A colorful male chickens with four female chickens standing next to a hay bale.

Highly Pathogenic Avian Influenza (HPAI) Is Afoot!

Dr. Julie SmithAnimal Health, Livestock diseases, Wildlife

(Top image by svklimkin from Pixabay)

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The poultry disease, highly pathogenic avian influenza (HPAI), has been spreading to regions across the United States and Canada in commercial and backyard poultry flocks. HPAI is a serious disease and requires rapid response because it is highly contagious and often fatal.

The US Department of Agriculture Animal and Plant Health Inspection Service (USDA APHIS) is tracking HPAI outbreaks. Click on the link below for the latest information on outbreaks and where they are located:

For information on poultry biosecurity to prevent diseases in your flocks, check the HFHA poultry biosecurity page for information on disease prevention strategies.


March 14, 2022

Since February 2022, animal health laboratories in several US states have confirmedOpens a new window the presence of highly pathogenic avian influenza (HPAI) carried by waterfowl that can be lethal to domesticated chickens and turkeys. HPAI is carried by waterfowl as they follow their migratory routes in the Atlantic and Mississippi flywaysOpens a new window . The virus can subsequently be picked up by domesticated fowl after they interact with wild birds or the environment recently visited by wild birds. It also can be spread on the footwear of people visiting or caring for domestic birds.

Map of US migratory bird flyways

Steps to prevent exposure of domesticated fowl to the virus include:

  • Prevent their contact with wild birds or places where wild birds have recently visited.
  • Change footwear before entering areas where domesticated fowl are housed.
  • Use protective shoe covers and hand sanitizer before caring for domestic fowl.

Ground-dwelling fowl (or gallinaceous birds) like chickens, guinea hens, turkeys, and game fowl are all susceptible to novel strains of HPAI. The current strain being detected is a Eurasian strainOpens a new window that has resulted in the loss of many poultry and turkeys in Europe and the United Kingdom in 2021.

This virus is classified as a “highly pathogenic” avian influenza virus based on the proteins it displays on its surface. Because these proteins are recognized by the immune system, they are also called antigens. The antigens on the 2022 HPAI virus are categorizedOpens a new window as H5N1 for the hemagglutinin and neuraminidase subtypes expressed. Virus strains expressing H5 and H7 proteins are frequently highly virulent and likely to cause death of infected domesticated fowl. Wildfowl are often less affected and can be effective carriers of the virus.

While the risk to general public health is considered low, those with greater risk of exposure such as poultry workers and huntersOpens a new window should take precautions. Resources for poultry workers are also available in Spanish, Vietnamese, Tagalog, and Chinese from the USDA Defend the FlockOpens a new window resources center.

To report sightings of deaths among wild or domestic fowl, call your state veterinarian’s office or the USDA’s toll-free number at 1-866-536-7593.

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About the Author

Dr. Julie Smith

Dr. Julie Smith is a research professor at the University of Vermont. Julie received her B.S. in biological sciences, D.V.M., and Ph.D. in animal nutrition at Cornell University. Since 2002, she has applied her veterinary background to programs in the areas of herd health, calf and heifer management, and agricultural emergency management. She has taught courses in animal welfare, calf biology and management, and ABCs of biosecurity to undergraduates, mostly in the Department of Animal and Veterinary Sciences. As a veterinarian and spouse of a dairy farmer, Julie is well aware of the animal health and well-being concerns of dairy animals. Julie has conducted trainings for Extension educators, livestock producers, and community members on the risks posed by a range of animal diseases, whether they already exist in the United States, exist outside of the United States, or pose a risk to both animal and human health. In all cases, she emphasizes the importance of awareness and prevention. In addition, she has led a number of projects on biosecurity and emergency disease preparedness.