title: Febrile infants with urinary tract infections at very low risk for adverse events and bacteremia.
abstract: BACKGROUND
  There is limited evidence from which to derive guidelines for the management of febrile infants aged 29 to 60 days with urinary tract infections (UTIs). Most such infants are hospitalized for ≥48 hours. Our objective was to derive clinical prediction models to identify febrile infants with UTIs at very low risk of adverse events and bacteremia in a large sample of patients.
  
  
  METHODS
  This study was a 20-center retrospective review of infants aged 29 to 60 days with temperatures of ≥38°C and culture-proven UTIs. We defined UTI by growth of ≥50,000 colony-forming units (CFU)/mL of a single pathogen or ≥10,000 CFU/mL in association with positive urinalyses. We defined adverse events as death, shock, bacterial meningitis, ICU admission need for ventilator support, or other substantial complications. We performed binary recursive partitioning analyses to derive prediction models.
  
  
  RESULTS
  We analyzed 1895 patients. Adverse events occurred in 51 of 1842 (2.8% [95% confidence interval (CI): 2.1%-3.6%)] and bacteremia in 123 of 1877 (6.5% [95% CI: 5.5%-7.7%]). Patients were at very low risk for adverse events if not clinically ill on emergency department (ED) examination and did not have a high-risk past medical history (prediction model sensitivity: 98.0% [95% CI: 88.2%-99.9%]). Patients were at lower risk for bacteremia if they were not clinically ill on ED examination, did not have a high-risk past medical history, had a peripheral band count of <1250 cells per μL, and had a peripheral absolute neutrophil count of ≥1500 cells per μL (sensitivity 77.2% [95% CI: 68.6%-84.1%]).
  
  
  CONCLUSIONS
  Brief hospitalization or outpatient management with close follow-up may be considered for infants with UTIs at very low risk of adverse events.
authors.affiliation: Pediatric Emergency Medicine, Morgan Stanley Children's Hospital of New York, Columbia University College of Physicians and Surgeons, New York, New York, USA. schnadower_d@kids.wustl.edu
authors.forename: David
authors.initials: D
authors.lastname: Schnadower
authors.forename: Nathan
authors.initials: N
authors.lastname: Kuppermann
authors.forename: Charles G
authors.initials: CG
authors.lastname: Macias
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Freedman
authors.forename: Marc N
authors.initials: MN
authors.lastname: Baskin
authors.forename: Paul
authors.initials: P
authors.lastname: Ishimine
authors.forename: Camille
authors.initials: C
authors.lastname: Scribner
authors.forename: Pamela
authors.initials: P
authors.lastname: Okada
authors.forename: Heather
authors.initials: H
authors.lastname: Beach
authors.forename: Blake
authors.initials: B
authors.lastname: Bulloch
authors.forename: Dewesh
authors.initials: D
authors.lastname: Agrawal
authors.forename: Mary
authors.initials: M
authors.lastname: Saunders
authors.forename: Donna M
authors.initials: DM
authors.lastname: Sutherland
authors.forename: Mercedes M
authors.initials: MM
authors.lastname: Blackstone
authors.forename: Amit
authors.initials: A
authors.lastname: Sarnaik
authors.forename: Julie
authors.initials: J
authors.lastname: McManemy
authors.forename: Alison
authors.initials: A
authors.lastname: Brent
authors.forename: Jonathan
authors.initials: J
authors.lastname: Bennett
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Plymale
authors.forename: Patrick
authors.initials: P
authors.lastname: Solari
authors.forename: Deborah J
authors.initials: DJ
authors.lastname: Mann
authors.forename: Peter S
authors.initials: PS
authors.lastname: Dayan
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001419:Bacteria / Q000302:isolation & purification; D005260:Female; D005334:Fever / Q000175:diagnosis / Q000209:etiology* / Q000382:microbiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D016920:Meningitis, Bacterial / Q000150:complications* / Q000188:drug therapy; D011379:Prognosis; D012307:Risk Factors; D014552:Urinary Tract Infections / Q000150:complications* / Q000175:diagnosis / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents