Exotic Newcastle Disease Pathology
The nature, cause, origin, and progress of Exotic Newcastle Disease.
The Newcastle disease viruses belong to the Paramyxoviridae virus family, that can be categorized into three groups
- velogenic strains - which are highly pathogenic and easily transmitted
- mesogenic strains - which show intermediate pathogenicity
- lentogenic strains - which show low pathogenicity in chickens
Exotic Newcastle Disease (END) is cause by a velogenic strain. It is a contagious and fatal viral disease affecting all species of birds. END is probably one of the most infectious diseases of poultry in the world (causes 90% mortality in poultry). END is so deadly that many birds die without showing any signs of disease. A death rate of almost 100 percent can occur in unvaccinated poultry flocks. Exotic Newcastle can infect and cause death even in vaccinated birds.
While the virus is readily inactivated by a variety of disinfectants including quaternary ammonium, bleach, and Lysol, it survives for weeks in organic material and carcasses especially in warm, humid conditions. In a warm and humid environment the virus will live on birds’ feathers, manure, and other materials. It can survive for extremely long periods in frozen material. However, the virus is destroyed rapidly by dehydration and by the ultraviolet rays in sunlight.