CBNAAT: a Novel Diagnostic Tool For Rapid And Specific Detection Of Mycobacterium Tuberculosis In Pulmonary Samples

Mycobacterium tuberculosis remains to be one of the most significant causes of death from an infectious agent. Rapid diagnosis of tuberculosis and detection of Rifampicin (RIF) resistance are essential for effective disease management. CBNAAT (Cartridge Based Nucliec Acid Amplification Test) also known as Gene Xpert MTB/RIF assay is a novel integrated diagnostic device for the diagnosis of tuberculosis and rapid detection of RIF resistance in clinical specimens. We determined the performance of the MTB/RIF assay for rapid diagnosis of tuberculosis and detection of rifampin resistance in smear-positive and smear-negative pulmonary specimens obtained from possible tuberculosis patients. Aim of the study - To assess diagnostic usefulness of Gene Xpert MTB/RIF assay technique in management of tuberculosis. Material and Methods : This is an Observational study conducted in the department of pulmonary medicine Maharajah’s Institute of Medical Sciences, Vizianagaram between June 2012 and December 2013. Two hundred and five Sputum samples were obtained from Tuberculosis suspects. All samples were tested on Gene Xpert for MTB/RIF detection after AFB microscopy. Results : 108(52.68%) sputum samples were AFB smear positive and 96 (47.32%) were negative. In MTB/RIF assay 144 (70.24%) were MTB positive and 61 (29.76%) were negative. Chi-Square test was applied; P value is <0.001. All results are highly significant. The MTB/RIF assay also detected 4 RIF-resistant specimen and 140 RIF-susceptible specimens, and the results were confirmed by drug susceptibility testing. Conclusions: The MTB/RIF test is a simple method, and routine staff with minimal training can use the system. It helps to avoid injudicious use of anti-tuberculosis drug.