As summer temperatures rise, health officials nationwide are tracking a significant surge in cyclosporiasis, a rare parasitic illness linked to contaminated fresh produce.

The infection is caused by Cyclospora cayetanensis, a microscopic parasite that spreads when individuals consume food or water contaminated with human feces. While the Centers for Disease Control and Prevention (CDC) initially reported 145 cases across 17 states through mid-June, recent state data indicates a much larger outbreak. Michigan alone has since reported over 1,200 cases, marking one of the largest Cyclospora outbreaks in the state’s history.

The parasite is typically introduced to the food supply before it reaches consumers and cannot be passed directly from person to person. Health officials note that the illness is most commonly tied to fresh fruits, herbs, and vegetables.

“We usually see it spread among more of our vegetables and lettuce, fruits,” said Stephen Miller of the Hamilton County Health Department.

Commonly affected produce includes:

• Leafy Greens & Herbs: Spinach, cilantro, basil, and parsley

• Berries: Raspberries, blueberries, and blackberries

• Vegetables: Snow peas and green onions

Symptoms generally appear about a week after ingestion. If you contract the illness, you may experience:

• Severe watery diarrhea

• Stomach cramps and nausea

• Vomiting and fatigue

• Chills and loss of appetite

Without medical intervention, cyclosporiasis can persist for weeks or even months. However, health officials note that the infection can be effectively treated with prescription antibiotics. Anyone experiencing prolonged gastrointestinal symptoms is urged to contact a healthcare provider.

Investigating agencies are still working to pinpoint the exact source of the current outbreak, as no single food item has been identified. In the meantime, health officials stress that thorough handwashing—especially for restaurant workers and food handlers—is critical to preventing spread.

To protect yourself at home, experts recommend washing all fresh fruits and vegetables under running water before eating, refrigerating cut produce promptly, and maintaining strict hand hygiene before preparing meals.