Equine Infectious Anemia: New Concepts

 

Ernest W. Zirkle, DVM, Chair of USAHA Subcommittee on EIA

 

 

The members of the Infectious Diseases of Horses Committee (IDOHC), Equine Infectious Anemia (EIA) Subcommittee proposed three resolutions at the annual meeting in St. Louis, Mo. which were approved by the parent committee and sent on to the general membership for approval.

 

Resolution # 1

Subject Matter: USDA, APHIS, VS Memorandum 555.8 Re Equine Infectious Anemia Testing Laboratories.

 

USAHA Committee on Infectious Diseases of Horses recognizes that improved policies and procedures should be implemented for approved laboratories conducting official EIA tests as a component of disease control.

 

Resolution: United States Animal Health Association requests that the United States Department of Agriculture (USDA), Animal and Plant Health Inspection Service (APHIS), Veterinary Services (VS), National Veterinary Services Laboratory (NVSL) implement the attached Veterinary Services (VS) memorandum 555.8, as revised by the Committee on Infectious Diseases of Horses at the 105th Annual meeting of USAHA held in St. Louis Missouri on 20 October 2002.

 

Following are the provisions of Memorandum 555.8 as approved by the Resolution

                  A. All initial requests for EIA laboratory approval should be made to the appropriate Area Veterinarian in Charge (AVIC). 

 

                  B.  Upon the recommendation of the AVIC and State animal health official, the following actions will be taken:

 

                             1. A Federal or State veterinary medical officer will review with laboratory officials the regulatory and technical responsibilities inherent in conducting and reporting official tests.

 

                             2.  The physical facilities of the laboratory will be inspected by a Federal or State animal health official.  Inspection results will be recorded on the enclosed laboratory inspection worksheet (Enclosure 1).  Laboratory inspection must be completed and the proposed facility found in compliance prior to participation of laboratory personnel in an EIA training course.

 

                             3. Upon completion of the laboratory inspection, the director of the laboratory will sign the enclosed agreement (Enclosure 2) acknowledging his or her understanding of the regulatory and technical responsibilities of the laboratory.

 

                  C.  The procedures outlined below will be followed by approved laboratories:

 

                             1. Only diagnostic test kits that have been officially approved and licensed by the USDA will be used.

 

                             2. The tests will be conducted according to test protocols as described in literature accompanying diagnostic test kits unless otherwise directed by official National Veterinary Services Laboratories (NVSL) protocols.   Appropriate control samples, as specified in instructions accompanying diagnostic test kits, must be included each time the test is performed.  In addition, for AGID tests, a weak positive sample obtained from either NVSL or an approved commercial source must be included each time the test is conducted.

 

                             3.  Negative test results will be reported to State and/or Federal animal health officials regularly, as instructed by those officials, in both the State where the laboratory is located and the State in which the animals were sampled.    State and/or Federal animal health officials shall be notified immediately or in no circumstances more than 24 hours after test completion if horses are positive to the EIA test. When requested by the State or Federal Animal Health Official, reports of monthly totals of EIA AGID and EIA ELISA tests performed by the     laboratory shall be provided.  EIA test results must be reported within 48 hours of test completion to the veterinarian submitting the sample.

 

                             4. Only samples collected and submitted by an accredited veterinarian, State or Federal animal health official, or military veterinarian will be accepted. 

 

                             5. Each equid sample shall be submitted on a state or federally approved individual animal identification form.  Information submitted with the sample(s) shall be legible and shall include the following:

 

                               a. Name, address, and phone number of submitting veterinarian.

                                b. Name and address of owner.

                                c. Location (including county) of equine(s) at the time of obtaining the samples.

                                d. Identification of the equine(s) sampled, including name, color, markings, tattoo,

                                    or registration numbers.

                                e. Age, breed, and sex of equine(s) sampled.

                                               

Note: The signature of the owner, o owner's agent on the individual animal frequ red at the discretion of

the submitting veterinarian. 

 

                             6.  Reports of test results shall include the name, address, and phone number of the laboratory that conducted the test and the type of test performed.

 

                             7.  Laboratories shall keep an original copy of each completed EIA individual animal test form for at least 12 months from date of completion.

