Influenza

What is influenza?

Influenza is a common and highly contagious respiratory illness caused by a virus. Various strains of the virus circulate throughout the world year-round and cause local outbreaks. In Canada, influenza season usually runs from November to April and an estimated 10-25% of Canadians get influenza each year. An estimated 6,700 Canadians die annually from influenza related complications and approximately 70,000 to 75,000 people are hospitalized.

How is it spread?

Influenza is spread through droplets that an infected person coughs or sneezes into the air. You can get the influenza by breathing in these droplets through your nose or mouth, or by the droplets landing directly on your eyes. The influenza virus is also found on the hands of people with influenza and on surfaces they have touched. It can survive outside the body on unwashed hands for 5 minutes, on tissues or clothing for 8-10 hours and on hard surfaces, such as tables and telephones, for 2 days. You can become infected if you shake hands with an infected person or touch a contaminated surface and transfer the virus to your own eyes, nose or mouth.

When is someone infectious?

Influenza takes 1-4 days to incubate in humans, but infected people become contagious before symptoms appear, often just the day after the virus enters the body. Adults remain infectious and they can spread the virus to others for about 6 days. Children can remain infectious for up to 10 days.

What are the symptoms?

A case of influenza typically starts with a headache, chills and cough, which are followed rapidly by fever, loss of appetite, muscle aches, fatigue, runny nose, sneezing, watery eyes, and throat irritation. Children may have nausea, vomiting and diarrhea but these symptoms are uncommon in adults.

How long will it last?

Symptoms of influenza generally last a week to ten days. But can last for up to one month. Some people are at greater risk for more severe complications.

How can I tell if it’s a cold or influenza?

Many people use the terms “flu” or “stomach flu” to describe other illnesses that may actually be a cold or a mild case of food poisoning. There is no such thing as “stomach flu”. Although the common cold is also caused by a virus, influenza and the common cold differ in several ways.

What precautions can I take to prevent becoming infected with influenza?

• Get the influenza shot (vaccination) every fall. It takes 2 weeks for the vaccine to become effective.
• Stay away from people sick with influenza. 
• Wash your hands regularly with soap and water to prevent both picking up and spreading the virus.

What should I do if I get influenza?

• Resting will provide comfort and allow your body to use its energy to fight the infection because you will probably feel very weak and tired until your temperature returns to normal.
• Drink plenty of fluids because they are needed to replace lost fluids because of fever. Warm liquids can help loosen mucus.
• Gargle with a glass of warm water to ease a sore throat. Sugarless hard candy or lozenges may also help.
• Do not smoke because it is very irritating to the damaged airways.
• Take medication recommended by your doctor to reduce fever and relieve aches and pains. If you buy over-the-counter medication at the drug store to treat your symptoms, check with the pharmacist to see if it’s the best one for you. Mention if you have a chronic illness or are taking any other medicine.
• Antibiotic treatment is not necessary in cases of viral respiratory infection, but may be required to treat bacterial infections, which occasionally complicate influenza-like illness, such as pneumonia.
• Antiviral medications can be prescribed to high risk patients to help shorten the disease.
• If you sneeze, blow your nose or cough use a tissue to smother it and immediately dispose of the tissue and wash your hands. The force of sneezing into a tissue will still allow the virus to pass through the tissue onto your hands. Tissues are for single use only, which means one sneeze, cough or nose blow only and then throw it out. If a sneeze or cough is coming and you do not have a tissue, turn your face into your shoulder or elbow. This is a referred to as a “guarded” sneeze and forces the germs into your sleeve or clothing and not out into the environment where other people are exposed. 
• If you are ill, stay home to avoid spreading the influenza virus to others. If you continue to work and socialize you can spread the virus to others who then become ill and spread the virus to their family and friends, who in turn pass it on to others. The circle of infection is repeated over and over.
• Do not visit friends or relatives in a hospital or long-term care facility if you have influenza.
• Do your best to avoid infants, people over 65 and individuals with chronic health problems because they are more susceptible to serious complications of influenza.

Where can I go for more information?

The following web sites provide information on influenza or you can contact Public Health at 376-9420 or 1-800-263-3456.

• Health Canada’s Influenza Information Web: http://www.hc-sc.gc.ca/dc-ma/influenza/index-eng.ph

• Ontario Ministry of Health and Long Term Care: www.healthyontario.com
• World Health Organization – Influenza: http://www.who.int/topics/ininfluenzaenza/en/
• Grey Bruce Health Unit for antiviral medication facts: www.publichealthgreybruce.on.ca