Avian influenza or avian flu, (commonly known as bird flu), is a type of influenza A virus that is mainly found in wild birds. Avian influenza can also infect domestic and commercial poultry, such as chickens and turkeys, and less commonly mammals, including dairy cattle. Human infections with avian influenza are rare. If people do become infected it is usually because they have had close contact with infected poultry or other animals or their environment.
Symptoms can include fever, body aches, cough, sore throat, red eyes, breathing problems, and sometimes, diarrhea and vomiting. Avian influenza does not spread easily from person to person. Avian influenza A (H5N1) was first detected in Canada in 2021 and continues to circulate worldwide with ongoing detections in various wild, domestic and backyard bird populations, and the virus has also been detected in various wild and domestic mammalian species.