 

                             8.   Annual proficiency testing conducted by approved laboratory personnel at each approved laboratory is required.  NVSL will supply the samples and evaluate test results.  Laboratories receiving approval within 6 months of the proficiency test distribution date are exempt from participating for the approval year only.

       

                             9.   Biennial inspections of approved laboratories by a Federal and/or State animal health official of the State where the laboratory is located may be required.  During these inspections, one of the items that should be reviewed is compliance with this memorandum.  It is also recommended that inspections be conducted on all laboratories that fail an annual proficiency test to determine that tests are being conducted according to official protocols and that personnel conducting the tests are considered qualified by VS.

 

                           10.  All EIA positive ELISA tests are to be confirmed by AGID. Confirmation testing must be conducted at a State, Federal, or university laboratory.  Samples from tests with discrepant results must be forwarded to NVSL.  NVSL may conduct ancillary testing on discrepant samples or request additional samples as they may deem necessary.

 

                  D.   Training

 

1. Personnel who perform EIA tests must be recognized as       qualified by VS.  The AVIC and State animal health official must recommend qualified personnel for training and approval by NVSL.  The training outlined below is the minimum required:

 

                                                a. For private laboratories: The person(s) responsible for conducting official tests for EIA will be trained at NVSL.  This training will include successful completion of an individual proficiency test.

 

                                                b. For Federal, State, and university laboratories: At least one individual who is actively involved in EIA testing must have received training at NVSL.  With approval of the AVIC and State animal health official, personnel previously trained at NVSL may train others in their laboratory to conduct the tests.  Training will include regulatory responsibility. Laboratories will notify NVSL of names of individuals who are being trained, and NVSL will certify training of these individuals by providing individual proficiency tests, which must be completed in accordance with standards established by NVSL.

 

                  E.  The AVIC, State animal health official, and NVSL will evaluate personnel who do not successfully complete proficiency testing in order to determine if additional training at NVSL is necessary or whether approval of the laboratory should be canceled.

 

                  F.  Laboratories approved to conduct EIA tests will inform the AVIC and NVSL of any change of address or telephone number and when any personnel trained by NVSL to conduct the tests are no longer employed.  If trained personnel are not available to conduct the tests, approval of the laboratory will be canceled.

 

V.  RECOMMENDATION FOR APPROVAL

Once the procedures in Section IV-B have been completed, the AVIC and the State animal health official may recommend approval of the laboratory.  A jointly signed memorandum and the originals of all completed documents (Enclosures 1 and 2) should be to:

 

Director

National Veterinary Services Laboratories

P.O. Box 844

Ames, IA 50010

 

         

VI. APPROVAL OF LABORATORIES

After the requirements in Sections IV-B and IV-D (laboratory inspection and training) have been satisfactorily completed, the laboratory will be approved by the Director of NVSL and will be notified of approval by a letter signed by the Director of NVSL.

 

VII.   MAINTENANCE OF LABORATORY APPROVAL

Laboratories are expected to follow the policies and procedures outlined in this Memorandum at all times.  Approved laboratories are subject to inspection by a Federal or State animal health official at any time during the laboratory’s normal business operation.

 

 

VIII.   REMOVAL OF LABORATORY APPROVAL

Laboratory approval will be withdrawn by the Administrator when any of the criteria for approval have not been met.  Approval will be removed in the following situations:  1) The laboratory requests removal, 2) The Director of NVSL recommends removal or 3) The Director of NVSL receives written recommendation for removal by concurrence of the AVIC and State animal health official.  In the latter two situations, the laboratory will be informed of recommendation for removal in a letter signed by the Administrator.  In all cases, written notification of the removal of laboratory approval will be provided to the laboratory.

 

VIII.   LIST OF APPROVED LABORATORIES

The Director of NVSL will maintain a current list of laboratories approved to conduct official tests for EIA.  This list will be updated regularly and available to the Regional Directors, AVICs, State animal health officials and other interested persons via the United States Department of Agriculture, Animal and Plant Health Inspection Services, Veterinary Services website. 

