Michigan Cyclosporiasis Outbreak Surpasses 3,300 Cases as Infections Spike Rapidly

Michigan is facing a severe cyclosporiasis outbreak, with confirmed cases surging to 3,309 as of July 14, 2026, and causing 44 hospitalizations. The outbreak, which has also affected Ohio and New York, has more than doubled in Michigan since the previous Friday. While health officials suspect lettuce or salad greens as the source, no definite product has been identified. The rapid spike follows a controversial CDC decision to scale back active surveillance of the cyclospora parasite.

Michigan cyclosporiasis outbreak surge

• ▪The cyclosporiasis outbreak in Michigan resulted in 44 hospitalizations as of July 9, 2026, with no deaths reported
• ▪Michigan health officials reported 3,309 cases of cyclosporiasis as of July 14, 2026, representing an increase of 669 cases since July 13, 2026
• ▪The hardest-hit areas in Michigan's cyclosporiasis outbreak are Monroe County and Wayne County, which includes Detroit
• ▪Michigan's cyclosporiasis case count more than doubled from 1,562 cases on July 10, 2026, to 3,309 cases on July 14, 2026
• ▪Ohio reported 434 cyclosporiasis cases and 28 hospitalizations since July 1, 2026, while New York reported 470 cases as of July 10, 2026

Lettuce contamination investigation

• ▪Preliminary investigation results from the Michigan Department of Health and Human Services suggest lettuce or salad greens may be the source of the cyclosporiasis outbreak
• ▪U.S. health officials have not identified a definite product as the source of the cyclosporiasis outbreak and are tracing foods through the supply chain

CDC surveillance program rollback

• ▪The Centers for Disease Control and Prevention removed cyclospora from the list of pathogens monitored under its Foodborne Diseases Active Surveillance Network program in 2025
• ▪The Centers for Disease Control and Prevention scaled back its FoodNet program to narrow its focus to Salmonella and Shiga toxin-producing E. coli

Cyclosporiasis transmission methods

• ▪Cyclosporiasis is an intestinal infection contracted by consuming food or water contaminated with feces containing the microscopic cyclospora parasite
• ▪Cyclosporiasis does not spread directly from person to person, and it can take weeks for symptoms to develop after ingesting the parasite

Gastrointestinal symptoms

• ▪The cyclospora parasite causes gastrointestinal symptoms including watery diarrhea, nausea, loss of appetite, weight loss, cramping, bloating, and increased gas
• ▪Children, older adults, and people with weakened immune systems face a higher risk of serious illness from cyclosporiasis