Improved Diagnostic Evaluation of Suspected Tuberculosis

ELISpot = enzyme-linked immunospot assay incorporating early secretory antigenic target-6 and culture filtrate protein-10; ELISpot^PLUS = enzyme-linked immunospot assay incorporating early secretory antigenic target-6, culture filtrate protein-10, and Rv3879c; TB = tuberculosis; TST= tuberculin skin testing. *Results were indeterminate because of no achievement of positive control (11 patients), high background (1 patient), peptide contamination (1 patient), inconclusive assay (1 patient), or defective ELISpot plate (1 patient). †Results were not available because of history of TB (clinically contraindicated) (45 patients), patient did not return for reading (8 patients), result not recorded (8 patients), reason unknown (3 patients), death (1 patient), test performed elsewhere (1 patient), or patient declined consent (1 patient). ‡Tuberculin skin test results were based on a 15-mm cutoff point and considered positive if induration was ≥15 mm on the Mantoux test or grade 3 to 4 on the Heaf test regardless of bacille Calmette–Guérin vaccination status.