Cyclosporiasis: What to know and how to prevent it

Houston, TX - Jul 16, 2026

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Cyclosporiasis, a parasite causing 'explosive diarrhea,' is making headlines across the country. Dr. Stacey Rose, associate professor of internal medicine and infectious diseases at Baylor College of Medicine, explains why this illness is not like others that spread from person to person.

"The bug itself is called Cyclospora cayetanensis. It is considered a parasite, a protozoa, which means it is essentially a single-cell organism and it's really tiny," Rose said.

She explains that a person gets the illness after consuming water or a food product, usually produce, that has been contaminated by the fecal matter of an infectious person. If you have cyclosporiasis, you'll have watery, non-bloody diarrhea.

"Diarrhea from cyclosporiasis can last awhile. You're going to be feeling it for several days or weeks, leading to the potential for dehydration," Rose said. "It can also take up to two weeks from when you consume the infectious material to when you develop symptoms."

Infants, older adults and those with underlying medical illnesses are at higher risk for dehydration related to any diarrheal disease. Rose says Pedialyte is a good option for rehydration, as it provides the right balance of electrolytes.

To prevent cyclosporiasis:

• Wash your hands with soap and water before eating or preparing food.
• Wash your produce for a good amount of time to rinse off contaminated material.
• Cook your food at a higher temperature to kill the parasite.

"If you buy a head of lettuce, remove the outer layer. It is less likely that the inner layer will be contaminated. Then, you would still need to wash it," Rose said.

To be officially diagnosed with cyclosporiasis, you will need to seek care from a healthcare provider. There are specific tests, like a gastrointestinal pathogen panel where providers can determine if you have the illness.

For treatment, a doctor may prescribe antibiotics that can help shorten the illness. Also, ask your doctor before self-treating with over-the-counter medications. Loperamide (Imodium) could potentially help with cyclosporiasis symptoms but would not cure the infection. For some, symptoms will go away on their own.