Avian Influenza Virus (Bird Flu)
Avian influenza viruses usually infect birds, but rare cases of human infection with these viruses have been reported. Humans that get avian influenza usually have come in direct contact with infected birds, birds that have died from avian influenza, or bird droppings from infected birds. However, in the US in March of 2024 a human case of avian influenza was identified in a worker with exposure to cattle that had tested positive for HPAI. It’s important to understand that risk to humans is primarily associated with close, prolonged interaction with sick animals, therefore persons who work closely with infected birds or mammals will be at highest risk.
Avian influenza is also referred to as “Avian Influenza A”. There are two types of Avian Influenza A: Highly Pathogenic Avian Influenza (HPAI) and Low Pathogenic Avian Influenza (LPAI). Most avian influenza viruses are either H5 or H7 viruses (these are subtypes of the viruses based on proteins on the surface of the viruses). The difference between HPAI and LPAI is based on the virus itself, but also the virus’ ability to cause severe illness and death in chickens. Chickens are used as a marker to determine if a particular virus is LPAI or HPAI, but these viruses cause disease and death in many other species of birds, both wild and domestic, especially those important to the US economy like turkeys and chickens and in mammals including cattle and other livestock. Some of these viruses are highly pathogenic (cause severe disease and death in infected poultry), but most are low pathogenic (cause either no signs of disease or mild disease in poultry). In the US, we are most concerned about HPAI viruses because they can be devastating to our agricultural community. Both HPAI and LPAI present a very low risk to humans and infections in humans are rare.
HPAI typically infects wild birds, primarily waterfowl, such as ducks; however, it can infect many types of birds and other animals. Wild birds infected with highly pathogenic viruses can experience no symptoms to extremely severe symptoms, including death. Rarely, domestic birds, such as chickens or livestock may also get infected with HPAI. In these cases, the Georgia Department of Agriculture (GDA) and the U.S. Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) respond to control the outbreak on the farm. In rare instances, the HPAI or “bird flu” virus can be transmitted to humans or other susceptible animals primarily through direct exposure to infected birds or the environment where the infected birds live. Currently, HPAI has not been documented to transmit easily between people or other susceptible mammals. For more information about “bird flu” in humans, please visit the following CDC’s Bird Flu in People.
It is important to remember that HPAI mostly impacts production and economic stability for our agricultural industries. It is safe to consume properly handled and cooked poultry and livestock products, including meat, eggs, and pasteurized milk.
Disease Reporting in Humans
Novel influenza A virus infections in humans, including HPAI, are immediately reportable to the Georgia Department of Public Health (DPH). More about what needs to be reported, who needs to report diseases, and how to report can be found on the DPH Notifiable Disease Reporting page.
Current US Situation as of April 2024
There is ongoing surveillance throughout the U.S. and the world to monitor for "bird flu" in wild birds, commercial poultry, and backyard birds. In the U.S., the U.S. Department of Agriculture, U.S. Department of the Interior and the U.S. Department of Health and Human Services work together on this surveillance and have one of the strongest surveillance programs worldwide. The Highly Pathogenic Avian Influenza (HPAI) H5N1 strain has been identified in the United States in wild birds, commercial poultry, backyard flocks, and mammals in the last 2 years. HPAI in dairy cows was confirmed in multiple U.S. states in the spring of 2024. A person working with to cattle tested positive for the HPAI (H5N1) virus. This person’s only symptom is eye redness (consistent with conjunctivitis), and they are recovering. This is only the second case of H5N1 bird flu in the United States; the first was in a poultry worker in Colorado in 2022. The risk for the general public remains low; there is no sign of person-to-person spread of this virus at this time nor mutations that make it a higher risk to persons who do not work closely with animals infected with the virus. Continued updates can be found on the CDC’s Update: Human Infection with Highly Pathogenic Avian Influenza A(H5N1) Virus in Texas.
Properly handled and cooked meat, pasteurized milk, and eggs are safe to consume as these processes kill bacteria and viruses, including bird flu viruses. People who choose to consume unpasteurized (raw) milk or raw cheeses should know these products can harbor dangerous microorganisms that can pose serious health risks to consumers.
Those at greater risk (such as those working with infected birds or other animals), should follow specific CDC recommendations to reduce the risk of infection. If you have contact with birds, cattle, or other livestock that may be infected with HPAI and experience any symptoms, please call 866-PUB-HLTH (866-782-4584).
More information on surveillance and positive results in both domestic and wild birds can be found on the USDA APHIS & CDC websites:
The Georgia Department of Public Health works closely with partners at the Georgia Department of Agriculture (GDA) on all animal and human-related public health concerns. Please refer to the Georgia Department of Agriculture webpage for up-to-date guidance on Avian Influenza in animals: Georgia Department of Agriculture information on Avian Influenza.
Other Resources
- CDC information on Avian Influenza (Bird Flu)
- H5N1 Bird Flu: Current Situation Summary | Avian Influenza (Flu) (cdc.gov)
- USDA APHIS information on Avian Influenza
Page last updated 4/12/24