Avian influenza, or bird flu, is a disease that is spread among birds and is caused by flu viruses. Water birds (such as ducks, geese, gulls, and swans) can carry bird flu without looking sick, but bird flu can cause sickness and death in poultry birds (such as chickens and turkeys). Infected birds carry the virus in their saliva, nasal fluid, and feces.
There are many types of bird flu viruses. The viruses that can cause severe disease and death in poultry are called highly pathogenic avian influenza (HPAI). Low pathogenic avian influenza viruses cause no signs of illness or mild disease in poultry.
Some bird viruses can infect humans and other animals, but the risk is low. How sick a person becomes depends on the type of bird flu. Symptoms can range from no or mild illness to severe disease and death.
Transmission
Wild birds can carry HPAI virus without looking sick and spread the virus to poultry birds (such as chickens and turkeys). Among poultry, HPAI can cause sickness and death, spread quickly and be difficult to control. It can spread from an infected bird’s saliva, nasal fluid and feces.
The risk to the general population is low. It is rare for a person to be infected with HPAI. There has only been one human case reported in the U.S.
Infection may occur after breathing in HPAI virus from the air, or from touching something that has the virus on it and then touching their mouth, eyes or nose. Most infections occur after extended and unprotected contact with infected birds. Poultry workers, backyard bird owners and wild bird handlers are at higher risk for HPAI.
Signs in Birds
Some wild water birds that have been infected may show no signs of illness. Signs of HPAI in poultry include:
If you own or care for chickens or other types of poultry, learn more about how to protect them from bird flu by visiting the USDA and Cornell Cooperative Extension.
How to Protect Yourself
To protect yourself from infection:
Bird flu is not a risk to food safety. Poultry and eggs that are safely handled and cooked to an internal temperature of 165 degrees F are safe to eat.
If you feel sick after having contact with sick or dead birds, contact your health care provider.
In 2016, over 100 cats and one person in NYC tested positive for a low pathogenic avian influenza known as H7N2. There is no current outbreak of H7N2 in NYC.