 

NOTE: This Resolution has been reviewed, revised and approved by USDA, VS and given a new number Memorandum 555.16. It will be sent to all laboratories, AVICs, Regional Directors and State Veterinarians with a letter highlighting the significant changes/expectations of laboratories.

 

The biggest change for the laboratories is the inclusion of a weak positive sample in every AGID setup.

 

 

Resolution # 2

Subject Matter: Equine Infectious Anemia Testing Standards

Background Information: Equine Infectious Anemia (EIA) is an infectious disease of horses that impacts the equine industry. The Committee on Infectious Diseases of Horses recognizes that improved testing standards for both private and institutional laboratories should be implemented to enhance current EIA prevention and control programs.

Resolution: United States Animal Health Association requests that the United States Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services, National Veterinary Services Laboratory review and consider adopting the attached EIA Testing Standards through the proposed rule process. 

Following are the provisions of Resolution # 2

1.      Any laboratory testing for Equine Infectious Anemia (EIA) must be approved as per VS Memorandum 555.8 and will be termed an EIA ELISA Laboratory.

  1. The primary test for all EIA testing is an USDA licensed EIA ELISA test, which is the only test run at all EIA ELISA laboratories.

  2. EIA ELISA tests must be read on a spectrophotometer (ELISA plate reader).

  3. A positive and negative control sample must be used on all ELISA test plate. runs and on each

  4. A printout with spectrophotometer readings of all tests is required and must be kept on file, with a copy of corresponding EIA test charts, at the EIA ELISA Laboratory for at least three years, available for regulatory scrutiny.

  5. Certified personnel conducting EIA ELISA tests must successfully complete individual proficiency tests annually.  If 100 % proficiency is not achieved in the time permitted by NVSL, one retest within an additional thirty days, is allowed.  Failure of the retest will result in the withdrawal of certification and approval of the individual to perform the EIA ELISA test.

  6. EIA ELISA Laboratories and ELISA test printouts will be inspected annually by state and/or federal animal health officials.

  7. When AGID testing is required for special circumstances (export testing, international movement with specific AGID requirement, etc.) EIA ELISA Laboratories must forward samples to an EIA Reference Laboratory.

2.       ELISA  positive samples must be retested in duplicate immediately in the same EIA  ELISA Laboratory.  If confirmed positive, the sample shall be termed a “Confirmed Positive Sample”.

 

3.      Confirmed Positive Sample test results must be immediately reported (within twenty-four hours) to the State Veterinarian and AVIC. A second blood sample, termed the “Regulatory Sample” may be collected by a State or Federal animal health official or by a licensed, accredited veterinarian upon specific authorization from the State Veterinarian or AVIC.

 

4.      Confirmed Positive Samples and Regulatory Samples must be forwarded to an “EIA Reference Laboratory”.

  1. An EIA Reference Laboratory must be a state, federal, or university laboratory.

  2. An EIA Reference Laboratory must stock all USDA licensed EIA ELISA test kits.

  3. EIA Reference Laboratory personnel must be trained under NVSL authority as per Memorandum 555.8 in ELISA and AGID testing.  Laboratory personnel must pass individual proficiency tests annually.

  4. An EIA Reference Laboratory must commit to a turnaround time of no longer than forty-eight normal business hours after receipt of Confirmed Positive Samples and Regulatory Samples sent to them.

 

5.      The EIA Reference Laboratory must test both the Confirmed Positive Sample and the Regulatory Sample with all USDA licensed EIA ELISA kits and an AGID test.

 

6.      Criteria for determination of tests results at an EIA Reference Laboratory:

  1. Positive results on all USDA licensed EIA ELISA tests and positive AGID = Positive.

  2. Samples with any other combination of results will be forwarded to an EIA National Referral Laboratory and tested with all approved EIA tests.

 

7.      EIA National Referral Laboratory is either National Veterinary Service Laboratory (NVSL) in Ames, IA or the Kentucky EIA Referral Laboratory at the Gluck Equine Research Center, University of Kentucky, Lexington, KY.  EIA Referral Laboratories must commit to a turnaround time of no longer than seventy-two normal business hours after receipt of samples from EIA Reference Laboratories.

