What is Influenza?

Influenza, commonly called "the flu" is caused by viruses that infect the respiratory tract. Influenza infection often causes a more severe illness that such other viral respiratory infections as the common cold. Influenza viruses are divided into three types, designated A, B, and C. Types A and B are responsible for epidemics of respiratory illness that occur almost every winter. Influenza type C usually causes either a very mild respiratory illness or no symtoms at all.

What are the symptoms and how soon do they occur after exposure to an ill person?

Illness will usually begin very suddenly 1-5 days after exposure and commonly lasts for 2-7 days. Most people who get the flu recover completely in 1 to 2 weeks. Rarely, some people develop serious and potentially life-threatening complications, such as pneumonia. This is especially true for "high risk" groups (See below). Influenza symptoms usually include fever, cough, headache, runny or stuffy nose, muscle aches and fatigue. In an average year, influenza is associated with about 20,000 deaths nationwide and many more hospitalizations.

When does influenza occur?

Influenza occurs in the late fall and winter in the United States.

Who can get influenza?

Anyone. Children have the highest rates of infection. Flu-related complications can occur at any age; however, the elderly and people with chronic health problems are more likely to develop serious complications than are younger, healthier people.

How is influenza spread?

Influenza is spread from person to person by coughing and sneezing or by hand contact. Flu viruses can enter the body through the mucous membranes of the eyes, nose, or mouth. The greatest risk of infection is in highly populated areas where people live in crowded conditions, and in schools.

Can you get influenza from domestic pets and animals?

Animals such as pigs, horses and birds can become ill with their own influenza viruses. Pigs have spread their influenza viruses ( known as "swine flu") to people.

Is there a treatment for influenza?

Persons with influenza should rest, drink plenty of fluids and take medication such as aspirin or acetaminophen to relieve fever and discomfort. Children with the flu should not take aspirin because of the risk of complications. Antibiotics are not effective against flu viruses.. Influenza A may respond to treatment with amantadine or rimantadine if taken within 48 hours after the onset of illness. This is not a replacement for the influenza vaccine. Influenza B does not respon to amantadine or rimantadine treatment.

Can you get influenza more than once?

Yes. More than one type of influenza can go around each winter so people can get the flu more than once a year. People will usually get influenza many times in their life.

Is there a vaccine for influenza?

Yes. Different strains of influenza circulate at different times. A new vaccine is issued each flu season. People who need the vaccine should get vaccinated every year. People who are at risk for getting a serious case of influenza or a complication should get the vaccine. This also includes anyone who has close contact with people who are at risk for getting a serious case of influenza and anyone who wishes to avoid getting the flu. The vaccine should be given 6 to 8 weeks before flu season in order to stimulate enough antibodies to prevent infection or reduce the severity of the illness.

How can you prevent the spread of influenza?

Persons who are ill with fever and cough should stay home. They should not go to school or work. They could easily spread to disease to other people. Unfortunately, flu also can be spread by persons whose symptoms are not yet apparent. People should cover their mouth and nose when coughing or sneezing. A safe and effective vaccine is available for persons at high risk or anyone wishing to avoid influenza.

What groups of individuals are at highest risk for complications?

The following are at greatest risk for developing complications from the flu: Persons 65 years and older, persons with chronic lung, heart or kidney disease, asthma, diabetes or a poorly functioning immune system, residents and workers in nursing homes, and health care providers.

How many people get vaccinated against influenza? Nationally, only 30% of persons younger than 65 were vaccinated in l997. During the same year, about 66% of those older than 65 years were vaccinated.