Characteristics of the study participantsa

  • a Abbreviations: ExC, exposed controls; LTBI, latent TB infection; LTBItt, treated LTBI; TB, tuberculosis; NTB, non-TB; NA, not available; —, not done; TST, tuberculin skin test; st-IGRA, short-term IGRA; lt-IGRA, long-term IGRA; +, positive; −, negative.

  • b Statistical significance of results of multiple-group comparisons is indicated as follows: #, P ≤ 0.08; *, P < 0.05; **, P < 0.005; ***, P < 0.001 (versus ExC).

  • c Infiltrates (with or without cavitation) or fibrotic scars consistent with TB.

  • d Screening tests for LTBI/TB were performed before IPT and were not repeated.

  • e One case was detected by positive culture of the pleural tissue sample.

  • f Induration diameter.