Frequently Asked Questions about Avian Influenza
About Bird Flu
Wild birds that carry bird flu viruses include waterbirds, like ducks, geese and swans, and shorebirds, like storks. Bird flu viruses can easily spread from wild birds to poultry, like chickens and turkeys. Some wild birds can carry bird flu viruses without appearing sick, but poultry, like chickens and turkeys, can get very sick and die from bird flu. If you raise backyard poultry or ducks, your birds can get bird flu if they have contact with infected wild birds or share food, sources of water, and environments with them. Most common songbirds or other birds found in the yard, like cardinals, robins, sparrows, blue jays, crows or pigeons, do not usually carry bird flu viruses that are dangerous to poultry or people.
Human infections with bird flu viruses are rare but can occur, usually after close contact with infected birds. The current risk to the general public from bird flu viruses is low; however, it is important to remember that risk depends on exposure, and people with more exposure might have a greater risk of infection. There is existing federal guidance around bird flu exposures for different groups of people, including people with occupational or recreational exposure, such as hunters pdf icon[297 KB, 2 pages]external icon and poultry producersexternal icon, and also for the general public, as well as health care providers.
Recommendations
As a general precaution, people should avoid direct contact with wild birds and observe them only from a distance, if possible. Wild birds can be infected with bird flu viruses without appearing sick. If possible, avoid contact with poultry that appear ill or have died. Avoid contact with surfaces that appear to be contaminated with feces from wild or domestic birds, if possible. CDC has information about precautions to take with wild birds. As a reminder, it is safe to eat properly handled and cooked poultry and poultry products in the United States. The proper handling and cooking of poultry and eggs to an internal temperature of 165˚F kills bacteria and viruses, including H5N1 bird flu viruses.
CDC has guidance for specific groups of people with exposure to poultry, including poultry workers and people responding to poultry outbreaks. If you must handle wild birds or sick or dead poultry, minimize direct contact by wearing gloves and wash your hands with soap and water after touching birds. If available, wear respiratory protection such as a medical facemask. Change your clothing before contact with healthy domestic poultry and birds after handling wild birds, and discard the gloves and facemask, and then wash your hands with soap and water. Additional information is available at Information for People Exposed to Birds Infected with Avian Influenza Viruses of Public Health Concern.
What CDC is Doing
Right now, the H5N1 bird flu situation is primarily an animal health issue. The U.S. Department of Interior and USDA APHIS are the lead federal agencies for this situation. They are respectively responsible for outbreak investigation and control of bird flu in wild birds and in domestic poultry. CDC is the lead federal agency on the human health side.
Because flu viruses are constantly changing, CDC is monitoring these viruses to look for genetic changes suggesting they might spread more easily to and between people, and cause serious illness in people, or for changes that suggest reduced susceptibility to antivirals, as well as changes in the virus that might mean a new vaccine virus should be developed.
CDC has been monitoring for illness among people exposed to H5N1 virus-infected birds in the U.S. since these outbreaks were detected in U.S. wild birds and poultry in late 2021 and into 2022.
One human case of avian influenza A (H5N1) has been reported in the United States in a person involved in culling (depopulating) of H5N1 virus-infected poultry. This one H5N1-positive human case does not change the human health risk assessment for the general public, which CDC considers to be low. CDC will continue to watch this situation closely for signs that the risk to human health has changed. Signals that could raise the public health risk might include multiple reports of H5N1 virus infections in people from exposure to birds, or identification of spread from one infected person to a close contact. CDC also is monitoring H5N1 viruses for genetic changes that have been associated with adaptation to mammals, which could indicate the virus is adapting to spread more readily from birds to people.
