Bird flu, also called avian influenza A, is a viral infection that occurs in birds. It is carried by wild birds. When it infects domestic birds, such as chickens, ducks, and turkeys, 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 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 happens when there are worldwide epidemics of flu caused by a new flu virus to which people have little or no immunity.
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, 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.
The symptoms of bird flu are similar to the symptoms of human flu. Typical symptoms are:
More severe infections can cause:
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 bird flu is done in special labs using blood and samples of mucus from the lungs.
Doctors are working to find the best treatment for bird flu in humans. Some antiviral medicines seem to be effective: oseltamivir (Tamiflu) and zanamivir (Relenza). In addition to these medicines, bird flu usually requires hospital care. Care received in the hospital includes oxygen, help with your breathing, and IV fluids (fluids given into your vein).
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, as they have in the past. 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.
There are no current recommendations against travel to countries where bird flu is common. If you travel to one of these places:
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.
Scientists are developing a promising experimental vaccine. If it is found to be effective against bird flu, shots of this vaccine could be given to people to help prevent infection.
For more information contact the Centers for Disease Control or visit their Web site at http://www.cdc.gov.
Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.
HIA File INF4543F.HTM Release 9.0/2006
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