Table 2.
Results of routine TB diagnostic tests, Xpert Ultra and the MPT64 test performed on samples
| Positive samples/total samples (%) | |||||||
|---|---|---|---|---|---|---|---|
| Number of cases | Micro-scopya | Culture | 1-step PCR | Nested-PCR | Xpert Ultra | MPT64 test | |
| TB cases | |||||||
| All samples | 31 | 6/27 (22) | 16/26 (62) | 6/18 (33) | 7/11 (64) | 4/7 (57) | 10/31 (32) |
| Lymph node biopsies | 7 | 1/6 (17) | 2/6 (33) | 0/5 (0) | 2/2 (100) | N/A | 3/7 (43) |
| Other biopsies | 12 | 2/9 (22) | 5/8 (63) | 1/7 (14) | 4/6 (67) | N/A | 4/12 (33) |
| Pus samples | 2 | 0/2 (0) | 1/2 (50) | 1/1 (100) | N/A | 1/2 (50) | 1/2 (50) |
| Lymph node aspirates | 7 | 3/7 (43) | 5/7 (71) | 4/4 (100) | 1/3 (33) | 3/4 (75) | 2/7 (29) |
| Fluid samples | 3 | 0/3 (0) | 3/3 (100) | 0/1 (0) | N/A | 0/1 (0) | 0/3 (0) |
| Confirmed TB case -confirmed sample | 22b | 5/19 (26) | 16/17 (94) | 6/13 (46) | 7/9 (78) | 4/5 (80) | 8/22 (36) |
| Culture positive sample | 16 | 4/16 (25) | 16/16 (100) | 5/12 (42) | 2/4 (50) | 4/5 (80) | 3/16 (19) |
| Culture positive, PCR positive sample | 6 | 3/6 (50) | 6/6 (100) | 5/5 (100) | 2/2 (100) | 3/3 (100) | 3/6 (50) |
| Culture positive, PCR negative sample | 8 | 1/8 (13) | 8/8 (100) | 0/7 (0) | 0/2 (0) | 1/2 (50) | 0/8 (0) |
| 1-step PCR positive sample | 6 | 4/6 (67) | 5/6 (83) | 6/6 (100) | 1/1 (100) | 3/3 (100) | 4/6 (67) |
| Nested-PCR positive sample | 7 | 1/4 (25) | 2/2 (100) | 1/1 (100) | 7/7 (100) | 1/1 (100) | 5/7 (71) |
| Confirmed TB case -unconfirmed sample | 4 | 0/3 (0) | 0/4 (0) | 0/3 (0) | N/A | N/A | 2/4 (50) |
| Clinically diagnosed TB case | 5 | 1/5 (20) | 0/5 (0) | 0/2 (0) | 0/2 (0) | 0/2 (0) | 0/5 (0) |
| Non-TB cases | |||||||
| All samples | 243 | 7/139 (5) | 0/226 (0) | 0/40 (0) | 0/24 (0) | 1/41 (2) | 39/243 (16) |
| Lymph node biopsies | 17c | 1/13 (8) | 0/14 (0) | 0/4 (0) | 0/4 (0) | 0/2 (0) | 0/17 (0) |
| Other biopsies | 52d | 2/35 (6) | 0/40 (0) | 0/16 (0) | 0/17 (0) | 1/8 (13) | 1/52 (2) |
| Pus samples | 13e | 3/13 (23) | 0/13 (0) | 0/4 (0) | 0/1 (0) | 0/8 (0) | 4/13 (31) |
| Lymph node aspirates | 4f | 1/2 (50) | 0/2 (0) | 0/2 (0) | 0/2 (0) | 0/1 (0) | 2/4 (50) |
| Fluid samples | 157 | 0/76 (0) | 0/157 (0) | 0/14 (0) | N/A | 0/22 (0) | 32/157 (20) |
Abbreviations: TB, tuberculosis; PCR, polymerase chain reaction
aMicroscopy performed at microbiology laboratory and/or pathology laboratory. A sample with discordant microscopy results between the laboratories (n = 2) is registered as microscopy positive
bOne of the nested-PCR positive patients was not started on TB treatment, and only followed by controls
c6 cases of NTM infection (2 NTM culture positive, 1 NTM specific PCR positive, 3 given a clinical diagnosis)
d2 cases of NTM infection (2 NTM specific PCR positive)
e3 cases of NTM infection (3 microscopy and NTM culture positive)
f1 case of NTM infection (microscopy, NTM culture and NTM specific PCR positive. This case was also MPT64 positive)