HealthLink BC File #12b, November 2009

Facts about Seasonal Influenza (the Flu)

• What is influenza?
• How can influenza be prevented?
• How is influenza spread?
• What are the symptoms?
• Home Treatment
• When should I see a doctor?
• Is it influenza or a cold?

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What is influenza?

Influenza, often called the ‘flu’, is an infection of the nose, throat and lungs caused by an influenza virus.

A person with influenza is also at risk of other infections. These include viral or bacterial pneumonia, an infection of the lungs. The risk of complications is greater for seniors 65 years and older, very young children, and people who have lung or heart diseases, certain chronic health problems, or weakened immune systems. Healthy pregnant women in the second half of their pregnancy are at greater risk of being hospitalized following infection with seasonal influenza virus.

In Canada, it is estimated that between 2,000 to 8,000 people die from seasonal influenza and its complications every year.

How can influenza be prevented?

You can reduce the risk of catching influenza, or spreading it to others, by:

• washing your hands regularly.
• disposing of tissues properly.
• coughing and sneezing into your shirt sleeve rather than your hands.
• staying home when ill.
• getting the influenza vaccine.

The seasonal influenza vaccine, also known as the flu shot, can help prevent you from getting sick with influenza or from spreading it to others. In addition to the seasonal influenza vaccine, a separate vaccine for pandemic H1N1 influenza is available. For more information on these vaccines, see the following HealthLink BC Files #12d Seasonal Influenza (Flu) Vaccine and #108b Pandemic H1N1 (pH1N1) Influenza Vaccine.

How is influenza spread?

Influenza spreads easily from person to person through coughing, sneezing, or close face-to-face contact. The virus can also spread when a person touches tiny droplets from coughs or sneezes on another person or object and then touches their face before washing their hands.

An adult can spread the virus from about 1 day before to 5 days after symptoms start. Children can spread the virus up to 21 days after symptoms start.

What are the symptoms?

Influenza symptoms can include fever, headache, muscle pain, runny nose, sore throat, extreme tiredness, and cough. Children may also experience nausea, vomiting, or diarrhea. Although colds and other viruses may cause similar symptoms, those due to the influenza virus tend to be worse.

Symptoms can begin about 1 to 4 days, or an average of 2 days, after a person is first exposed to the influenza virus. Fever and other symptoms may last up to 7 to 10 days, with the cough and weakness lasting up to two more weeks.

Home Treatment

If you do get sick with influenza or the flu, home treatment can help to ease symptoms. Home treatment may include:

• Get plenty of rest. Bed rest will also help you avoid spreading the virus to others.
• Drink plenty of extra fluids to replace those lost from fever.
• Avoid smoking and breathing other people's smoke.
• Breathe moist air from a hot shower or from a sink filled with hot water to help clear a stuffy nose.
• Anti-influenza drugs or antivirals are available by prescription, but these must be started early. They will shorten symptoms by about 3 days if given within 12 hours and by about 1.5 days if given within 2 days of the start of symptoms. Over-the-counter medications can help relieve symptoms such as pain and fever. These are not recommended for children under 6 years of age. Non-prescription influenza remedies are also available at the pharmacy.

When should I see a doctor?

If you believe that you have a condition that puts you at higher risk for complications,
consult your doctor early if you develop flu-like symptoms. Antiviral medication is most effective if given within 48 hours of symptom onset, and the sooner the better. You should also call your doctor if you notice worsening symptoms, such as shortness of breath or difficulty breathing, chest pain, or signs of dehydration (dizziness when standing, low urine output).

Is it influenza or a cold?

The following table can help you determine whether you have influenza or a cold.

For more information, see the following HealthLink BC Files:

#12a Why Seniors Should Get the Influenza (Flu) Vaccine

#12c Influenza (Flu) Immunization: Myths and Facts

#12d Influenza (Flu) Vaccine

#85 Hand Washing for Parents and Kids

Complete List of HealthLink BC File Topics