1. GeneXpert MTB/RIF assay(n=117)
Smear + / -
Culture +ve
Gene xpert + ve
75 (64%)
(Live bacilli)
(37 Pulm & 48 EPTB)
Smear & Culture - ve
Gene xpert +ve
37 (32%)
(Dead bacilli)
Smear & Culture + ve
Gene xpert -ve
5 (4%)
(Atypical Mycobacteria)

2. GENE XPERT PERFORMANCE SPUTUM (n = 54)
Gold Standard
Gene xpert+ve
Gene xpert - ve
Culture+ve
15 (T+ve)
0 (F-ve) Aty Mb
Culture -ve
5 (F +ve) Dead
34 (T –ve)

3. GENE XPERT PERFORMANCE BRONCHIAL WASH (n = 52)
Gold Standard
Gene xpert+ve
Gene xpert - ve
Culture+ve
12 (T+ve)
0 (F-ve) Aty Mb
Culture -ve
3 (F +ve) Dead
37 (T –ve)

4. GENE XPERT PERFORMANCE Extra-Pulmonary Samples (n=153)
Specimen
No.
C+ ve
GeX +ve
Sensitivity (%)
Specificity(%)
PPV(%)
NPV (%)
CSF 78 4
100
89.19
33.3
Asp. Pus 26 18
52.63
43.75
Tissue (bon) 23 11
78.95 50
Lymph node 15
63.64

5. Extra-Pulmonary Samples – Culture & GeneXpert Negative (n=61)
SPECIMEN
NO.
Pleural fluid 26
Ascitic fluid 22
Synovial fluid 6
Aspirated fluid 5
Pericardial fluid 1
Peritoneal fluid

6. GENE XPERT PERFORMANCE-Sensitivity
Analytical sensitivity
5 genome copies of purified DNA
131 CFU/ml of M.tb
Sensitivity = 100%
Negative Predictive value = 100%
Test accuracy = 100%
(detected all smear +ve / Culture +ve)

7. GENE XPERT PERFORMANCE -Specificity
Specimen
Specificity (%)
PPV (%)
Sputum 87 75
Bronchial wash 93 80
CSF 90 33
Asp. Pus 53 44
Tissue (bone) 79 50
Lymph node 64
32% Dead bacilli - Already treated cases ??