Control of Emerging and Re-Emerging Poultry Respiratory Diseases in the United States

NON-TECHNICAL SUMMARY: Respiratory diseases are the major group of diseases affecting poultry. Consequently, losses induced by these diseases are of major economic impact on the producer, the local economy and the US economy. Many endemic respiratory infectious diseases in the USA continue to decrease the profitability of commercial poultry production. Viruses, bacteria and fungi cause respiratory diseases or interact to cause disease. Reduce the impact of threats to agricultural production by expanding the knowledge base needed to rapidly and effectively manage pests, disease, and natural disasters.

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APPROACH: Objective 1: Identify reservoirs of infectious respiratory disease agents in wilds and poultry. Surveillance of Avian Influenza (low Path H7N2 and others) virus in commercial poultry, wild birds and live poultry markets in New England. Routine surveillance program of testing poultry and wild birds in Connecticut and other New England states will be performed. On going routine surveillance program initiated by the USDA will be part of this project to identify the reservoir of the AI viruses circulating in New England States. Dead birds at the commercial farms will be tested with Directogen tests for the present of type A influenza viral antigen. Directogen positive samples will then be tested with the H7 and H5 specific PCR tests. Objective 2: Develop improved diagnostic capabilities including real time PCR as well as other rapid on-farm tests for economically important respiratory diseases. Real time PCR will be developed to test the samples and collaborative efforts will be utilized with other experiment stations. Multiplex PCR assays for respiratory disease agents developed in our laboratory will be utilized on clinical samples for detection of Infectious bronchitis virus (IBV), avian inluenza virus and avian mycoplasmas. Multiplex Real Time PCR will be developed to test more than one respiratory disease agent in the clinical samples. We will collaborate with other experiment stations to monitor IBV genotypes in commercial chickens in the Mid-Atlantic, Midwest, and Northeast regions. Novel genotypes are known to arise in layers raised in multi-age flock management systems. These genotypes may spread to other layers and broilers. Objective 4: Develop new prevention and control strategies for poultry respiratory diseases In-ovo vaccination of DNA vaccine for IBV: The purpose of this study is to use plasmid DNA vaccines containing the surface glycoprotein S and S1 genes of IBV respectively in ovo immunization and their effects in protection against IBV infection. The plasmid DNA (S1 &S) vaccines will be administered into the egg's albumin on 14th days of embryonating SPF chicken eggs using in-ovo technique respectively. Subsequently, the hatched chicks will be challenged with the live pathogenic IB virus. Their immune response and pathogenicity will be characterized. In the event of success, this in-ovo DNA immunization may become one of the most important innovations in the DNA vaccination of poultry. It will be used in commercial in-ovo vaccination as a much safer vaccine than the attenuating live IBV vaccines used currently.