Types of Avian Influenza

• The disease has two primary forms in birds: a low pathogenic form that is relatively mild, and a high pathogenic form that can spread quickly and has a very high mortality rate. While the risk is generally low, certain strains of the bird flu can infect humans.
  
  

Transmission

• The bird flu virus is spread through the nasal secretions, saliva and feces of infected birds. Domesticated fowl that come in contact with the virus, either directly with infected birds or with surfaces that have become contaminated, can acquire the disease.
  
  

Cell Fusion

• Once within the host, the virus will fuse to the plasma membrane of a permissive cell within the respiratory tract, particularly those of the nose, mouth and throat.
  
  

Genetic Reproduction

• The virus enters the cytoplasm of the cell, and then moves to the nucleus. Once the virus enters the nucleus, it deposits genetic material and replicates its genome.
  
  

Extracellular Activity

• Virus particles will then leave the cell and invade surrounding tissues to infect other cells.
  
  

Infectious Stage

• Once it has proliferated within the body, the virus will be shed from the mucous membranes into the saliva, nasal discharge and feces of the host.