Cyclosporiasis cases have surged in Quebec, with reports jumping 166% this year, while Michigan health officials investigate lettuce or salad greens as a potential source of a larger outbreak affecting thousands in the U.S.
For context, cyclosporiasis is a foodborne illness caused by the Cyclospora parasite, which can lead to weeks of severe symptoms, including watery diarrhea, stomach cramps, bloating, and fatigue.
Quebec sees unprecedented rise in cases
Quebec has recorded 85 cyclosporiasis cases since January, a sharp increase from the annual average of 32 cases reported during the same period from 2022 to 2025, according to the province’s health ministry. The ministry noted that while most cases in Canada were previously travel-related—primarily to Mexico—fewer than five of the recent Quebec cases involved travel to the U.S.
None of the Quebec cases appear linked to Michigan’s outbreak, where state health officials reported 4,312 cases and 102 hospitalizations as of Thursday. Michigan’s case count surged by more than 500 in a single day, with officials warning that while lettuce or salad greens are suspected, other food items cannot be ruled out.
U.S. outbreak reaches nearly 7,000 cases
The U.S. Centers for Disease Control and Prevention (CDC) reported 1,645 confirmed cyclosporiasis cases since May 1, with 141 hospitalizations and no deaths. Over 5,100 additional cases remain under investigation, far exceeding the 249 cases reported by this time last year.
In Canada, the Public Health Agency of Canada (PHAC) stated it is not currently investigating any Cyclospora outbreaks. PHAC noted that infections typically rise in spring and summer due to increased consumption of imported fresh produce. The agency emphasized that Cyclospora is not commonly found on food or in drinking water in Canada.
