Wisconsin Reporting Cases of Illness Linked to Microscopic Parasite

Tuesday, July 7th, 2026 -- 9:01 AM

(Lance Schultels, Milwaukee Journal Sentinel) Wisconsin is one of 17 states reporting cases of an intestinal illness linked to a microscopic parasite that can sometimes cause "explosive" diarrhea.

The disease, known as cyclosporiasis, infects the small intestine and "usually causes watery diarrhea with frequent and sometimes explosive bowel movements," according to the Centers for Disease Control and Prevention.

There were 145 cases reported nationwide between May 1 and June 16, including 20 involving hospitalizations, the agency's most recent surveillance report says. However, federal health officials say there isn't yet any evidence of a single, multistate outbreak that links all of the cases, though investigations are still ongoing.

The intestinal disease is caused by a microscopic parasite called Cyclospora cayetanensis. The number of reported cases typically rises in the spring and summer, but typically the disease is not life threatening. People become infected by consuming contaminated food or water.

People living or traveling in tropical or subtropical places may be at increased risk, though the CDC notes that the current cases involve people who became sick after eating food in the United States and didn't report any travel during the two weeks prior to getting sick.

Not all people infected with cyclosporiasis show symptoms, but in addition to diarrhea, it commonly causes:

• Loss of appetite
• Weight loss
• Cramping
• Bloating
• Increased gas
• Nausea
• Fatigue

Less common symptoms include vomiting, body aches, headache, low-grade fever and other flu-like symptoms. The timing between infection and becoming sick is typically about a week, but can be as short as two days or longer than two weeks.

If left untreated, the illness can last over a month, and symptoms can clear before returning one or more times. Wisconsin was one of the less affected states by the outbreak, with only between 1 and 10 affected individuals. But the CDC says the true number of cases is likely higher because some recover without being tested and treated.

The best way to prevent the illness is by avoiding contaminated food or water and following safe food-handling practices:

• Wash hands with soap and water before and after handling raw fruits and vegetables
• Wash fruits and vegetables under water before eating, cutting or cooking
• Scrub firm fruits and vegetables, such as melons and cucumbers, with a produce brush
• Cut away damaged or bruised areas on fruits and vegetables
• Put cut, peeled or cooked fruits and vegetables in the refrigerator as soon as possible

Feel free to contact us with questions and/or comments.