D. Whole Flock Program(Appendix 1)

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1.

Initial Qualifying Test for ENROLLED Status:

a.
All sheep ≥ 180 days of age (calculated from birth date) within the flock must be sampled (see Section C for specifics).
b.
All sheep < 180 days within the enrolled flock must be identified and recorded as described in Section C.
c.
No pre-screening of animals is permitted prior to submission of samples.
i.
Pre-screening means first submitting samples for non-official testing, removing the POSITIVE samples and submitting the rest for official testing.

2.

Results from the Qualifying Test for ENROLLED Status.

a.
Once results have been recorded and POSITIVE sheep and their offspring < 180 days of age have been removed, the flock status is ENROLLED.
i.
If the Initial Qualifying test is NEGATIVE, the status can be designated as ENROLLED – NEGATIVE.
ii.
If the flock test is NEGATIVE go to Section D-5, Qualifying Test for “B” Status.

3.

If the flock test is not NEGATIVE then, (Appendix 4)

a.
All sheep with a POSITIVE test must be removed as well as their lambs < 180 days of age within 30 days of the test date.
b.
All sheep with a SUSPECT test may be immediately removed.
i.
If they are not they must be held in an Isolation Facility and must be removed or be retested within 30 days of the test date (see Section C).
ii.
If SUSPECT or POSITIVE results are obtained on the retest, the sheep must be removed from the flock within 30 days of the retest date.
iii.
The HYPHEN Elitest does not have a SUSPECT category.
c.
As of the date of the initial Qualifying Test for Enrolled Status, all biosecurity requirements must be followed.
4.
Follow-up Qualifying Test after a POSITIVE Whole Flock test.
a.
Must be scheduled between 120 and 240 days after the date of the initial Qualifying test date.
b.
If this test is NEGATIVE, then the status is ENROLLED – NEGATIVE. Go to Section D.5:  Qualifying Test for “B” Status.
c.
If one or more samples are POSITIVE, then go to back to Section D.3 and follow the protocol.

5.

Qualifying Test for “B” status - Whole Flock Test

a.
To achieve “B” status, the flock must receive two consecutive NEGATIVE whole flock tests 365 (no more than 395) days apart.
b.
All sheep ≥ 180 days of age must be tested within 7 days of each other.
c.
If the flock Qualifying Test for “B” status is NEGATIVE, then go to Section D.6.
d.
If the flock qualifying test for “B” status is not NEGATIVE, then go to Section D.3 and follow the protocol.
i.
If < 5% of animals have a POSITIVE or SUSPECT test, then go to Section D.7.
e.
All biosecurity requirements must be followed.

6.

Qualifying Test for “A” status - Random Sample Test

a.
To achieve “A” status, the flock must receive
i.
Two (2) consecutive NEGATIVE whole flock tests 365 (no more than 395) days apart and
ii.
An additional NEGATIVE random sample flock test 365 (no more than 395) days later.
b.
365 (no more than 395) days after the second consecutive NEGATIVE flock test, a randomly selected proportion of all sheep ≥ 365 days of age must be tested (note change of age).
c.
The statistically derived sample of sheep will be randomly selected and be large enough to detect MV infection at a prevalence of ≥ 5% with a 95% confidence interval (Appendix 9)
i.
This sample size assumes a sensitivity of 99% and a specificity of 100% i.e. will find 99 of 100 infected animals and will not misidentify any healthy animals as infected.
d.
All sheep in the flock must be recorded on the OMVFSP forms, including those not tested.
e.
If all sheep tested receive a NEGATIVE test, then the flock will be awarded “A” status.
f.
If more than one (1) sheep receives a POSITIVE test, then the producer must follow the protocol as outlined in Section D.3.
i.
If only one (1) sheep receives a POSITIVE test, go to Section D.8.
g.
All biosecurity requirements must be followed.

7.

To maintain “A” status, the producer must

 
a.
Perform an annual random flock test 365 (no longer than 395) days after the previous NEGATIVE flock test, following the protocol as outlined in Section D.6.
 
b.
All biosecurity requirements must be followed.
 
c.
Failure to do so without indicating extenuating circumstance in writing to the OMVFSP Coordinator may result in a loss of status.

This person is the OMVFSP Coordinator at the Ontario Sheep Marketing Agency 130 Malcolm Rd, Guelph, Ontario N1K 1B1.

8.

Maintaining “A” status - Closed Flock Designation:

a.
After achieving “A” status, Closed Flocks as defined in Section B, may choose to randomly test the flock at intervals of up to 2 years, specifically up to 790 days apart.
b.
Producers who wish to be designated as a closed flock must ask for such designation in writing from the project administrator.
c.
Otherwise the protocol as outlined in Section D.5 must be followed.

9.

