The US Centers for Disease Control and Prevention (CDC) has launched an investigation into a significant outbreak of Cyclospora infections, a parasite that causes severe gastrointestinal distress including explosive diarrhea. As of July 3, 2026, the agency has identified over 200 confirmed cases across at least 12 states, with the number expected to rise as more reports come in.
Outbreak Details and Symptoms
Cyclospora cayetanensis, the microscopic parasite responsible, is typically transmitted through contaminated food or water. Symptoms include watery diarrhea (often explosive and frequent), loss of appetite, weight loss, stomach cramps, bloating, nausea, and fatigue. The illness can last from a few days to several weeks, and relapses are common. The CDC notes that the incubation period is about one week on average.
The outbreak appears to be linked to a common food source, though the specific item has not yet been identified. Previous Cyclospora outbreaks in the US have been associated with imported fresh produce such as cilantro, raspberries, and salad mixes. The CDC is working with state health departments to trace the source.
Geographic Spread and Public Health Response
Cases have been reported in California, Texas, Florida, New York, Illinois, and several other states. Health officials are urging clinicians to test patients with compatible symptoms and report cases promptly. The CDC has issued a health advisory recommending that healthcare providers consider Cyclospora infection in patients with prolonged diarrheal illness, especially if they have traveled or consumed imported produce.
“We are seeing a higher number of cases than usual for this time of year,” said Dr. Sarah Park, a CDC epidemiologist. “It is critical that we identify the contaminated product quickly to prevent further infections.”
Prevention and Treatment
Cyclospora infections are treatable with a specific antibiotic, trimethoprim-sulfamethoxazole, commonly known as Bactrim. The CDC emphasizes that over-the-counter anti-diarrheal medications are not effective and may worsen symptoms. Prevention relies on thorough washing of fresh produce, though the parasite can be difficult to remove entirely.
The CDC advises consumers to be aware of the outbreak and to follow food safety guidelines. Anyone experiencing symptoms should seek medical attention and mention the possibility of Cyclospora infection.
