Bird Flu (Avian Influenza): Common Questions and Current Answers
June 2007*
Part 1: About Bird Flu
Are influenza (the flu) and avian influenza (bird flu) the same thing? What’s the
difference?
The flu is a contagious respiratory illness caused by influenza viruses. It can cause mild
to severe illness, and can sometimes lead to death. Young children, the elderly and
people with certain health conditions, are at highest risk for serious flu complications. The
best way to prevent this illness is by getting a flu vaccination each fall.
The flu is reasonably common in the United States. In the average year:
5 percent to 20 percent of the population gets the flu.
more than 200,000 people are hospitalized from flu complications.
about 36,000 people die from flu.
Bird flu is an infection caused by avian (bird) influenza (flu) viruses. These flu viruses
occur naturally among birds. Wild birds worldwide carry the viruses in their intestines,
but usually do not get sick from them. However, bird flu is very contagious among birds and can
be fatal to domesticated birds, including chickens, ducks and turkeys.
While both conditions are respiratory illnesses caused by Type A influenza viruses, they are not
the same. There are many different subtypes of “Type A” influenza viruses.
When we talk about “bird flu” viruses, we are referring to influenza A subtypes chiefly
found in birds, which do not usually infect humans.
No. However, if you have been vaccinated against the flu and develop flu-like symptoms, your
treating physician may be able to diagnose bird flu more quickly and treat you accordingly.
The same steps that can protect you from the common cold should be taken to protect you from the
flu and even from bird flu. See Part 3: Important Ways To Prevent Contagious
Respiratory Illnesses.
Infected birds shed flu virus in their saliva, nasal secretions and feces. Susceptible birds
become infected when they come in contact with contaminated excretions or surfaces that are
contaminated with excretions. It is believed that most cases of bird flu infection in humans have
resulted from contact with infected poultry or contaminated surfaces.
The World Health Organization does not consider bird flu a food-borne disease, and no evidence
exists to suggest that people are likely to become infected from eating properly cooked
poultry. People who handle infected poultry are most at risk.
If a person is infected with bird flu, how contagious is he or she to other
humans?
The spread of avian influenza viruses from one ill person to another has been reported but is
still considered a very rare event. The question of why transmission appears to be limited is
still being analyzed. Until more is known, avoiding exposure to sick people and taking steps to
avoid respiratory illnesses (see Part 3) are excellent preventive measures.
Symptoms of bird flu in humans have ranged from typical flu-like symptoms (fever, cough,
shortness of breath, diarrhea, sore throat and muscle aches) to eye infections, pneumonia,
severe respiratory diseases (such as acute respiratory distress), and other severe and
life-threatening complications. The symptoms may depend on which bird-flu strain a victim is
exposed to, but the current mortality rate appears to be high.
To most people, the risk from bird flu is generally low because the viruses occur mainly among
birds and do not usually infect humans. However, during an outbreak of bird flu among
poultry (domesticated chicken, ducks, turkeys), there is a possible risk to people who have
contact with infected birds or surfaces that have been contaminated with excretions from
infected birds.
The first known case of bird flu in a human was seen in 1997 during an outbreak of bird flu in
poultry in Hong Kong. The virus caused severe respiratory illness in 18 people, 6 of
whom died. Since that time, there have been other cases of bird flu infection among
humans.
Recent human cases of bird flu infection that have occurred in Azerbaijan, Cambodia, Djibouti,
Egypt, Iraq, Thailand, China, Vietnam, Indonesia, the Lao People’s Democratic Republic
(Laos), Nigeria and Turkey have coincided with bird flu outbreaks in poultry. No human cases have
been reported in the United States. The World Health Organization’s web site is a
good reference for updates (http://www.who.int/csr/disease/avian_influenza/en
/).
While the risk of infection among humans remains very low, more than 50 percent of those who have
been infected have died. Most of these cases have occurred from direct contact with
infected poultry or contaminated surfaces. Data from such incidences suggests that human-to-human
transmission requires very close contact with an ill person, usually with a family
member. So far, spread of bird flu virus from person to person has been rare.
Why are health officials warning about an avian-flu pandemic?
The warnings stem from the fact that all influenza viruses have the ability to change. That is
why a new formulation of flu vaccine must be developed each year. Scientists are concerned
that the bird flu virus could one day infect humans and spread easily among us. Because these
viruses do not commonly infect humans, there is little or no immune protection against
them in the human population. If the bird flu virus were able to become highly contagious in
humans, an influenza pandemic could begin. An influenza pandemic is a global outbreak of
disease that occurs when a new influenza A virus appears or “emerges” in the human
population, causes serious illness, and then spreads easily from person to person
worldwide. Past influenza pandemics have led to high levels of illness, death, social disruption,
and economic loss and no one can predict when a pandemic might occur. Experts from
around the world are watching the bird flu situation in Asia very closely and are preparing for
the possibility that the virus may begin to spread more easily and widely among
humans.
What is the risk to people who live and work in the United States from the bird flu outbreak
in Asia and Europe?
The current risk to Americans, as of this date, from the bird flu outbreak in Asia and Europe is
low. The highly pathogenic strain of bird flu virus found in Asia and Europe has
not been found in the United States. There have been no human cases of bird flu in the
United States.
Is there a vaccine to protect humans from bird flu virus?
