Camelid TB Serology Quarterly Report: 1st October to 31st December 2021
Source: environment.data.gov.uk (2024-10-03)

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

Camelid TB Serology
Quarterly Report
Number: 27
Report Period 1st October to 31st December 2021
Issued 05/Jan/2022

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TB Free Withdrawn [OTFW] status is determined on epidemiological grounds)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)
PAR-COL-W
Wales only - camelids under restriction due to sharing a holding (colocation) with an
OTFW cattle herd or with other non-bovine animals affected by a culture-confirmed
incident
Serial Test:
SER-SUS (replaces PA
TB strongly suspected but not currently confirmed by laboratory culture – herd under
restrictions. If infection is confirmed the initial High Specificity (serial) test results can
be reinterpreted at High Sensitivity on request from the APHA case vet.
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;
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:
Table 1 – High Sensitivity / Parallel 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
05 Jan 2022
Table 1a
Country
No.
Samples
Tested
England
505
Wales
34
Non GB
30
Total for Q4
569
Number of Samples tested and Submission Reason  2021 Q4 (October - December)
Table 1b
Submission
Reason
No. Samples
Tested
Parallel
PAR-TB
77
PAR-TRC
11
Parallel
Sum:
88
Serial
SER-CHK
2
SER-COL
2
SER-CONT
240
Serial
Sum:
244
Commercial/Private Testing
SER-MVT
41
SER-RHT
1
Commercial/Private Testing
Sum:
42
SER-SUS
195
Sum:
195
Total for Q4
Sum:
569

Quarterly Camelid Serology Report
05 Jan 2022
Table 2a
Country
No.
Samples
Tested
England
1678
Wales
290
Non GB
36
Total for Q4
2004
Number of Samples tested and Submission Reason 2021 up to end of Q4 (January - December)
Table 2b
APHA/DEFRA
Submission
Reason
No.
Samples
Tested
Parallel
PAR-COL-W
7
PAR-SUS
5
PAR-TB
337
PAR-TRC
11
Parallel
Sum:
360
Serial
SER-CHK
10
SER-COL
17
SER-CONT
1077
SER-EPI
4
Serial
Sum:
1108
Commercial/Private Testing
SER-MVT
63
SER-RHT
5
Commercial/Private Testing
Sum:
68
SER-SUS
468
Sum:
468
Total for 2021 up to end
of Q4
2004

Quarterly Camelid Serology Report
05 Jan 2022
Table 3a
Submissions Received and Test Positivity in 2021 Q4
Country
Submission
Reason
No.
Submissions
No. Samples
Tested
No.
Positive
Samples
% Positive
Samples
England
Parallel
PAR-TB
3
77
8
10.4%
PAR-TRC
3
11
1
9.1%
Parallel
6
88
9
10.2%
Serial
SER-CHK
2
2
0
0
SER-COL
2
2
0
0
SER-CONT
18
206
3
1.5%
Serial
22
210
3
1.4%
Commercial/Private Testing
SER-MVT
3
11
0
0
SER-RHT
1
1
0
0
Commercial/Private Testing
4
12
0
0
SER-SUS
5
195
6
3.1%
5
195
6
3.1%
England Total
37
505
18
3.6%
Wales
Serial
SER-CONT
4
34
0
0
Serial
4
34
0
0
Wales Total
4
34
0
0
Non GB
Commercial/Private Testing
SER-MVT
1
30
0
0
Commercial/Private Testing
1
30
0
0
Non GB Total
1
30
0
0
Totals for Q4
42
569
18
3.2 %
Test Positivity in 2021 Q4 (October - December)

Quarterly Camelid Serology Report
05 Jan 2022
Table 3b
Submissions Received and Test Positivity in 2021 up to the end of Q4
Country
Submission
Reason
No.
Submissions
No. Samples
Tested
No.
Positive
Samples
% Positive
Samples
England
Parallel
PAR-TB
12
277
32
11.6%
PAR-TRC
3
11
1
9.1%
Parallel
15
288
33
11.5%
Serial
SER-CHK
5
5
2
40.0%
SER-COL
8
17
0
0
SER-CONT
94
979
19
1.9%
SER-EPI
1
4
0
0
Serial
108
1,005
21
2.1%
Commercial/Private Testing
SER-MVT
8
27
0
0
SER-RHT
2
5
0
0
Commercial/Private Testing
10
32
0
0
SER-SUS
9
353
13
3.7%
9
353
13
3.7%
England Total
142
1,678
67
4.0%
Wales
Parallel
PAR-COL-W
1
7
2
28.6%
PAR-SUS
1
5
0
0
PAR-TB
3
60
5
8.3%
Parallel
5
72
7
9.7%
Serial
SER-CHK
3
5
0
0
SER-CONT
10
98
2
2.0%
Serial
13
103
2
1.9%
SER-SUS
2
115
1
0.9%
2
115
1
0.9%
Wales Total
20
290
10
3.4%
Non GB
Commercial/Private Testing
SER-MVT
2
36
0
0
Commercial/Private Testing
2
36
0
0
Non GB Total
2
36
0
0
Totals up to
end Q4
164
2,004
77
3.8 %
Test Positivity in 2021 up to end of Q4 (January - December)

Quarterly Camelid Serology Report
05 Jan 2022
Submissions Received in 2021 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
114
6
63
65
248
TC0603
Camelid TB Enferplex - 4
Spot
118
444
284
393
1,239
TC0611
Chembio DPP VetTB lateral
flow rapid antibody test
81
88
255
122
546
TC0867
Camelid TB Antibody
ELISA
173
241
316
165
895
Table 4: Number of samples Tested by Test Code