Avian influenza is a viral disease caused by various strains of avian influenza viruses that can be classified as low pathogenic avian influenza (LPAI) or highly pathogenic avian influenza (HPAI). It remains a global disease with potential high consequence with the potential to threaten wildlife, agriculture, and human health.
The USGS National Wildlife Health Center (NWHC) in collaboration with multiple partners conducts research into the ecology of avian influenza virus and surveillance for highly pathogenic avian influenza (HPAI) viruses leading to several significant findings towards early detection and response to HPAI.
Avian Influenza (AI) is a global disease with potential high consequence. Wild birds, in particular certain species of waterfowl and shorebirds, are considered to be the natural reservoirs for avian influenza viruses. These subtypes that naturally occur in wild species usually cause little or no disease. In domestic birds, however, some AI viruses can be more pathogenic and mutation or recombination of a virus acquired from wild birds can increase disease potential. In recent years, spill-back has occurred negatively affecting wild birds.
Avian influenza viruses (AIV) are classified by a combination of two groups of proteins found on the surface of the virus: hemagglutinin proteins (H), of which there are 18 (H1-H18), and neuraminidase proteins (N), of which there are 11 (N1-N11). Additional information on avian influenza viruses are available in the Field Manual of Wildlife Diseases.
AI strains are divided into two groups based on the pathogenicity of the virus, or the ability of the virus to produce disease. Most AI strains are classified as low pathogenic avian influenza (LPAI) and cause few clinical signs in infected birds. LPAI generally does not pose a significant health threat to humans. However, LPAI is monitored because two strains of LPAI— the H5 and H7 strains–can mutate into highly pathogenic forms. On the other hand, highly pathogenic avian influenza (HPAI) strains frequently fatal to birds and easily transmissible between susceptible species.
Avian Influenza Movement in the Atlantic
Highly pathogenic avian influenza outbreaks in domestic poultry cause large economic losses to the U.S. economy. It has been thought that Eurasian strains of avian influenza viruses enter the United States through the Pacific Flyway (Alaska to Baja California) and that this route is the most likely avenue for emerging Eurasian AIV strains to enter North America. However, AIV also frequently infects domestic poultry and wild ducks in Europe and Africa and migrating wild birds that use the east Atlantic flyway may also risk introducing Eurasian strain viruses to North America via this route. With the on-going European outbreaks of HPAI there is a risk of moving these viruses to North America as well.
The USGS National Wildlife Health Center, in collaboration with the National Institutes of Health Centers of Excellence for Influenza Research and Surveillance (CEIRS), the University of Iceland, and other partners, has explored the ecology and movement of AI viruses in the North Atlantic region since 2010. This research has demonstrated the importance of the migratory bird flyways in this region to the intercontinental movement of viruses between Europe and North America. AI viruses from both continents, as well as recombinations of both strains, were isolated in Iceland, sometimes from within a single flock of birds, showing that this region is a hotspot of virus movement and genetic reassortment. These studies also demonstrated the longer-term persistence of portions of these viruses within the North Atlantic avian community.
Highly pathogenic AI viruses have been frequently found in wild and domestic European birds, significantly in 2006, and annually since then. This continued European epizootic increases the risk of HPAIV being transported from Europe to North America as bird populations migrate through the North Atlantic to breeding sites in Greenland and Canada, and highlights the importance of these studies. Stakeholders include federal and state agencies, North Atlantic and European countries, and commercial poultry businesses who have an interest in protecting wildlife and/or domestic animals by identifying the risks of HPAIV entering the United States through North Atlantic wild bird flyways. Significant findings from this research in the North Atlantic include:
- Gulls and marine birds are an integral component of AIV ecology in this region;
- Genetic sequence data revealed frequent mixing of North American and Eurasian AIV lineages in the North Atlantic;
- Icelandic viruses were discovered to have genetic relationships with viruses causing seal mortalities in Europe; and
- No HPAIV has been identified, however, viruses with genetic relationships to HPAIV H5N1 viruses have been detected in Iceland.
