Influenza
Seasonal influenza, commonly known as the flu, is an infection in the airways caused by the influenza virus. It’s called 'seasonal' influenza because the virus circulates annually in the winter season in Canada.
In addition to seasonal influenza, you have probably heard about avian influenza and pandemic influenza. It is important to understand the differences.
Seasonal influenza is a contagious respiratory illness caused by the influenza virus. It is easily caught and easily spread. Influenza typically starts with a headache, chills and cough, followed rapidly by fever, loss of appetite, muscle aches and fatigue, running nose, sneezing, watery eyes and throat irritation. Nausea, vomiting and diarrhea may also occur, especially in children. Influenza also lowers the body's ability to fight off other infections which can lead to pneumonia, bronchitis or other complications. In addition, influenza can worsen a current medical condition such as diabetes, lung disease, heart disease, kidney disease or cancer. Between 4000 and 8000 Canadians can die of influenza and its complications annually, depending on the severity of the season.
More information on seasonal influenza:
- Flu, You and What to Do
- What's the Difference? A cold and the flu.
- Influenza Immunization Resources for the Public
- Resources on Thimerosal
- Influenza Immunization Resources for Health Care Providers
- Public
Funding for Influenza Immunization in Canada table
- FAQs
- Kids and Students!
- FluWatch: Influenza Activity in Canada
- Flu in the Workplace
Avian influenza, or bird flu, is caused by avian influenza viruses which occur naturally in birds. It is a contagious viral infection that can affect all species of birds but can, less commonly, infect mammals. People have contracted avian influenza from direct contact with infected birds. Limited, inefficient human-to-human transmission is suspected in some of these cases.
More information on avian influenza:
- Public Health Agency of Canada
- Centers for Disease Control and Prevention (United States)
- World Health Organization
Pandemic influenza is influenza that causes a global outbreak, or pandemic, of serious illness that spreads easily from person to person. Pandemics of influenza have occurred three to four times each century, for unknown reasons, following the emergence of a new strain of the influenza virus. Since people have little or no protection against the new strain it can spread rapidly around the world, causing a pandemic.
Currently, there is no pandemic influenza in the world. The last three pandemics occurred in 1918-19, 1957-58 and 1968-69. Although it is impossible to predict with any certainty when the next influenza pandemic will hit, experts agree that we are overdue for one.
More information on pandemic influenza:
