Distribution of Highly Pathogenic Avian Influenza H5 and H5N1 in North America, 2021/2022. Updated November 27, 2022.
How is avian influenza spread?
State and federal government experts continue to evaluate how Highly Pathogenic Avian Influenza (HPAI) viruses can spread and impact wild and domestic birds.
The global spread of HPAI subtype H5N8 has been driven in large part by migratory waterfowl. Knowledge about migratory patterns and intercontinental associations of waterfowl, as well as genetic analyses of viral strains support the hypothesis that HPAI H5N8 entered North America from Asia via migratory birds.
Wild waterfowl and other species shed the virus into the environment through their oral and nasal secretions and feces.
Learn more: USGS Avian Influenza
Related Content
Can people get avian influenza?
While rare, human infections with avian influenza viruses have occurred. The Centers for Disease Control and Prevention considers the risk to the general public from HPAI H5 infections in wild birds, backyard flocks, and commercial poultry, to be low. To date, no humans or other mammals have shown signs of disease from the HPAI viruses found in North America but field personnel handling live or...
Can wild birds spread avian influenza to domestic poultry?
Although it is possible for domestic poultry to become infected with avian influenza from direct contact with wild birds, it is more likely that avian influenza viruses are spread indirectly to poultry on contaminated feed, clothing, and equipment. Agricultural agencies encourage producers to prevent wild birds and other wildlife from coming into direct contact with their poultry, and to avoid...
How do scientists study avian influenza in wild birds?
To learn more about the impacts of avian influenza on wild birds and the role wild birds may play in the spread of the virus, experts from government agencies have gathered samples from hundreds of thousands of live-captured, apparently healthy wild birds, hunter-harvested birds, and dead wild birds of all species. Testing methods include analyses of fecal samples and swabs of the bird’s trachea...
What is the meaning of the numbers next to the “H” and “N” in avian influenza designations?
Avian influenza (AI) viruses are classified by a combination of two groups of proteins: hemagglutinin or “H” proteins, of which there are 16 (H1 to H16), and neuraminidase or “N” proteins, of which there are nine (N1 to 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. AI...
What are the different types of avian influenza?
Avian Influenza (AI) type A viruses are divided into subtypes based on two proteins on the surface of the virus: Hemagglutinin (HA), of which there are 16 subtypes (H1-H16) Neuraminidase (NA), of which there are 9 subtypes (N1-N9) Many combinations of HA and NA proteins are possible (i.e., H5N1, H5N2, H7N2, H7N8, etc). AI viruses are also classified into two groups based on their ability to...
What is chronic wasting disease?
Chronic wasting disease (CWD) is a fatal, neurological illness occurring in North American cervids (members of the deer family), including white-tailed deer, mule deer, elk, and moose. Since its discovery in 1967, CWD has spread geographically and increased in prevalence locally. CWD is contagious; it can be transmitted freely within and among cervid populations. No treatments or vaccines are...
What is White-nose Syndrome?
White-nose syndrome is an emergent disease of hibernating bats that has spread from the northeastern to the central United States at an alarming rate. Since the winter of 2007-2008, millions of insect-eating bats in at least 40 states and eight Canadian provinces have died from this devastating disease. The disease is named for the white fungus, Pseudogymnoascus destructans , that infects skin of...
![showing current distribution of Highly Pathogenic Avian Influenza virus detections.](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/media/images/20221127%20HPAI%20Distribution%20in%20NA.jpg?itok=D3pMMY9w)
Distribution of Highly Pathogenic Avian Influenza H5 and H5N1 in North America, 2021/2022. Updated November 27, 2022.
![Avian Influenza Transmission Risk Model Web Application Virtual Tour](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/video/youtube-WDGeIYmswhw.jpg?itok=nLfZZoxK)
The Avian Influenza Transmission Risk Model web application depicts the intricate connections between 16 layers of administrative, environmental, and economic data in an application that runs inside a web browser. To view and manipulate the full web application, please visit https://www.pwrc.usgs.gov/ai.
The Avian Influenza Transmission Risk Model web application depicts the intricate connections between 16 layers of administrative, environmental, and economic data in an application that runs inside a web browser. To view and manipulate the full web application, please visit https://www.pwrc.usgs.gov/ai.
![Blue-winged teal in Texas with an inset that shows the avian influenza virus](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/BWTE_closeup_Andy_Ramey.jpg?itok=Tx6jOYbT)
Blue-winged teal in Texas. Inset shows avian influenza virus
Blue-winged teal in Texas. Inset shows avian influenza virus
Scientists sampling Forster's Tern chicks for avain influenza during salt pond restoration work in south San Francisco Bay salt ponds.
Scientists sampling Forster's Tern chicks for avain influenza during salt pond restoration work in south San Francisco Bay salt ponds.
Scientists prepare to release Forster's Tern chicks following sampling for avian influenza study.
Scientists prepare to release Forster's Tern chicks following sampling for avian influenza study.
What are the differences between low pathogenic and highly pathogenic avian influenza viruses and how are influenza viruses grouped?
linkListen to hear the answer.
A USGS scientist takes a sample from a northern pintail duck (Anas acuta) to be tested for avian influenza.
A USGS scientist takes a sample from a northern pintail duck (Anas acuta) to be tested for avian influenza.
![Mallard duck being held by scientists with gloved hands while another scientist swabs duck's cloacal.](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/media/images/Mallard%20Swabbing.jpg?itok=ENK0d6Bx)
USGS biologists swab a hen mallard duck for avian influenza in Rio Grande County, Colorado.
USGS biologists swab a hen mallard duck for avian influenza in Rio Grande County, Colorado.
