title: Comparison of the tuberculin skin test and interferon gamma release assay for the screening of tuberculosis in adolescents in close contact with tuberculosis TB patients.
abstract: BACKGROUND
  The tuberculin skin test (TST) frequently yields false positive results among BCG-vaccinated persons thereby limiting its diagnostic value particularly in settings with high BCG vaccination rate. We determined the agreement between IGRA and TST using 2 cutoff values and identified possible relationships between the results of these tests and the development of active tuberculosis.
  
  
  METHODS
  Adolescents aged 11-19 years in close contact with smear-positive tuberculosis cases and with normal chest radiographs were recruited from middle and high schools in South Korea. The TST was conducted by trained nurses, and blood was drawn for the QuantiFERON-TB Gold In-Tube (QFT-GIT). Participants were followed up for 2 years to check for incidence tuberculosis.
  
  
  RESULTS
  A total of 2,982 subjects were included in the study, the average age was 15.1 years (SD 1.3), 61% had BCG vaccination scars. The agreement of QFT-GIT and the TST was low (κ = 0.38, 95% CI 0.32 to 0.42) using 10 mm cutoff; however, when the 15 mm cutoff was used, the agreement was intermediate (κ = 0.56, 95% CI 0.50 to 0.61). The odds ratio (OR) for the development of active tuberculosis was 7.9 (95% CI 3.46 to 18.06) for QFT-GIT positive patients, 7.96 (95% CI 3.14-20.22) for TST/QFT-GIT+ and the OR 4.62 (95% CI 2.02 to 10.58) and 16.35 (95% CI 7.09 to 37.71) for TST 10 mm and 15 mm cutoff respectively.
  
  
  CONCLUSIONS
  The results of this study suggest that the TST cutoff point for patients aged 11-17 years would be 15 mm in other study. The OR of QFT-GIT for the development of active tuberculosis and its intermediate agreement with TST using 15 mm cutoff demonstrates its role as an adjunct diagnostic tool to current clinical practice. Positive responders to both TST and QFT-GIT at the outset may benefit from chemoprophylaxis.
authors.affiliation: Division of Tuberculosis and Bacterial Respiratory Infections, Korea National Institute of Health, Cheongwon-gun, Chungcheongbuk-Do, Republic of Korea.
authors.forename: Seung-Eun
authors.initials: SE
authors.lastname: Song
authors.affiliation: Division of Tuberculosis and Bacterial Respiratory Infections, Korea National Institute of Health, Cheongwon-gun, Chungcheongbuk-Do, Republic of Korea.
authors.forename: JiYeon
authors.initials: J
authors.lastname: Yang
authors.affiliation: Division of Tuberculosis and Bacterial Respiratory Infections, Korea National Institute of Health, Cheongwon-gun, Chungcheongbuk-Do, Republic of Korea.
authors.forename: Kil Soo
authors.initials: KS
authors.lastname: Lee
authors.affiliation: Division of Tuberculosis and Bacterial Respiratory Infections, Korea National Institute of Health, Cheongwon-gun, Chungcheongbuk-Do, Republic of Korea.
authors.forename: Hyungjun
authors.initials: H
authors.lastname: Kim
authors.affiliation: Division of Tuberculosis and Bacterial Respiratory Infections, Korea National Institute of Health, Cheongwon-gun, Chungcheongbuk-Do, Republic of Korea.
authors.forename: Young Mi
authors.initials: YM
authors.lastname: Kim
authors.affiliation: Division of Tuberculosis and Bacterial Respiratory Infections, Korea National Institute of Health, Cheongwon-gun, Chungcheongbuk-Do, Republic of Korea.
authors.forename: Seonghan
authors.initials: S
authors.lastname: Kim
authors.affiliation: Division of Tuberculosis and Bacterial Respiratory Infections, Korea National Institute of Health, Cheongwon-gun, Chungcheongbuk-Do, Republic of Korea.
authors.forename: Mi-Sun
authors.initials: MS
authors.lastname: Park
authors.affiliation: The Korean Institute of Tuberculosis, Cheongwon-gun, Chungcheongbuk-Do, Republic of Korea.
authors.forename: Su Yeon
authors.initials: SY
authors.lastname: Oh
authors.affiliation: The Korean Institute of Tuberculosis, Cheongwon-gun, Chungcheongbuk-Do, Republic of Korea.
authors.forename: Jin Bum
authors.initials: JB
authors.lastname: Lee
authors.affiliation: The Korean Institute of Tuberculosis, Cheongwon-gun, Chungcheongbuk-Do, Republic of Korea.
authors.forename: EunPyo
authors.initials: E
authors.lastname: Lee
authors.affiliation: Division of Tuberculosis and Bacterial Respiratory Infections, Korea National Institute of Health, Cheongwon-gun, Chungcheongbuk-Do, Republic of Korea.
authors.forename: Sang-Hee
authors.initials: SH
authors.lastname: Park
authors.affiliation: The Korean Institute of Tuberculosis, Cheongwon-gun, Chungcheongbuk-Do, Republic of Korea.
authors.forename: Hee-Jin
authors.initials: HJ
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D001500:BCG Vaccine; D002648:Child; D016358:Contact Tracing / Q000379:methods*; D005260:Female; D006801:Humans; D059425:Interferon-gamma Release Tests; D008297:Male; D014374:Tuberculin Test; D014376:Tuberculosis / Q000175:diagnosis* / Q000453:epidemiology; D055815:Young Adult
chemical_list: D001500:BCG Vaccine