Questions and Answers about Avian Influenza (Bird Flu) and Human Illness

Updated: September 2008

What is avian influenza (bird flu)?

Avian influenza, also called bird flu, is a disease of birds, usually wild ducks and geese. Sometimes, this disease can also spread from wild birds into domestic poultry. Although bird flu and human flu are both caused by influenza viruses, each virus generally affects either birds or people, not both.

What is seasonal human flu?

Seasonal flu is a contagious respiratory illness caused by human influenza viruses. It can cause mild to severe illness and at times can lead to death. Human flu viruses change a little bit every year which is why people can get sick from the flu more than once. It is also why a new flu vaccine is produced each year; the vaccine must be made to protect against the particular viruses circulating that year.

What is a pandemic?

Rarely, the influenza virus undergoes a major change that results in a completely new virus. If the new virus spreads easily from person to person it is called a pandemic. Bird flu is not the same as pandemic flu. All human influenza pandemics in the past have been caused by human influenza viruses. It is possible that a bird flu virus may adapt to humans leading to a pandemic, however just the presence of a bird flu virus does not indicate a pandemic.

Is highly pathogenic H5N1 the same as bird flu?

Like human influenza viruses, there are many types of avian influenza viruses. One strain of severe bird flu, called highly pathogenic H5N1, has been circulating in Asia since 1997 and has more spread to Europe and Africa.

What does highly pathogenic mean?

Avian influenza viruses are categorized based on their genetic makeup, impact on bird health and other factors as being either "high pathogenic avian influenza" (HPAI) or "low pathogenic avian influenza" (LPAI). Most avian flu viruses found in wild ducks and geese are categorized as LPAI and do not cause obvious illness in infected birds. Some of these will mutate into highly pathogenic forms which cause severe clinical illness and death in birds, particularly poultry species.

Why is bird flu getting so much attention right now?

The highly pathogenic H5N1 virus has caused more concern than other bird flu viruses because:

  • The mortality (death) rate is high among confirmed human cases;
  • A few cases of person-to-person spread have been reported;
  • The disease has continued to occur despite control efforts, and has spread to other regions of the world;
  • The disease has been transmitted from birds to non-human mammals;
  • Genetic studies confirm that the virus is continuing to change, raising the concern that it could evolve into a virus that can spread easily from person to person.

The highly pathogenic H5N1 virus is not currently causing a human influenza pandemic. However, these characteristics have raised concerns about the potential for a pandemic to occur.

How are people getting sick from the highly pathogenic H5N1 strain of bird flu?

The highly pathogenic H5N1 virus is found in the saliva, nasal discharges and feces of infected birds. In countries where this disease is found, families frequently raise birds for their own meals, and ducks and chickens often roam freely and contaminate the neighborhood. Human infections have occurred as a result of direct, prolonged contact with infected birds or heavily contaminated environments, and from slaughtering and preparing infected birds for food. At this time the virus is not easily spread from person to person. If it starts spreading from person to person more readily, the way human flu viruses do, it could become a major threat to public health.

How is the highly pathogenic H5N1 strain of bird flu spreading from place to place?

Healthy birds become infected from direct contact with sick birds, or contact with areas or objects contaminated by sick birds. Much of the spread is probably a result of movement of infected live birds and products to and from markets. Wild birds may also have the virus but do not always get sick. If they are infected but not sick, they might be able to spread the virus to new areas when they migrate.

Do we have avian influenza in New York State?

LPAI virus strains are commonly found in wild birds and sometimes in domestic poultry in the United States. These mild strains of avian influenza usually affect small numbers of birds and generally do not cause obvious illness. LPAI viruses are not considered a human health risk. The New York State Department of Agriculture and Markets (NYSDAM) performs routine monitoring for avian influenza in live poultry markets and commercial and backyard poultry farms. When any avian influenza is found in poultry, the NYSDAM takes action to eliminate the virus.

The New York State Department of Environmental Conservation performs routine monitoring for avian influenza in wild birds. There have been no HPAI strains of bird flu found in New York. The HPAI H5N1 virus currently affecting birds in Asia and Europe has not been found anywhere in North or South America.

Is anything being done to prevent the highly pathogenic H5N1 strain of bird flu from spreading to New York State?

The risk of highly pathogenic H5N1 bird flu arriving in New York is reduced by federal laws restricting bird imports from affected countries, and by NYSDAM surveillance and control procedures. It is illegal to import poultry or poultry products from countries that are affected by this disease.

What can I do to protect myself and my family from bird flu viruses?

The highly pathogenic H5N1 virus does not currently pose a risk to people living in the United States. Unless this virus changes so that it spreads easily from person to person, it is not likely to become a significant threat to people living in the U.S. If the highly pathogenic H5N1 virus ever gets into the U.S., any precautions necessary to prevent human infection will be publicized by the appropriate authorities.

There are general precautions that can be taken to reduce the chance of getting sick from any disease carried by animals:

  • Wash hands after contact with animals;
  • Avoid contact with animals that appear to be sick, including birds;
  • Thoroughly cook eggs and meat prior to eating, and wash all utensils and preparation areas thoroughly with soap and hot water;
  • Wash hands frequently when preparing food;
  • Owners of domestic livestock, including poultry and waterfowl, should contact their local veterinarian if any of their animals appear sick;
  • Hunters should hunt and process only healthy-appearing animals and should wear gloves when handling any animal.

What can I do to protect myself and my family from bird flu viruses if I am traveling to another country?

Persons traveling internationally to countries where outbreaks of highly pathogenic H5N1 are occurring should avoid poultry farms, contact with animals in live food markets, and any surfaces that appear to be contaminated with feces from poultry or other animals. More health information for travelers is available from the Centers for Disease Control and Prevention at:

Will the flu shot protect me against the highly pathogenic H5N1 strain of bird flu?

The flu shot for humans protects against the current human flu viruses, not bird flu viruses. A vaccine is being developed against HPAI H5N1 bird flu in case it changes and becomes a threat to humans, but it is not currently available.

Should I ask my doctor for a prescription anti-flu drug?

Tamiflu® and other antiviral drugs are usually used to treat people who are at risk for developing life-threatening complications from the flu. There is no reason to routinely ask for one of these drugs to keep at home. Over-use could result in limited supplies for those who need it most. In addition, over-use in other countries has already caused the bird flu virus to develop some resistance to one drug, and continued over-use may cause more problems. Finally, all drugs, including antivirals, can cause side effects and should only be used when necessary under the direction of a health care provider.

How are we preparing for any outbreak of bird flu or a potential pandemic?

NYSDAM and the United States Department of Agriculture have prevention and preparedness programs in place to deal with any outbreak of avian influenza in poultry.

Because scientists cannot predict if HPAI H5N1 will cause a pandemic, federal, state and local governments and others are focusing on comprehensive public health efforts – increased monitoring for outbreaks, international cooperation, antiviral and vaccine stockpiles, and building capacity for vaccine production – that will help protect us no matter when or where a pandemic strain emerges.