Camelid TB Serology Quarterly Report 1st Jan - 31st March 2018
Source: environment.data.gov.uk (2024-10-03)

Camelid TB Serology Quarterly Report. Camelid TB Serology Quarterly Report.

Camelid TB Serology
Quarterly Report
Number: 12
Report Period 1st January to 31st March 2018
Issued 04 April 2018

Submission Reason
Explanation
APHA /DEFRA
At Government expense
Parallel Test:
PAR-TB
TB breakdown herd with confirmed M. bovis infection (including Wales where Officially
TB Free Withdrawn [OTFW] status is determined on epidemiological grounds)
PAR-SUS
TB strongly suspected but not currently confirmed by laboratory culture – herd under
restrictions
PAR-TRC
Forward  tracing(s) from an M. bovis-infected camelid herd (includes camelid herds in
Wales only co-located on the same premises with infected cattle, sheep, deer, goats
& pigs)
Serial Test:
SER-CONT
Herd not under restriction but contiguous to a TB-infected herd
SER-COL
Herd not under restriction but co-located with an infected herd of cattle, deer, goats
etc. (Eng & Scot only)
SER-EPI
Herd not under restriction but TB tested due to an epidemiological link with a known
infected herd (e.g. back-tracing)
Commercial/Private
At Owner expense
SER-MVT
Pre- or post-movement test
SER-EXP 
Pre-export test
SER-DIAG
Diagnostic to exclude TB from a differential diagnoses in a herd not restricted (TB
strongly suspected)
SER-RHT
Monitoring - voluntary routine testing (herd nor restricted)
Quarterly Camelid Serology Report
Test Criteria
The camelid TB serology (antibody) test comprises two separate antibody tests in a test package that can be applied
flexibly to increase the sensitivity or specificity of the test as required, by using a parallel or serial test interpretation
respectively. The sensitivity and specificity values of combined antibody testing for camelids were described under AHVLA
Project FT1477 as follows (see also Rhodes et al., 2012);
Sensitivity = 81.3% [71.9-91.6]    [95% confidence intervals]
Specificity = 95.8% [93.3-98.2]
Parallel Test (e.g. confirmed breakdown herd test – for increased sensitivity):
Serial Test (e.g. movement test – for increased specificity):
Sensitivity = 55.8% [42.3-69.3]
Specificity = 99.7% 99.1-100]
N.B. The above combined test used by APHA from 1st October 2014 comprised the IDEXX ELISA and the Chembio
STAT-PAK lateral flow tests. Replacement of the STAT-PAK with the DPP VetTB lateral flow test by Chembio led to the
exchange of the STAT-PAK in the APHA camelid combined test with the new DPP VetTB test. APHA validation data
showed the DPP VetTB to have similar test specificities when used in the above combined test with the IDEXX ELISA
(Parallel 92.9% [89.6-96.2]; Serial 99.6% [98.7-100]). Preliminary data also suggested that the sensitivity of the DPP
VetTB is equivalent to that of the STAT-PAK.
Rhodes, S., Holder, T., Clifford, D., Dexter, I., Brewer, J., Smith, N., Waring, L., Crawshaw, T., Gillgan, S., Lyashchenko,
K., Lawrence, J., Clarke, J., de la Rua-Domenech, R., Vordermeier, M., 2012. Evaluation of gamma interferon and
antibody tuberculosis tests in alpacas. Clin Vaccine Immunol 19, 1677-1683.
From November 2015 the enferplex ELISA was incorporated into APHA’s options for statutory camelid test purposes (the
enferplex may not be used for private testing). The 2-spot enferplex may be use as one of the two tests required for the
Parallel Test, while the 4-spot enferplex may be used as a stand-alone test in place of the high specificity Serial Test: the
sensitivity and specificity values of the two test options above (for increased sensitivity or increased specificity) are not
altered by this flexible use of test options.

