Analysis of Different Tests for Diagnosis of Pulmonary Tuberculosis

For the diagnosis of pulmonary tuberculosis phenotypic and genotypic tests were analysed. On 269 pulmonary specimens comprising of Sputum (139), Bronchoalveolar lavage (B. A. L.) (90), Pleural fluid (21) and Endotracheal secretions (E. T.) (19) ZeihlNeelson (ZN) stain, Automated TB culture, Line Probe Assay (LPA), Nucleic Acid Amplification Test (NAAT) (TrueNat) and Real Time PCR (RTPCR) (Hi media) were performed. A total of 123 (45.72%) specimens were positive either by single or multiple tests together. Of these highest positivity was seen in 72 (58.54%) sputum specimens followed by 35 (28.46%) B. A. L., 9 (7.32%) pleural fluids and 7 (5.69%) E. T. secretions. Highest positivity amongst the tests was seen with 121 (98.37%) NAAT test, 119 (96.74%) Culture and 116 (94.31%) RTPCR while it was low with 83 (67.48%) ZN stain and 81 (65.85%) LPA test. All five tests were positive in 77 (62.60%) and Culture, NAAT and RTPCR were simultaneously positive 36 (29.27%). Molecular tests of NAAT and RTPCR are most favored tests for diagnosis of TB which can be substantiated by Culture if required.