Description of 42 sputum smear-negative or sputum non-producing subjects undergoing sputum induction for the investigation of possible tuberculosis (subjects are categorised by final diagnoses of active TB; quiescent or latent TB; and not TB, and percentage value of PPD-specific CD4+ IFN-γ+ lymphoc

Abbreviations: AFB = acid-fast bacilli; BCG+ = Bacille-Calmette-Guerin vaccinated; CXR = chest radiograph; DRC = Democratic Republic of Congo; HIV+ = Human immunodeficiency virus positive; IDU = injecting drug user; IS = induced-sputum; LN = lymph node; LRTI = lower respiratory tract infection; Mtb = Mycobacterium tuberculosis; na = not applicable; ND = not done; SLE = systemic lupus erythematosis; TST = tuberculin skin test; TB = tuberculosis