Summary (tl;dr)

A parasitic illness, cyclosporiasis, causing severe and "explosive" diarrhea, is currently spreading across at least 18 U.S. states, including North Carolina, prompting an investigation by the Centers for Disease Control and Prevention (CDC) to identify the contaminated food or water source.

Essential Background

Cyclosporiasis is an intestinal infection caused by the microscopic parasite Cyclospora cayetanensis. People become infected by consuming food or water contaminated with feces containing the parasite. Outbreaks in the United States have historically been linked to fresh produce, such as raspberries, basil, and cilantro, often contaminated during growth or packaging. For instance, North Carolina experienced a localized Cyclospora outbreak in Wake County in August 2024, which was also attributed to contaminated herbs and vegetables.

The Full Story

The U.S. Centers for Disease Control and Prevention (CDC) is actively investigating a widespread outbreak of cyclosporiasis that has led to over 400 reported cases of severe, watery, and often "explosive" diarrhea across 18 states, including North Carolina. Between May 1 and June 16, 2026, the CDC identified 145 domestically acquired cases across 17 states, resulting in 20 hospitalizations. Michigan, in particular, has reported an unusually high number of cases, with over 300 since June 22, significantly exceeding its typical annual count. Other states, including New York, Texas, and Illinois, have also seen substantial case numbers. Investigators believe the infections are linked to contaminated food items consumed within the U.S., as most patients did not report international travel prior to their illness. The exact source of contamination, however, remains unknown, with health officials working to identify multiple potential clusters and sources across affected states. No deaths have been reported in connection with this ongoing outbreak.

Why It Matters

The current surge in cyclosporiasis cases is alarming due to its widespread nature and the persistent challenge in identifying the specific source of contamination, which has implications for public food safety. The illness can cause prolonged and debilitating gastrointestinal symptoms, including frequent and explosive diarrhea, leading to hospitalizations in severe instances. The lack of a clear, single contaminated food item raises concerns about broader supply chain issues or multiple contaminated products. Public health officials are urging vigilance in food handling and preparation, particularly with fresh produce, and advising individuals experiencing symptoms to seek medical attention to prevent further spread and ensure proper treatment.

Geographic Location

• North Carolina, United States (state affected by Cyclospora outbreak)
• New York, United States (state with the highest reported cluster of Cyclospora cases)
• Michigan, United States (state investigating a large and growing increase in Cyclospora cases)
• Texas, United States (state with reported Cyclospora cases)
• Illinois, United States (state with reported Cyclospora cases)