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 spread the virus through 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) and raptors (such as hawks and falcons). HPAI in poultry can cause sickness and death, spread quickly, and be difficult to control. The virus can spread to other birds from an infected bird’s saliva, mucous and feces.
Bird flu viruses usually do not infect people, but rare cases of human infection have been reported in the U.S.
Farm workers, backyard bird owners, and wild bird handlers may be at higher risk of getting bird flu. People can get infected if body fluids from an animal with bird flu gets into a person’s eyes, nose, or mouth, or is breathed in.
Eating or drinking raw milk products from cows with bird flu may also pose a risk for infection. Pasteurized milk products are safe to eat or drink.
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. Pasteurized milk and milk products are also safe to eat or drink.
If you feel sick after having contact with sick or dead birds, contact your health care provider.
Mammals can become infected if they eat infected birds or spend time in an area with bird flu viruses. The H5N1 virus has been found in several mammals, including dairy cattle, stray and domestic cats, foxes, skunks, farmed mink, sea mammals, and even zoo animals, such as tigers and leopards.
Cats can get bird flu if they eat infected birds, drink raw milk or spend time in areas where other animals are sick with bird flu. Signs of illness in cats may include fever, runny nose, watery eyes, difficulty breathing, loss of appetite, vomiting, diarrhea and behavior changes.
Getting sick with bird flu from cats is unlikely, but pet owners should always make sure to avoid close contact with sick cats.