Avian Influenza


Influenza A (H5NI) and other 

‘bird flu’ viruses​​



Avian Influenza (AI) or 'bird flu' is a viral disease caused by influenza type A viruses and is divided into two categories, Low Pathogenic (LPAI) and Highly Pathogenic (HPAI), referring to the severity of infection in birds. HPAI is of concern because it can cause widespread, severe illness among bird populations. There are several types of HPAI, including the most well-known, H5N1. These viruses spread naturally among wild bird populations but can also infect domestic poultry and other animals.

Human cases of bird flu are not common, but occasional cases have occurred.


Frequently Asked Questions

Does 'bird flu' only infect birds?

No. 'Bird flu' most commonly infects waterfowl populations like geese, ducks, and swans and can easily spread to poultry like chickens and turkeys. 'Bird flu' has been detected in wild mammals such as foxes, bears, seals, and sea lions, and in domesticated animals like dogs and cats. Often these animals are infected after eating an ill or dead bird infected with 'bird flu'. Recently, infections have been seen in livestock such as cows and goats. Occasionally, 'bird flu' can infect humans.

Common backyard birds and songbirds like robins, cardinals, and crows do not usually carry 'bird flu' viruses that are dangerous to people or poultry.


Who is at risk?

At this time, the U.S. Centers for Disease Control and Prevention (CDC) considers the human health risk to the U.S. public from HPAI A(H5N1) viruses to be low. People who have prolonged, unprotected work or recreational exposure to infected wild birds or poultry and livestock (cows and goats) including carcasses, feces, and their contaminated environment are at greatest risk. This can include backyard flocks kept at the home.


How is it spread?

'Bird flu' infects the respiratory and intestinal tract of birds, causing birds to shed the virus in their saliva, mucus, and feces. The virus can spread when enough virus gets into a person's nose, eyes, or mouth or is inhaled. 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.


What are the symptoms of 'bird flu'?

  • Birds: Sudden death, lack of energy and appetite, decreased egg production or soft-shelled or misshapen eggs, nasal discharge, coughing and sneezing, incoordination, or diarrhea.
  • Humans: 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.
  • Other animals: Symptoms noted in dairy cows include decreased milk production and low appetite.


How can I prevent myself from getting sick?

Members of the general public are advised to observe wild birds from a distance. 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 look to be contaminated with wild bird feces, if possible. It is also advised that all persons aged 6 months and older receive an annual flu vaccination. However, the flu vaccine does not protect against avian influenza.


Recommendations for Farm Workers

  • 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 with soap and water after touching birds, and change your clothes before contact with healthy domestic poultry and after handling wild birds.


Recommendations for Backyard Flock Owners

  • 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.


With recent cases of 'bird flu' in dairy cows, is my milk safe to drink?

Yes. According to the U.S. Department of Agriculture (USDA) and Food and Drug Administration (FDA), there is no concern about the safety of commercial milk products at this time. Dairies are required to only send milk from healthy animals for processing. Milk from cows infected with 'bird flu' or suspected of having 'bird flu' is diverted or destroyed so it does not enter the human food supply. Commercial milk products are required to go through a process called pasteurization before they can be sold for human consumption. Pasteurization has been proven to kill bacteria or viruses, including influenza, that may be present in dairy products. As before, the FDA and MDH continue to advise consumers against consuming raw, unpasteurized milk as it can contain dangerous microorganisms that can cause illness in humans.

What if there are infected chickens at a poultry farm? Will my eggs be safe to eat?

According to the FDA, the likelihood that infected eggs or poultry have entered the market is low, and proper storage and preparation of these food products further lowers risk. Infection in a flock is identified quickly and birds and poultry products from affected farms are destroyed so they do not enter the commercial food supply chain. There are additional safeguards in place like testing of flocks and federal inspection programs.

The FDA website provides information on the proper storage and preparation of eggs at home. Properly handling and preparing eggs and poultry can protect them from viruses and bacteria, including avian influenza.

As always, the USDA reminds consumers that proper food safety is important every day and advises people to adhere to the four safe food preparation steps: Clean, Separate, Cook, and Chill.

If you are a backyard flock owner concerned about possible HPAI A(H5N1) infection in your flock, immediately contact the Maryland Department of Agriculture for guidance at 410-841-5810.

​What should I do if exposed to a sick or dead animal with HPAI A(H5N1) 'bird flu'? People who may have been exposed to an animal with known or suspected HPAI A(H5N1) infection should contact​ their local or state health department and monitor themselves for 10 days for signs and symptoms of the disease.

​​What should I do if I get sick?

Anyone who becomes ill within 10 days of exposure to an animal with known or suspected HPAI (H5N1) 'bird flu' should immediately contact their health care provider and local health department, isolate themselves from others in the home and not go to work or school, and remain isolated until otherwise directed.

What is the treatment for 'bird flu'?

Your healthcare provider may prescribe you an antiviral drug. These medications are most effective when taken as soon as possible after symptoms start. Make sure that you take your medication as prescribed by a healthcare provider.


Who should I call if I have found an animal who is sick or died from a known or suspected HPAI A(H5N1) infection?

  • ​For wild animals: 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.
  • For agricultural animals: Report any suspected agricultural animals to the Maryland Department of Agriculture by calling 410-841-5810. Commercial chicken growers and backyard flock owners can seek guidance by emailing their questions about an outbreak to md.birdflu@maryland.gov.​

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