TABLE 1.
Results obtained by the Xpert MTB/RIF Ultra assay according to the source and MTUBC culture of the specimens
| Clinical sample | Total no. of samples | Samples MTUBC culture positive |
Sensitivity (%) | Samples MTUBC culture negative |
Specificity (%) | ||
|---|---|---|---|---|---|---|---|
| GXU+a | GXU−b | GXU+ | GXU− | ||||
| Sterile fluids | 44 | 60.5 | 100 | ||||
| Pleural fluid | 24 | 10 | 11 | 47.6 | 0 | 3 | |
| Cerebrospinal fluid | 4 | 3 | 0 | 100 | 0 | 1 | |
| Joint fluid | 9 | 7 | 1 | 87.5 | 0 | 1 | |
| Ascitic fluid | 3 | 1 | 2 | 33.3 | 0 | 0 | |
| Pericardial fluid | 4 | 2 | 1 | 66.6 | 0 | 1 | |
| Nonsterile fluids | 29 | 93.7 | 100 | ||||
| Gastric aspirate | 5 | 3 | 1 | 75 | 0 | 1 | |
| Urine | 24 | 12 | 0 | 100 | 0 | 12 | |
| Lymph nodes | 25 | 16 | 1 | 94.1 | 0 | 8 | 100 |
| Abscess aspirates | 20 | 64.7 | 100 | ||||
| Cervical abscess | 6 | 4 | 1 | 80 | 0 | 1 | |
| Skin abscess | 6 | 2 | 2 | 50 | 0 | 2 | |
| Paravertebral abscess | 3 | 2 | 1 | 66.6 | 0 | 0 | |
| Osteitis pus | 5 | 3 | 2 | 60 | 0 | 0 | |
| Tissues | 24 | 86.6 | 100 | ||||
| Skin biopsy | 8 | 2 | 0 | 100 | 0 | 6 | |
| Intervertebral disc biopsy | 2 | 2 | 0 | 100 | 0 | 0 | |
| Bone biopsy | 4 | 2 | 0 | 100 | 0 | 2 | |
| Pleural biopsy | 2 | 2 | 0 | 100 | 0 | 0 | |
| Rectal biopsy | 1 | 0 | 1 | 0 | 0 | 0 | |
| Costal cartilage biopsy | 1 | 1 | 0 | 100 | 0 | 0 | |
| Liver biopsy | 1 | 1 | 0 | 100 | 0 | 0 | |
| Cervical tissue | 1 | 1 | 0 | 100 | 0 | 0 | |
| Mediastinal tissue | 1 | 0 | 1 | 0 | 0 | 0 | |
| Synovial tissue | 3 | 2 | 0 | 100 | 0 | 1 | |
| Joint biopsy | 18 | 0 | 0 | 0 | 18 | ||
| Stool | 8 | 4 | 1 | 80 | 0 | 3 | 100 |
| Total | 168 | 82 | 26 | 75.9 | 0 | 60 | 100 |
a
GXU+, positive results from GeneXpert MTB/RIF Ultra.
b
GXU−, negative results from GeneXpert MTB/RIF Ultra.