Avian Influenza was identified in 1901 as an avian virus. In 1955, a specific species of influenza virus was identified as the cause of what was called in these times “Avian Fever”. Since then, Avian Influenza viruses have been found to cause a wide array of clinical signs and give rise to varying degrees of illness in domestic poultry.
Avian Influenza movie clip
The Disease’s Viruses
Influenza viruses are classified into three main species: B, A and C. Under every main species, many additional sub-species can be found. There’s another method of Avian Influenza viruses’ classification, in accordance with their level of virulence towards poultry. There are Low Pathogenic Avian Influenza Viruses (LPAI), Moderately Pathogenic and High Pathogenic Avian Influenza viruses (HPAI). Only when a disease is caused by pathogenic viruses, it is regarded as a “registered disease”, which requires appropriate government measures.
The range of clinical signs is wide and most of them are not specifically indicative of Avian Influenza. The Influenza may be expressed as a respiratory, gastrointestinal, reproductive or nervous-system disease. The first signs of the disease are commonly a decrease in feed consumption and in egg-laying. Other clinical signs may be coughing, sneezing, swollen head, etc. However, poultry sudden death may occur without any preceding clinical signs.
Spread of Disease
Disease outbreaks are usually the outcome of direct or indirect contact between domestic and wild birds. When one domestic fowl is afflicted, the disease spreads rapidly to the entire flock. Different flock might infect each other through movement of infected poultry, contaminated equipment, trucks, people, etc. Airborne transmission is only possible between poultry in close proximity to each other.
Procedure for handling Avian Influenza - in Hebrew