Enhanced FMD Surveillance using Rapid Diagnostic Testing for Indigenous Viruses that Clinically Mimic FMD

NON-TECHNICAL SUMMARY: In recent years there has been a growing awareness of the critical need to expand the current USDA veterinary diagnositc and surveillance activities and supplement federal activities with state and regional expertise and facilities. The project proposes to develop an assay to be used routinely on the differential diagnosis of endemic disease that may mimic the high-risk foreign animal disease, foot and mouth disease.

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APPROACH: Real-time PCR assays for BVDV and VMDV developed and currently being validated in our ongoing project to improve diagnostic surveillance will be modified and adapted into a multiplex format using molecular beacon technology. Bench-validation of the developed assay will be performed using clinical case material available through a national network of state and university diagnostic labs, and the USDA/APHIS foreign animal disease diagnostic laboratory.

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PROGRESS: 2002/10 TO 2007/09 <BR>
OUTPUTS: The study had no additional activity following the most recent progress report. Information on a 2006 national high-throughput demonstration project, introducing the technology developed as an outcome of this project was distributed through the National Animal Health Laboratory Network and animal agriculture-related news item on the web and in public press. <BR>PARTICIPANTS: Hietala SK. CAHFS, University of California, Davis. Crossley, BM. CAHFS, University of California, Davis. Ardans A. CAHFS, UC Davis. McCready P. Lawrence Livermore National Laboratory. Thurmond MC. UC Davis. McKenna T. USDA APHIS PIADC. Beckham T. USDA APHIS PIADC. Martin B. USDA APHIS NAHLN. McBride M. LLNL. Hullinger P. LLNL. Hindson B. LLNL. The project involved training of professional staff, technical staff, and University students in molecular techniques and new technologies. The project additionally provided the forum for a multi-agency collaboration that included technical, veterinary professional, regulatory agency, and information technology interfaces. TARGET <BR>AUDIENCES: The target audience for the project is USDA APHIS and DHS individuals involved in foreign animal disease surveillance and response.
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IMPACT: 2002/10 TO 2007/09<BR>
The concept of a Foot and Mouth Disease look-alike disease diagnostic panel grew out of the 2001 outbreak FMD in the UK where nearly 10 million sheep, pigs and cows were destroyed and export bans were placed on livestock and animal products. The outbreak identified a critical need for differential detection of FMDV and endemic look-alike disease agents. The project was initiated as collaboration between the CAHFS, UC Davis and USDA APHIS, grew over the years to include the NAHLN, DHS, and the Lawrence Livermore National Laboratory. Initial components of the study focused on proof of principle by development of an FMDV realtime PCR assay, and subsequent BVDV differential realtime PCR assay. In 2006 a national demonstration project introduced the existing outcome of the multi-year project in the form of a new multiplex PCR test approach with high-throughput, integrated, field to laboratory data handling and testing capabilities. The approach utilizes diagnostic samples submitted for routine detection of endemic diseases that clinically mimic foreign animal diseases, such as foot and mouth disease, as a sample source for enhanced national foreign animal disease surveillance. The multiplex PCR assay was designed and formatted for effective response to both animal disease surveillance as well as emergency disease response needs. The assay approach is a PCR-based multiplex FMD rule-out panel that simultaneously tests for the presence of nucleic acid target sequences for 7 different viruses, including those that produce clinical disease closely mimicking FMD, such as bovine viral diarrhea virus, bluetongue virus, bovine herpesvirus-1, the parapox viruses, swine vesicular disease, and vesicular exanthema of swine. Three of the viruses selected for the panel are on the USDA Foreign Animal Disease (FAD) Reportable list for livestock species, including FMD, vesicular exanthema of swine and swine vesicular disease. The remainder are "look-alike" disease agents that can produce clinical signs indistinguishable from FMD. The formal USDA field validation trials continue under USDA APHIS and NAHLN direction and in collaboration with USDA ARS, DHS, and the Lawrence Livermore Laboratory. An armored RNA construct containing FMD, CSF, and vesicular disease virus PCR targets was simultaneously designed and validated to serve as a foreign animal disease assay training and proficiency tool, as well as to provide a viable laboratory option for a non-infectious and traceable quality control sample.