Evaluation of GeneXpert MTB/RIF for the Detection of Mycobacterium Tuberculosis in a Tertiary Care Hospital, Pakistan

Abstract

Objectives: To evaluate the diagnostic concert of GeneXpert MTB/RIF assay for the analysis of pulmonarytuberculosis and detection of Rifampicin resistance using sputum samples.Methodology: The retrospective descriptive cross-sectional study was conducted at the department of microbiology.Federal Government Polyclinic (FGPC), Islamabad, Pakistan, from August 2023 to July 2024. A total of 771 participants,referred by their physicians as TB suspects, were consecutively enrolled in the study from various wards of FGPC andother healthcare facilities in Islamabad, Pakistan. Sputum samples were collected from these participants andexamined using light microscopy following Ziehl-Neelsen (ZN) staining. All samples were processed using theGeneXpert MTB/RIF Assay.Results: Out of the 771 sputum samples, Mycobacterium tuberculosis was detected in 89 (11.54%) cases using theGeneXpert MTB/RIF assay. Rifampicin-resistant M. tuberculosis was found in 8 out of these 89 cases (8.98 %). Maleand female ratio of the patients was almost equal. Males were found to be 406 (57.4%) while 365 (42.5%) werefemales. The data were expressed as mean, median, and mode, and analyzed using the Statistical Package for SocialSciences (SPSS) version 25.0. Simple descriptive statistics (frequencies and percentages) were calculated for eachcategorical variable. The diagnostic accuracy, i.e., sensitivity, specificity, positive predictive value (PPV), and negativepredictive value (NPV) of the GeneXpert MTB/RIF assay compared to traditional methods was calculated.Conclusion: The GeneXpert MTB/RIF has higher sensitivity and specificity to conventional ZN smear microscopy. It isa simple, rapid, and accurate test for detecting Mycobacterium tuberculosis in sputum specimens.Keywords: GeneXpert MTB/RIF; Pakistan; Pulmonary tuberculosis; Rifampicin resistance