Bird flu is a disease caused by avian influenza A viruses that usually spread between birds, not people.

One subtype of bird flu, caused by avian influenza A(H5) virus, is spreading worldwide in wild birds and causing sporadic outbreaks in U.S. poultry and dairy cows. In addition to spreading to an increasing number of mammals, H5 bird flu has caused some rare human infections.

For agricultural animals: In Maryland, report any unusual or sudden increases in sick domestic type birds, backyard residential flocks, or other agricultural animals  to the MDA Animal Health Program at 410-841-5810. Commercial chicken growers and backyard flock owners can email questions about the outbreak to [email protected]

​For wild animals: Anyone who sees sick or dead wild birds should not handle or move them. Call the USDA Wildlife Services Office, toll-free for callers in Maryland, at 1-877-463-6497. For phone numbers outside of Maryland, please call 410-349-8130. Operators are available from 8:00 a.m. to 4:30 p.m., Monday through Friday, except for State and Federal holidays.

The reported signs and symptoms of avian influenza A virus infections in humans have ranged from no symptoms or mild symptoms to moderate to severe disease and complications, including resulting in death.

Mild signs and symptoms may include:

• eye redness and irritation (conjunctivitis)
• mild fever (temperature of 100ºF [37.8ºC] or greater) or feeling feverish*,
• cough
• sore throat
• runny or stuff nose
• muscle or body aches
• headaches
• fatigue

Eye redness has been the predominant symptom among recent U.S. cases of avian influenza A(H5) virus infection.

Less common symptoms include diarrhea, nausea, or vomiting.

*Fever may not always be present

Signs and Symptoms of Moderate to Severe Disease

• high fever
• shortness of breath or difficulty breathing
• altered consciousness.
• seizures

More information about symptoms of avian influenza A(H5) virus infections in people, including timing of symptoms, and complications, is available at Signs and Symptoms of Bird Flu in People.

Exposure to infected sick or dead animals is the main risk factor for getting bird flu. Exposure to surfaces contaminated with animal secretions/excretions also is another risk. Eating undercooked or uncooked poultry, eggs, or consuming unpasteurized milk from infected dairy cows, could also be an exposure risk for infection with avian influenza A viruses.

People with job-related or recreational exposures to birds or other avian influenza A(H5) virus-infected animals are at greater risk of infection.

These workers are currently most likely to be exposed:

• Poultry and dairy and other livestock farmers and workers
• Other livestock workers
• Backyard bird flock owners
• Veterinarians and veterinary staff
• Animal health responders
• Public health responders
• Dairy laboratory workers
• Food processing workers handling raw milk and other confirmed or potentially contaminated materials
• Slaughterhouse workers performing certain tasks on lactating dairy cattle
• Zoo or other wild animal facility workers, such as:
  • Sanctuary workers
  • Aquarium workers
  • Wild animal rehabilitation center workers
• Hunters

People with job-related or recreational exposures to birds or infected mammals should take precautions to protect against bird flu. More information on how to stay health around backyard poultry is available at Backyard Poultry | Healthy Pets, Healthy People | CDC.

The best way to prevent bird flu is to avoid sources of exposure whenever possible. People should avoid direct contact with sick or dead wild birds, poultry, and other animals and observe them only from a distance. If you must have direct/close contact with sick or dead wild birds, poultry, or other animals, including dairy cows, wear recommended PPE.

• Do not touch surfaces or materials (e.g., animal litter or bedding material) contaminated with saliva, mucous, or animal feces from birds or other animals with confirmed or suspected avian influenza A virus infection.
• Do not touch or consume raw milk or raw milk products, especially from animals with confirmed or suspected avian influenza A virus infection. Choosing pasteurized milk and products made with pasteurized milk is the best way to keep you and your family safe. Pasteurization kills bacteria and viruses, like avian influenza A viruses, in milk.
• Cook poultry, eggs, and beef to a safe internal temperature to kill bacteria and viruses. More information about safe handling and cooking of poultry is available at Chicken and Food Poisoning. Refer to CDC’s safer foods table for a complete list of safe internal temperatures.

There are tests that can detect avian influenza virus infections. People with recent exposure to infected (or suspected to be infected) birds, animals, or their byproducts and who have symptoms can be tested. Reach out to your health care provider or to the health department if you need to be tested.

Flu antiviral drugs can treat avian influenza A virus infections. People who develop bird flu symptoms following exposure to infected animals should receive treatment with flu antivirals (oseltamivir) as soon as possible. Antiviral treatment works best within 48 hours of developing symptoms. Antiviral treatment should not be delayed while waiting for testing results.

• Use personal protective equipment (PPE) like gloves, an N95 respirator if available, or, if not available, a well-fitting facemask (e.g., a surgical mask), and eye protection.
• Avoid touching your mouth, nose, or eyes after contact with birds or surfaces that may be contaminated with saliva, mucous, or feces from wild birds or domestic birds.
• Wash your hands thoroughly throughout the day and before eating.

• Do not touch sick or dead birds or any surfaces or water that may be contaminated.
• Wear the proper PPE when working with animals you think may be sick.
• Always wash your hands before and after handling birds and when moving birds from one coop to another.