Update: Cyclosporiasis Investigation Continues in Michigan

The Michigan Department of Health and Human Services (MDHHS) continues to investigate an ongoing outbreak of cyclosporiasis, a foodborne illness caused by a parasite that affects the intestines. As of July 13, 2026, 2,640 cases have been reported in Michigan.

Early investigation findings suggest that lettuce or salad greens may be a possible source, although no specific product, brand, grower, or supplier has been identified. The investigation is ongoing, and other food sources have not been ruled out.

How to reduce your risk:

MDHHS recommends the following steps when preparing or eating lettuce and salad greens:

• Choose whole heads of lettuce when possible instead of pre-washed bagged lettuce or salad kits.
• Remove and discard the outer 2–3 layers of leaves before preparing.
• Wash inner leaves thoroughly under clean running water.
• When possible, cook greens to at least 158°F to reduce risk.
• Continue to wash all fresh produce under running water, even if you plan to peel or cook it.

Cyclospora is not linked to swimming or recreational water activities. The current investigation is focused on possible foodborne exposure, especially contaminated produce.

Symptoms and when to seek care:

Symptoms may include:

• Frequent, watery diarrhea
• Nausea
• Stomach cramps
• Loss of appetite or fatigue

Symptoms can appear up to two weeks after exposure. If you have ongoing watery diarrhea, contact your healthcare provider and ask about testing for cyclospora.

For more information and the latest updates from MDHHS.

Additional information is available from the CDC:
https://www.cdc.gov/cyclosporiasis/