Table 2.

Revised Classification of Intrathoracic Tuberculosis Case Definitions for Diagnostic Evaluation Studies in Children

Case Definition	Refined Criteriaa
Confirmed tuberculosis	Bacteriological confirmation obtained Requires Mycobacterium tuberculosis to be confirmed (culture or Xpert MTB/RIF assay) from at least 1 respiratory specimen
Unconfirmed tuberculosis	Bacteriological confirmation NOT obtained AND at least 2 of the following: Symptoms/signs suggestive of tuberculosis (as defined) Chest radiograph consistent with tuberculosis Close tuberculosis exposure or immunologic evidence of M. tuberculosis infection Positive response to tuberculosis treatment (requires documented positive clinical response on tuberculosis treatment—no time duration specified) - With M. tuberculosis infection Immunological evidence of M. tuberculosis infection (TST and/or IGRA positive) - Without M. tuberculosis infection No immunological evidence of M. tuberculosis infection
Unlikely tuberculosis	Bacteriological confirmation NOT obtained AND Criteria for “unconfirmed tuberculosis” NOT met - With M. tuberculosis infection Immunological evidence of M. tuberculosis infection (TST and/or IGRA positive) - Without M. tuberculosis infection No immunological evidence of M. tuberculosis infection

Abbreviations: IGRA, interferon-γ release assay; TST, tuberculin skin test.

^a All children should have symptoms compatible with tuberculosis as determined by the treating clinician.