Bird flu (avian influenza)
Bird flu is caused by a type of influenza virus that rarely infects
humans. But when bird flu does strike humans, it's often deadly. More
than half the people who become infected with bird flu die of the
In recent years, outbreaks of bird flu have occurred in Asia, Africa and
parts of Europe. Most people who have developed symptoms of bird flu
have had close contact with sick birds. In a few cases, bird flu has
passed from one person to another.
Health officials worry that a global outbreak could occur if a bird flu
virus mutates into a form that transmits more easily from person to
person. Researchers are working on vaccines to help protect people from
Signs and symptoms of bird flu typically begin within two to five days
of infection. In most cases, they resemble those of conventional
* Sore throat
* Muscle aches
Some people also experience nausea, vomiting or diarrhea. And in a few
cases, a mild eye infection (conjunctivitis) is the only indication of
When to seek medical advice
See your doctor immediately if you develop a fever, cough and body
aches, and have recently traveled to a part of the world where bird flu
occurs. Be sure to let your doctor know if you visited any farms or
Bird flu occurs naturally in wild waterfowl and can spread into domestic
poultry, such as chickens, turkeys, ducks and geese. The disease is
transmitted via contact with an infected bird's feces, or secretions
from its nose, mouth or eyes.
Open-air markets, where eggs and birds are sold in crowded and
unsanitary conditions, are hotbeds of infection and can spread the
disease into the wider community.
According to the Food and Drug Administration, bird flu cannot be
transmitted by eating properly cooked poultry meat or eggs from infected
birds. Poultry meat is safe to eat if it's been cooked to an internal
temperature of 165 F (74 C). Eggs should be cooked until the yolk and
white are firm.
The greatest risk factor for bird flu seems to be contact with sick
birds or with surfaces contaminated by their feathers, saliva or
droppings. The World Health Organization (WHO) has confirmed a handful
of cases of limited human-to-human transmission of bird flu. But unless
the virus begins to spread more easily among people, infected birds or
associated material presents the greatest hazard.
The pattern of human transmission remains mysterious. Young children
seem especially vulnerable to the virus, although some experts note that
children are more likely to have contact with sick birds or to play on
ground contaminated with droppings. What's more, people of all ages have
contracted and died of bird flu. At this point, too few people have
been infected to know all the possible risk factors for bird flu.
People with bird flu may develop life-threatening complications, including:
* Collapsed lung
* Respiratory failure
* Kidney dysfunction
* Heart problems
Although bird flu kills more than half the people it infects, the number
of fatalities is still low because so few people have had bird flu.
According to the World Health Organization, a few hundred people have
died of bird flu since 2003.
In contrast, the Centers for Disease Control and Prevention estimates
that seasonal influenza is responsible for tens of thousands of deaths
each year in the United States alone.
Preparing for your appointment
If you suspect that you have bird flu, you need to see your family
physician. If you are very ill, you may need to be hospitalized.
What you can do
You may want to write a list that includes:
* Detailed descriptions of the symptoms
* Record of recent travel to an area where bird flu is prevalent
* Information about past medical problems
* Information about the medical problems of parents or siblings
* Questions you want to ask the doctor
What to expect from your doctor
In addition to listening to your description of symptoms, your doctor
will perform a physical exam. He or she may also take a sample of fluid
from your throat or nose. To be useful, these samples must be taken
within the first few days after symptoms appear.
Tests and diagnosis
Samples of fluids from your nose or throat can be tested for the
presence of a flu virus. In the past, these types of tests could take
hours or even weeks to complete. When more-rapid tests became available,
they couldn't distinguish between bird flu and other types of
influenza. The Food and Drug Administration recently approved a type of
test that can identify bird flu viruses in less than an hour.
X-rays may be useful in assessing the condition of your lungs, which can
help determine the proper diagnosis and the best treatment options for
your signs and symptoms.
Treatments and drugs
Many influenza viruses have become resistant to the effects of a
category of antiviral drugs that includes amantadine and rimantadine.
Health officials recommend the use of oseltamivir (Tamiflu) and possibly
zanamivir (Relenza) instead.
These drugs must be taken within two days after the appearance of
symptoms, something that may prove logistically difficult on a worldwide
scale, even if there were enough to go around. Because they're in short
supply, it's not entirely clear how flu drugs would be allocated if
there were a widespread epidemic.
Bird flu vaccine
The Food and Drug Administration has approved one vaccine to prevent
infection with one strain of H5N1 bird flu virus. This vaccine isn't
available to the public, but the U.S. government is stockpiling it and
will distribute it in the event of an outbreak. It's intended to help
protect adults ages 18 to 64 and could be used early in such an outbreak
to provide limited protection until another vaccine — designed to
protect against the specific form of the virus causing the outbreak — is
developed and produced.
Researchers continue to work on other types of bird flu vaccines. One of
the stumbling blocks is that most vaccines need chicken eggs for their
development and production. Bird flu viruses are lethal to chicken eggs.
Recommendations for travelers
If you're traveling to Southeast Asia or to any region with bird flu outbreaks, consider these public health recommendations:
* Avoid domesticated birds. If possible, avoid rural areas, small farms and open-air markets.
* Wash your hands. This is one of the simplest and best ways to
prevent infections of all kinds. When you're traveling, alcohol-based
hand sanitizers containing at least 60 percent alcohol are an excellent
choice. They are effective, easy to use, don't require water and they're
safe for children.
* Ask about a flu shot. Before traveling, ask your doctor about a
flu shot. It won't protect you specifically from bird flu, but it may
help reduce the risk of simultaneous infection with bird and human flu
Poultry and egg products
Because heat destroys avian viruses, WHO officials don't consider cooked
poultry a health threat. Even so, it's best to take precautions when
handling and preparing poultry, which is often contaminated with
salmonella or other harmful bacteria.
* Avoid cross-contamination. Carefully wash cutting boards, utensils
and all surfaces that have come into contact with raw poultry in hot,
* Cook thoroughly. Cook chicken until the juices run clear, and it reaches a minimum internal temperature of 165 F (74 C).
* Steer clear of raw eggs. Because eggshells are often contaminated
with bird droppings, avoid mayonnaise, hollandaise sauce, ice cream, and
any other foods containing raw or undercooked eggs.