Camelid TB Serology Quarterly Report: 1st October 2020 to 31st December 2020
Source: environment.data.gov.uk (2024-10-03)

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

Camelid TB Serology
Quarterly Report
Number: 23
Report Period 1st October to 31st December 2020
Issued 06 January 2021

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TB Free Withdrawn [OTFW] status is determined on epidemiological grounds)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)
SER-CHK
Inconclusive Reactor check test – e.g. where private Enferplex test has produced a
2-spot-positive result on 2 consecutive occasions
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 generally 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 (see Rhodes et al., 2012) and re-assessed in May 2018 to show the following test
performance;
Table 1 – High Sensitivity / Parallel test options:
IDEXX /DPP VetTB
ENFER 2-SPOT/DPP VetTB
IDEXX/ENFER 2-SPOT
% Se
74
71
75
95% C.I.
65.4-82.6
62.1-79.9
66.5-83.5
% Sp
96
96.7
97.3
95% C.I.
93.8-98.2
95.8-99.4
95.4-99.1
Fishers Exact [2-sided] test showed no significant difference in sensitivity or specificity between any of these three test options.
Table 2 – High Specificity / Serial test options:
Fishers Exact [2-sided] test showed no significant difference in test sensitivity or specificity between these two test options.
ENFER 4-SPOT
IDEXX/DPP VetTB
% Se
60
56
95% C.I.
50.4-69.9
46.3-65.7
% Sp
99.66
100
95% C.I.
98.9-100
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.

Quarterly Camelid Serology Report
06 Jan 2021
Table 1a
Country
No.
Samples
Tested
England
178
Wales
22
Non GB
2
Total for Q4
202
Number of Samples tested and Submission Reason  2020 Q4 (October - December)
Table 1b
Submission
Reason
No. Samples
Tested
Parallel
PAR-SUS
25
PAR-TB
35
Parallel
Sum:
60
Serial
SER-CHK
5
SER-COL
23
SER-CONT
106
Serial
Sum:
134
Commercial/Private Testing
SER-DIAG
2
SER-MVT
6
Commercial/Private Testing
Sum:
8
Total for Q4
Sum:
202

Quarterly Camelid Serology Report
06 Jan 2021
Table 2a
Country
No.
Samples
Tested
England
1521
Wales
93
Non GB
2
Total for Q4
1616
Number of Samples tested and Submission Reason 2020 up to end of Q4 (January - December)
Table 2b
APHA/DEFRA
Submission
Reason
No.
Samples
Tested
Parallel
PAR-SUS
27
PAR-TB
893
Parallel
Sum:
920
Serial
SER-CHK
10
SER-COL
68
SER-CONT
513
SER-EPI
7
Serial
Sum:
598
Commercial/Private Testing
SER-DIAG
3
SER-EXP
31
SER-MVT
57
SER-RHT
3
Commercial/Private Testing
Sum:
94
                   
4
Sum:
4
Total for 2020 up to end
of Q4
1616

Quarterly Camelid Serology Report
06 Jan 2021
Table 3a
Submissions Received and Test Positivity in 2020 Q4
Country
Submission
Reason
No.
Submissions
No. Samples
Tested
No.
Positive
Samples
% Positive
Samples
England
Parallel
PAR-SUS
2
25
2
8.0%
PAR-TB
3
31
5
16.1%
Parallel
5
56
7
12.5%
Serial
SER-CHK
3
4
0
0
SER-COL
5
21
0
0
SER-CONT
13
91
0
0
Serial
21
116
0
0
Commercial/Private Testing
SER-MVT
3
6
0
0
Commercial/Private Testing
3
6
0
0
England Total
29
178
7
3.9%
Wales
Parallel
PAR-TB
1
4
0
0
Parallel
1
4
0
0
Serial
SER-CHK
1
1
0
0
SER-COL
1
2
0
0
SER-CONT
4
15
0
0
Serial
6
18
0
0
Wales Total
7
22
0
0
Non GB
Commercial/Private Testing
SER-DIAG
1
2
0
0
Commercial/Private Testing
1
2
0
0
Non GB Total
1
2
0
0
Totals for Q4
37
202
7
3.5 %
Test Positivity in 2020 Q4 (October - December)

Quarterly Camelid Serology Report
06 Jan 2021
Table 3b
Submissions Received and Test Positivity in 2020 up to the end of Q4
Country
Submission
Reason
No.
Submissions
No. Samples
Tested
No.
Positive
Samples
% Positive
Samples
England
Parallel
PAR-SUS
3
27
4
14.8%
PAR-TB
11
889
75
8.4%
Parallel
14
916
79
8.6%
Serial
SER-CHK
7
9
1
11.1%
SER-COL
17
59
2
3.4%
SER-CONT
65
434
6
1.4%
SER-EPI
1
7
0
0
Serial
90
509
9
1.8%
Commercial/Private Testing
SER-DIAG
1
1
0
0
SER-EXP
2
31
1
3.2%
SER-MVT
14
57
0
0
SER-RHT
1
3
0
0
Commercial/Private Testing
18
92
1
1.1%
                   
1
4
0
0
1
4
0
0
England Total
123
1,521
89
5.9%
Wales
Parallel
PAR-TB
1
4
0
0
Parallel
1
4
0
0
Serial
SER-CHK
1
1
0
0
SER-COL
2
9
1
11.1%
SER-CONT
10
79
2
2.5%
Serial
13
89
3
3.4%
Wales Total
14
93
3
3.2%
Non GB
Commercial/Private Testing
SER-DIAG
1
2
0
0
Commercial/Private Testing
1
2
0
0
Non GB Total
1
2
0
0
Totals up to
end Q4
138
1,616
92
5.7 %
Test Positivity in 2020 up to end of Q4 (January - December)

Quarterly Camelid Serology Report
06 Jan 2021
Submissions Received in 2020 up to end of Q4
Analysis
Analysis Description
Q1
No.
samples
tested
Q2
No.
samples
tested
Q3
No.
samples
tested
Q4
No.
samples
tested
Totals up to end Q4
TC0503
Camelid TB Enferplex - 2
Spot
6
416
436
31
889
TC0603
Camelid TB Enferplex - 4
Spot
101
49
112
54
316
TC0611
Chembio DPP VetTB lateral
flow rapid antibody test
129
59
114
118
420
TC0867
Camelid TB Antibody
ELISA
135
461
548
147
1,291
Table 4: Number of samples Tested by Test Code