title: Evaluation of the accuracy of leukocyte esterase testing to detect pyuria in young febrile children: prospective study.
abstract: OBJECTIVE
  To study the accuracy and clinical application of the dipstick leukocyte esterase test in the detection of pyuria in young febrile children suspected to have urinary tract infection.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Regional hospital, Hong Kong.
  
  
  METHODS
  Urine samples were taken from 215 children younger than 2 years who were suspected to have urinary tract infection (fever without an obvious focus of infection).
  
  
  METHODS
  The accuracy of the dipstick leukocyte esterase test in detecting significant pyuria defined as a leukocyte count >or=10 mm(3) (>or=0.01 x 10(9) /L).
  
  
  RESULTS
  Two hundred and fifty-four urine samples collected by bag, midstream clean-catch, suprapubic bladder aspiration, or urethral catheterization were examined. Using urine microscopy results as a reference, the sensitivity and specificity of the leukocyte esterase test in detecting significant pyuria were found to be 72.0% and 85.8%, respectively; the positive and negative predictive values were 55.4% and 92.6%, respectively; and the positive and negative likelihood ratios were 5.1 and 0.3, respectively.
  
  
  CONCLUSIONS
  The dipstick leukocyte esterase test cannot accurately detect pyuria in young febrile children. It is also not appropriate as a screening test to exclude pyuria, reduce the need for the microscopic examination of urine, or indicate when a hospital admission for probable urinary tract infection is needed.
authors.affiliation: Department of Paediatrics, Pamela Youde Nethersole Eastern Hospital, 3 Lok Man Road, Chai Wan, Hong Kong.
authors.forename: S F
authors.initials: SF
authors.lastname: Yuen
authors.forename: F N
authors.initials: FN
authors.lastname: Ng
authors.forename: L Y
authors.initials: LY
authors.lastname: So
mesh_terms: D004950:Esterases / Q000097:blood*; D005334:Fever / Q000175:diagnosis*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007962:Leukocytes / Q000201:enzymology*; D011446:Prospective Studies; D011776:Pyuria / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D014552:Urinary Tract Infections / Q000175:diagnosis*
chemical_list: D004950:Esterases