Urinary tract infections

August 1, 2012

Even in the pre-Prevnar, pre-conjugated Hib vaccine era, urinary tract infection was the most common bacterial infection found in infants who presented with fever without localizing clinical findings.

Vaccines have nearly eliminated invasive Haemophilus influenzae type b infection in the United States and significantly diminished the frequency of serious infection because of Streptococcus pneumoniae, yet suspicion of UTI in febrile infants remains as important as ever.

Among febrile infants younger than 12 months with no focal findings, 6.5% of girls and 3.3% of boys will have a UTI. That percentage rises to 8% of febrile girls aged between 12 and 24 months and falls to 1.9% for boys in their second year of life.

Lacking evidence to assure us otherwise, experts have, in the past, recommended that diagnosis of the first UTI in an infant younger than 24 months should prompt renal and bladder ultrasound examination as well as a voiding cystourethrogram (VCUG), with the intent to provide long-term antibiotic prophylaxis for infants whose VCUG was abnormal.

New guidelines have now been published in consideration of accumulated evidence that demonstrates that 1) the vast majority of infants who develop their first UTI do not have significant vesicoureteral reflux demonstrable on VCUG, and 2) antibiotic prophylaxis is not beneficial in preventing subsequent UTIs in infants with mild to moderate reflux.4

Kenneth Roberts, MD, lead author of the new guidelines and chair of the American Academy of Pediatrics Subcommittee on Urinary Tract Infection, 2009-2011, has provided a practical discussion in this month's issue of many of the recommendations included in the guidelines.

There are some aspects of Roberts' article and of the guidelines themselves that should be emphasized:
1) Accurate diagnosis and appropriate initial therapy are as important as ever. Pediatricians must maintain a high index of suspicion for UTIs in febrile infants, and diagnostic tests should be obtained in a manner that assures accurate interpretation of findings.
2) The recommendations for management apply to uncomplicated, first UTIs in infants with normal anatomy.

One of the most important functions of a physician is to understand when guidelines do not apply. Although each child is unique, some are more susceptible to certain conditions than are others. It's our job to determine which child is at greater risk and to individualize care for that child.

REFERENCES

1. Hoberman A, Chao HP, Keller DM, Hickey R, Davis HW, Ellis D. Prevalence of urinary tract infection in febrile infants. J Pediatr. 1993;123(1):17-23.

2. Roberts KB, Charney E, Sweren RJ, et al. Urinary tract infection in infants with unexplained fever: a collaborative study. J Pediatr. 1983;103(6):864-867.

3. Bauchner H, Philipp B, Dashefsky B, Klein JO. Prevalence of bacteriuria in febrile children. Pediatr Infect Dis J. 1987;6(3):239-242.

4. Subcommittee on Urinary Tract Infection, Steering Committee on Quality Improvement and Management, Roberts KB. Urinary tract infection: clinical practice guideline for the diagnosis and management of the initial UTI in febrile infants and children 2 to 24 months. Pediatrics. 2011;128(3):595-610.