General questions about pandemic flu

Influenza viruses cause infections of the respiratory tract (breathing tubes and lungs). In some persons, complications of influenza can be severe, including pneumonia.

Pandemic influenza is a global outbreak of disease from a new influenza A virus that is unlike past influenza viruses. Because people have not been infected with a similar virus in the past, most or all people will not have any natural immunity (protection) to a new pandemic virus.

A pandemic flu is a new influenza virus that could be a much more serious flu virus than seen in a typical flu season. Different from the typical strains of flu, humans would have no or little natural resistance to a new strain of influenza. As a result, pandemic flu is likely to be more severe, affect more people, and cause more deaths than seasonal influenza.

Also, there is a vaccine for seasonal flu, which is prepared each season against new variations of the seasonal influenza. There is no vaccine available at this time for a pandemic flu, and it is expected to take at least six months after a pandemic flu appears to develop a vaccine.

Because most or all people would not have immunity to a new pandemic virus, large numbers of persons around the world can be infected. If the pandemic virus causes severe disease, many people may develop serious illnesses. Some of those who develop severe influenza will die.

Once a pandemic virus develops, it can spread rapidly causing outbreaks around the world. The U.S. Centers for Disease Control and Prevention (CDC) predicts that as much as 25% to 30% of the US population could be affected. In King County alone, a severe pandemic flu could make 540,000 people ill, 270,000 would need outpatient care, over 59,000 would need hospitalization, and 11,500 could die.

High levels of illness and death during a pandemic could lead to other forms of social and economic disruption. With so many people in so many places becoming ill, caring for the ill, and looking after their children at home, the available workforce will be reduced. Impacts of a pandemic on everyday life may include school and business closings, the interruption of basic services such as public transportation and food delivery, and cancellation of large public gatherings.

Public Health ? Seattle & King County is working with federal, state, and other local government agencies to respond to pandemic influenza and to maintain essential health care and community services if an outbreak should occur. In fact, governments all around the world are preparing for the possibility of a pandemic outbreak under the leadership of the World Health Organization.

It is not possible to prevent or stop a pandemic once it begins. A person infected with influenza virus can be contagious for 24 hours before the onset of symptoms, and for five to seven days thereafter, making it extremely easy for the virus to spread rapidly to large numbers of people.

Although the federal government is stockpiling medical supplies and antiviral drugs, no country in the world has enough antiviral drugs to protect all their citizens. Anti-viral drugs can be used to treat severe cases as long as there was a reasonable chance that the drugs might help save lives. Antiviral drugs might also be prioritized for people who work in essential occupations, such as health care workers.

Other strategies for slowing the spread of a severe influenza outbreak could include temporarily closing schools, sports arenas, theaters, restaurants, taverns, and other public gathering places and facilities.

There currently is no vaccine to protect humans against a pandemic influenza virus because the pandemic virus has not yet fully developed. However, vaccine development efforts are under way to protect humans against a pandemic influenza virus that might develop from the current bird flu virus in Asia. (See information on bird flu below).

Influenza pandemics occur naturally. There were 3 pandemics in the 20th century. The pandemic of 1918-19 was the most severe pandemic on record, in which 50 million or more persons around the world died, including approximately 650,000 Americans.

It is not possible to predict accurately when influenza pandemics will occur or how severe they will be. However, the current outbreak of avian influenza in Asia, Europe, and Africa has influenza experts concerned that a pandemic is developing that may be severe.

New human influenza viruses arise from bird influenza viruses that then change to a form that can infect humans and spread readily from person to person. The current bird flu outbreak in Asia, Europe, and Africa is caused by a type of influenza A virus called ? H5N1.? The H5N1 outbreak among domestic chickens and ducks in Asia is widespread and uncontrolled. Human infections and deaths due to the avian H5N1 virus have occurred. Most of these cases involved direct or close contact with infected birds or surfaces possibly contaminated from feces of infected birds. However, at this time, the virus has not developed the ability to pass easily from person to person and cause outbreaks in humans.

Public Health - Seattle & King County 
Centers for Disease Control and Prevention (CDC)
Get this free guide: Pandemic Influenza Planning: Guide for Individuals and Families. The guide includes checklists and information on how to prepare for a potential pandemic.
For information on the vaccine development process, visit the National Institutes of Health.

Wash your hands frequently.
Wash thoroughly with warm water and soap for 20 seconds.
Make sure to wash your hands before eating, or touching your eyes, nose and mouth.
If caring for ill persons, wash hands after providing assistance.
Always wash your hands after sneezing, blowing your nose, or coughing, or after touching used tissues or handkerchiefs.
If hand washing is not possible, use an alcohol-based hand cleaner.
Avoid touching your mouth, nose and eyes.
When coughing and sneezing, cover your mouth and nose with tissue, or cough and sneeze into your upper sleeve. Put used tissues in the trash.
Don't share items such as cigarettes, towels, lipstick, toys or anything else that might be contaminated with germs.
Don't share food, utensils or beverage containers with others.

See your health care provider as soon as you can if you have a cough and a fever, and follow their instructions, including taking medicine as prescribed and getting rest.
If asked, use a mask when visiting your health care provider.
Visit Public Health's Stop Germs web site for more information and educational materials on stopping germs and staying healthy.