DIAGNOSTIC PERFORMANCE OF GENE XPERT MTB/RIF ASSAY IN PLEURAL FLUID: AN OBSERVATIONAL STUDY AT TERTIARY CARE CENTER

INTRODUCTION: Tuberculosis (TB) caused by Mycobacterium tuberculosis is a global health concern. According to Global TB Report 2021, the incidence of tuberculosis was 19,33,381. Late diagnosis and delay in treatment causes increase in mortality and morbidity. A reliable and rapid diagnostic tool is the priority for TB control. WHO has approved Gene Xpert MTB/RIF in December 2010 which is a Cartridge Based Nucleic Acid Amplification Test (CBNAAT). A new automated diagnostic molecular test which is not only sensitive (detects 131 CFU/ml of mycobacterium tuberculosis but also a rapid test (results are available in 2 hours) in comparison to liquid culture which are time consuming and necessitates biosafety procedures and require trained laboratory staff. OBJECTIVE: To evaluate the diagnostic yield of Gene Xpert MTB/RIF assay in pleural fluid. MATERIAL AND METHOD: A Cross-Sectional Observational study observational study was done in Department of Microbiology, MLN Medical College, Prayagraj from January 2023 to December 2023. The GeneXpert MTB/RIF (Cepheid, Sunnyvale, CA, USA) was performed on pleural fluid along with detection of presence of Mycobacterium tuberculosis it also detected Rifampicin resistance. RESULT: This study revealed the mean age of pleural fluid sample patients to be 42.0 years. GeneXpert MTB positivity was observed in 22.7% of pleural fluid samples. The diagnostic performance for pleural fluid samples showed a sensitivity of 89.47%, specificity of 100%, PPV of 100.0%, NPV of 96.55%, and an overall accuracy of 97.3%. CONCLUSION: The Xpert MTB/RIF assay demonstrates high sensitivity and specificity in detecting Mycobacterium tuberculosis in CSF and pleural fluid samples. Its rapid and accurate diagnostic capabilities is a valuable tool for improving diagnosis of tuberculosis in a resource-limited areas.