TABLE 1.
Diagnostic performance of the cobas MTB assay for identification of Mycobacterium tuberculosis complex nucleic acid from primary samplesa
| Sample source | No. of samples/total (% [95% CI]) |
|||
|---|---|---|---|---|
| Sensitivity |
Specificity | |||
| Smear-positive | Smear-negative | Pooled | ||
| Germany | 32/33 (97.0 [84.7, 99.5]) | 14/24 (58.3 [38.8, 75.5]) | 46/57 (80.7 [68.7, 88.9]) | 219/222b (98.6 [96.1, 99.5]) |
| Sierra Leone | 42/42 (100.0 [91.6, 100.0]) | 3/3 (100.0 [43.9, 100.0]) | 45/45 (100.0 [92.1, 100.0]) | NAc |
| All samples | 74/75 (98.7 [92.8, 99.8]) | 17/27 (63.0 [44.2, 78.5]) | 91/102 (89.2 [81.7, 93.9]) | 219/222 (98.6 [96.1, 99.5]) |
a
Culture was used as a reference standard. CI, confidence interval.
b
A total of 18/222 (8.1%) of the investigated Mycobacterium tuberculosis complex (MTBC)-negative samples grew nontuberculous mycobacteria (Mycobacterium avium complex, n = 9; Mycobacterium kansasii, n = 6; and Mycobacterium abscessus, n = 3).
c
Only MTBC culture-positive samples from Sierra Leone were analyzed. NA, not applicable.