Bird flu (avian flu or avian influenza) is type of influenza virus that mainly affects wild or domesticated birds. Bird flu spreads easily among birds, although transmission to humans is not common. Most human infections occur after exposure to infected birds or their droppings. The H5N1 strain of avian influenza virus arose in the late 1990s and proved to be highly pathogenic (causing severe illness and death) in birds. Since then, other strains of bird flu have been identified that also have the ability to cause severe disease and death. Human infections with a new avian influenza A (H7N9) virus were first reported in China in March 2013.
Bird flu symptoms and signs resemble those of influenza infection and include
Other symptoms can occur, like
- sore throat,
- runny nose,
- eye infections,
- nausea and vomiting,
- muscle aches,
As in birds, bird flu can lead to complications, including pneumonia and multiorgan failure, and has a high mortality (death) rate in infected humans.