What is bird flu?
Bird flu is an infection caused by a certain kind of
influenza virus. Although there are many kinds of bird
flu, the kind that now concerns health workers is the H5N1 bird flu virus. This
virus is found in wild birds. Most of the time, wild
birds don't get sick from the virus. But wild birds can easily pass the virus
to birds that are being raised for food, such as chickens, ducks, and turkeys.
The virus can cause them to get very sick.
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. But experts believe that the virus may eventually spread to
all parts of the world. So far, no cases of H5N1 bird flu in humans have been
found in Canada or the United States.
What causes bird flu?
Bird flu is caused by a virus. After a wild bird
infects a farm-raised bird, the virus can easily and quickly spread among
hundreds or thousands of birds. Sick birds must then be killed to stop the
virus from spreading.
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.
don't need to worry about getting sick with bird flu virus. You cannot get bird
flu from eating fully cooked chicken, turkey, or duck, because heat kills the
Why are people so worried about bird flu?
In a few cases, experts think that bird flu was passed
from one person to another person, not from a bird to a person. Because viruses
can change quickly (mutate), experts worry that bird flu will one day be passed
easily from person to person. This is a scary possibility, because the H5N1
bird flu virus can make people sicker than other kinds of flu viruses. Even
though only a few hundred people are known to have been sick with bird flu,
more than half of them have died.
Experts also worry because the
H5N1 bird flu virus is so different from other flu viruses that our bodies do
immunity against it. Not having immunity means that our bodies
have a hard time fighting the virus. It also means that anyone, including those
who are otherwise very healthy, can get seriously ill if he or she gets this
kind of bird flu.