Provincial Cyclospora outbreak

Advisory Alert

July 14, 2017

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Ontario is experiencing a large Cyclospora outbreak. Fifty-two locally-acquired cases have been reported between May 1 and July 11, 2017. Additional cases continue to be reported. To date in 2017, one case has been confirmed in Sudbury and Manitoulin district; however, this was travel-related and not linked to the current outbreak.

The purpose of this communication is to provide information about cyclosporiasis to support prompt diagnosis and treatment of infected patients.

What is cyclosporiasis?

Cyclosporiasis is a gastrointestinal illness caused by the parasite Cyclospora cayetanensis. It commonly presents as frequent watery diarrhea and other symptoms such as anorexia, fatigue, abdominal cramps, nausea, and myalgia. Left untreated, symptoms usually last 6 to 7 weeks and may vary in intensity. Symptoms typically improve within 2 to 3 days of starting TMP-SMX therapy.

How is Cyclospora infection acquired?

People are infected by ingesting contaminated food or water. As Cyclospora is not endemic in Canada, most reported cases in Ontario are infected when visiting an endemic country (e.g. countries in the Caribbean, South and Central America, South and South East Asia). Most outbreaks in Ontario occur in the spring and summer. Outbreaks of locally-acquired infections have been related to produce such as berries or herbs imported from endemic countries. It is unlikely to spread from person to person.

For more information including links to testing information, visit:

For all reporting, inquiries or comments, please contact: Sudbury & District Health Unit at 705.522.9200, ext. 464.


Associate Medical Officer of Health

This item was last modified on July 17, 2017