title: Value of adding an IGRA to the TST to screen for latent tuberculous infection in Greek health care workers.
abstract: METHODS
  Ioannina University Hospital, Ioannina, Greece.
  
  
  OBJECTIVE
  To evaluate the value of adding an interferon-gamma release assay (IGRA) to the tuberculin skin test (TST) for detecting latent tuberculous infection (LTBI) in a Greek university hospital among health care workers (HCWs) predominantly vaccinated with bacille Calmette-Guérin (BCG).
  
  
  METHODS
  Of 788 HCWs enrolled, 68.1% were BCG-vaccinated. A TST ⩾ 10 mm was considered positive and was followed by the QuantiFERON-TB(®) Gold In-Tube assay (QFT-GIT) in a two-step strategy.
  
  
  RESULTS
  Of the enrolled HCWs, 36.4% were TST-positive, of whom only 14.4% were IGRA-positive. Agreement between the tests was poor (κ = 0.019; 95%CI -0.014-0.05, P = 0.355). Both TST and IGRA positivity increased with TST diameter, from 5.7% in TST 10-14 mm to 48.8% in TST ⩾20 mm. TST-positive, IGRA-negative results were most likely in younger, recently BCG-vaccinated HCWs (84.6% in those aged 20-29 years) and less likely in older HCWs (45% in those aged 50-59 years). The two-step strategy would have been more cost saving compared to the TST-only approach if adherence to LTBI treatment in our cohort had been ⩾24%.
  
  
  CONCLUSIONS
  Poor overall agreement between TST and QFT-GIT was found. Use of IGRA as a second step in TST-positive cases offers an appropriate tool for LTBI detection among BCG-vaccinated HCWs in low-TB-incidence settings.
authors.affiliation: Department of Pulmonary Medicine, University Hospital of Ioannina, Ioannina, Greece.
authors.forename: A
authors.initials: A
authors.lastname: Charisis
authors.affiliation: Department of Family Medicine, University Hospital of Ioannina, Ioannina, Greece.
authors.forename: A
authors.initials: A
authors.lastname: Tatsioni
authors.affiliation: Department of Microbiology, University Hospital of Ioannina, Ioannina, Greece.
authors.forename: C
authors.initials: C
authors.lastname: Gartzonika
authors.affiliation: Department of Pulmonary Medicine, University Hospital of Ioannina, Ioannina, Greece.
authors.forename: A
authors.initials: A
authors.lastname: Gogali
authors.affiliation: Department of Microbiology, University Hospital of Ioannina, Ioannina, Greece.
authors.forename: D
authors.initials: D
authors.lastname: Archimandriti
authors.affiliation: Department of Pulmonary Medicine, University Hospital of Ioannina, Ioannina, Greece.
authors.forename: C
authors.initials: C
authors.lastname: Katsanos
authors.affiliation: Department of Pulmonary Medicine, University Hospital of Ioannina, Ioannina, Greece.
authors.forename: A
authors.initials: A
authors.lastname: Efthymiou
authors.affiliation: Department of Pulmonary Medicine, University Hospital of Ioannina, Ioannina, Greece.
authors.forename: S
authors.initials: S
authors.lastname: Katsenos
authors.affiliation: Department of Pulmonary Medicine, University Hospital of Ioannina, Ioannina, Greece.
authors.forename: G
authors.initials: G
authors.lastname: Daskalopoulos
authors.affiliation: Department of Microbiology, University Hospital of Ioannina, Ioannina, Greece.
authors.forename: S
authors.initials: S
authors.lastname: Levidiotou
authors.affiliation: Department of Pulmonary Medicine, University Hospital of Ioannina, Ioannina, Greece.
authors.forename: S H
authors.initials: SH
authors.lastname: Constantopoulos
authors.affiliation: Department of Pulmonary Medicine, University Hospital of Ioannina, Ioannina, Greece.
authors.forename: A K
authors.initials: AK
authors.lastname: Konstantinidis
mesh_terms: D000328:Adult; D001500:BCG Vaccine / Q000008:administration & dosage; D001431:Bacteriological Techniques / Q000191:economics; D003362:Cost-Benefit Analysis; D003430:Cross-Sectional Studies; D005260:Female; D006115:Greece; D017721:Hospital Costs; D006785:Hospitals, University; D006801:Humans; D059425:Interferon-gamma Release Tests / Q000191:economics; D055985:Latent Tuberculosis / Q000175:diagnosis* / Q000191:economics / Q000382:microbiology / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D009786:Occupational Health Services / Q000191:economics; D010564:Personnel, Hospital / Q000191:economics; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D014374:Tuberculin Test; D014611:Vaccination; D055815:Young Adult
chemical_list: D001500:BCG Vaccine