Risk of invasive waterfowl interaction with poultry production: Understanding potential for avian pathogen transmission via species distribution models
USGS highly pathogenic avian influenza research strategy
USGS role and response to highly pathogenic avian influenza
Field Manual of Wildlife Diseases
Why bother about wildlife disease?
Microbial water quality during the northern migration of Sandhill Cranes (Grus canadensis) at the central Platte River, Nebraska
U.S. Geological Survey, National Wildlife Health Center, 2011 report of selected wildlife diseases
Surveillance plan for the early detection of H5N1 highly pathogenic avian influenza virus in migratory birds in the United States: surveillance year 2009
Disease emergence and resurgence—the wildlife-human connection
Related Content
Can people get avian influenza?
While rare, human infections with avian influenza viruses have occurred. The Centers for Disease Control and Prevention considers the risk to the general public from HPAI H5 infections in wild birds, backyard flocks, and commercial poultry, to be low. To date, no humans or other mammals have shown signs of disease from the HPAI viruses found in North America but field personnel handling live or...
Can wild birds spread avian influenza to domestic poultry?
Although it is possible for domestic poultry to become infected with avian influenza from direct contact with wild birds, it is more likely that avian influenza viruses are spread indirectly to poultry on contaminated feed, clothing, and equipment. Agricultural agencies encourage producers to prevent wild birds and other wildlife from coming into direct contact with their poultry, and to avoid...
How do scientists study avian influenza in wild birds?
To learn more about the impacts of avian influenza on wild birds and the role wild birds may play in the spread of the virus, experts from government agencies have gathered samples from hundreds of thousands of live-captured, apparently healthy wild birds, hunter-harvested birds, and dead wild birds of all species. Testing methods include analyses of fecal samples and swabs of the bird’s trachea...
What is the meaning of the numbers next to the “H” and “N” in avian influenza designations?
Avian influenza (AI) viruses are classified by a combination of two groups of proteins: hemagglutinin or “H” proteins, of which there are 16 (H1 to H16), and neuraminidase or “N” proteins, of which there are nine (N1 to 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. AI...
What are the different types of avian influenza?
Avian Influenza (AI) type A viruses are divided into subtypes based on two proteins on the surface of the virus: Hemagglutinin (HA), of which there are 16 subtypes (H1-H16) Neuraminidase (NA), of which there are 9 subtypes (N1-N9) Many combinations of HA and NA proteins are possible (i.e., H5N1, H5N2, H7N2, H7N8, etc). AI viruses are also classified into two groups based on their ability to...
What is chronic wasting disease?
Chronic wasting disease (CWD) is a fatal, neurological illness occurring in North American cervids (members of the deer family), including white-tailed deer, mule deer, elk, and moose. Since its discovery in 1967, CWD has spread geographically and increased in prevalence locally. CWD is contagious; it can be transmitted freely within and among cervid populations. No treatments or vaccines are...
What is White-nose Syndrome?
White-nose syndrome is an emergent disease of hibernating bats that has spread from the northeastern to the central United States at an alarming rate. Since the winter of 2007-2008, millions of insect-eating bats in at least 40 states and eight Canadian provinces have died from this devastating disease. The disease is named for the white fungus, Pseudogymnoascus destructans , that infects skin of...
![showing current distribution of Highly Pathogenic Avian Influenza virus detections.](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/media/images/20221127%20HPAI%20Distribution%20in%20NA.jpg?itok=D3pMMY9w)
Distribution of Highly Pathogenic Avian Influenza H5 and H5N1 in North America, 2021/2022. Updated November 27, 2022.
Distribution of Highly Pathogenic Avian Influenza H5 and H5N1 in North America, 2021/2022. Updated November 27, 2022.
![Avian Influenza Transmission Risk Model Web Application Virtual Tour](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/video/youtube-WDGeIYmswhw.jpg?itok=nLfZZoxK)
The Avian Influenza Transmission Risk Model web application depicts the intricate connections between 16 layers of administrative, environmental, and economic data in an application that runs inside a web browser. To view and manipulate the full web application, please visit https://www.pwrc.usgs.gov/ai.
The Avian Influenza Transmission Risk Model web application depicts the intricate connections between 16 layers of administrative, environmental, and economic data in an application that runs inside a web browser. To view and manipulate the full web application, please visit https://www.pwrc.usgs.gov/ai.
![Blue-winged teal in Texas with an inset that shows the avian influenza virus](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/BWTE_closeup_Andy_Ramey.jpg?itok=Tx6jOYbT)
Blue-winged teal in Texas. Inset shows avian influenza virus
Blue-winged teal in Texas. Inset shows avian influenza virus
Scientists sampling Forster's Tern chicks for avain influenza during salt pond restoration work in south San Francisco Bay salt ponds.
Scientists sampling Forster's Tern chicks for avain influenza during salt pond restoration work in south San Francisco Bay salt ponds.
Scientists prepare to release Forster's Tern chicks following sampling for avian influenza study.
Scientists prepare to release Forster's Tern chicks following sampling for avian influenza study.
What are the differences between low pathogenic and highly pathogenic avian influenza viruses and how are influenza viruses grouped?
linkListen to hear the answer.
A USGS scientist takes a sample from a northern pintail duck (Anas acuta) to be tested for avian influenza.
A USGS scientist takes a sample from a northern pintail duck (Anas acuta) to be tested for avian influenza.
![Mallard duck being held by scientists with gloved hands while another scientist swabs duck's cloacal.](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/media/images/Mallard%20Swabbing.jpg?itok=ENK0d6Bx)
USGS biologists swab a hen mallard duck for avian influenza in Rio Grande County, Colorado.
USGS biologists swab a hen mallard duck for avian influenza in Rio Grande County, Colorado.