Urinary Tract Infection in Outpatient Febrile Infants Younger Than 30 Days of Age

A 10-Year Evaluation

William Bonadio, MD; Gary Maida, MD


Pediatr Infect Dis J. 2014;33(4):342-344. 

In This Article


The study was approved by the Institutional Review Board of Maimonides Medical Center. A retrospective review of medical records of consecutive febrile (rectal temperature ≥38.0°C measured by healthcare provider or ≥100.4°F measured by caretaker within 24 hours of ED visit) infants aged ≤30 days evaluated in the pediatric ED of Maimonides Medical Center from 2004 to 2013 was performed. As per protocol, all febrile infants ≤30 days of age receive a comprehensive sepsis evaluation (lumbar puncture [LP], complete blood count [CBC] and blood culture [BC], urinalysis [UA] and urine culture [UC] obtained by bladder catheterization) and are hospitalized for parenteral antibiotic therapy pending culture results. Pyuria was present with either dipstick positive for leukocyte esterase or urinalysis microscopy with ≥10 white blood cells (WBC) per high-powered field. UTI was present with UC positive for a single bacterial pathogen isolated from a bladder catheterized-obtained sample with a colony count of either: (1) ≥50,000 CFU/mL or (2) 10,000–50,000 colony forming units per mL (CFU/mL) with associated pyuria.[5–7] We included the latter criteria to maximize inclusion of all "treatment-indicated" cases, avoiding misclassifying neonates with fever, pyuria and UC isolation of a single uropathogen at lower colony counts as "asymptomatic bacteruria" or "contaminant". Urine dipstick test was positive when manifesting either + leukocyte esterase or + nitrite. Urosepsis occurred with simultaneous isolation of an identical bacterial pathogen in urine and blood.

All radiographic studies were interpreted by a pediatric radiologist. Ultrasound diagnosis of pelviectasis was made when there was isolated linear fullness of the collecting system. Ultrasound diagnosis of hydronephrosis was made when there was distention proximal to the collecting system—graded as "mild" if distal to the renal calyces and either "moderate" or "severe" if involving the renal calyces. Voiding cystourethrogram (VCUG) diagnosis of vesicoureteral reflux (VUR) was graded per the International System of Radiographic Grading of Vesicoureteral Reflux criteria.[8]