Avian influenza

Avian influenza, commonly known as bird flu, refers to a large group
of different influenza viruses that primarily affect birds. Wild birds
can carry the viruses, but usually do not get sick from them. However,
some domesticated birds, including chickens, ducks and turkeys can become
infected, and will often die from the virus. Each year, there is a flu
season for birds just as there is for humans and, as with people, some
forms of the flu are worse than others.

On rare occasions, these avian flu viruses can infect other species,
including pigs and humans. The vast majority of avian flu viruses do
not infect humans. H5N1, the strain of avian flu currently affecting
countries in the Africa, Europe and Asia, has the potential to develop
into a human pandemic, since it might ultimately adapt into a strain
that is spread easily from person to person. Once this adaptation occurs,
it will no longer be a bird virus--it will be a human influenza virus.

Why is public health watching the avian flu so closely?

  • Changes in flu viruses are common. So far, the H5N1 virus has not changed enough to spread easily from person to person.
  • Whenever an avian flu virus infects people, there is a chance that the virus could mutate, or change, to a new virus that spread easily from person to person.
  • Our immune systems would not recognize a new virus, and could have problems fighting it off. That means the new virus could cause serious illness and death.
  • When a new virus is not controlled easily, it could be able to spread rapidly around the world and cause a pandemic.


Can people catch avian flu viruses?

People usually do not become infected with avian flu viruses, but a small number of highly pathogenic avian flu infections from H5N1 have been reported. Many of those infected have died. Most people who were infected with high pathogenic avian flu had very close contact with sick birds.

How does avian flu spread?

Infected birds spread particles of the virus from mouth and nose fluids, and from their droppings. Birds that do not show signs of illness from the disease can spread the virus.

People can be infected with the virus from contact with infected birds or their droppings. This includes contact during plucking, handling or playing with infected birds, or contact with surfaces contaminated with droppings from infected birds.

What are the signs of avian flu in people?

Many of the human cases reported had typical flu symptoms, including fever, cough, sore throat, headache and muscle aches. Some people developed severe pneumonia and some died from respiratory failure.

Is there a test for avian flu?

There are tests for avian flu in birds. Those tests are being used to monitor the spread of H5N1 around the world and to watch for N5N1 in birth in North America. No birds in North America have tested positive for H5N1. There is no routine testing for avian flu in humans in Sonoma County at this time, since there is no avian flu risk, but if a person becomes ill after traveling to an area with known avian flu, the doctor will try to find out whether he or she has been exposed to sick birds.

Is there a flu shot to prevent avian flu?

Not yet. Scientists in several countries are working together to make an effective vaccine to prevent avian flu. Vaccines are made to prevent certain viruses. The flu shot you got in the fall is a formula that prevents the specific types of human flu that are circulating in humans this year -- not avian flu.

What is the treatment for avian flu in people?

Just like most other infections caused by viruses, there is no medicine to cure avian flu. If the illness is caught early, prescription antiviral medicines that are used for the common flu may help shorten the length and decrease the severity of the illness.

Is it safe to travel?

The U.S. Centers for Disease Control and Prevention has not warned Americans to avoid travel to Asia or any other areas where there have been outbreaks of avian flu. Travel recommendations are updated as needed at www.cdc.gov/travel. Travelers to countries with highly pathogenic avian flu should avoid live or dead birds; live bird markets; poultry farms; and bird cages and poultry cooking equipment.