Diagnosis of Pulmonary and Extra Pulmonary Tuberculosis: How Best is CBNAAT when Compared to Conventional Methods of TB Detection?

Abstract

Background: Globally, India is a home for more than 25% of global Tuberculosis (TB) burden. The sensitivity of smear microscopy and its inability to detect drug resistance limits its impact on TB control. We compared the cartridge-based nucleic acid amplification test (CBNAAT) results for diagnosis of pulmonary and extrapulmonary tuberculosis with the conventional meth-ods like sputum smear and solid culture examination.
Methods: A descriptive study was conducted at Government General and Chest Hosptial, Hyderabad, India during 2014 to 2016. The study population included all the pulmonary and ex-trapulmonary presumptive TB cases who were subjected for further investigations.
Results: Of the two hundred samples received, 110 (55%) were sputum samples and 90 (45%) were extrapulmonary samples. For pulmonary samples, the sensitivity and specificity for CB-NAAT samples were 79.2% and 89.5% respectively; while that for sputum smear were 41.5% and 98.2% respectively. For extrapulmonary samples, the sensitivity and specificity for CB-NAAT samples were 85.7% and 93.5% respectively; while that for sputum smear were 60.7% and 100% respectively.
Conclusion: CBNAAT is one of the rapid diagnostic tests available in the country and it should be routinely used under the public and private health sector effectively to detect a tuberculosis case.