Flu (Influenza) Facts

What is the flu (influenza)?
Influenza is a virus. There are three types of influenza viruses (A, B, and C). Influenza types A and B cause respiratory illnesses.

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. Symptoms usually include fever, cough, headache, muscle aches, and fatigue.

When does influenza occur?
Influenza occurs in the late fall and winter in the United States.

Who can get influenza?
Anyone. Persons at highest risk for severe illness are the elderly, the very young, pregnant women, and those with chronic medical problems such as heart or lung conditions, diabetes, or trouble with their immune system.

How is influenza spread?
Influenza is spread by air droplets from an ill person to other people generally by coughing and sneezing.

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 and drink lots of fluids. Early treatment with antiviral medications may be helpful. This is not a replacement for the influenza vaccine.

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 be vaccinated every year. People who are at risk for getting a serious case of influenza or a complication should get the vaccine. The vaccine may not prevent someone from getting the flu, but it can lessen the severity of symptoms. It takes about 2 weeks to build up antibodies after receiving the vaccine.

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 the disease to other people. People should cover their mouth and nose when coughing or sneezing. A safe and effective vaccine is available, especially for persons at high risk (listed above) or anyone wishing to avoid influenza. Because the virus may change slightly from year to year the vaccine is changed each year and should be received each influenza season. For more on prevention click here.