Cyclosporiasis outbreak reaches nearly 1,000 confirmed cases in Michigan as parasite spreads across US

An explosive cyclosporiasis outbreak in Michigan reaches 992 confirmed cases, nearly 20 times the state's annual average. The outbreak, which has hospitalized 36 people, is suspected to be linked to contaminated produce, though no specific source is identified. Meanwhile, the CDC reports 145 cases across 17 other states, and Ohio reports 177 cases. Health officials advise thorough washing and cooking of produce to prevent infection.

Michigan cyclosporiasis outbreak scale

• ▪The Centers for Disease Control and Prevention detected 145 cyclosporiasis cases across 17 states, excluding Michigan, since May 1, 2026
• ▪The 992 confirmed cyclosporiasis cases in Michigan represent a nearly 20-fold increase compared to the state's typical average of 50 cases per year
• ▪In neighboring Ohio, the state department of health has reported 177 cases of cyclosporiasis as of July 8, 2026
• ▪The Michigan Department of Health and Human Services confirmed 992 cases of cyclosporiasis in Michigan since June 22, 2026, with Southeast Michigan seeing a rapid rise
• ▪At least 36 people in Michigan have been hospitalized due to the cyclosporiasis outbreak as of July 8, 2026

Cyclospora parasite transmission sources

• ▪Cyclospora cayetanensis is a unicellular parasite that typically spreads through food or water contaminated with feces
• ▪The Michigan Department of Health and Human Services' working hypothesis is that the cyclosporiasis outbreak is linked to contaminated produce
• ▪No specific produce, grower, supplier, or type of produce has been identified as the source of the Michigan cyclosporiasis outbreak as of July 8, 2026

Gastrointestinal symptoms from infection

• ▪The most common symptom of cyclosporiasis is explosive watery diarrhea, which can be accompanied by cramping, bloating, low-grade fever, nausea, and vomiting
• ▪It typically takes about one week from the time of infection with Cyclospora cayetanensis to become symptomatic, ranging from two days to two weeks

Imported produce contamination risk

• ▪None of the initial 145 patients sickened in the multi-state cyclosporiasis wave reported traveling outside the United States
• ▪The Centers for Disease Control and Prevention considers May 1 through August 31 to be peak cyclosporiasis season
• ▪Previous foodborne outbreaks of cyclosporiasis in the United States have been linked to imported fresh produce, including raspberries, basil, snow peas, mesclun lettuce, and cilantro

Food washing prevention measures

• ▪Food handlers are advised to wash all produce thoroughly under running water and cook greens, herbs, and berries whenever possible to kill the parasite
• ▪The Michigan Department of Health and Human Services advises food entities in Southeast Michigan to select whole produce over pre-washed bagged mixes