Newcastle disease

Newcastle disease is a severe, systemic, and fatal viral disease of poultry due to virulent strains of avian paramyxovirus type 1. Clinical signs in unvaccinated birds include sudden death, lethargy, and respiratory distress. Diagnosis is based on laboratory confirmation. Vaccines prevent clinical signs but not infection, and the control of the disease is challenging in enzootic regions. Newcastle disease (ND) is an infection of domestic poultry and other bird species with virulent Newcastle disease virus (NDV). Newcastle disease is not a food safety or public health concern. Virulent NDV is capable of producing a devastating disease in domestic fowl, with vast social and economic consequences. It is a worldwide problem that presents primarily as an acute respiratory disease; however, depression, nervous signs, or diarrhea may be the predominant clinical form. Severity of ND depends on the virulence and genetic type of the infecting virus and host susceptibility.