Bird Flu Resources

What is bird flu?

Bird flu, or avian influenza, is a disease that occurs naturally in wild and domestic birds, caused by influenza viruses. The avian flu virus that is of most concern now is the H5N1 subtype, which is spreading across Asia, Africa and Europe. H5N1 is very contagious among birds and is likely being spread by migratory birds. Avian influenza viruses do not usually infect humans, but the H5N1 strain does.

Why is it a threat to humans?

The danger of avian flu is that the influenza virus could develop into a new strain that could be easily transmitted among humans. This might happen because the virus mutates. Or, the virus might recombine with elements of the more common seasonal influenza viruses in humans. Because humans would have little or no immune protection against this new strain, it could easily be spread from person to person, causing a global outbreak, or “pandemic.”

Have humans contracted avian flu?

More than 100 cases of H5N1 infections in humans have been reported, most of them in Southeast Asia. Other cases have also been reported in Europe and Africa. More than half of the people who were sick have died. For current information on human cases, please visit the World Health Organization’s webpage:
www.who.int/csr/disease/avian_influenza/country/en/index.html

How is avian flu spread?

Many of the people infected by H5N1 probably picked up the virus through contact with domestic birds, either directly or by touching surfaces containing the birds’ secretions. In humans, flu viruses are found in respiratory fluids and are spread, for example, by coughing and sneezing.

What are the symptoms of avian flu in humans?

According to the Centers for Disease Control and Prevention, the reported symptoms of avian influenza in humans have ranged from typical influenza-like symptoms (such as fever, cough, sore throat, and muscle aches) to eye infections, pneumonia, acute respiratory distress, viral pneumonia, and other severe and life-threatening complications.

Flu is usually more of a nuisance (like a cold) than a life-threatening disease. What makes avian flu so dangerous?

Avian flu should not be confused with seasonal, or “common,” flu. Most people have some immunity to some strains of the flu, and a vaccine is available. People have not developed any immunity to avian flu, which is a key reason for why it’s so dangerous. Scientists are still trying to determine how H5N1 makes people sick. One way they are doing this is by studying other viruses, such as the Spanish flu virus, which was closely related to avian flu viruses and caused millions of human deaths in 1918.

Will bird flu cause the next influenza pandemic?

Influenza pandemics occurred three times during the last century, and many health officials believe H5N1 has the potential to cause the next pandemic. It is still impossible to predict, however, exactly when a pandemic might occur, how severe it might be or which flu virus might cause it.

Why is it so hard to predict an influenza pandemic, especially if we already have influenza drugs and vaccines?

Influenza viruses evolve extremely quickly, and the changes that would allow a bird flu virus to spread easily from human to human are complex and poorly understood. We don’t know how quickly a new strain would travel through the human population or how soon it might become resistant to available drugs. The vaccines used for one flu virus are not effective against other strains, particularly strains that have not circulated before among humans. In fact, a vaccine can only be developed after the new strain has appeared and been isolated. This process can often take up to six months, with even longer times required to mass produce the vaccine.

Who is likely to be most vulnerable to pandemic flu?

It’s very difficult to say who will be most affected by a pandemic, since this depends on many variables, including how prepared a particular community is. According to the National Vaccine Advisory Committee and the Advisory Committee on Immunization Policy, it’s likely that the greatest risk of hospitalization and death will be in infants, the elderly and those with underlying health conditions, as was the case during the influenza pandemics of 1957 and 1968. However, the 1918 Spanish flu also disproportionately affected young people with healthy immune systems.
www.hhs.gov/pandemicflu/plan/appendixd.html

How will we deal with a pandemic if it occurs?

Potential approaches include careful monitoring and surveillance in order to detect new cases early, treatment with antiviral drugs, development and distribution of vaccines, “social distancing” (closing schools and workplaces, canceling events, etc.), quarantining people who are sick or who have been exposed to the virus, and restricting travel.

In November, 2005, U.S. President George W. Bush announced a “National Strategy for Pandemic Influenza,” and in May 2006 the White House released the “Implementation Plan for the National Strategy for Pandemic Influenza,” which outlines how the federal government is preparing for a pandemic. For more information, please visit:
www.whitehouse.gov/homeland/pandemic-influenza-implementation.html

What does AAAS say about the White House plan?

AAAS welcomes the attention to this threat shown by both the Administration and Congress, which have dedicated significant funding for preparedness and prevention activities. The Administration’s recently released plan provides a valuable first step toward preparing the United States to prepare for and respond to a pandemic. In addition, this plan and its implementation should evolve as the underlying science improves and we learn more learn more about the virus and its mechanisms for transmission.

What are we doing to treat infected birds or to stop the virus from spreading among birds?

Culling infected or exposed birds is an important early step. Mass vaccination is another line of defense. A third approach, known as “biosecurity,” involves keeping bird populations separate and away from humans and other animals.

Where can I get information about staying safe during an influenza pandemic?

For safety and other public health information, please visit:
The Department of Health and Human Services (www.pandemicflu.gov)
The Centers for Disease Control and Prevention (www.cdc.gov/flu/)
The World Health Organization (www.who.int/csr/disease/avian_influenza/en/index.html)

Where can I get more information about the science of avian flu?

More information is available to AAAS members/Science subscribers:
www.sciencemag.org/marketing/influenza