HPAI and other influenzas circulate in freshwater waterfowl. It is also possible that sea ducks, which regularly move between continents, could play a role in how HPAI moves and evolves around the world. In collaboration with CEIRS, State Wildlife Agencies, Ducks Unlimited, and hunting guides, the NWHC has conducted surveillance in wild sea ducks in the Northeastern United States, Alaska, Canada, and Iceland over the past 6 years. This research has shown that sea duck avian influenzas often differ from those carried by freshwater ducks. This research is currently defining environmental factors that affect AI transmission in marine environments.
Quantitative Applications in Disease Ecology
Human, agricultural, and wildlife health depend on each other. Therefore, risk assessment, prediction, and management of wildlife diseases are important for our nation’s health and economy. However, monitoring and evaluating wildlife health is difficult and expensive. This leads to incomplete and biased datasets that are difficult to analyze with traditional methods. A project is underway to develop new statistical and mathematical techniques and package them into user-friendly tools. Some examples of new tools in development are the ability to analyze and interpret complex data, assess risk of future or ongoing disease outbreaks, estimate the effects of disease on individuals, populations, and ecosystems, and evaluate potential management solutions. This project, performed in partnership with the Department of Statistics at the University of Wisconsin-Madison, is broadly applicable to a variety of wildlife diseases, but is currently working on new statistical methods for predicting virus isolation of avian influenzas.
Minor Spillover of Avian Influenza Between Wild and Domestic Birds
In another study, NWHC reserachers also analyzed the genomes of HPAIV that spread in the United States during 2014-2015 and resulted in over $3 billion in losses to the U.S. poultry industry. As infection and transmission of pathogens in wild birds are difficult to measure during a fast-moving outbreak, the NWHC used cutting-edge modeling techniques to analyze genetic similarity between HPAIVs infecting wild birds and poultry. Analyses indicated that even though the viruses likely evolved in Asia, they easily infected and spread among North American wild birds. The viruses were also able to spread between domestic and wild birds (i.e., spillover). However, the rate of spillover was minor, and the poultry outbreak persisted without need for ongoing transmission from wild birds. Techniques used in this study can also be used to examine transmission and adaptation of avian influenza within waterfowl populations and between waterfowl and poultry.
Avian Influenza Surveillance
The USGS National Wildlife Health Center is a member of the U.S. Interagency Steering Committee for Surveillance for Highly Pathogenic Avian Influenza in Wild Birds. The NWHC performs both passive and active surveillance for the detection and monitoring of avian influenza. Check out the Avian Influenza Surveillance page to learn more.
Below are publications related to avian influenza.
Avian influenza virus prevalence in marine birds is dependent on ocean temperatures
Artificial intelligence and avian influenza: Using machine learning to enhance active surveillance for avian influenza viruses
Aerosol transmission of gull-origin Iceland subtype H10N7 influenza A virus in ferrets
Predicting the initial spread of novel Asian origin influenza A viruses in the continental USA by wild waterfowl
Lethal infection of wild raptors with highly pathogenic avian influenza H5N8 and H5N2 viruses in the USA, 2014–15
Influenza A virus recovery, diversity, and intercontinental exchange: A multi-year assessment of wild bird sampling at Izembek National Wildlife Refuge, Alaska
Inferring epidemiologic dynamics from viral evolution: 2014–2015 Eurasian/North American highly pathogenic avian influenza viruses exceed transmission threshold, R0 = 1, in wild birds and poultry in North America
Identification of two novel reassortant avian influenza a (H5N6) viruses in whooper swans in Korea, 2016
Retrospective analysis of the epidemiologic literature, 1990–2015, on wildlife-associated diseases from the Republic of Korea
No evidence of infection or exposure to Highly Pathogenic Avian Influenzas in peridomestic wildlife on an affected poultry facility
Antigenic characterization of H3 subtypes of avian influenza A viruses from North America
U.S. Geological Survey science strategy for highly pathogenic avian influenza in wildlife and the environment (2016–2020)
Below are news stories related to avian influenza.
Below are FAQs related to avian influenza.
What is Avian Influenza?
Avian influenza (AI) is caused by an influenza type A virus that can infect poultry such as chickens, turkeys, pheasants, quail, domestic ducks, geese, and guinea fowl. It is carried by wild waterfowl (ducks and geese) and shorebirds. Learn more: USGS Avian Influenza
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 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 the difference between low pathogenic and highly pathogenic avian influenza?
