(NDV) is an acute viral disease of
domestic poultry and many other bird species. It is caused by an RNA virus,
(NDV), synonymous with avian Paramyxovirus-1. Isolates are classified into
1 of 3 virulence groups by chicken embryo inoculation as virulent (velogenic), moderately
virulent (mesogenic) or low virulence (lentogenic). Virulent (NDV) strains
are endemic in poultry in most of Asia, Africa and some countries of the Americas.
The US and Cananda are free of these strains and maintain that staus with import
restrictions destroying diseased poultry. Diagnosis may be confirmed by isolation
of a hemagglutinating virus identified by inhibition with (NDV) antiserum.
A rise in hemagglutination-inhibition antibodies in paired serum samples also confirms
the disease.
