Characterization of avian paramyxovirus type 1 strains isolated in Germanyduring 1992 to 1996

In Germany all avian paramyxoviruses (APMV) isolated in regional laboratori es are collected and characterized by the National Reference Laboratory. Fr om 1992 until 1.996, 635 APMV-1 virus isolates were submitted from almost a ll regions. Of these viruses, 371 were isolated from chickens, 39 from othe r poultry, 171 from pigeons and 54 from exotic birds. All isolates were exa mined for virulence in intracerebral pathogenicity index (ICPI) tests, for their ability to react with a panel of monoclonal antibodies (mAb) and thei r thermostability. In addition, the nucleotide sequences of the cleavage si te of the fusion protein of a few virus isolates were determined. Most isol ates from chickens and other poultry were of the velogenic pathotype, This virus was responsible for the epizootic in 1993 to 1995 in many small flock s. The same virus was obtained from some pigeons and some exotic birds. The pathogenicity of the velogenic/epizootic virus was high with most viruses giving ICPI values of 1.8 to 1.9, and the sequences of the cleavage site of all velogenic isolates tested were closely related. However, viruses isola ted at the beginning of the epizootic period differed from viruses isolated towards the end in their reaction with some mAbs, 149 virus isolates were identified as pigeon variant PMV-1 (PPMV-1), Most of these were obtained fr om pigeons but a few were isolated from chickens and other birds. Most lent ogenic isolates proved to be vaccine virus strains.