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 methods 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 extrapulmonary 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 CBNAAT 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 CBNAAT 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