Influenza

Influenza or the flu is a common, infectious respiratory disease that begins in your nose and throat. It is highly contagious and spreads rapidly from person to person.

About Seasonal Influenza (flu)

Human influenza, or the flu, is a respiratory infection caused by the influenza virus. Strains circulate every year, making people sick. 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.
Most people will recover from influenza within a week or ten days, but some - including those over 65 and adults and children with chronic conditions, such as diabetes and cancer - are at greater risk of more severe complications, such as pneumonia. Between 2 000 and 8 000 Canadians can die of influenza and its complications annually, depending on the severity of the season.

• Fight Flu.ca - Your one-stop access to information about the flu
• Seasonal Influenza - Guidance: Infection Prevention and Control Measures for Healthcare Workers in Acute Care and Long-term Care Settings (2010)
• Seasonal Influenza Prevention and Immunization (the "flu shot")
• Access to the seasonal flu vaccine in Canada - How the flu shot makes its way from the laboratory to the doctor's office
• National Advisory Committee on Immunization Statements on Influenza Vaccination
• Evaluation of the effect of Ontario's Universal Infuenza Immunization Program (UIIP)

About H1N1 Flu Virus

Swine influenza viruses do not normally infect humans. From time to time, human infections do occur, resulting in H1N1 flu virus. H1N1 flu virus is a respiratory illness that causes symptoms similar to those of the regular human seasonal influenza.

• Clinical Public Guidance

About Avian Influenza ("bird flu")

Birds and other animals, including pigs, also contract and transmit influenza. Wild birds, in particular, are natural carriers of influenza A viruses. They have carried animal influenza viruses, with no apparent harm, for centuries. Migratory waterfowl (ducks, geese) are known to carry viruses of the H5 and H7 strains or subtypes. These viruses are usually in the low pathogenic form - in other words, they aren't as deadly to birds as highly pathogenic strains.

Currently, avian influenza H5N1 is circulating in Asia, Europe, and Africa, infecting many poultry populations and some humans. This strain is highly pathogenic, or highly deadly to birds, and has infected a limited number of people. There is no evidence this virus is transmitted from person to person.

• Information about Avian Influenza

About Pandemic Influenza

People are exposed to different strains of the influenza virus many times during their lives. Even though the virus changes, their previous bouts of influenza may offer some protection against infection caused by a similar strain of the virus. However, three to four times each century, for unknown reasons, a radical change takes place in the influenza A virus causing a new strain to emerge.

• Pandemic Influenza Information
• Pandemic Preparedness
• The Canadian Pandemic Influenza Plan for the Health Sector
• What is the difference between seasonal, avian and pandemic flu?

Influenza Surveillance

To see where the flu is active in Canada, visit FluWatch. FluWatch produces weekly surveillance reports from October to May in collaboration with provincial and territorial ministries of health, participating laboratories, the College of Family Physicians of Canada and sentinel doctors.

• FluWatch web site

Emerging Respiratory Infections

The information provided on this site is directed primarily to health/public health professionals and aims to provide guidelines and standards for the detection, rapid response and control of outbreaks due to an emerging respiratory pathogen.

• Emerging Respiratory Infections site (for Health Professionals)

National Advisory Committee on Immunization (NACI) Statements

The National Advisory Committee on Immunization (NACI) provides the Public Health Agency of Canada with ongoing and timely medical, scientific, and public health advice relating to immunization. Past and present annual statements on Influenza vaccination can be accessed on the NACI web site.

• National Advisory Committee on Immunization (NACI) web site