Screening for latent tuberculosis infection in South Korean healthcare workers using a tuberculin skin test and whole blood interferon-γ assay

Kyung Jong Lee, Young Ae Kang, Young Mi Kim, Sang Nae Cho, Jin Wook Moon, Moo Suk Park, Se Kyu Kim, Joon Chang, Young Sam Kim

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This study compared the results of a tuberculin skin test (TST) and a whole-blood interferon-γ release assay (IGRA) to screen latent tuberculosis (TB) infection (LTBI) according to risk of TB exposure in South Korea. A cross-sectional comparison of 82 healthcare workers (HCWs) was performed from June 2009 to January 2010. Participants were grouped according to their risk for TB exposure: group 1, frequent and direct contact with active TB patients (n = 35); group 2, no known history of direct contact with active TB patients (n = 47). For the TST (10-mm induration cut-off), the positive response rate was 42.9% in group 1 and 34.0% in group 2 (p = 0.42). For the IGRA, the positive response rate was 40% in group 1 and 10.6% in group 2 (p = 0.002). Results obtained from the TST and the IGRA were not in significant agreement. The working duration of HCWs in TB-related departments was the only significant risk factor for LTBI (odds ratio 1.03; p = 0.031). Further, the IGRA can more accurately discriminate LTBI compared to the TST, based on the risk of TB exposure. These results suggest that the IGRA is diagnostically useful for LTBI in South Korean HCWs.

Original languageEnglish
Pages (from-to)672-678
Number of pages7
JournalScandinavian Journal of Infectious Diseases
Issue number9
Publication statusPublished - 2010 Sep 1


All Science Journal Classification (ASJC) codes

  • Immunology and Microbiology(all)
  • Microbiology (medical)
  • Infectious Diseases

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