title: Use of the QuantiFERON-TB Gold test to confirm latent tuberculosis infection in a Canadian tuberculosis clinic.
abstract: METHODS
  Capital Health Tuberculosis (TB) Clinic, Edmonton, Alberta, Canada.
  
  
  OBJECTIVE
  To analyze the QuantiFERON-TB Gold In-Tube test (QFT) results after implementation as a routine test for tuberculin skin test (TST) positive patients.
  
  
  METHODS
  From November 2004 until January 2007, patients who were TST-positive and were eligible for preventive treatment based on Canadian guidelines, were offered a QFT.
  
  
  RESULTS
  Of 1446 TST-positive patients, only 566 (39.6%) were QFT-positive. Categorized by reason for TST testing, 43.1% of 304 contacts, 32.8% of 348 employment screens and 24.2% of 298 post secondary school screens were QFT-positive. In contrast, 59.7% of 290 immigration screens were QFT-positive. A multivariate analysis found that QFT positivity was associated with older age, larger TST size, high-incidence TB region of birth, history of TB and chest X-ray findings suggestive of previous TB.
  
  
  CONCLUSIONS
  Implementation of the QFT as a secondary test for latent TB infection (LTBI) can significantly reduce the number of patients given LTBI treatment in a low-incidence country such as Canada.
authors.affiliation: Department of Medicine, University of Alberta, Edmonton, Alberta, Canada. Dennis.Kunimoto@ualberta.ca
authors.forename: Dennis
authors.initials: D
authors.lastname: Kunimoto
authors.forename: E
authors.initials: E
authors.lastname: Der
authors.forename: A
authors.initials: A
authors.lastname: Beckon
authors.forename: L
authors.initials: L
authors.lastname: Thomas
authors.forename: M
authors.initials: M
authors.lastname: Egedahl
authors.forename: A
authors.initials: A
authors.lastname: Beatch
authors.forename: G
authors.initials: G
authors.lastname: Williams
authors.forename: G
authors.initials: G
authors.lastname: Tyrrell
authors.forename: R
authors.initials: R
authors.lastname: Ahmed
authors.forename: N
authors.initials: N
authors.lastname: Brown
authors.forename: R
authors.initials: R
authors.lastname: Long
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000416:Alberta / Q000453:epidemiology; D000554:Ambulatory Care Facilities / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods* / Q000706:statistics & numerical data; D008875:Middle Aged; D011237:Predictive Value of Tests; D011933:Reagent Kits, Diagnostic; D015203:Reproducibility of Results; D012307:Risk Factors; D014374:Tuberculin Test / Q000379:methods* / Q000706:statistics & numerical data; D014376:Tuberculosis / Q000175:diagnosis* / Q000453:epidemiology; D055815:Young Adult
chemical_list: D011933:Reagent Kits, Diagnostic