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

Non-Technical Summary- Respiratory infectious diseases continue to cause significant economic losses to producers of commercial poultry in the Delmarva peninsula region as well as other poultry producing areas in the United States. The purpose of this research is to monitor emerging agents of respiratory disease and characterize them so that effective control measures may be implemented. Control of these diseases will help ensure a safe and adequate supply of poultry and eggs for the consumer.
<p> Approach- <p> <ol>
<li>Identify reservoirs of infectious respiratory disease agents in wild birds in the US. Will survey auction markets for avian influenza virus (AIV ) in conjunction with the state veterinarian's office. Active and passive surveillance of commercial poultry will be performed. Will monitor infectious bronchitis virus (IBV) genotypes in commercial chickens in the Mid-Atlantic, Midwest, and Northeast regions in collaboration with Indiana and Connecticut. Will monitor Newcastle disease virus (NDV) in commercial broilers on Delmarva.</li>
<li>Develop improved diagnostic capabilities including real time PCR as well as other rapid on farm tests for economically important respiratory diseases. Will develop microarray diagnostics for rapid characterization of AIV. Will send mycoplasma cultures from field cases to Connecticut for multiplex PCR analysis.</li>
<li>Investigate the pathogenesis and polymicrobial interactions of specific infectious agents associated with poultry respiratory diseases. Will perform low path (LP) AIV pathogenesis studies in chickens and turkeys to determine dissemination and persistence in tissues and will also assess the impact of immunosuppressive agents and concurrent infections with other respiratory viruses on subsequent infections with LP AIV. Will investigate AIV and host mechanisms associated with pathogenicity in chickens. Will evaluate interactions of pathogenic E. coli and macrophage using microarrays to define pathogenic determinants. Will develop and evaluate a full-length RNA molecular clone of the IBV to define pathogenic determinants in collaboration with Maryland. Will assess potential replication interference of NDV and IBV vaccine strains following simultaneous application using quantitative RT-PCR and other parameters. Will determine the effect of virulent and very virulent Mareks disease virus infection on respiratory diseases of poultry.</li> <li>Develop new prevention and control strategies for poultry respiratory diseases. Will collect and characterize IBDV field isolates from various regions of the US. Will continue to evaluate a genetically modified vaccine for infectious laryngotracheitis virus. Will evaluate the efficacy of NDV live and inactivated vaccines for poultry.</li></ol>