An outbreak of Newcastle disease in free-living pheasants (Phasianus colchicus)

The epidemiology of an outbreak of Newcastle disease in a population of approximately 12 000 free-living pheasants (Phasianus colchicus) on the island of Faeno in Denmark in 1996 is described. The mortality epizootic demonstrated over an observation period of 3 weeks. A total of 70 avian paramyxovirus serotype 1 (APMV-1) isolates was made from the flock. The intra cerebral pathogenicity indices of the 4 isolates tested were in the range 1.78-1.88. By means of immunoperoxidase monolayer assay with murine monoclonal antibodies and sequence analysis of an RT-PCR amplified segment of the F-0 viral protein it was found, that thr virus belonged to the highly virulent C1 antigenic group and that the amino acid sequence at the F-0 cleavage site corresponded with the sequences of virulent APMV-1 strains. Based on the epidemiological circumstances it is believed that the virus mas transmitted to the pheasants by feral birds.