Camelid TB Serology Quarterly Report: 1st April to 30th June 2023
Source: environment.data.gov.uk (2024-10-03)

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

Camelid TB Serology
Quarterly Report
Number: 33
Report Period 1st April to 30th June 2023
Issued 05/Jul/2023

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TB Free Withdrawn [OTFW] status is determined on epidemiological grounds)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 Jul 2023
Table 1a
Country
No.
Samples
Tested
England
93
Wales
54
Total for Q2
147
Number of Samples tested and Submission Reason  2023 Q2 (April - June)
Table 1b
Submission
Reason
No. Samples
Tested
Parallel
PAR-TB
30
Parallel
Sum:
30
Serial
SER-COL
5
SER-CONT
88
Serial
Sum:
93
Commercial/Private Testing
SER-DIAG
1
SER-EXP
8
SER-MVT
6
SER-RHT
9
Commercial/Private Testing
Sum:
24
Total for Q2
Sum:
147

Quarterly Camelid Serology Report
05 Jul 2023
Table 2a
Country
No.
Samples
Tested
England
419
Wales
100
Total for Q2
519
Number of Samples tested and Submission Reason 2023 up to end of Q2 (January - June)
Table 2b
APHA/DEFRA
Submission
Reason
No.
Samples
Tested
Parallel
PAR-COL-W
37
PAR-TB
54
Parallel
Sum:
91
Serial
SER-COL
8
SER-CONT
274
Serial
Sum:
282
Commercial/Private Testing
SER-DIAG
1
SER-EXP
8
SER-MVT
21
SER-RHT
9
Commercial/Private Testing
Sum:
39
SER-SUS
107
Sum:
107
Total for 2023 up to end
of Q2
519

Quarterly Camelid Serology Report
05 Jul 2023
Table 3a
Submissions Received and Test Positivity in 2023 Q2
Country
Submission
Reason
No.
Submissions
No. Samples
Tested
No.
Positive
Samples
% Positive
Samples
England
Parallel
PAR-TB
1
30
7
23.3%
Parallel
1
30
7
23.3%
Serial
SER-COL
1
5
0
0
SER-CONT
8
34
0
0
Serial
9
39
0
0
Commercial/Private Testing
SER-DIAG
1
1
0
0
SER-EXP
2
8
0
0
SER-MVT
2
6
0
0
SER-RHT
2
9
0
0
Commercial/Private Testing
7
24
0
0
England Total
17
93
7
7.5%
Wales
Serial
SER-CONT
4
54
0
0
Serial
4
54
0
0
Wales Total
4
54
0
0
Totals for Q2
21
147
7
4.8 %
Test Positivity in 2023 Q2 (April - June)

Quarterly Camelid Serology Report
05 Jul 2023
Table 3b
Submissions Received and Test Positivity in 2023 up to the end of Q2
Country
Submission
Reason
No.
Submissions
No. Samples
Tested
No.
Positive
Samples
% Positive
Samples
England
Parallel
PAR-TB
2
54
8
14.8%
Parallel
2
54
8
14.8%
Serial
SER-COL
2
8
0
0
SER-CONT
19
211
1
0.5%
Serial
21
219
1
0.5%
Commercial/Private Testing
SER-DIAG
1
1
0
0
SER-EXP
2
8
0
0
SER-MVT
6
21
0
0
SER-RHT
2
9
0
0
Commercial/Private Testing
11
39
0
0
SER-SUS
1
107
0
0
1
107
0
0
England Total
35
419
9
2.1%
Wales
Parallel
PAR-COL-W
1
37
4
10.8%
Parallel
1
37
4
10.8%
Serial
SER-CONT
8
63
0
0
Serial
8
63
0
0
Wales Total
9
100
4
4.0%
Totals up to
end Q2
44
519
13
2.5 %
Test Positivity in 2023 up to end of Q2 (January - June)

Quarterly Camelid Serology Report
05 Jul 2023
Submissions Received in 2023 up to end of Q2
Analysis
Analysis Description
Q1
No.
samples
tested
Q2
No.
samples
tested
Totals up to end Q2
TC0503
Camelid TB Enferplex - 2
Spot
24
30
54
TC0603
Camelid TB Enferplex - 4
Spot
278
26
304
TC0611
Chembio DPP VetTB lateral
flow rapid antibody test
70
91
161
TC0867
Camelid TB Antibody
ELISA
94
121
215
Table 4: Number of samples Tested by Test Code