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Influenza (flu) is a contagious illness caused by influenza viruses that infect the respiratory tract. The illness can be mild to severe and can be fatal in some people. Although anyone can become infected with influenza, the elderly, young children, or anyone with other health problems are at greater risk from developing more severe illness or suffer from the complications of influenza, such as pneumonia. Every year, more than 36,000 Americans die from influenza-related complications.
Influenza is spread by respiratory droplets from close contact with infected persons or contact with contaminated surfaces or objects. Infection can occur when influenza viruses contact the eyes, mouth, or nose, or through inhaling droplets from a sneeze or cough. Sometimes people may become infected by touching surfaces or objects contaminated with influenza viruses and then touching their eyes, mouth, or nose. Infected persons may be able to spread the virus to others about one day before they develop symptoms and up to five days after becoming sick. That means that you may be able to spread the flu to someone else before you even know you are sick, as well as while you are sick.
Symptoms usually include:
Symptoms usually start about 1-4 days after being exposed and last 2-7 days.
See your health care provider. A health care professional usually diagnoses influenza by reviewing your symptoms and sometimes will collect a nose or throat swab to test for influenza viruses.
Influenza is usually treated by relieving the symptoms with fever reducers, throat or cough drops, water, and plenty of rest. If the diagnosis is made at the very beginning of the illness, a doctor may prescribe antiviral medication.
The best protection is to get a flu shot every year before the flu season starts. Since influenza viruses change over time, it is important to get a shot each year. Each year the vaccine is remade to include the types of flu virus expected to cause illness during that flu season. The vaccine begins to protect you within a few days after vaccination, but the vaccine is not fully effective until about 14 days after vaccination.
Good respiratory hygiene is important to prevent the spread of ALL respiratory infections, including influenza.
Influenza vaccines protect against three different influenza viruses. The vaccine comes in two forms: the flu shot and the nasal spray.
In general, anyone who wants to reduce their chances of getting the flu can get vaccinated. However, certain people should get vaccinated each year either because they are at high risk of having serious flu-related complications or because they live with or care for high risk persons. During flu seasons when vaccine supplies are limited or delayed, the Advisory Committee on Immunization Practices (ACIP) makes recommendations regarding priority groups for vaccination.
People who should get vaccinated each year are:
People who have had a severe allergic reaction to eggs or to a previous flu shot or have had a history of Guillain-Barré syndrome (GBS) should NOT get a flu shot.
Vaccination with the nasal-spray flu vaccine is an option for healthy* people 2-49 years of age who are not pregnant. The one exception is healthy persons who care for persons with severely weakened immune systems who require a protected environment; these healthy persons should get the flu shot. Some people should not be vaccinated without first consulting a physician. They include:
For additional information on influenza, please visit the Centers for Disease Control and Prevention (CDC) Web site at: http://www.cdc.gov/flu/.
Updated on October 17, 2008