 

8.      All costs associated with testing beyond the initial ELISA tests are to be borne by the national EIA Control Program.

 

NOTE

 

This resolution was approved as noted above but since it is an entirely new concept and there were some critical comments in the parent committee the subcommittee is meeting in the near future to  review and hear from critics in an effort to revise to  make revisions before starting the rulemaking process.

 

 

Resolution #3

Subject Matter: Equine Infectious Anemia; Proposed Recommendations Based on UM & R and VS Memoranda 555.7 and 555.8

 

Background Information: Equine Infectious Anemia (EIA) is an infectious disease of horses that impacts the equine industry. The current EIA Uniform Methods and Rules and VS Memoranda 555.7 and 555.8 are in need of revision to reflect contemporary methods of diagnosis, prevention and control of this disease.

Resolution: United States Animal Health Association requests that the United States Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services initiate a dialogue with industry, state and/or regional representatives on the EIA Uniform Methods and Rules and VS Memoranda #555.7 and 555.8 in order to develop a cooperative program for the national control of EIA. In that regard, seven (7) recommendations included in the attached EIA Subcommittee Report are offered for review and potential inclusion in the Code of Federal Regulations (CFR) 75.4 through the proposed rulemaking process.

 

This recommendation has seven major components:

(A) The subcommittee recommends that consideration of specific elements of the EIA UM&R regarding EIA testing requirements for interstate movement of horses be incorporated into the CFR, title 9, part 75. The CFR currently regulates the movement of EIA reactors only, and there is a need for a federal requirement to have a negative EIA testing status for horses moving interstate. Thus, the sections 2 through 5 and 7 through 10 would be added to part 75.4 as follows:

Part 75-Communicable diseases in horses, asses, ponies, mules, and zebras Equine Infectious Anemia (Swamp Fever) 75.4

1. Definitions

2. General restrictions

3. Certificates and permits for interstate movement of equids

4. Handling in transit of equids moved interstate

5. Restrictions on interstate movement of equids because of EIA

6. EIA reactor equids

7. EIA exposed equids

8. Other interstate movements

9. Testing procedures for EIA in equids

10. Official EIA tests

11. Approval of laboratories, and diagnostic or research facilities

12. Denial and withdrawal of approval of laboratories and diagnostic or research facilities

(Sections 1, 6, 11, and 12 are currently part of 75.4.)

 

(B) The subcommittee reviewed and updated Memorandum 555.8 which is now 555.16 strengthening interstate movement testing and laboratory standards as attached.

(C) The subcommittee agrees (there was one negative vote and one abstention) that the need for permanent and unique forms of identification of horses for EIA testing is obvious and inevitable. The subcommittee therefore recommends that permanent and unique forms of equine identification should include, but not be limited to, the following: (a) radio frequency implantable devices (RFID), known also as "transponders" or "microchips", (b) biometric applications of iris or facial anatomy, (c) alpha- angle freeze mark, and (d) lip tattoo of a breed registry. Each of these could be linked to a database or integrated circuitry (IC) card, known also as "smart card".

 

(D) The subcommittee encourages states to develop quality assurance programs for its EIA laboratories in addition to the USDA proficiency testing. Where states believe more oversight is needed, they could supplement, not replace, existing protocols with additional blind samples or check tests and/or laboratory inspections

 

(E) The subcommittee endorses USDA-APHIS-VS offering inspection guidelines and courses for inspection of laboratories for EIA testing. These courses will be offered on a fee-recovery basis. The subcommittee further encourages states to train their own inspectors based on guidelines written by USDA.

 

(F) With the cooperation of the industry, the subcommittee recommends information about the number of EIA kits sold to each lab be sent to the USDA-APHIS-VS Senior Staff Veterinarian for Equine Programs quarterly for the purpose of monitoring EIA laboratories. This protected information will be available only to the State Veterinarians and AVIC's for their states only.

 

(G)  The subcommittee endorses EIA testing standards (Discussed above)

 

NOTE

This resolution did not pass the General Membership and therefore will go back to the drawing board of the Subcommittee.  Permanent ID was one of the major areas of concern.  The Subcommittee will revise and have a proposal at the USAHA meeting in October.