International Journal of Mycobacteriology (Jan 2023)
Utility of laboratory diagnostic tests in women suspected of genital tuberculosis attending a tertiary care teaching hospital
Abstract
Background: Genital Tuberculosis is a form of extrapulmonary tuberculosis, which if not diagnosed early can lead to complications. The objective of this study was to determine the sensitivity and specificity of Xpert Mycobacterium tuberculosis/rifampin (MTB/RIF) assay in genital tuberculosis (TB) in comparison with culture as a gold standard. Methods: The results of the Xpert MTB/RIF assay performed from January 2020 to August 2021 were compared with the results of culture by Mycobacterium Growth Indicator Tube (MGIT) 960. Results: Out of 75 specimens, fluorescent microscopy and liquid culture using MGIT and Xpert assay were positive in 3 (4%), 21 (28%), and 14 (18%), respectively. The sensitivity and specificity of the Xpert MTB/RIF assay were 66.67% and 100%. All smear-positive specimens were positive by culture and Xpert assay. Three specimens were positive by all the tests, i.e., microscopy, culture, and Xpert assay. Fifty-four specimens were negative by microscopy, culture, and Xpert assay. Discordance between the results of culture and Xpert assay was observed in seven specimens which were culture positive and Xpert assay negative. Three (21.42%) out of 21 culture-positive specimens showed monoresistance to rifampicin by Xpert MTB/RIF assay and culture drug susceptibility testing. Conclusion: Xpert MTB/RIF assay showed good sensitivity and specificity compared to liquid culture in genital TB. This test is easy to perform, provides results in 2 h, and can also detect rifampicin resistance, which is a surrogate marker for multidrug-resistant TB. Hence, the Xpert assay can be used under the National TB Elimination Program for early and rapid diagnosis of TB in endometrial specimens to prevent complications like infertility.
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