Prophylaxis for Recurrent UT Infections in Children

Abstract & Commentary

By Hal B. Jenson, MD, FAAP, Chief Academic Officer, Baystate Health Professor of Pediatrics and Dean of the Western Campus of Tufts University School of Medicine, Springfield MA, is Associate Editor for Infectious Disease Alert.

Synopsis: A large primary care pediatric study of recurrent urinary tract infections found a 12% per year recurrence rate with risk factors being white race, age 3-5 years, and grade 4-5 vesicoureteral reflux. Antimicrobial prophylaxis did not reduce the risk for recurrence but was associated with increased risk of recurrent infection caused by resistant organisms.

Source: Conway PH, et al. Recurrent urinary tract infections in children. Risk factors and association with prophylactic antibiotics. JAMA 2007;298:179-186.

From a network of 27 primary care practices with 74,974 children in urban, suburban, and semirural settings in 3 states during 2001-2006, 666 children < 6 year of age who were otherwise healthy had a urinary tract infection (UTI), for a first-UTI incidence rate of 0.007 per person-year. Of these children, 611 were evaluable, most were female (543 [88.9%]) and 83 (13.6%; 0.12 per person-year after the first UTI) had a recurrent UTI. A nested case-control analysis of these 83 children showed that the risk factors for recurrence of UTI were white race (0.17 per person-year; hazard ratio [HR] 1.97; 95% confidence interval [CI], 1.22-3.16), age 4-5 years (0.22 per person-year; HR 2.47; 95% CI, 1.19-5.12), and grade 4-5 vesicoureteral reflux (0.60 per person-year; HR 4.38; 95% CI, 1.26-15.29). Sex and grade 1-3 vesicoureteral reflux were not associated with risk of recurrence. Race was considered as white vs non-white because < 3% of children were Asian and there were no Native American children, and ethnicity was not analyzed separately because < 3% of the children were Hispanic. Most children did not have a voiding cystourethrogram (VCUG; 400 [65.5%]) and did not receive antimicrobial prophylaxis (483 [79.1%]). Prophylactic antimicrobials that were prescribed included trimethoprim-sulfamethoxazole (61%), amoxicillin (29%), nitrofurantoin (7%), or other antimicrobials (3%). Resistant organisms including Escherichia coli (78%), other gram-negative bacilli (16%), Enterococcus (4%), and other organisms (2%) were cultured from 51 (61%) of the 83 recurrent cases. Antimicrobial prophylaxis was not associated with decreased risk of recurrent UTI but was associated with an increased risk of infections caused by resistant organisms, from 53.1% to 89.5% (odds ratio, 7.5;95% CI, 1.60 35.17).


Urinary tract infection is a frequent diagnosis among young children. This large study showed a cumulative incidence of UTI among children in the first 6 years of life of 4.2%. Recurrence is a significant concern, and in this study the recurrence rate for children < 6 years of age following diagnosis of a first UTI was 12% per year. This recurrence rate is lower than the rates previously reported in other studies from referral populations.

The optimal management of urinary tract infections in children is shaped largely by consensus opinion because of the paucity of high-quality controlled trials. The 1999 American Academy of Pediatrics practice guideline for UTI (American Academy of Pediatrics: Practice parameter: The diagnosis, treatment, and evaluation of the initial urinary tract infection in febrile infants and young children. Pediatrics 1999;103:843-852.) recommends an imaging study after a first UTI for children < 2 years of age to evaluate for vesicoureteral reflux, which is present in about one-third of children with UTI and theoretically increases the risk for recurrent UTI and subsequent renal scarring. If reflux is present, daily antimicrobial prophylaxis is usually recommended to prevent recurrent UTI. This new study showed no association between antimicrobial prophylaxis and risk for recurrent UTI, and a > 7-fold risk of recurrent infection caused by resistant organisms. Given these findings, and other recent randomized controlled pediatric trials of antimicrobial prophylaxis that showed no reduction in the risk of UTI recurrence or renal scarring, there may be no specific benefit of prescribing antimicrobial prophylaxis following an uncomplicated first UTI in young children. It may complicate treatment of recurrent UTI because of selection for resistant organisms. Regardless of the administration of prophylactic antibiotics, close follow-up is essential and may be preferred as the core of the management strategy by many physicians and families for children without urogenital tract abnormalities following a first UTI.