Camelid TB Serology Quarterly Report: 1st July 2020 to 30th September 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: 22
Report Period 1st July to 30th September 2020
Issued 07 October 2020

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TB Free Withdrawn [OTFW] status is determined on epidemiological grounds)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
07 Oct 2020
Table 1a
Country
No.
Samples
Tested
England
652
Wales
9
Total for Q3
661
Number of Samples tested and Submission Reason  2020 Q3 (July - September)
Table 1b
Submission
Reason
No. Samples
Tested
Parallel
PAR-TB
436
Parallel
Sum:
436
Serial
SER-CHK
4
SER-COL
16
SER-CONT
139
SER-EPI
7
Serial
Sum:
166
Commercial/Private Testing
SER-DIAG
1
SER-EXP
31
SER-MVT
27
Commercial/Private Testing
Sum:
59
Total for Q3
Sum:
661

Quarterly Camelid Serology Report
07 Oct 2020
Table 2a
Country
No.
Samples
Tested
England
1343
Wales
71
Total for Q3
1414
Number of Samples tested and Submission Reason 2020 up to end of Q3 (January - September)
Table 2b
APHA/DEFRA
Submission
Reason
No.
Samples
Tested
Parallel
PAR-SUS
2
PAR-TB
858
Parallel
Sum:
860
Serial
SER-CHK
5
SER-COL
45
SER-CONT
407
SER-EPI
7
Serial
Sum:
464
Commercial/Private Testing
SER-DIAG
1
SER-EXP
31
SER-MVT
51
SER-RHT
3
Commercial/Private Testing
Sum:
86
                   
4
Sum:
4
Total for 2020 up to end
of Q3
1414

Quarterly Camelid Serology Report
07 Oct 2020
Table 3a
Submissions Received and Test Positivity in 2020 Q3
Country
Submission
Reason
No.
Submissions
No. Samples
Tested
No.
Positive
Samples
% Positive
Samples
England
Parallel
PAR-TB
4
436
30
6.9%
Parallel
4
436
30
6.9%
Serial
SER-CHK
3
4
0
0
SER-COL
3
9
1
11.1%
SER-CONT
16
137
2
1.5%
SER-EPI
1
7
0
0
Serial
23
157
3
1.9%
Commercial/Private Testing
SER-DIAG
1
1
0
0
SER-EXP
2
31
1
3.2%
SER-MVT
3
27
0
0
Commercial/Private Testing
6
59
1
1.7%
England Total
33
652
34
5.2%
Wales
Serial
SER-COL
1
7
1
14.3%
SER-CONT
1
2
0
0
Serial
2
9
1
11.1%
Wales Total
2
9
1
11.1%
Totals for Q3
35
661
35
5.3 %
Test Positivity in 2020 Q3 (July - September)

Quarterly Camelid Serology Report
07 Oct 2020
Table 3b
Submissions Received and Test Positivity in 2020 up to the end of Q3
Country
Submission
Reason
No.
Submissions
No. Samples
Tested
No.
Positive
Samples
% Positive
Samples
England
Parallel
PAR-SUS
1
2
2
100.0%
PAR-TB
8
858
70
8.2%
Parallel
9
860
72
8.4%
Serial
SER-CHK
4
5
1
20.0%
SER-COL
12
38
2
5.3%
SER-CONT
52
343
6
1.7%
SER-EPI
1
7
0
0
Serial
69
393
9
2.3%
Commercial/Private Testing
SER-DIAG
1
1
0
0
SER-EXP
2
31
1
3.2%
SER-MVT
11
51
0
0
SER-RHT
1
3
0
0
Commercial/Private Testing
15
86
1
1.2%
                   
1
4
0
0
1
4
0
0
England Total
94
1,343
82
6.1%
Wales
Serial
SER-COL
1
7
1
14.3%
SER-CONT
6
64
2
3.1%
Serial
7
71
3
4.2%
Wales Total
7
71
3
4.2%
Totals up to
end Q3
101
1,414
85
6.0 %
Test Positivity in 2020 up to end of Q3 (January - September)

Quarterly Camelid Serology Report
07 Oct 2020
Submissions Received in 2020 up to end of Q3
Analysis
Analysis Description
Q1
No.
samples
tested
Q2
No.
samples
tested
Q3
No.
samples
tested
Totals up to end Q3
TC0503
Camelid TB Enferplex - 2
Spot
6
416
436
858
TC0603
Camelid TB Enferplex - 4
Spot
101
49
112
262
TC0611
Chembio DPP VetTB lateral
flow rapid antibody test
129
59
114
302
TC0867
Camelid TB Antibody
ELISA
135
461
548
1,144
Table 4: Number of samples Tested by Test Code