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Influenza (the "flu")

Influenza is a disease caused by the influenza virus. Symptoms of influenza include sudden onset of headache, chills and cough followed by a fever, appetite loss, muscle aches and tiredness. Influenza is one of the major causes of outbreaks in long-term care homes and daycares. For more information, see the health unit's fact sheet on "Cold vs. Flu".  

Influenza surveillance begins on September 1 each year and ends on August 31 of the following year. The majority of influenza cases occur in the winter months between November and April.

The following graph shows the number of influenza cases in Simcoe Muskoka between 2000-01 and 2007-08. There are many factors that influence how many cases are reported to the health unit, as explained on the Infectious Diseases page.  

Graph - Number of Influenza cases in Simcoe Muskoka 2000-2008

The following graph shows the incidence rate of influenza in Simcoe Muskoka and Ontario between 2000-01 and 2007-08. The incidence rate in Simcoe Muskoka was similar to the Ontario rate until 2003-04 when it climbed higher than the Ontario rate. There is alot of variability in both rates, which means that there are many peaks and valleys and it is difficult to determine whether an increase is significant or whether it is within the expected range for this disease.