Table 3.
Comparison of performances of diagnostic tests in tissues and clinical samples
| Specimen type | No. (%) of positive specimens | |||||||
|---|---|---|---|---|---|---|---|---|
| Group of early diagnosis | Group of delayed diagnosis | |||||||
| AFB smear | MTB-PCR | Histology/cytology | MTB culture | AFB smear | MTB-PCR | Histology/cytology | MTB culture | |
| Tissue | ||||||||
| Lymph node, cervical | 2/5 | 4/5 | 4/5 | 2/4 | 0/4 | 3/4 | 3/3 | 2/2 |
| Lymph node, non-cervical | 2/7 | 5/7 | 7/7 | 3/4 | 2/5 | 4/5 | 4/5 | 0/3 |
| Bone | 2/9 | 8/9 | 5/8 | 8/9 | 0/4 | 2/4 | 2/4 | 3/4 |
| Omentum | 1/7 | 5/7 | 5/7 | 2/5 | 0/4 | 3/4 | 4/4 | |
| Liver/spleen/bone marrow | 0/4 | 2/4 | 1/3 | 2/4 | 3/8 | 6/8 | 5/7 | 0/3 |
| Other soft tissue | 5/7 | 6/7 | 4/7 | 4/5 | 2/3 | 3/3 | 2/3 | 2/2 |
| Clinical samples | ||||||||
| Sputum | 9/26 | 8/18 | 26/26 | 0/10 | 3/5 | 10/10 | ||
| Bronchoscopic specimens | 1/4 | 3/4 | 4/4 | |||||
| CSF | 0/4 | 1/4 | 0/4 | 2/4 | 0/2 | 1/2 | 0/2 | 1/2 |
| Pleural fluid | 0/7 | 1/7 | 6/7 | 2/7 | 0/2 | 0/2 | 2/2 | 0/2 |
| Ascites | 0/12 | 3/12 | 11/12 | 6/11 | 0/2 | 0/2 | 2/2 | 0/2 |
| Other fluid | 1/8 | 7/7 | 7/7 | 0/2 | 1/2 | 0/2 | 1/2 | |
| Total | 23/100 (23.0) | 53/91 (58.2) | 43/60 (71.7) | 68/90 (75.6) | 7/46 (15.2) | 26/41 (63.4) | 24/33 (72.7) | 19/32 (59.3) |
Abbreviations: AFB acid-fast bacilli, CSF cerebrospinal fluid, FUO fever of unknown origin, TB-PCR tuberculosis polymerase chain reaction, MTB Mycobacterium tuberculosis