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Giardiasis

Giardiasis is a disease caused by the protozoa Giardia lamblia, also known as Giardia intestinalis. Symptoms of giardiasis include diarrhea, abdominal cramps, bloating, frequent, loose stools and weight loss. Symptoms may disappear and reappear over long periods of time. It is spread by consuming contaminated food or water or through close contact with an infected person. For more information, see the Health Unit's fact sheets page on giardiasis.

The following graph shows the number of giardiasis cases in Simcoe Muskoka between 2000 and 2010.  There are many factors that influence how many cases are reported to the Health Unit, as explained on the Infectious Diseases page.  In recent years, there have been between 30 and 60 cases of giardiasis per year.

Provincial definitions classify cases as confirmed, probable or suspect based on clinical and/or laboratory diagnostic criteria.  The provincial case definition for giardiasis changed in April 2009 to include a definition for probable cases whereas before there was no such classification.  The definitions of confirmed and probable cases from 2009 onwards are comparable to confirmed cases before 2009.

The following graph shows the incidence rate of giardiasis in Simcoe Muskoka and Ontario between 2000 and 2010. The Simcoe Muskoka incidence rate is lower than the Ontario rate for most years. Both rates experience an overall decrease between this time period.