T‐Spot.TB outperforms tuberculin skin test in predicting development of active tuberculosis among household contacts

摘要: Background and Objective In Hong Kong, neonatal Bacillus Calmette–Guerin (BCG) vaccination is practiced with 99% coverage. This study was to compare the performance of T-Spot.TB tuberculin skin test (TST) in predicting tuberculosis (TB) among household contacts. Methods From 1 March 2006 31 July 2010, 1049 asymptomatic contacts smear-positive patients were simultaneously tested TST, then followed for up 5 years development TB. Attending clinicians subjects blinded results T-Spot.TB. Results T-Spot.TB gave a significantly higher positive rate (32.7% vs 22.1%) better association exposure time than TST at 15 mm cut-off. Agreement between using cut-offs 5, 10 relatively poor (kappa 0.25–0.41) irrespective presence or absence BCG scar. Only positivity negatively associated Both (incidence ratio test-positive test-negative subjects, IRR: 8.2) (IRR: 4.1, 6.1 2.8, 5 mm, 10 mm 15 mm, respectively) helped predict Using cut-off 56% future TB cases 62.5% bacteriologically confirmed missed. Lowering 5 mm could achieve sensitivity comparable that T-Spot.TB, but expense lower specificities, more tests (thus requiring treatment) per case predicted. Conclusions T-Spot.TB outperformed high-income area widespread