영문초록
Tuberculin skin test (TST) is still the mainstay in the diagnosis of LTBI due to the cost and facility requirement of interferon-gamma releasing assay (IGRA). Epidemiologic data of TST in general population in one country can be an important basis for TB control strategy. However, these data of Korea is lack till now. We analyzed TST in young general population from 2008 to 2011. We performed TST for military conscripts of one term per year. Induration ≥ 10 mm 48-72 hrs after intradermal injection was defined as positive. Participants with chest radiograph showing active TB lesion were excluded from this study. A total of 4,774 participants were enrolled. All participants were male and median age was 21 (range 18-29). TST positive rate decreased 21.2% in 2008 to 15.3% in 2009, but it was stationary till 2011 (15.4%). In multivariate analysis, previous TB history, familial TB history, BCG scar and birth year were associated with positive TST (odds ratio [95% confidence interval]=3.94 [2.46-6.31], 2.75 [1.58-4.79], 1.41 [1.20-1.65] and 0.87 [0.82-0.91], respectively). Ages was deleted in analysis due to multi-collinearity with birth year. Number of participants with two BCG scars decreased dramatically for those born after 1985 and it affected TST positive rate decrease from 32.8% to 21.7%. TST positive rate in general population is decreasing. Several factors including BCG vaccination and TB history seem to affect this rate. This data can be an important basis for TB control strategy in Korea.