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Foodborne Parasite Cyclospora Sickens Hundreds Across U.S., Nearly 600 in Michigan

Cyclospora cayetanensis oocysts — Image credit: CDC/ DPDx - Melanie Moser via CDC's Public Health Image Library

Cases of cyclosporiasis are surging across the U.S. this summer, with federal and state public health officials together reporting more than 700 cases of Cyclospora infection since May 2026.

Past foodborne cyclosporiasis outbreaks reported in North America have been linked to produce items including bagged salad mixes and kits, fresh herbs, raspberries, snow peas, and green onions.

Michigan Reports 572 Cases in Addition to CDC’s 145

The Michigan Department of Health (MDOH) alone has reported 572 cyclosporiasis cases within the state since late June, with counties in Southeast Michigan the most affected. For comparison, in a typical year, Michigan reports approximately 50 Cyclospora infections.

According to the latest figures (current through June 16) from the U.S. Centers for Disease Control and Prevention (CDC), an additional 145 cases of cyclosporiasis have been reported in 17 states—not including Michigan—since May 1. These cases have not yet been associated as part of a larger outbreak by CDC. Investigations to identify potential clusters and potential sources of illness are ongoing.

The Growing Prevalence of Cyclospora

Since the 1990s, the prevalence of Cyclospora cayetanensis has had an upward trajectory, trending toward possible endemicity. As explained by expert Larry Keener, CFS, PA in Food Safety Magazine, domestic cases of Cyclospora infections more than doubled from 537 in 2016 to 1,194 in 2017, and then nearly tripled to 3,519 cases in 2018. Between 2019 and 2022, the number of laboratory-confirmed cases of cyclosporiasis in the U.S. ranged from a high in 2019 of 2,408 cases to a low in 2021 of 1,024 cases. By 2023, there were nearly 3,000 cases of cyclosporiasis reported in the U.S.

Cyclosporiasis is now considered an "important neglected parasitic infection" by CDC. It is also a nationally notifiable disease.

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Bailee Henderson is the Director of Content Strategy for Food Safety Magazine. In the day-to-day, she covers industry-relevant current events, regulatory affairs, and scientific developments. She also produces the Food Safety Five Newsreel and edits the twice-weekly Food Safety Digest newsletter. Notably, Bailee's coverage for Food Safety Magazine has been featured in national televised news segments including CBS Sunday Morning and MSNBC's Rachel Maddow Show. She can be reached at hendersonb@bnpmedia.com.