Receiving a POSITIVE or SUSPECT MV test result after receiving a Whole Flock NEGATIVE test (Appendix 10a):

a.
If after receiving one (1) whole flock NEGATIVE test (“Enrolled-Negative”) and at the “B” status Qualifying test, one or more samples test POSITIVE or SUSPECT:
i.
If ≥ 5 % of the samples are POSITIVE or SUSPECT (e.g. 5 or more of each 100 samples)
(1)
Those POSITIVE sheep and their lambs < 180 days of age, and those SUSPECT sheep that retest POSITIVE as outlined in B.10.b, must be removed within 30 days of the test date
(a) The status will change to ENROLLED and
(b) The flock must start at Section D.3 to reestablish a NEGATIVE flock status.
(2)
It is recommended that the producer schedule a visit with the flock veterinarian to discuss where the program may have broken down (e.g. break in biosecurity). Appendix 8.
b.
If the number of sheep receiving a POSITIVE or SUSPECT result represents a flock prevalence of <5% (e.g. ≤ 4 samples of each 100 samples tested), then flock status can be regained through the following method:
i.
The POSITIVE and SUSPECT samples will be retested by the Animal Health Diagnostic Laboratory using a more specific MV diagnostic test, i.e. the CAEV/MVV Antibody Test Kit, (IDEXX Laboratories, Hoofddorp, The Netherlands).
(1)
Only the OMVFSP coordinator has the authority to request this to be done by the diagnostic laboratory.
(2)
This will be done before any results are sent to the owner and flock veterinarian.  Only final results will be forwarded to the owner and flock veterinarian.
(3)
The owner will be billed by OSMA for the additional test(s).
(4)
The HYPHEN Elitest has excellent sensitivity, i.e. ability to detect all infected sheep which is critical for the success of the program.  However when the prevalence of MV infection is very low – the test may have a small number of false positive results.  To determine if this is the case, a more specific but less sensitive test is used to retest these samples (IDEXX).  The risk is that this procedure may miss a true positive animal so for that reason, the recommendation (but not requirement) will be made by the OMVFSP coordinator that any animal(s) testing positive on the HYPHEN Elitest should be culled regardless of future test results.
(5)
The HYPHEN Elitest has no SUSPECT category.
ii.
If one or more of the samples test POSITIVE or SUSPECT on this retest, then all samples that initially tested POSITIVE or SUSPECT are considered to be POSITIVE and
(1)
The status of the flock is ENROLLED and
(2)
The flock must start at D.3 to reestablish a NEGATIVE flock status.
(3)
It is recommended that the producer schedule a visit with the flock veterinarian to discuss where the program may have broken down (e.g. break in biosecurity). Appendix 8.
iii.
If all of the samples test NEGATIVE on retest, then
(1)
The whole flock test is considered NEGATIVE.
(2)
It is strongly recommended that all sheep with an initial POSITIVE or SUSPECT test result be removed from the flock as outlined in Section D.9.b.i.(4).
(a) This is because rarely some sheep with MVV will not fully seroconvert (i.e. change test status from POSITIVE to NEGATIVE and back again) but yet may infect other sheep in the flock.
c.
This only applies if the flock has on its previous Whole Flock test, received a NEGATIVE result and is not to be used in situations when infection has been detected at any level in the previous Whole Flock test.
10.
If after a Random Sample test (“A” status) one or more samples are POSITIVE: (Appendix 10b)
a.
If more than one (1) sample is POSITIVE or SUSPECT regardless of the number of sheep tested, then the flock prevalence is > 5 %,
i. The status is ENROLLED and
ii. The flock must start at Section D.3 to reestablish a NEGATIVE flock status.
b.
If only one sample is POSITIVE or SUSPECT, and the previous status was “A”, then “A” status can be reestablished by following the protocol at Section D.9.b.
i. Only the OMVFSP Coordinator has the authority to request a retest of the POSITIVE or SUSPECT sample. This will be done before any results are sent to the owner and flock veterinarian.  Only final results will be forwarded to the owner and flock veterinarian.
ii. The owner will be billed by OSMA for the additional test.
iii. The HYPHEN Elitest has excellent sensitivity, i.e. ability to detect all infected sheep which is critical for the success of the program.  However when the prevalence of MV infection is very low – the test may have a small number of false positive results.  To determine if this is the case, a more specific but less sensitive test is used to retest these samples (IDEXX).  The risk is that this procedure may miss a true positive animal so for that reason, the recommendation will be made by the OMVFSP coordinator that any animals testing positive on the HYPHEN Elitest should be culled.
iv. The HYPHEN Elitest has not SUSPECT category.
c.
It is recommended that the producer schedule a visit with the flock veterinarian to discuss where the program may have broken down (e.g. break-down in biosecurity). Appendix 8.
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