PEDIATRIC UROLOGY

Follow-up urine cultures and fever in children with urinary tract infection
Currie ML, Mitz L, Raasch CS, Greenbaum LA
Department of Pediatrics, Medical College of Wisconsin, Milwaukee, USA
Arch Pediatr Adolesc Med. 2003; 157: 1237-40

• Background: The American Academy of Pediatrics practice parameter for urinary tract infection suggests a repeat urine culture if the expected clinical response is not achieved within the first 48 hours of therapy. The utility of repeat urine cultures and clinical significance of fever at 48 hours is unclear.
• Objectives: To determine the frequency of positive repeat urine cultures in children admitted to the hospital with urinary tract infection, and to describe the fever curves of children admitted to the hospital with urinary tract infection.
  Design and Methods: We reviewed all cases of urinary tract infection in children 18 years and younger who were admitted during a 5-year period to Children’s Hospital of Wisconsin (Milwaukee). We recorded temperatures from hospital admission to discharge, age, sex, initial and follow-up culture results, antibiotics received, imaging performed, and medical history.
• Results: Urinary tract infection was identified in 364 patients, and 291 (79.9%) had follow-up urine cultures. None were positive. Follow-up cultures produced 21,388.50 US dollars in patient charges. Fever lasted beyond 48 hours in 32% of patients. Older children were more likely to have fever beyond 48 hours.
• Conclusions: Follow-up urine cultures were of no utility in children hospitalized for urinary tract infection, including those with fever lasting beyond 48 hours or those with an underlying urologic disease. Fever beyond 48 hours is common and should not be used as a criterion for obtaining a repeat urine culture. These conclusions are valid for children with vesicoureteral reflux. Such an approach would result in significant cost savings.
  
  
• Editorial Comment
  The authors challenge yet another dogma of medical practice. Most all of us have been taught that, when treating pyelonephritis in children, it is important to obtain a follow-up urine culture in about 48 hours in order to be certain the therapy is working. This would seem empirically to be even more important in situations in which the child remains febrile. Yet, the authors found that of 291 follow-up cultures, not a single one was positive! This was true even if the child remained febrile and independent of whether the child had reflux. The estimated cost of these negative cultures was over $21,000! In an era of rising health-care costs, this is an important finding.
  In a side observation, the authors found that 32% of children with febrile UTIs remained febrile for more than 48 hours and the rate was even higher in those over age 1. It would be interesting in a follow-up study to determine whether those who remained febrile longer had a higher rate of renal scarring, but that was not evaluated in this study.

Dr. Barry A. Kogan
Chief and Professor of Urology and Pediatrics
Albany Medical College
Albany, New York, USA