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Flock of white chickens

Q: What is avian influenza?

Avian influenza is a virus that is carried by migratory waterfowl, including ducks and geese. Domestic poultry, including chickens and turkeys, are very susceptible to the disease.

There are currently two strains of avian influenza being reported in the United States. One is considered a high pathogen strain, while the other is a low pathogen strain. Both types of avian influenza rarely cause disease in waterfowl, but these birds can transmit it to domestic poultry where it can cause either a mild or a severe disease with high mortalities. Lower pathogen strains still lead to infected birds, but do not have the high mortality rates and over time can change into high pathogen strains. This is why when either is detected, the entire poultry flock is euthanized and the area quarantined.

Q: Where did it come from?

The current cases are believed to have originated in in migratory birds. Migratory birds fly down the four major flyways, which begin near the Arctic Circle and cross the United States. Alabama is located between two major flyways, the Mississippi and the Atlantic Flyways.

Q: How is avian influenza transmitted?

Infected waterfowl can shed the virus in secretions from the mouth, nostrils, and eyes and also excrete it in their droppings. Contact with contaminated droppings is the most common means of bird-to-bird transmission, although airborne secretions are another important means of transmission, especially within poultry houses. The spread of avian influenza between poultry facilities can often be traced to the movement of infected birds or contaminated people and equipment (including clothing, boots, and vehicles).

Q: Is chicken safe to eat?

Poultry is safe to eat. Infected flocks do not enter the human food chain. As soon as a flock is identified as having avian influenza, the chickens are euthanized and their remains are disposed of, usually on the farm.

Q: How important is effective biosecurity in reducing spread of avian influenza?

Practicing good sanitation and following appropriate biosecurity measures are the first line of defense against avian influenza. Strong biosecurity measures take many forms.

  • Isolating poultry from other animals
  • Restricting/minimizing access to people and unsanitized equipment
  • Keeping the area around the poultry buildings clean and uninviting to wild birds
  • Sanitizing the facility between flocks
  • Cleaning equipment entering and leaving the farm
  • Having an all in, all out policy regarding the placement and removal of the birds.
  • Properly disposing of bedding material and mortalities

Q: What happens now that there is a confirmed case in a neighboring state?

  • A control zone has been established around the site where the disease was confirmed. The control zone is made up of an infected zone, buffer zone, and surveillance zone. The size of the zones may vary but generally are about 6 miles in diameter.
  • Birds in the infected flock have been euthanized as a first measure to stop the spread of the disease.
  • Testing is required at least weekly in the infected and buffer zones of all poultry premises. These samples will be collected by trained personnel and tested in one of the state diagnostic labs, amounting to thousands of samples daily.
  • All flocks that test positive must have flock plans and compliance agreements to cover procedures necessary to develop response and emergency plans.
  • Quarantine and control zones will restrict movement of poultry and equipment especially in the infected zone. Poultry plants in a control zone may experience delays. This could affect other industries also, especially the cattle industry if a stockyard or other livestock is located within a control zone.

Q: Would vaccinating chickens solve the problem?

With more than $46.3 billion invested in the United States poultry industry, the issue of vaccinating the flocks is complicated. One of the issues federal officials face is weighing the consequences of vaccinating the birds. Vaccination records could increase poultry Russia and China.


Download a PDF of Avian Influenza FAQ, March 2020 Update, ANR-2304.

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