title: Evaluation of the enhanced amplified Mycobacterium tuberculosis direct test for direct detection of Mycobacterium tuberculosis complex in respiratory specimens.
abstract: OBJECTIVE
  To evaluate the performance of the enhanced Mycobacterium Tuberculosis Direct Test (E-MTD), for the direct detection of M tuberculosis complex (MTBC) in respiratory specimens.
  
  
  METHODS
  Two hundred seventy-four respiratory specimens from 151 patients in respiratory isolation were tested with the E-MTD, and the results were compared with the results of mycobacterial smear, culture, and the earlier form of the test, MTD-1.
  
  
  RESULTS
  Forty-one specimens were culture positive for mycobacteria (20 MTBC and 21 nontuberculous mycobacteria), 23 of which were smear positive (16 MTBC, 7 nontuberculous mycobacteria). Twenty-four specimens were positive by E-MTD, and 21 were positive by MTD-1. Of the 20 MTBC culture-positive specimens, 19 were positive by the E-MTD and 19 were positive by the MTD-1. The remaining specimens were MTBC negative by all methods. After resolution of discrepancies, the sensitivity, specificity, and positive and negative predictive values were 95.2%, 100%, 100%, 99.6% for the MTD-1 and 95.2%, 98.8%, 87.0%, and 99.6%, for the E-MTD. For the E-MTD smear-positive and smear-negative specimens, these same values were 93.8%, 100%, 100%, and 87.5% and 100%, 98.8%, 62.5%, and 100%, respectively.
  
  
  CONCLUSIONS
  The results suggest that the E-MTD is a reliable method for the direct detection of MTBC in smear-positive respiratory specimens.
authors.affiliation: Division of Microbiology, Department of Pathology, University of Texas Medical Branch, Galveston 77555, USA.
authors.forename: M B
authors.initials: MB
authors.lastname: Smith
authors.forename: J S
authors.initials: JS
authors.lastname: Bergmann
authors.forename: M
authors.initials: M
authors.lastname: Onoroto
authors.forename: G
authors.initials: G
authors.lastname: Mathews
authors.forename: G L
authors.initials: GL
authors.lastname: Woods
mesh_terms: D001431:Bacteriological Techniques / Q000706:statistics & numerical data; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology; D003951:Diagnostic Errors; D005069:Evaluation Studies as Topic; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000235:genetics* / Q000302:isolation & purification*; D021141:Nucleic Acid Amplification Techniques; D012680:Sensitivity and Specificity; D013183:Sputum / Q000382:microbiology; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000382:microbiology*