The Prevalence rate of tuberculin skin test positive by contacts group to predict the development of active tuberculosis after school outbreaks

Hee Jin Kim, Byung Chill Chun, Amy M. Kwon, Gyeong Ho Lee, Sungweon Ryu, Soo Yeon Oh, Jin Beom Lee, Se Hwa Yoo, Eui Sook Kim, Je Hyeong Kim, Choi Shin, Seung Heon Lee

Research output: Contribution to journalReview article


Background: The tuberculin skin test (TST) is the standard tool to diagnose latent tuberculosis infection (ITBI) in mass screening. The aim of this study is to find an optimal cut-off point of the TST+ rate within tuberculosis ( I B) contacts to predict the active TB development among adolescents in school I B outbreaks. Methods: The Korean National Health Insurance Review and Assessment database was used to identify active TB development in relation to the initial TST (cut-off, 10 mm). The 7,475 contacts in H9 schools were divided into two groups: Incident TIJ group (43 schools) and no incident TB group (4(> schools). ITBI treatment was initiated in (>07 of the 1,7(51 TST+ contacts. The association with active TB progression was examined at different cut-off points of the TST+ rate. Results: The mean duration of follow-up was 3.9±0.9 years. Thirty-three contacts developed active TB during the 4,504 person-years among the TST+ contacts without ITBI treatment (n-1,154). The average TST+ rate for the incident TB group (n=43) and no incident TB group (n=46) were 31.0% and 15.5%, respectively. The TST+ rate per group was related with TB progression (odds ratio [OR], 1.025; 95% confidence interval [CI], 1.001-1.050; p=0.037). Based on the TST+ rate per group, active TB was best predicted at TST+ > 16% (OR, 3.11; 95% CI, 1.29-7.51; area under curve, 0.64). j Conclusion: Sixteen percent of the TST+ rate per group within the same grade students can be suggested as an optimal cut-off to predict active TB development in middle and high schools TB outbreaks.

Original languageEnglish
Pages (from-to)349-355
Number of pages7
JournalTuberculosis and Respiratory Diseases
Issue number4
Publication statusPublished - 2015



  • Adolescent
  • Disease outbreaks
  • Latent tuberculosis
  • Tuberculin test
  • Tuberculosis

ASJC Scopus subject areas

  • Pulmonary and Respiratory Medicine
  • Infectious Diseases

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