Avian Influenza

Avian influenza (AI) has appeared periodically in regions all over the world, including the United States. The virus spreads easily among wild birds, which are the natural hosts of avian influenza viruses, but certain strains can also infect domesticated birds (including chickens, turkeys, ducks and, rarely, pet birds); humans (rarely); and a variety of other mammals.

Most outbreaks of avian influenza in the United States have been associated with milder strains of the virus (those having low pathogenicity). These infections do not normally cause clinical signs of disease in waterfowl, but may cause disease in poultry. Outbreaks have been resolved through the combined efforts of veterinarians, the poultry industry, and local, state, and federal governmental agencies. There is ongoing surveillance in multiple animal species, including poultry and swine. Additionally, the U.S. Department of Agriculture (USDA) and Centers for Disease Control and Prevention (CDC) are working closely together to monitor both animal and human influenza viruses.

More serious (highly pathogenic) strains of avian influenza virus can devastate entire flocks of poultry and result in major economic losses, and potentially affect people and other animal species. The avian influenza virus strains that have affected poultry flocks and other birds in Asia, Europe, and Africa since the end of 2003 have resulted in loss of human and animal lives.