Bird flu is an infection caused by a certain kind of avian influenza virus. Healthcare providers are more concern of the H5N1 and H7N9 bird flu viruses.
These viruses are found in wild birds, and does not cause any symptoms. Usually bird flu virus is not passed from birds to people. But since 1997, some people have become sick with this serious, deadly kind of bird flu. Most of these infections have been in Asian countries among people who have had close contact with birds raised on farms.
What causes bird flu?
Bird flu is caused by strains of influenza virus. After a wild bird infects a farm-raised bird, the virus can easily and quickly spread among hundreds or thousands of birds. People who come into contact with sick chickens, ducks, or turkeys are more likely to get the virus.
Bird flu virus can be passed through bird droppings and saliva on surfaces such as cages, tractors, and other farm equipment.