title: Screening for latent tuberculosis infection in South Korean healthcare workers using a tuberculin skin test and whole blood interferon-gamma assay.
abstract: This study compared the results of a tuberculin skin test (TST) and a whole-blood interferon-gamma 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.
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Kyung
authors.initials: K
authors.lastname: Jong Lee
authors.forename: Young
authors.initials: Y
authors.lastname: Ae Kang
authors.forename: Young
authors.initials: Y
authors.lastname: Mi Kim
authors.forename: Sang-Nae
authors.initials: SN
authors.lastname: Cho
authors.forename: Jin
authors.initials: J
authors.lastname: Wook Moon
authors.forename: Moo
authors.initials: M
authors.lastname: Suk Park
authors.forename: Se
authors.initials: S
authors.lastname: Kyu Kim
authors.forename: Joon
authors.initials: J
authors.lastname: Chang
authors.forename: Young
authors.initials: Y
authors.lastname: Sam Kim
mesh_terms: D000328:Adult; D016009:Chi-Square Distribution; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D006282:Health Personnel; D006801:Humans; D007371:Interferon-gamma / Q000097:blood*; D055985:Latent Tuberculosis / Q000097:blood / Q000175:diagnosis*; D008297:Male; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D011237:Predictive Value of Tests; D056910:Republic of Korea; D012307:Risk Factors; D018709:Statistics, Nonparametric; D014374:Tuberculin Test / Q000379:methods*
chemical_list: D007371:Interferon-gamma