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


METHODS
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.
Institute of Medicine, Chung Shan Medical University, No.110 Sec.1 Jianguo N. Rd.,Taichung, Taiwan.
Hung-Chang
HC
Hung
Chi-Ho
CH
Chan
Shih-Ming
SM
Tsao
Shiuan-Chih
SC
Chen
Tzu-Chin
TC
Wu
Min-Chi
MC
Lu
Der-Jinn
DJ
Wu
Shu-Ju
SJ
Huang
Yuan-Ti
YT
Lee
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D012680:Sensitivity and Specificity; D013183:Sputum / Q000382:microbiology*; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis*; D055815:Young Adult