The designation of low or highly pathogenic avian influenza refers to the potential for these viruses to kill chickens. The designation of “low pathogenic” or “highly pathogenic” does not refer to how infectious the viruses may be to humans, other mammals, or other species of birds. Most strains of avian influenza are not highly pathogenic and cause few signs of disease in infected wild birds...
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...
Below are partners associated with avian influenza projects.
- Overview
Avian influenza is a viral disease caused by various strains of avian influenza viruses that can be classified as low pathogenic avian influenza (LPAI) or highly pathogenic avian influenza (HPAI). It remains a global disease with potential high consequence with the potential to threaten wildlife, agriculture, and human health.
The USGS National Wildlife Health Center (NWHC) in collaboration with multiple partners conducts research into the ecology of avian influenza virus and surveillance for highly pathogenic avian influenza (HPAI) viruses leading to several significant findings towards early detection and response to HPAI.
Avian Influenza (AI) is a global disease with potential high consequence. Wild birds, in particular certain species of waterfowl and shorebirds, are considered to be the natural reservoirs for avian influenza viruses. These subtypes that naturally occur in wild species usually cause little or no disease. In domestic birds, however, some AI viruses can be more pathogenic and mutation or recombination of a virus acquired from wild birds can increase disease potential. In recent years, spill-back has occurred negatively affecting wild birds.
Avian influenza viruses (AIV) are classified by a combination of two groups of proteins found on the surface of the virus: hemagglutinin proteins (H), of which there are 18 (H1-H18), and neuraminidase proteins (N), of which there are 11 (N1-N11). Additional information on avian influenza viruses are available in the Field Manual of Wildlife Diseases.
AI strains are divided into two groups based on the pathogenicity of the virus, or the ability of the virus to produce disease. Most AI strains are classified as low pathogenic avian influenza (LPAI) and cause few clinical signs in infected birds. LPAI generally does not pose a significant health threat to humans. However, LPAI is monitored because two strains of LPAI— the H5 and H7 strains–can mutate into highly pathogenic forms. On the other hand, highly pathogenic avian influenza (HPAI) strains frequently fatal to birds and easily transmissible between susceptible species.
Avian Influenza Movement in the Atlantic
Brown pelicans and gulls float and fly along a coastline. (Credit: Elizabeth A. Sellers, USGS. Public domain.) Highly pathogenic avian influenza outbreaks in domestic poultry cause large economic losses to the U.S. economy. It has been thought that Eurasian strains of avian influenza viruses enter the United States through the Pacific Flyway (Alaska to Baja California) and that this route is the most likely avenue for emerging Eurasian AIV strains to enter North America. However, AIV also frequently infects domestic poultry and wild ducks in Europe and Africa and migrating wild birds that use the east Atlantic flyway may also risk introducing Eurasian strain viruses to North America via this route. With the on-going European outbreaks of HPAI there is a risk of moving these viruses to North America as well.
The USGS National Wildlife Health Center, in collaboration with the National Institutes of Health Centers of Excellence for Influenza Research and Surveillance (CEIRS), the University of Iceland, and other partners, has explored the ecology and movement of AI viruses in the North Atlantic region since 2010. This research has demonstrated the importance of the migratory bird flyways in this region to the intercontinental movement of viruses between Europe and North America. AI viruses from both continents, as well as recombinations of both strains, were isolated in Iceland, sometimes from within a single flock of birds, showing that this region is a hotspot of virus movement and genetic reassortment. These studies also demonstrated the longer-term persistence of portions of these viruses within the North Atlantic avian community.
Highly pathogenic AI viruses have been frequently found in wild and domestic European birds, significantly in 2006, and annually since then. This continued European epizootic increases the risk of HPAIV being transported from Europe to North America as bird populations migrate through the North Atlantic to breeding sites in Greenland and Canada, and highlights the importance of these studies. Stakeholders include federal and state agencies, North Atlantic and European countries, and commercial poultry businesses who have an interest in protecting wildlife and/or domestic animals by identifying the risks of HPAIV entering the United States through North Atlantic wild bird flyways. Significant findings from this research in the North Atlantic include:
- Gulls and marine birds are an integral component of AIV ecology in this region;
- Genetic sequence data revealed frequent mixing of North American and Eurasian AIV lineages in the North Atlantic;
- Icelandic viruses were discovered to have genetic relationships with viruses causing seal mortalities in Europe; and
- No HPAIV has been identified, however, viruses with genetic relationships to HPAIV H5N1 viruses have been detected in Iceland.
