The causative agent of bird flu is a virus. Specifically, it is an influenza virus that primarily affects birds, but can also infect humans and other animals. The virus is classified as a type A influenza virus and is further divided into subtypes based on the proteins on its surface, including H5N1 and H7N9.
The virus is transmitted through contact with infected birds, their saliva, nasal secretions, or feces. In humans, bird flu can cause a range of symptoms, from mild to severe, including fever, cough, and difficulty breathing. In some cases, it can lead to severe respiratory illness, pneumonia, and even death.
It is important to note that while the virus is primarily a concern for birds, it can occasionally infect humans, particularly those who work with birds or live in close proximity to them.