Research

Molecular based diagnostic tests developed by our team and others, particularly real-time PCR and RT-PCR, have become the standard for routine diagnostics of many poultry pathogens (52-68). However, the diagnostic tests for the common poultry respiratory diseases, except for the USDA program diseases AI and Newcastle disease, are not standardized between laboratories and generally have not gone through a vigorous evaluation to assure fitness for purpose. Although many diagnostic laboratories are doing molecular diagnostics, the availability of tests for common pathogens is often limited in many state diagnostic laboratories because individual laboratories cannot afford to develop new tests and/or validate existing tests to assure their customers of the value of the test. This proposal plans a cooperative exercise with select diagnostic laboratories to evaluate by bioinformatics and laboratory testing different diagnostic test to identify the most promising ones.
It is proposed that the commonly used diagnostic tests for IBV, ILTV, aMPV, and Mycoplasma be compared for specificity and sensitivity. A different pathogen will be evaluated in the first four years of the project.

Year 1. IBV

Year 2. ILTV

Year 3. aMPV

Year 4. Mycoplasma

Year 5. The fifth year will be used for follow up evaluations and to do a proficiency trial for each pathogen. The proficiency panel will include widely representative inactivated or de novo synthesized samples for each pathogen, with a goal of 10 samples per pathogen. Participating laboratories will be expected to return results within two weeks of receipt and group blinded results and individual results will be prepared and returned to each diagnostic laboratory.

Potential impact: Many of the commonly used molecular diagnostic tests for poultry diseases in the U.S. are “homebrew” tests either created by individual diagnostic laboratories or they are from a published paper. In most of these cases the tests have not gone through a strict validation process that assures both specificity and sensitivity. This project will provide a methodical comparison of commonly used tests using a bioinformatics approach to provide comparison data that represents a wide cross section of the poultry industry in the U.S. The results of the analysis for each pathogen, which will be an independent analysis, will provide diagnostic laboratories assurance of test performance and provide a higher level of service to the poultry industry and encourage more frequent testing. Because of the consideration of foreign isolates in the analysis, selected tests will have a greater likelihood of detecting exotic poultry isolates allowing more rapid diagnosis. The final result will be improved diagnostic testing for poultry pathogens in the United States that will better inform the poultry producer allowing them to make better disease control issues.