“…The two main available tests are the tuberculin skin test (TST) and interferon-γ release assays (IGRAs). Though TST shows high sensitivity in individuals with normal immune responses 12 the sensitivity in people with previous Bacille Calmette-Guérin (BCG) vaccination, prior exposure to nontuberculous mycobacteria and immunosuppressant medication is lower 7 . Though some studies suggest the T-SPOT blood test which is a type of IGRA to diagnose latent TB 7,13 , a study by Ratnatunga et al in Sri Lanka showed no advantage in using T-SPOT.TB over TST 14 .…”