What is bird flu (avian influenza A H5N1)?
Bird flu, also called avian influenza A, is a viral infection that
occurs in birds. It is carried by wild birds. It can also infect
domestic birds, such as chickens, ducks, and turkeys. When it
infects birds, it makes them sick and sometimes kills them. There
are many strains of influenza. The type of bird flu that is very
deadly is called influenza A H5N1.
Viruses often change (mutate). They may then spread more easily
among animals and humans. They can also become more deadly. The
strain of influenza that is now common in birds in Asia could
change into a flu that spreads more easily to humans. National and
world health organizations worry that a mutated bird flu virus
could cause a world-wide epidemic (pandemic). Many people have at
least some immunity to human viruses, which means their body can
more easily fight the virus. A pandemic flu happens when there are
worldwide epidemics of flu caused by a new flu virus to which
people have little or no immunity.
How does it occur?
Currently it is very rare for humans to become infected. The risk
from bird flu is generally low to most people because the virus
occurs mainly among birds and does not usually infect humans.
However, when there is an outbreak of bird flu among domesticated
chickens, ducks, turkeys, there is a risk that it will spread from
these birds to people. The virus is in the saliva, nasal
secretions, blood, and droppings of infected birds. People can
become infected by having contact with the infected birds or with
surfaces that are dirty from excretions of infected birds.
Very rarely has the infection seemed to have spread from one
person to another.
What are the symptoms of bird flu when people have it?
The symptoms of bird flu are similar to the symptoms of human flu.
Typical symptoms are:
- headache
- fever
- cough
- sore throat
- muscle aches.
It can cause severe breathing problems.
How is it diagnosed?
Bird flu is diagnosed from your symptoms, a physical exam, and
your personal history of possible exposure. Your provider will
want to know if you were around dead or sick birds or if you have
traveled to an area where the virus is active. Testing for the
bird flu virus is done in special labs using blood and samples of
mucus from the lungs.
What is the treatment?
Doctors are working to find the best treatment for bird flu in
humans. Antiviral medicines, such as oseltamivir (Tamiflu) and
zanamivir (Relenza), may be given. In addition to these medicines,
hospital care is usually needed. Treatment at the hospital
includes oxygen, help with your breathing, and IV fluids (fluids
given into the vein).
How long will the effects last?
Mild cases of bird flu do not usually cause serious problems. More
severe infections can cause:
- pneumonia
- severe respiratory disease
- death.
What can be done to prevent bird flu?
Sick or exposed birds are being destroyed in most countries with
known bird flu. Nearby farms are being quarantined. Some countries
have stopped getting birds from affected countries. Hopefully
these actions will stop the spread of the virus. Also, a new rapid
test that can diagnose bird flu within hours has been developed.
It's 90% accurate. That could be important in controlling
outbreaks.
The USFDA recently approved a vaccine that gives humans protection
against the bird flu virus. It can be given as a shot to adults
from 18 through 64 years of age who are at increased risk of
exposure to the H5N1 influenza virus. The vaccine is not available
to the public commercially. It cannot be obtained from a doctor's
office. It has been purchased by the US federal government for the
US Strategic National Stockpile. If it is ever needed, it will be
distributed by the US Department of Health and Human Services.
There are no current recommendations against travel to countries
where bird flu is common. If you travel to one of these places:
- Avoid all contact with chickens, ducks, or turkeys or any wild
birds, and avoid poultry farms and live poultry markets where
there could be H5N1-infected poultry. Don't touch surfaces
that might be dirty with poultry secretions, blood, or
droppings.
- Clean your hands often, using either soap and water or
waterless alcohol-based hand rubs when soap is not available.
- Do not eat uncooked or undercooked poultry or poultry
products. You will not become infected with the virus from
eating infected poultry or eggs if they are thoroughly cooked
to a temperature of at least 160 degrees F (71 degrees C).
Thorough cooking kills the virus.
If you need to spend time around someone who has bird flu, use a
mask that protects you from virus that might be in the saliva or
the breath of the infected person.
For more information contact the Centers for Disease Control or
visit their Web site at http://www.cdc.gov/flu/avian/.
This content is reviewed periodically and is subject to
change as new health information becomes available. The
information is intended to inform and educate and is not a
replacement for medical evaluation, advice, diagnosis or
treatment by a healthcare professional.
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