Diagnostic accuracy of Xpert MTB/RIF assay in extrapulmonary tuberculosis
Indian J Med Microbiol
; 2018 Sep; 36(3): 357-363
Article
| IMSEAR
| ID: sea-198807
Introduction: The WHO endorsed Xpert Mycobacterium tuberculosis/rifampicin (MTB/RIF) assay, has been evaluated for pulmonary TB in a number of studies but very few have investigated it for extrapulmonary specimens. The present study evaluates the performance of Xpert MTB/RIF assay in the diagnosis of extrapulmonary TB (EPTB). Aim and Objectives: The aim of the study is to determine sensitivity and specificity of Xpert MTB/RIF assay for diagnosis of EPTB and RIF resistance in comparison to culture on Lowenstein–Jensen (LJ) medium and proportion method (PM), respectively. Materials and Methods: A total of 738 specimens from clinically suspected cases of EPTB were subjected to Ziehl–Neelsen staining, Xpert MTB/RIF assay and culture on LJ medium. PM was done on MTB isolates. Results: The sensitivity, specificity of Xpert MTB/RIF assay for diagnosis of EPTB were 84.91% (95% confidence interval [CI] 72.41%–93.25%) and 86.72% (95% CI 83.94%–89.17%) and for RIF resistance detection were 60.00% (95% CI 32.29%–83.66%) and 94.74% (95% CI 73.97%–99.87%), respectively. Among culture-positive cases, the sensitivity of Xpert MTB/RIF assay was 94.12% in smear positive and 80.56% in smear-negative cases. Xpert MTB/RIF showed maximum sensitivity of MTB detection from lymph node specimens (100% [95% CI 54.07%–100.00%]) and other body fluids (100% [95% CI 15.81%–100.00%]). Conclusion: The present study establishes Xpert MTB/RIF assay as a promising tool in the rapid diagnosis of EPTB and detection of RIF resistance.
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Index:
IMSEAR
Type of study:
Diagnostic_studies
Journal:
Indian J Med Microbiol
Journal subject:
Microbiology
Year:
2018
Type:
Article