HPAI and other influenzas circulate in freshwater waterfowl. It is also possible that sea ducks, which regularly move between continents, could play a role in how HPAI moves and evolves around the world. In collaboration with CEIRS, State Wildlife Agencies, Ducks Unlimited, and hunting guides, the NWHC has conducted surveillance in wild sea ducks in the Northeastern United States, Alaska, Canada, and Iceland over the past 6 years. This research has shown that sea duck avian influenzas often differ from those carried by freshwater ducks. This research is currently defining environmental factors that affect AI transmission in marine environments.
Migration flyways (Public domain) Quantitative Applications in Disease Ecology
Human, agricultural, and wildlife health depend on each other. Therefore, risk assessment, prediction, and management of wildlife diseases are important for our nation’s health and economy. However, monitoring and evaluating wildlife health is difficult and expensive. This leads to incomplete and biased datasets that are difficult to analyze with traditional methods. A project is underway to develop new statistical and mathematical techniques and package them into user-friendly tools. Some examples of new tools in development are the ability to analyze and interpret complex data, assess risk of future or ongoing disease outbreaks, estimate the effects of disease on individuals, populations, and ecosystems, and evaluate potential management solutions. This project, performed in partnership with the Department of Statistics at the University of Wisconsin-Madison, is broadly applicable to a variety of wildlife diseases, but is currently working on new statistical methods for predicting virus isolation of avian influenzas.
Minor Spillover of Avian Influenza Between Wild and Domestic Birds
Commercial poultry farm (Public domain) In another study, NWHC reserachers also analyzed the genomes of HPAIV that spread in the United States during 2014-2015 and resulted in over $3 billion in losses to the U.S. poultry industry. As infection and transmission of pathogens in wild birds are difficult to measure during a fast-moving outbreak, the NWHC used cutting-edge modeling techniques to analyze genetic similarity between HPAIVs infecting wild birds and poultry. Analyses indicated that even though the viruses likely evolved in Asia, they easily infected and spread among North American wild birds. The viruses were also able to spread between domestic and wild birds (i.e., spillover). However, the rate of spillover was minor, and the poultry outbreak persisted without need for ongoing transmission from wild birds. Techniques used in this study can also be used to examine transmission and adaptation of avian influenza within waterfowl populations and between waterfowl and poultry.
Avian Influenza Surveillance
The USGS National Wildlife Health Center is a member of the U.S. Interagency Steering Committee for Surveillance for Highly Pathogenic Avian Influenza in Wild Birds. The NWHC performs both passive and active surveillance for the detection and monitoring of avian influenza. Check out the Avian Influenza Surveillance page to learn more.
- Multimedia
- Publications
Below are publications related to avian influenza.
