Backyard Poultry | Healthy Pets, Healthy People | CDC - CDC

Avian influenza, or bird flu, is a contagious respiratory illness caused by influenza viruses. Some avian influenza viruses that primarily circulate in animals have infected people on rare occasion. When influenza viruses that normally circulate in animals cause an infection in people, this is called a "novel" virus infection. Not all influenza viruses found in birds are known to cause human infections.

How it spreads: Flu viruses are highly contagious. People can get infected through contact with saliva, nasal secretions, and droppings (poop) from infected animals. People also can get infected through contact with virus-contaminated surfaces, poultry coops, pig pens, and supplies. Less often, people can get infected by touching an infected animal and then touching their own eyes, nose, or mouth.

Who is at risk: It is rare for avian flu to spread to people. Anyone can get the flu, but children younger than 5 years old, pregnant people, adults 65 and older, and people with weakened immune systems are at high risk for serious flu complications.

People who work closely with large numbers of birds, such as producers, are more likely to get bird flu if their animals are infected.

Signs in poultry: Birds can be infected with flu viruses without showing symptoms. Signs that poultry may be infected range from decreased egg production to extremely high death rates.

Symptoms in people: People infected with avian flu viruses can have symptoms similar to the human seasonal flu, such as fever, fatigue, lack of appetite, and coughing. They may also have red eyes, nausea, abdominal pain, diarrhea, and vomiting. Some people can have serious flu complications, including inflammation of the heart (myocarditis), brain (encephalitis), or muscle (myositis, rhabdomyolysis) tissues, and multi-organ failure (for example, respiratory and kidney failure).