H5 in Other Animals
Yes, although H5 bird flu viruses primarily infect different types of wild birds and domestic poultry, H5 bird flu viruses can infect other animals as well. H5 bird flu viruses have previously been known to occasionally infect mammals that eat (presumably infected) birds or poultry including but not limited to wild or feral animals such as foxes; stray or domestic animals such as cats and dogs; and zoo animals such as tigersexternal icon and leopardsexternal icon. Recently, sporadic H5 virus infections in mammals, including wild foxesexternal icon and skunksexternal icon, have been reported in Canadaexternal icon, the U.S.external icon and other countries. The reports of H5 bird flu viruses in these mammals in the U.S. and Canada are not surprising given the widespread outbreaks of H5 bird flu in wild birds.
There is little evidence of bird flu viruses spreading to people via an intermediary animal in the past. In 2016, CDC confirmed one human infection with H7N2 bird flu virus in a person who had close, prolonged unprotected exposure to the respiratory secretions of sick cats infected with H7N2 bird flu virus at a New York City animal shelter. A second human infection with H7N2 bird flu virus was later found in someone who also had exposure to the sick, infected cats. Existing evidence suggests it is unlikely that people would be infected by H5 bird flu virus through contact with H5-virus infected wild, stray, feral, or domestic animals, but it is possible, especially with prolonged and unprotected exposure to infected animals. People who have had direct contact with infected or potentially infected sick or dead animals, including animals that might have eaten H5-virus infected birds, should monitor their health for fever and symptoms of H5 virus infection.
Signs and Symptoms may include:
- Fever (Temperature of 100°F [37.8°C] or greater) or feeling feverish/chills*
- Cough
- Sore throat
- Difficulty breathing/Shortness of breath
- Conjunctivitis (eye tearing, redness, irritation, or discharge from eye)
- Headaches
- Runny or stuffy nose
- Muscle or body aches
- Diarrhea
*Fever may not always be present
Call your state/local health department immediately if you develop any of these signs or symptoms during the 10-days after your exposure to an infected animal. Discuss your potential exposure and ask about testing for H5 virus. If testing is indicated, isolate as much as possible until test results come back and/or you have recovered from your illness. Additionally, close contacts (family members, etc.) of people who have been exposed to H5 bird flu viruses should also monitor their health for 10 days after their exposure for signs and symptoms of illness. If close contacts of people who have been exposed to H5 bird flu viruses develop signs and symptoms of illness, they should also contact their state health department.
CDC is actively looking into this situation to assess potential human health implications, including looking at H5 viruses found in these mammals to see whether these viruses have undergone any changes seen in the past that have been associated with bird flu viruses spreading easily among poultry, infecting people more easily, and causing severe illness in people. The detection of the current predominant H5 bird flu virus in mammals, including foxes and skunks, does not change the human health risk assessment for the general public, which CDC considers to be low. Right now, the H5 bird flu virus situation is primarily an animal health issue. The U.S. Department of Interior (DOI) and U.S. Department of Agriculture (USDA) are the lead federal departments for H5 virus infections in animals. In general, people should avoid wild birds and animals that appear sick or dead and also keep their pets away from sick or dead birds and animals.
State and local governments have different policies for collecting dead and testing sick or dead animals, so check with your state health department, state veterinary diagnostic laboratory, or state wildlife agency for information about reporting animals that look sick or are dead in your area.
There are a number of state and federal partners* involved in monitoring and reporting animals with confirmed H5 virus infections, and potentially exposed people, including**:
- USDA APHIS Veterinary Services
- USDA APHIS Wildlife Services
- USDHHS Centers for Disease Control and Prevention
- USDOI US Geological Survey
- USDOI US Fish and Wildlife Services
- National Forest Service
- National Park Service
- In affected states:
- State Departments of Agriculture
- State Departments of Animal Health
- State Departments of Environmental Conservation
- State Departments of Fish and Wildlife
- State Departments of Natural Resources
- Divisions of Game, Fish, and Parks
- Divisions of Wildlife Resources
- State Parks
- State Departments of Public Health
*Names and groups involved vary by state and federal response authorities.
**Other state and federal response authorities may be involved depending on where the sick or infected animals are located.