Filter Total Items: 79Avian influenza virus prevalence in marine birds is dependent on ocean temperatures
Waterfowl and shorebirds are the primary hosts of influenza A virus (IAV), however, in most surveillance efforts, large populations of birds are not routinely examined; specifically marine ducks and other birds that reside predominately on or near the ocean. We conducted a long-term study sampling sea ducks and gulls in coastal Maine for IAV and found a virus prevalence (1.7%) much lower than is tAuthorsJeffrey S. Hall, Robert J. Dusek, Sean Nashold, Joshua L. TeSlaa, Bradford R. Allen, Daniel A. GrearArtificial intelligence and avian influenza: Using machine learning to enhance active surveillance for avian influenza viruses
Influenza A viruses are one of the most significant viral groups globally with substantial impacts on human, domestic animal and wildlife health. Wild birds are the natural reservoirs for these viruses, and active surveillance within wild bird populations provides critical information about viral evolution forming the basis of risk assessments and countermeasure development. Unfortunately, activeAuthorsDaniel P. Walsh, Ting Fung Ma, Hon S. Ip, Jun ZhuAerosol transmission of gull-origin Iceland subtype H10N7 influenza A virus in ferrets
Subtype H10 influenza A viruses (IAVs) have been recovered from domestic poultry and various aquatic bird species, and sporadic transmission of these IAVs from avian species to mammals (i.e., human, seal, and mink) are well documented. In 2015, we isolated four H10N7 viruses from gulls in Iceland. Genomic analyses showed four gene segments in the viruses were genetically associated with H10 IAVs tAuthorsMinhui Guan, Jeffrey S. Hall, Xiaojian Zhang, Robert J. Dusek, Alicia K. Olivier, Liyuan Liu, Lei Li, Scott Krauss, Angea Danner, Tao Li, Wiriya Rutvisuttinunt, Xiaoxu Lin, Gunnar T. Hallgrimsson, Sunna B. Ragnarsdottir, Solvi R. Vignisson, Josh TeSlaa, Sean Nashold, Richard Jarman, Xiu-Feng WanPredicting the initial spread of novel Asian origin influenza A viruses in the continental USA by wild waterfowl
Using data on waterfowl band recoveries, we identified spatially explicit hotspots of concentrated waterfowl movement to predict occurrence and spatial spread of a novel influenza A virus (clade 2.3.4.4) introduced from Asia by waterfowl from an initial outbreak in North America in November 2014. In response to the outbreak, the hotspots of waterfowl movement were used to help guide sampling for cAuthorsAlan B. Franklin, Sarah N. Bevins, Jeremy W. Ellis, Ryan S. Miller, Susan A. Shriner, J. Jeffrey Root, Daniel P. Walsh, Thomas J. DeLibertoLethal infection of wild raptors with highly pathogenic avian influenza H5N8 and H5N2 viruses in the USA, 2014–15
An outbreak of highly pathogenic avian influenza (HPAI) led to heavy losses of poultry in commercial farms in North America in 2014–15. Enhanced surveillance by virologists and pathologists at the US Geological Survey National Wildlife Health Center and its partners resulted in the identification of lethal infections with clade 2.3.4.4 subgroup icA2 H5N8 and novel reassortant H5N2 viruses in diverAuthorsSusan Knowles, Valerie I. Shearn-Bochsler, Hon S. IpInfluenza A virus recovery, diversity, and intercontinental exchange: A multi-year assessment of wild bird sampling at Izembek National Wildlife Refuge, Alaska
Western Alaska is a potential point-of-entry for foreign-origin influenza A viruses (IAVs) into North America via migratory birds. We sampled waterfowl and gulls for IAVs at Izembek National Wildlife Refuge (NWR) in western Alaska, USA, during late summer and autumn months of 2011–2015, to evaluate the abundance and diversity of viruses at this site. We collected 4842 samples across five years froAuthorsAndrew B. Reeves, Jeffery S. Hall, Rebecca L. Poulson, Tyrone F. Donnelly, David E. Stallknecht, Andrew M. RameyInferring epidemiologic dynamics from viral evolution: 2014–2015 Eurasian/North American highly pathogenic avian influenza viruses exceed transmission threshold, R0 = 1, in wild birds and poultry in North America
Highly pathogenic avian influenza virus (HPAIV) is a multihost pathogen with lineages that pose health risks for domestic birds, wild birds, and humans. One mechanism of intercontinental HPAIV spread is through wild bird reservoirs, and wild birds were the likely sources of a Eurasian (EA) lineage HPAIV into North America in 2014. The introduction resulted in several reassortment events with NorthAuthorsDaniel R. Grear, Jeffrey S. Hall, Robert J. Dusek, Hon S. IpIdentification of two novel reassortant avian influenza a (H5N6) viruses in whooper swans in Korea, 2016
