Cyclosporiasis Outbreak 2026: Cases Top 1,500 in Michigan as Parasite Spreads Nationwide
Medically reviewed by Editorial Team | Last updated: July 13, 2026 | Data current as of July 10, 2026 Quick Answer Cyclosporiasis is a diarrheal illness caused by the parasite Cyclospora cayetanensis , usually picked up from contaminated fresh produce. A large 2026 outbreak has pushed Michigan's case count past 1,500 (44 hospitalized), with additional cases confirmed in states including Ohio, New York, and Texas. The source of contamination has not yet been identified. Most healthy people recover, and the antibiotic trimethoprim-sulfamethoxazole (TMP-SMX) is the CDC's recommended treatment. A fast-moving outbreak of cyclosporiasis — an intestinal infection caused by a microscopic parasite typically carried on fresh produce — has become one of the largest seen in the United States in years. Michigan has borne the brunt of it, but health departments in several other states are reporting cases as investigators work to trace the contamination back to its source. Below i...