There currently is no commercially available vaccine to protect humans against the bird flu virus
that is being seen in Asia and Europe. However, vaccine development efforts are taking
place. Research studies to test a vaccine to protect humans against bird flu virus began in April
2005, and clinical trials are under way. Avian-flu vaccines developed by several vaccine
manufacturers are undergoing preliminary testing by the U.S. government, and the National
Institute of Allergy and Infectious Diseases. An experimental bird flu vaccine is available
and is being procured and stored in the national vaccine stockpile. A universal vaccine that would be effective against all
types of influenza is under development in the U.K. and other countries.
Laboratory studies suggest that the prescription medicines approved for human flu viruses
should work in other types of flu infections in humans. Four different influenza
antiviral drugs (amantadine, rimantadine, oseltamivir, and zanamivir) are approved by the U.S.
Food and Drug Administration (FDA) for the treatment and/or prophylaxis of
influenza.
However, two of these medications (amantadine and rimantadine) have not been effective against
the current strain of bird flu virus when used to treat humans infected by it in Asia. At
this time, the World Health Organization considers oseltamivir (TAMIFLU) the treatment of choice
for bird flu in humans. Zanamivir might be used as an alternative.
Before any international travel to an area affected by avian influenza
Visit CDC's Travelers’ Health Web page on Southeast Asia at http://www.cdc.gov/travel/seasia.htm to educate yourself and
others traveling with you about any disease risks and CDC health recommendations for travel in
areas you plan to visit. For a list of affected areas and other information about avian
influenza, see this website: http://www.cdc.gov/flu/avian/index.htm.
Be sure you are up to date with all your vaccinations, and see your doctor or health care
provider, ideally four to six weeks before travel, to get any additional vaccination,
medications or information you may need.
The anti-viral medication oseltamivir (TAMIFLU) may be effective in preventing or treating
avian influenza. These medications may not be readily available overseas and the U.S.
State Department encourages American citizens traveling or living abroad to consult with their
physician regarding use of these medications. There is no provision for the U.S.
government to provide American citizens traveling or living abroad with medications, including in
the event of a pandemic.
Assemble a travel health kit containing basic first aid and medical supplies. Be sure to
include a thermometer and alcohol-based hand gel for hand hygiene.
Identify in-country health care resources in advance of your trip.
Check your health insurance plan or get additional insurance that covers medical evacuation
in case you become sick.
During international travel to an area affected by avian influenza
In addition to the methods noted in Part 3 to prevent respiratory illnesses, specific
measures are important to minimize the risk of bird flu.
Avoid all direct contact with poultry, including touching well-appearing, sick, or dead
chickens and ducks. Avoid places such as poultry farms and bird markets where live poultry
are raised or kept, and avoid handling surfaces contaminated with poultry feces, feathers or secretions.
As with other infectious illnesses, one of the most important preventive practices is careful
and frequent hand washing with soap and water to remove potentially infectious material
from your skin and help prevent disease transmission. Waterless alcohol-based hand gels may be
used when soap is not available and hands are not visibly soiled.
If you become sick with symptoms such as a fever, difficulty breathing, or cough, or with any
illness that requires prompt medical attention, a U.S. consular officer can assist you in
locating medical services and informing your family or friends. Inform your health care provider
of any possible exposures to avian influenza.
When preparing food, it is important to follow good hygiene practices, regardless of where
you are. However, it is particularly important to keep the following in mind when cooking
and dining in areas impacted by bird flu:
Influenza viruses are destroyed by heat; therefore, as a precaution, all foods from poultry,
including eggs and poultry blood, should be thoroughly cooked.
Separate raw meat from cooked or ready-to-eat foods. Do not use the same chopping board or
the same knife for preparing raw meat and cooked or ready-to-eat foods.
Do not handle either raw or cooked foods without washing your hands in between.
Do not place cooked meat back on the same plate or surface it was on before it was cooked.
All foods from poultry, including eggs and poultry blood, should be cooked thoroughly. Egg
yolks should not be runny or liquid. Because influenza viruses are destroyed by heat, the
cooking temperature for poultry meat should reach 70°C (158°F).
Wash egg shells in soapy water before handling and cooking, and wash your hands afterwards.
Do not use raw or soft-boiled eggs in foods that will not be cooked.
After handling raw poultry or eggs, wash your hands and all surfaces and utensils thoroughly
with soap and water.
Part 3: Important Ways To Prevent Contagious
Respiratory Illnesses
The flu is a contagious respiratory illness caused by influenza viruses. The best way to prevent
this illness is by getting a flu vaccination (shot) each fall. In addition to getting a flu shot,
there are steps we all can take to protect everyone at home, school or work from getting the flu.
These include:
Avoid close contact with people who are sick.
If you are sick, avoid exposing others, especially high-risk individuals. Keeping your
distance from others when sick can protect them from getting sick.
Cover your mouth and nose with a tissue when coughing or sneezing, and then throw it away.
Also recommended is covering your mouth with your sleeve.
Wash your hands often, especially after coughing or sneezing, before and after food
preparation and eating, after bathroom use, after handling animals and animal waste, when your
hands are dirty, and more often when someone at home is sick.
Teach and remind children to do the same.
Use soap and warm water for 15 to 20 seconds (the time it takes to sing Happy Birthday
twice!)
When soap and water are not available, alcohol-based disposable hand wipes or gel sanitizers
may be used.
Take medication to relieve the symptoms of flu, but never give aspirin to children or
teenagers who have flu-like symptoms – and particularly fever – without first speaking
to your doctor.
Adapted from Centers for Disease Control and Prevention Avian Influenza Fact Sheets. Other Sources include World Health Organization, The Wall Street Journal and The New England Journal of Medicine.
*This information is subject to change based on clinical and other scientific information that may result from research into avian flu, and on any government recommendations or requirements that may be made.
Overview
