Listeriosis

Listeriosis is a disease caused by the bacteria Listeria monocytogenes. Symptoms of listeriosis include vomiting, nausea, diarrhea, cramps, severe headache, constipation and persistent fever. This uncommon disease can have serious consequences for high risk groups such as pregnant women and their fetuses, the elderly and very young. Listeriosis is spread by consuming contaminated food or drinks. Soft cheeses, deli meats and unpasteurized milk are some examples of commonly contaminated foods. For more information, see the Health Unit's fact sheets page on listeria.

The following graph shows the number of listeriosis 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. There have been between zero and three cases in Simcoe Muskoka every year since 2000.

Provincial definitions classify cases as confirmed, probable or suspect based on clinical and/or laboratory diagnostic criteria. The graphs below include cases that are classified as confirmed.

The following graph shows the incidence rate of listeriosis in Simcoe Muskoka and Ontario between 2000 and 2010. The incidence rate in Simcoe Muskoka is comparable to the Ontario rate. Both rates have remained low and relatively stable during this time period, except for the increase in listeriosis cases in 2008 when a national outbreak associated with deli meats lead to the recall of more than 200 products.