Molecular techniques in mycobacterial detection.

Abstract

Abstract Objective.—To assess the clinical utility of the commercial nucleic acid amplification (NAA) tests (ie, Amplified Mycobacterium Tuberculosis Direct Test, Gen-Probe, Inc and AMPLICOR Mycobacterium tuberculosis Test, Roche Molecular Systems, Inc) for direct detection of Mycobacterium tuberculosis complex. Data Sources.—Review of the English-language literature. Conclusions.—The performance of both NAA tests is excellent (sensitivity, ≥95%; specificity, 100%) when testing respiratory specimens that are smear-positive for acid-fast bacilli (AFB). Only the Gen-Probe assay is approved for testing respiratory specimens regardless of the AFB smear result. Data from 3 studies showed that the sensitivity of the Mycobacterium Tuberculosis Direct Test in smear-negative patients ranged from 83% to 85%, and that the specificity was 99%. Both NAA tests have been used to test nonrespiratory specimens; in some studies, the performance was comparable to the performance obtained for respiratory specimens, whereas i...