4-Avian Influenza (Fowl Plague) Avian influenza is a viral disease (known as fowl plague) affecting the respiratory, digestive and/or nervous system of many species of birds. Etiology: type A influenza virus of family Orthomyxoviridae -Numerous subtypes based on surface antigens, hemagglutinin (H) and neuraminidase (N). -Viruses of H5 (H5N2) and H7 (H7N1) subtypes are considered pathogenic, H1N1 (swine flu) in turkeys. -H4N8, H4N6, H3N8 in exotic birds. -H5N1 in chickens and humans, Hong Kong, 1997 and 2002.
Clinical signs: The clinical signs vary greatly and depend on many factors including the age and species of poultry affected, husbandry practices, and the inherent pathogenicity of the influenza virus strain.
The Clinical signs may include: A-Mild form (Mildly Pathogenic). B- Systemic form (Highly Pathogenic).