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Policy

SCAHLS New Test Development and Evaluation Policy

1. Purpose

This Policy establishes agreed mechanisms and guidelines for the development, evaluation and communication of new tests developed in Australia and New Zealand for infectious animal diseases, for use in veterinary laboratories. It is consistent with international (OIE) guidelines and is intended to ensure a uniform understanding of the way in which new tests are developed, evaluated and communicated.

2. Scope

This Policy applies to new tests developed in Australia and New Zealand for use in production animals as well as feral, captive and leisure animals.

3. Background

The Subcommittee on Animal Health Laboratory Standards (SCAHLS) seeks to sustain and improve the quality of livestock and livestock products and to assure market access through the application of best practice to veterinary laboratory services.

4. Policy

SCAHLS has a mandate to facilitate the development and adoption of new diagnostic methods. New Test Development is facilitated by:

  • Maintaining a register of new test methods under development to reduce duplication;
  • Promoting the establishment of collaborative links between institutions.

New Test Evaluation is facilitated by:

  • Developing and communicating information on validation requirements for new tests that will be included in the Australian and New Zealand Standard Diagnostic Procedures (ANZSDP’s), including validation templates and guidelines for authors;
  • Coordinating independent evaluation of new test methodologies and validation data for tests that are to be included in the ANZSDPs;
  • Providing feedback to submitters following the evaluation process.

Adoption of new diagnostic methods is facilitated by:

  • Monitoring and communicating new test developments;
  • Providing a transparent and auditable process for evaluating new diagnostic tests developed for the livestock industries and assisting their inclusion, as appropriate, into standard test procedures (eg ANZSDP)
  • Promoting the uptake of new tests by Australian and New Zealand laboratories.

5. Application

This Policy is designed to assist laboratory scientists in the development and evaluation of new diagnostic tests through to their inclusion (where appropriate) in ANZSDPs.

5.1. Examination of Fitness for Purpose (the reasons why a test is performed)

When developing a new test, consideration of the purpose for which the test will be used must be considered. This particularly applies to test evaluation/validation because it is important to ensure that the test is evaluated using samples from the same population as those that the test will be used on.

The 6 levels described by OIE for ‘Fitness for Purpose’ and which are accepted in Australia and New Zealand are:

  1. To demonstrate population 'freedom' from infection (prevalence apparently zero) in the following categories:
    • a) 'free' with or without vaccination,
    • b) historical 'freedom',
    • c) re-establishment of 'freedom' following outbreaks;
  2. To demonstrate freedom from infection or agent in individual animals or products for trade purposes;
  3. To demonstrate efficiency of eradication policies;
    • (a) To confirm diagnosis of clinical cases in groups of animals OR
    • (b) To confirm diagnosis of clinical cases in individuals;
  5. To estimate prevalence of infection to facilitate risk analysis (surveys, classification of herd health status, implementation of disease control measures);
  6. To determine immune status in individual animals or populations (post-vaccination).

5.2. Priorities for SCAHLS approval process

Consistent with best current practice all tests used in Australian/New Zealand animal health laboratories should be adequately validated. Although it is not practical for SCAHLS to evaluate all new tests, SCAHLS expects test developers to seek approval for new tests applicable to:

  • National disease control/eradication and surveillance programs
  • Health certification testing (for livestock destined for international export)
  • Tests developed for exotic disease and required to be transferred to other laboratories. The above tests (when approved) will be included in ANZSDPs (as a matter of course) and will carry the statement ‘Approved by SCAHLS for the stated purpose’ – the stated purpose being any one or a combination of 1-6 above.

5.3. Requirements for SCAHLS approval

It is recognised by SCAHLS that there are 5 stages in the validation process as outlined by the OIE. These include:

  1. Feasibility
  2. Development and standardisation
  3. Assay performance characterisation
  4. Monitoring performance (including transferability – tested in another lab)
  5. Maintenance/extended validation criteria

Submitters are expected to complete the relevant validation template for serological or nucleic acid detection methods, which detail the continuum of the developmental approach in a standard format. Tests may be submitted as extensions to an existing assay where the minor changes would not be expected to impact significantly on the fitness for purpose of the assay involved. (Tests on different animal species could reasonably be expected to have quite different specificity) In the case of an extension, submitters must complete the validation template for extension of existing assays. Completed templates should be provided to the Executive Officer of SCAHLS.

New tests submitted for approval must have reached at least stage 4 before submission to SCAHLS. Assuming the submission contains all of the elements of the validation template in sufficient detail and quality, SCAHLS may approve a test for the stated purpose.

The process for test evaluation and the cost of the assessment by the independent reviewers are outlined in the SCAHLS Standard Operating Procedure Process for Managing New Test Development and evaluation.

After approval by SCAHLS a recommendation goes to Animal Health Committee (AHC) seeking their approval of the new test and its inclusion in the appropriate ANZSDP.

6. Exclusions

New tests that are developed for use in individual laboratories that do not fit with the priorities outlined above, do not require SCAHLS approval, but should nevertheless be validated.

SCAHLS expects laboratory managers responsible for the introduction of such new tests to develop a system of independent review prior to implementation, as a routine practice.

In cases where individual reagents are changed in a standard test, SCAHLS expects managers to ensure that the laboratory verifies that any new critical reagent performs adequately against standard reagents before the new reagent is used in routine diagnostic testing.

It is desirable but not essential for a new test to be published in a peer-reviewed scientific journal prior to submission to SCAHLS for test evaluation.

7. Legal implications

Neither SCAHLS, nor its Members, are legally liable for any repercussions for conferring SCAHLS ‘Approval’ for any given test or for not granting ‘Approval’. By submitting a dossier for SCAHLS evaluation the submitter agrees to current SCAHLS procedures and policies.

8. Implementation

The evaluation process applies to all tests as nominated in 5.3. from 10 March 2006 onward. Tests already in common use will be assessed by SCAHLS for approval on a priority basis.

Although SCAHLS has no formal authority to force laboratories to use an ‘Approved’ test, SCAHLS recommends, through its members and associated networks, that approved tests are used where possible. NATA Supplementay Requirement for Veterinary Testing states that laboratories ‘should” use ANZSDPs ‘where appropriate’.

SCAHLS encourages all laboratories to collect and store samples that may be useful for validation purposes, especially for uncommon diseases, so that when validation is needed, sufficient samples are available, even if it means aggregation of samples from various laboratory sources.

9. Accompanying documentation

All accompanying documentation supporting this Policy can be found on the SCAHLS website (www.scahls.org.au) or from the SCAHLS EO,

  • SCAHLS Standard Operating Procedure for managing new test approvals.
  • SCAHLS validation templates for serological and nucleic acid detection tests.
  • SCAHLS validation template for extension of existing assays.
  • SCAHLS ANZSDP SOP and Guide for Authors. This Policy replaces the ‘Guidelines for New Diagnostic Tests’ Version 1.

10. Definitions

In the context of non-standard methods, in-house methods and standard methods that have been modified or are being used outside their intended application - VALIDATION is the demonstration of technical soundness, method performance and limitations of the method and an indication of the suitability of the method for its intended use. Validation studies should include evaluations of uncertainty of measurement (where relevant), detection limit (or sensitivity), selectivity of the method (or specificity), linearity, limit of repeatability and/or reproducibility and robustness against external influences.

In the context of "standard" methods (i.e. kit methods validated by the manufacturer, methods in the ANZSDPs, etc) -

VERIFICATION is the demonstration of the ability to achieve the performance specifications of the manufacturer/standard method under the testing laboratory's own conditions.