BackgroundOn November 20, 2016 two novel strains of H5N6 highly pathogenic avian influenza virus (HPAIVs) were isolated from three whooper swans (Cygnus cygnus) at Gangjin Bay in South Jeolla province, South Korea. Identification of HPAIVs in wild birds is significant as there is a potential risk of transmission of these viruses to poultry and humans.ResultsPhylogenetic analysis revealed that GangAuthorsJipseol Jeong, Chanjin Woo, Hon S. Ip, Injung An, Youngsik Kim, Kwanghee Lee, Seong-Deok Jo, Kidong Son, Saemi Lee, Jae-Ku Oem, Seung-Jun Wang, Yongkwan Kim, Jeonghwa Shin, Jonathan M. Sleeman, Weonhwa JheongRetrospective analysis of the epidemiologic literature, 1990–2015, on wildlife-associated diseases from the Republic of Korea
To assess the status of research on wildlife diseases in the Republic of Korea (ROK) and to identify trends, knowledge gaps, and directions for future research, we reviewed epidemiologic publications on wildlife-associated diseases in the ROK. We identified a relatively small but rapidly increasing body of literature. The majority of publications were focused on public or livestock health and relaAuthorsJusun Hwang, Kyunglee Lee, Young-Jun Kim, Jonathan M. Sleeman, Hang LeeNo evidence of infection or exposure to Highly Pathogenic Avian Influenzas in peridomestic wildlife on an affected poultry facility
We evaluated the potential transmission of avian influenza viruses (AIV) in wildlife species in three settings in association with an outbreak at a poultry facility: 1) small birds and small mammals on a poultry facility that was affected with highly pathogenic AIV (HPAIV) in April 2015; 2) small birds and small mammals on a nearby poultry facility that was unaffected by HPAIV; and 3) small birds,AuthorsDaniel A. Grear, Robert J. Dusek, Daniel P. Walsh, Jeffrey S. HallAntigenic characterization of H3 subtypes of avian influenza A viruses from North America
Besides humans, H3 subtypes of influenza A viruses (IAVs) can infect various animal hosts, including avian, swine, equine, canine, and sea mammal species. These H3 viruses are both antigenically and genetically diverse. Here, we characterized the antigenic diversity of contemporary H3 avian IAVs recovered from migratory birds in North America. Hemagglutination inhibition (HI) assays were performedAuthorsElizabeth Bailey, Li-Pong Long, Nan Zhao, Jeffrey S. Hall, John A Baroch, Jaqueline Nolting, Lucy Senter, Frederick L Cunningham, G Todd Pharr, Larry Hanson, Richard Slemons, Thomas J. DeLiberto, Xiu-Feng WanU.S. Geological Survey science strategy for highly pathogenic avian influenza in wildlife and the environment (2016–2020)
IntroductionThrough the Science Strategy for Highly Pathogenic Avian Influenza (HPAI) in Wildlife and the Environment, the USGS will assess avian influenza (AI) dynamics in an ecological context to inform decisions made by resource managers and policymakers from the local to national level. Through collection of unbiased scientific information on the ecology of AI viruses and wildlife hosts in a cAuthorsM. Camille Harris, John M. Pearce, Diann J. Prosser, C. LeAnn White, A. Keith Miles, Jonathan M. Sleeman, Christopher J. Brand, James P. Cronin, Susan De La Cruz, Christine L. Densmore, Thomas W. Doyle, Robert J. Dusek, Joseph P. Fleskes, Paul L. Flint, Gerald F. Guala, Jeffrey S. Hall, Laura E. Hubbard, Randall J. Hunt, Hon S. Ip, Rachel A. Katz, Kevin W. Laurent, Mark P. Miller, Mark D. Munn, Andrew M. Ramey, Kevin D. Richards, Robin E. Russell, Joel P. Stokdyk, John Y. Takekawa, Daniel P. Walsh - News
Below are news stories related to avian influenza.
- FAQ
Below are FAQs related to avian influenza.
What is Avian Influenza?
Avian influenza (AI) is caused by an influenza type A virus that can infect poultry such as chickens, turkeys, pheasants, quail, domestic ducks, geese, and guinea fowl. It is carried by wild waterfowl (ducks and geese) and shorebirds. Learn more: USGS Avian Influenza
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 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 the difference between low pathogenic and highly pathogenic avian influenza?
The designation of low or highly pathogenic avian influenza refers to the potential for these viruses to kill chickens. The designation of “low pathogenic” or “highly pathogenic” does not refer to how infectious the viruses may be to humans, other mammals, or other species of birds. Most strains of avian influenza are not highly pathogenic and cause few signs of disease in infected wild birds...
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...
- Partners
Below are partners associated with avian influenza projects.