Bird flu or avian influenza is an infection caused by different strains of avian influenza A virus. This virus infects wild water birds, but sometimes is passed to farm birds such as chicken, turkeys or ducks. The virus makes the farm birds very sick and many die. Sometimes the virus changes or mutates and spreads to people. The most common strains seen in humans include H5N1 and H7N9. H5N1 can cause serious illness and has a high death rate among humans. The virus strains are present worldwide but are more common in Asia, Europe, the Pacific, Near East and Africa. Only about 700 people have had the bird flu caused by H5N1. There have been no reported cases of the virus causing illness in people in the United States. The first reported case of a human infected by H5N1 was reported in 2014 in Canada.
Infections are caused by contact with sick or dead poultry infected with the virus. Infections do not normally spread between people, but there are a few cases where it has happened. Medical scientists worry that during an outbreak of bird flu, the virus may change or mutate so that it can be passed from human to human. This will cause the bird flu to spread much more rapidly over much larger areas.
Symptoms of bird flu in humans depends on which strain caused the infection. Some only cause mild illness while other strains like H5N1 can be very serious. In general symptoms may include fever, cough, sore throat, muscle aches, abdominal pain, diarrhea, pneumonia, and difficulty breathing. Diagnosis requires special lab tests. The best prevention is to avoid contact with sick or dead birds especially in areas with a known outbreak. Poultry and eggs should be properly cooked before eating. Treatment may include antiviral medications and supportive therapy. If you work with farm birds or come into contact with dead birds and develop flu symptoms, talk with your doctor about the most current testing and treatment options.