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Table 2 Results of routine TB diagnostic tests, Xpert Ultra and the MPT64 test performed on samples

From: Diagnosis of extrapulmonary tuberculosis using the MPT64 antigen detection test in a high-income low tuberculosis prevalence setting

  

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)

  1. Abbreviations: TB, tuberculosis; PCR, polymerase chain reaction
  2. 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
  3. bOne of the nested-PCR positive patients was not started on TB treatment, and only followed by controls
  4. c6 cases of NTM infection (2 NTM culture positive, 1 NTM specific PCR positive, 3 given a clinical diagnosis)
  5. d2 cases of NTM infection (2 NTM specific PCR positive)
  6. e3 cases of NTM infection (3 microscopy and NTM culture positive)
  7. f1 case of NTM infection (microscopy, NTM culture and NTM specific PCR positive. This case was also MPT64 positive)
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BMC Infectious Diseases

ISSN: 1471-2334

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