is correct. SUMMARY Continued attention to the need for and benefit of imaging procedures in children with urinary tract infection mandates that there be a randomized, controlled prospective trial of antimicrobial prophylaxis versus no treatment for children with various degrees of reflux.