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​​​​​​​​Avian Influenza ​


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Avian influenza, commonly known as “bird flu,” is caused by an influenza type A virus. Avian influenza viruses occur naturally in wild birds, especially waterfowl and shore or wading birds.  Wild bird species (such as ducks and geese) can carry and spread avian influenza viruses without becoming ill. However, since 2022, highly pathogenic avian influenza (HPAI) has been affecting wild waterfowl as well as domestic poultry species. HPAI in birds is very contagious and can cause serious disease and high mortality in domestic poultry such as chickens, quail, pheasants, guinea fowl, and turkeys. 

There are many species that are potentially susceptible to highly pathogenic avian influenza (HPAI). In addition to birds and poultry, H5N1 viruses have been detected in some mammals (see HPAI Detections in Mammals​). Infection may cause illness, including severe disease and death in some cases. AI has recently been reported by USDA in juvenile goats and dairy cattle.

For more information on AI, click here

Current Status in Pennsylvania

On Saturday, April 15, 2022, the Pennsylvania Department of Agriculture confirmed the state's first positive case of HPAI in domestic poultry. It was found in a flock of commercial layer chickens on a Lancaster County poultry farm. State and federal government, and private poultry industry representatives remain on high alert and are taking strict measures to protect Pennsylvania’s poultry industry.

For information on biosecurity visit the USDA's website here USDA APHIS | Defend the Flock Program.

To determine the location of your farm relative to an active control area or surveillance zone in PA, click here

Updates on cases in wild and domestic animals can be found on the USDA website.​


Biosecurity is vital for anyone who owns or works with poultry – whether on a commercial farm, in the wild, or at a hobby/ backyard farm. You should take proper steps to keep HPAI and other animal diseases from infecting your flock or spreading to other flocks. The best way to protect your birds is to follow good biosecurity.  Having a biosecurity plan in place, and following that plan daily, is vital to protect Pennsylvania’s poultry.  

If you don’t already have your premises registered with the department, please do so, and include current contact information. If you already have your premises registered with us, please make sure we have current contact information so we can reach you. Premise ID allows us to find your premises on a map in the event of a disease outbreak, and we can warn you if your flock is at risk due to a nearby infected flock.  

Reporting Requirements

If you suspect your poultry is infected with avian influenza, please report your concerns 24 hours a day, 7 days a week to the Pennsylvania Bureau of Animal Health and Diagnostic Services at 717-772-2852, option 1.

Sick or dead wild birds should be reported to the Pennsylvania Game Commission at 833-PGC-Hunt or

Subtypes of Avian Influenza

There are many different subtypes of influenza A viruses. These subtypes differ and are classified based on a combination of two groups of proteins on the surface of the influenza A virus: hemagglutinin or “H” proteins, of which there are 16 (H1-H16), and neuraminidase or “N” proteins, of which there are 9 (N1-N9). Many different combinations of “H” and “N” proteins are possible. Each combination is considered a different subtype, and can be further broken down into different strains. Avian influenza viruses are further classified by their pathogenicity—the ability of a particular virus strain to produce disease in domestic chickens.  HPAI virus strains are extremely infectious, often fatal to domestic poultry, and can spread rapidly from flock to flock. Low pathogenic avian influenza (LPAI) virus strains occur naturally in wild migratory waterfowl and shorebirds, usually without causing illness.

The avian influenza viruses that cause concern in poultry and wild birds are HPAI viruses and any virus designated as H5 or H7, because H5 and H7 viruses have the capability to convert from LPAI to HPAI. HPAI is considered a notifiable avian influenza (NAI), and when found in a country, the World Organization of Animal Health (OIE) must be alerted.

Other States’ HPAI Pages

Those with domesticated poultry affected by HPAI:

Pennsylvania’s Neighboring States

USDA Resources