Detection of Pulmonary Tuberculosis Using Cartridge Based Nucleic Acid Amplification Test (CBNAAT) and Fluorescent Microscopy

Background: With the advent of advanced laboratory methods for diagnosis of Pulmonary Tuberculosis (PTB), its detection now is increasingly relied upon rapid diagnostic methods like Cartridge based nucleic acid amplification test (CBNAAT) and Fluorescent Microscopy (FM). No study has been published regarding the effectiveness of CBNAAT and FM. This study aims to better the understanding of these methods for detection of PTB. The objective of the study was to compare CBNAAT and FM for detection of Mycobacterium tuberculosis (MTB) using sputum samples. Methods: A cross-sectional study was performed among 200 study population. 3 sputum samples from each patient were subjected to CBNAAT and 2 slide smears were prepared for Aura mine-O stained FM. Statistical analysis was done using SPSS 23 by Chi square test. P value less than 0.05 was taken as significant difference for this study. Result: Thirty-three (17%) patients were positive by FM and 58 (29%) by CBNAAT for MTB. Statistical analysis was done and the difference in positive yield was highly significant with P value <0.0001. Six (10%) patients were detected as Rifampicin resistance by CBNAAT out of which 2 were missed by FM. Among HIV patients 7(17%) were detected for MTB by CBNAAT and 1(2.5%) by FM. Conclusion: CBNAAT is a better method of detection as compared to FM in diagnosis of PTB.