Avian Paramyxoviruses—Other than Newcastle disease virus

SummaryNewcastle disease, possibly the most economically important disease of domestic poultry throughout the world, is caused by a paramyxovirus (NDV). In recent years numerous isolations of other paramyxoviruses serologically distinct from NDV have been made from domestic poultry, imported exotic birds and feral passerines, psittacines and waterfowl in many countries. At present there are seven recognised serotypes of avian paramyxoviruses—PMV-1 to PMV-7 (NDV being PMV-1), although several candidates for further serotypes await full evaluation. Avian paramyxoviruses, other than NDV, may be responsible for highly pathogenic disease in some avian species, but in experimental or uncomplicated field infections of domestic poultry they have tended to produce inapparent infection, relatively mild respiratory disease and/or egg production problems. However, there are reports of severe respiratory disease with high mortality in domestic poultry infected with avian paramyxoviruses in the presence of other exacerbative organisms.