Testing low prevalence populations (with the TST) will statistically result in most reactors being false positives.

From the previous link in which doctors at the University of Miami discuss the pros and cons of using the tuberculin skin test to test for TB;

Any induration appearing at the injection site after 48–72 hours is considered a reaction and is measured in millimeters (mm) and recorded. The proper interpretation of skin test reactions depends on TST sensitivity and specificity as well as the positive predictive value of a reactive test. Tuberculin skin test sensitivity is estimated to be nearly 100% in those with LTBI and possessing normal immune responsiveness. False-positive tests can occur in persons infected with NTM or in those previously vaccinated with BCG, thereby resulting in a lower specificity and positive predictive value in those individuals who have a low probability of LTBI. Consequently, regardless of how high of specificity the TST may have, testing low prevalence populations will statistically result in most reactors being false positives.

The evidence just keeps piling up.