Brazilian Journal of Infectious Diseases ()

Effectiveness of the BDProbeTec ET system for detection of Mycobacterium tuberculosis complex in sputum and bronchoalveolar lavage specimens

  • Hung-Chang Hung,
  • Chi-Ho Chan,
  • Shih-Ming Tsao,
  • Shiuan-Chih Chen,
  • Tzu-Chin Wu,
  • Min-Chi Lu,
  • Der-Jinn Wu,
  • Shu-Ju Huang,
  • Yuan-Ti Lee

DOI
https://doi.org/10.1590/S1413-86702012000300005
Journal volume & issue
Vol. 16, no. 3
pp. 242 – 249

Abstract

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OBJECTIVE: The diagnostic efficacy of the BDProbeTEC ET Mycobacterium tuberculosis (MTB) complex direct detection assay (DTB) performed on bronchoalveolar lavage (BAL) specimens and sputum smears was compared with acid-fast bacilli (AFB) smear microscopy. METHOD: AFB smear microscopy, DTB and culture results of 286 patients with pulmonary tuberculosis were retrospectively reviewed. A total of 120 patients provided expectorated sputum samples, and 166 patients provided BAL specimens. Culture results and clinical diagnosis were used as gold standards. RESULTS: The sensitivity and specificity of the DTB assay in detecting MTB in sputum specimens was significantly higher compared to AFB smear microscopy (83.7% and 82.4%, vs. 75.6%, and 41.2%, respectively). The sensitivity and specificity of the DTB assay in detecting MTB in sputum samples was 77.2% and 100% compared to clinical diagnosis, while AFB smear had a sensitivity and specificity of 70.3% and 26.3%, respectively. Compared to culture, DTB had a sensitivity and specificity of 82.8% and 93.2%, respectively, in detecting MTB from BAL specimens; AFB smear had a sensitivity and specificity of 41.9% and 87.7%, respectively. Compared to clinical diagnosis, DTB had a sensitivity and specificity of 67.2% and 100%, respectively, in detecting MTB from BAL specimens; AFB smear had a sensitivity and specificity of 34.8% and 79.5%, respectively. CONCLUSIONS: The superior performance of the DTB assay relative to AFB smear microscopy makes it a valuable tool to enable early diagnosis of MTB, thereby improving patient care and reducing transmission.

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