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. However, in poultry, some low pathogenic strains can mutate into highly pathogenic avian influenza strains that cause a contagious and severe illness among poultry and sometimes wild birds, and often death. The effect is dependent on the viral strain and host species.
Learn more: USGS Avian Influenza
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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 Avian Influenza?
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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...
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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...
Are birds the only species that is susceptible to West Nile Virus infection?
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- FAQ
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 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
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 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...
Are birds the only species that is susceptible to West Nile Virus infection?
West Nile Virus (WNV) has been detected in at least 48 species of mosquitoes, over 320 species of birds, at least 2 species of reptiles, and more than 25 mammalian species, including horses and humans. Birds are the natural host and reservoir of WNV. Although other animals are susceptible to WNV infection, only birds develop a high enough virus load to transmit the infection to an uninfected...
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