Quarterly Camelid Serology Report
04 Apr 2018
Table 1a
Country
No.
Samples
Tested
England
441
Wales
98
Total for Q1
539
Number of Samples tested and Submission Reason  2018 Q1 (January - March)
Table 1b
Submission
Reason
No.
Samples
Tested
Parallel
PAR-SUS
4
PAR-TB
87
PAR-TRC
3
Parallel
Sum:
94
Serial
SER-COL
84
SER-CONT
352
Serial
Sum:
436
Commercial/Private Testing SER-DIAG
1
SER-MVT
8
Commercial/Private Testin
Sum:
9
Total for Q1
Sum:
539

Quarterly Camelid Serology Report
04 Apr 2018
Table 2a
Country
No.
Samples
Tested
England
441
Wales
98
Total for Q1
539
Number of Samples tested and Submission Reason 2018 up to end of Q1 (January - March)
Table 2b
APHA/DEFRA
Submission
Reason
No.
Samples
Tested
Parallel
PAR-SUS
4
PAR-TB
87
PAR-TRC
3
Parallel
Sum:
94
Serial
SER-COL
84
SER-CONT
352
Serial
Sum:
436
Commercial/Private Testing
SER-DIAG
1
SER-MVT
8
Commercial/Private Testing
Sum:
9
Total for 2018 up to end
of Q1
539

Quarterly Camelid Serology Report
04 Apr 2018
Table 3a
Submissions Received and Test Positivity in 2018 Q1
Country
Submission
Reason
No.
Submissions
No. Samples
Tested
No.
Positive
Samples
% Positive
Samples
England
Parallel
PAR-SUS
2
4
0
0
PAR-TB
4
87
12
13.8%
PAR-TRC
1
3
3
100.0%
Parallel
7
94
15
16.0%
Serial
SER-COL
5
72
1
1.4%
SER-CONT
31
266
2
0.8%
Serial
36
338
3
0.9%
Commercial/Private Testing
SER-DIAG
1
1
0
0
SER-MVT
3
8
0
0
Commercial/Private Testing
4
9
0
0
England Total
47
441
18
4.1%
Wales
Serial
SER-COL
2
12
0
0
SER-CONT
4
86
1
1.2%
Serial
6
98
1
1.0%
Wales Total
6
98
1
1.0%
Totals for Q1
53
539
19
3.5 %
Test Positivity in 2018 Q1 (January - March)

Quarterly Camelid Serology Report
04 Apr 2018
Table 3b
Submissions Received and Test Positivity in 2018 up to the end of Q1
Country
Submission
Reason
No.
Submissions
No. Samples
Tested
No.
Positive
Samples
% Positive
Samples
England
Parallel
PAR-SUS
2
4
0
0
PAR-TB
4
87
12
13.8%
PAR-TRC
1
3
3
100.0%
Parallel
7
94
15
16.0%
Serial
SER-COL
5
72
1
1.4%
SER-CONT
31
266
2
0.8%
Serial
36
338
3
0.9%
Commercial/Private Testing
SER-DIAG
1
1
0
0
SER-MVT
3
8
0
0
Commercial/Private Testing
4
9
0
0
England Total
47
441
18
4.1%
Wales
Serial
SER-COL
2
12
0
0
SER-CONT
4
86
1
1.2%
Serial
6
98
1
1.0%
Wales Total
6
98
1
1.0%
Totals up to
end Q1
53
539
19
3.5 %
Test Positivity in 2018 up to end of Q1 (January - March)

Quarterly Camelid Serology Report
04 Apr 2018
Submissions Received in 2018 up to end of Q1
Analysis
Analysis Description
Q1
No.
samples
tested
Totals up to end Q1
TC0503
Camelid TB Enferplex - 2
Spot
34
34
TC0603
Camelid TB Enferplex - 4
Spot
232
232
TC0615
Camelid TB DPP VetTB
antibody test
296
296
TC0867
Camelid TB Antibody
ELISA
282
282
Table 4: Number of samples Tested by Test Code