title: Duration of fever affects the likelihood of a positive bag urinalysis or catheter culture in young children.
abstract: OBJECTIVE
  To test the hypothesis that there will be a clinically significant rise in the proportion of positive bag urinalyses and catheter cultures in young children with increasing duration of fever.
  
  
  METHODS
  This was a prospective cohort study of 818 infants and children age 3-36 months presenting to a tertiary care emergency department with documented fever without source. Following the documentation of fever from < 1 to > or = 5 days, bag specimens were collected for urinalysis. The primary outcome was the yield of positive bag dipsticks by day, defined as positive for nitrates or more than trace leukocyte esterase. The secondary outcome was positive catheter cultures on each day of fever.
  
  
  RESULTS
  Positive bag urinalyses increased with duration of fever: 14.8% (35/237) on day 1 versus 26.4% (43/163) on day 3 (relative risk [RR] = 1.8; 95% confidence interval [CI] = 1.2-2.7; P = .004). Positive catheter cultures increased in the same fashion: 4.8% (11/229) on day 1 versus 12.6% (20/159) on day 3 (RR = 2.6; 95% CI = 1.3-5.3; P = .005).
  
  
  CONCLUSIONS
  The yield of positive bag urinalyses and catheter cultures increased significantly in children with fever of 3 days or longer duration.
authors.affiliation: Department of Emergency Medicine, King Khalid University Hospital, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Hashim
authors.initials: H
authors.lastname: Bin Salleeh
authors.forename: David
authors.initials: D
authors.lastname: McGillivray
authors.forename: Mitch
authors.initials: M
authors.lastname: Martin
authors.forename: Hema
authors.initials: H
authors.lastname: Patel
mesh_terms: D002675:Child, Preschool; D015169:Colony Count, Microbial; D003937:Diagnosis, Differential; D005260:Female; D005334:Fever / Q000175:diagnosis / Q000652:urine*; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008297:Male; D011446:Prospective Studies; D013048:Specimen Handling / Q000295:instrumentation*; D016482:Urinalysis / Q000379:methods*; D014546:Urinary Catheterization / Q000295:instrumentation*; D014552:Urinary Tract Infections / Q000175:diagnosis* / Q000382:microbiology / Q000652:urine; D014556:Urine / Q000382:microbiology