What is the “Flu”?

Influenza (commonly called “the flu”) is a contagious respiratory illness caused by influenza viruses. Infection with influenza can result in illness ranging from mild to severe and life-threatening complications.

Symptoms of Flu

Symptoms of flu include fever (usually high), headache, extreme tiredness, dry cough, sore throat, runny or stuffy nose, and body aches. Gastro-intestinal symptoms, such as nausea, vomiting, and diarrhea, are much more common among children than adults.

Spread of Flu

The main way that influenza viruses are spread is from person to person in respiratory droplets of coughs and sneezes. This can happen when droplets from a cough or sneeze of an infected person are propelled (generally up to 3 feet) through the air and deposited on the mouth or nose of people nearby. In the northern hemisphere, winter is the time for flu. In the United States, the flu season can range from November through March and even past March in some years.

Preventing Flu

Vaccination: The single best way to prevent the flu is to get vaccinated each fall. In the absence of vaccine, however there are other ways to protect against flu. The influenza vaccine is formally recommended for all children 6 to 23 months of age. To produce a good response the first year that they get it, children under nine years of age need two doses of the vaccine given at least one month apart. Children over nine years and younger children who have previously had a flu shot only need a single injection each year.

Side effects: Vaccine side effects are usually mild, and may include soreness, redness or swelling where the shot was given, fever, and/or aches, and usually only last for 1-2 days. More serious side effects can rarely include a life-threatening allergic reaction.

Intra-nasal vaccine: FluMist, a nasal spray flu vaccine (no shots), has been approved and is ready to be given to healthy children and adults from age 5 to 49 years.

Antiviral Medications: Three antiviral drugs (amantadine, rimantadine and oseltamivir) are approved and commercially available for use in preventing flu. All of these medications are prescription drugs, and a doctor should be consulted before the drugs are used for preventing the flu.

Other habits for Good Health

The following steps may help prevent the spread of respiratory illnesses like flu:

• Avoid close contact
• Stay home when you are sick
• Cover your mouth and nose
• Clean your hands
• Avoid touching your eyes, nose or mouth

Diagnosing the Flu

Tests are available that can determine if you have the flu as long as you are tested within the first 2 or 3 days after your symptoms begin. In addition, a doctor’s examination may be needed to determine whether a person has another infection that is a complication of the flu.

Who is at special risk for complications?

Certain people are at increased risk for serious complications from the flu. This group includes people age 65 years and older and people of any age with chronic medical conditions. Pregnant women and children between 6 months and 23 months of age also are at increased risk from flu complications.

Complications from Flu

Some of the complications caused by flu include bacterial pneumonia, dehydration, and worsening of chronic medical conditions, such as congestive heart failure, asthma, or diabetes. Children may get sinus problems and ear infections.

Treating the Flu

Antiviral Medications: Four antiviral drugs (amantadine, rimantadine, zanamavir and oseltamivir) have been approved for treatment of the flu. All of these must be prescribed by a doctor. Antiviral treatment lasts for 5 days and must be started within the first 2 days of illness.

What to do if You Get Sick This Flu Season

If you develop the flu, it is advisable to get plenty of rest, drink a lot of fluids, and avoid using alcohol and tobacco. Also, you can take medications to relieve the symptoms of flu (but never give aspirin to children or teenagers who have flu-like symptoms – and particularly fever – without first speaking to your doctor.)

If, however, your flu symptoms are unusually severe (for example, if you are having trouble breathing), you should consult your health-care provider right away.

The Myth of the “Stomach Flu”

Many people use the term “stomach flu” to describe illnesses with nausea, vomiting, or diarrhea. These symptoms can be caused by many different viruses, bacteria, or even parasites. While vomiting, diarrhea and being nauseous or “sick to your stomach” can sometimes be related to the flu – particularly in children – these problems are rarely the main symptoms of influenza. The flu is a respiratory disease and not a stomach or intestinal disease.

Sources: CDC (Center for Disease Control and Prevention) and Pediatrics at About.com

Updated: December 28, 2004