Table 1. Results by specimen type of MTBc culture, smear microscopy, Xpert Ultra and diagnostic performance of Xpert Ultra with culture as the reference standard.
| Type of specimen | n | Culture (+) (n = 158) | Culture (-) (n = 1423) | Performance of Xpert Ultra | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| smear (+) | smear (-) | smear (+) | smear (-) | Sensitivity (%) (95% CI) | Specificity (%) (95% CI) | PPV (%) (95% CI) | NPV (%) (95% CI) | ||||||
| XU (+) (n = 72) | XU (-) (n = 0) | XU (+) (n = 72) | XU (-) (n = 14) | XU (+) (n = 2) | XU (-) (n = 10) | XU (+) (n = 77) | XU (-) (n = 1334) | ||||||
| Sputum | 521 | 58 | 0 | 35 | 7 | 1 | 5 | 12 | 403 | 93 (86,1–97,1) | 96,9 (94,8–98,4) | 87,7 (79,9–93,3) | 98,3 (96,6–99,3) |
| BAL and RA | 560 | 5 | 0 | 10 | 2 | 0 | 3 | 29 | 511 | 88,2 (63,6–98,5) | 94,7 (92,4–96,4) | 34,1 (20,5–49,9) | 99,6 (98,6–100) |
| Gastric fluid | 16 | 0 | 0 | 0 | 1 | 0 | 0 | 3 | 12 | NA | 80 (51,9–95,7) | NA | 92,3 (64–99,8) |
| Pulmonary biopsy | 23 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 23 | NA | NA | NA | NA |
| Lymph node | 196 | 7 | 0 | 16 | 1 | 0 | 1 | 24 | 147 | 95,8 (78,9–99,9) | 86,1 (80–90,9) | 48,9 (34,1–63,9) | 99,3 (96,3–100) |
| Tissue biopsy | 53 | 0 | 0 | 0 | 0 | 0 | 1 | 2 | 50 | NA | NA | NA | NA |
| Pleural fluid | 77 | 0 | 0 | 6 | 3 | 0 | 0 | 1 | 67 | 66,7 (29,9–92,5) | 98,5 (92,1–100) | 85,7 (42,1–99,6) | 95,7 (88–99,1) |
| Pericardial fluid | 19 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 19 | NA | NA | NA | NA |
| CSF | 51 | 0 | 0 | 0 | 0 | 0 | 0 | 2 | 49 | NA | NA | NA | NA |
| Osteoarticular | 27 | 2 | 0 | 1 | 0 | 1 | 0 | 2 | 21 | 100 (29,2–100) | 87,5 (67,6–97,3) | 50 (11,8–88,2) | 100 (83,9–100) |
| Pus | 34 | 0 | 0 | 4 | 0 | 0 | 0 | 2 | 28 | 100 (39,8–100) | 93,3 (77,9–99,2) | 66,7 (22,3–95,7) | 100 (87,7–100) |
| Urine | 4 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 4 | NA | NA | NA | NA |
XU, GeneXpert MTB/RIF Ultra assay; PPV, positive predictive value; NPV, negative predictive value; CI, confidence interval; BAL and RA, bronchoalveolar lavage and respiratory aspirate; NA, not applicable; CSF, cerebrospinal fluid.