Comparison study of genexpert MTB / RIF assay versus sputum smear microscopy results in presumptive tuberculosis cases in district Ghotki, Sindh.

Abstract

Objective: To evaluate the performance of GeneXpert MTB/RIF assay by comparing its results with sputum smear microscopy. Study Design: Comparative Cross-Sectional Study. Setting: Department of Outpatient (OPD), Taluka and District Head Quarter Hospitals of District Ghotki Sindh. Period: October 2022 to 2023. Methods: In this study 350 Participants were included and all sputum specimens were tested for both above mentioned diagnostic tools that are sputum smear microscopy and GeneXpert MTB/RIF assay during the period October 2022 to April 2023. All details regarding the study such as Demographic details, sputum smear microscopy results, and GeneXpert MTB/RIF assay test results of patients were collected. A case of pulmonary tuberculosis (PTB) was considered to be a patient having mycobacterium tuberculosis detected in sputum by GeneXpert MTB/RIF assay. Results: In this study, 61 cases (17.4%) out of 350 participants, were detected in GeneXpert MTB/ RIF assay and 35 cases (10%) out of 350 participants were positive in sputum smear microscopy. Male ratio is slightly higher than female among GeneXpert positive cases. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy sputum smear microscopy were 57%, 100%, 100%, 91.7%, and 92.5%, respectively, when GeneXpert test is taken as reference test. Conclusion: Sputum smear microscopy is as specific as GeneXpert but less sensitive test for the diagnosis of pulmonary tuberculosis than GeneXpert MTB/RIF assay.