How Does the Bird Flu Spread?

Avian influenza, also known as bird flu, is a viral infection that occurs in birds. Wild birds worldwide carry avian influenza and are usually unaffected by the virus. Domesticated birds, including turkeys, chickens and ducks, can also acquire the disease.

  1. Disease Forms

    • The low pathogenic form is relatively mild while the high pathogenic form can spread quickly and has a very high mortality rate in domesticated birds.

    Reproduction

    • The virus invades permissive cells in the nose, mouth or throat and replicates. Once mature, virus particles leave the cell and invade other cells.

    Spread of the Disease

    • The virus will be shed from the mucous membranes into the saliva, nasal discharge and feces. Domesticated birds that come in contact with the nasal secretions, saliva or feces of infected birds can become infected.

    Human Infection

    • During bird flu outbreaks in poultry, people that come in contact with infected birds or contaminated surfaces can become infected with the disease.

    Human to Human Transmission

    • Some human-to-human spread of bird flu, while inefficient and limited, has been reported. Scientists are concerned that the bird flu virus may change to a form that can infect humans and spread more easily.