Cyclosporiasis outbreak, Wisconsin impacted; foods possibly affected

A cyclosporiasis outbreak across the United States continues, and officials in Michigan are releasing more information about the types of foods that have been specifically linked to the outbreak in previous instances to help prevent further illnesses.

"Frequent, watery diarrhea" is one of several symptoms.

Wisconsin is currently reporting between 1-10 cases, per the U.S. Centers for Disease Control and Prevention.

Cyclosporiasis outbreak in Michigan

By the numbers:

In Michigan, the number of reported cases grew to 572 over the weekend, up from 170 on Tuesday, June 30.

Local perspective:

Cases remain the highest in Monroe, Lenawee, Washtenaw, Wayne, Shiawassee, Jackson, Oakland and Livingston counties. 

List of fruits, vegetables

FILE - Fresh raspberries. Getty Images

Big picture view:

As of July 4, 2026, no specific produce grower or supplier, or specific produce type has been identified as the source of the outbreak in southeast Michigan, the Michigan Department of Health and Human Services said. 

But they’re detailing foods that have been previously linked to the illness. 

Dig deeper:

The following foods have been specifically linked to previous Cyclospora outbreaks in the United States and Canada:

  • Bagged salad mixes and kits (pre-cut lettuce blends with romaine, iceberg, red cabbage, carrots)
  • Fresh cilantro (coriander leaves)
  • Fresh basil
  • Raspberries
  • Snow peas
  • Green onions (scallions)

What you can do:

If you are preparing or eating any of the following raw foods, take the following steps to reduce the risk of exposure: 

  • Lettuce/leafy greens: Buy whole heads of lettuce (rather than prewashed, bagged lettuce or salad mixes), throw away the outer 2–3 layers of leaves and wash the inner leaves under running water. For leafy greens that can be cooked, cooking is the safest option.
  • Cilantro, basil: Wash thoroughly under running water, separating the leaves.  Safest when cooked.
  • Raspberries: Their bumpy surface makes them especially hard to clean; the parasite can hide in the tiny crevices. Safest when cooked (pies, jams etc.). Consider frozen raspberries as an alternative (freezing may reduce but does not guarantee elimination of the parasite).
  • Snow peas: Wash under running water and rub the surface. Safest when cooked.
  • Green onions: Trim the root end and remove the outer layer, wash thoroughly under running water. Safest when cooked.

What is cyclosporiasis? 

Big picture view:

Cyclosporiasis is a diarrheal illness caused by infection with the parasite Cyclospora cayetanensis, which experts say is found in developing countries and is spread by food or water contaminated with feces.

Outbreaks have occurred in the US as a result of eating contaminated fresh produce in hot weather. 

It is not known to spread from person-to-person.

RELATED: CDC investigates parasite outbreak linked to 'explosive' diarrhea across 17 states

Cyclosporiasis symptoms

Timeline:

Symptoms occur two to 14 days after exposure and may include:

  • Frequent watery diarrhea
  • Loss of appetite and weight
  • Abdominal cramps and bloating
  • Nausea (vomiting is less common)
  • Low-grade fever

Anyone infected who does not get treatment, health experts say the illness may last for a few days to over a month. Symptoms could go away and then return one or more times.

Cyclosporiasis treatment

What you can do:

If you experience sudden, ongoing diarrhea, reach out to your health care provider and your local health department. 

Symptoms can be improved with an antibiotic.

The Source: Information in this article was taken from the Michigan Department of Health and Human Services and the U.S. Centers for Disease Control and Prevention.

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