By Kari Grant
Last updated on July 17, 2026
Cyclospora cayetanensis (sy-klo-SPOR-uh ky-uh-ten-EN-sis) is a parasite that causes intestinal illness in humans called cyclosporiasis. Parasites are complex organisms (eukaryotes) that require a living host to survive and reproduce, ranging from large tapeworms to tiny amoebas or protozoa like Giardia or Cryptosporidium. Parasites are not in the same category as simple prokaryotes like bacteria, fungi, mycobacteria, viruses, and spores though they may also be microscopic.
Cyclospora transmission occurs by ingestion of food or water contaminated with fecal matter containing this parasite with symptoms presenting within 2-14 days after exposure. Common symptoms include watery diarrhea with frequent bowel movements, loss of appetite, stomach cramps/pain, bloating, increased gas, nausea, and fatigue, all of which can last a few days to a month or longer without receiving proper treatment from your doctor. The current hospitalization rate for confirmed cases of cyclosporiasis is 9% with no reported deaths.
The CDC is monitoring the current outbreak across multiple U.S. states and has confirmed at least 1,645 cases since May 1, 2026, with more than 5,100 cases that require additional testing to confirm the presence of Cyclospora cayetanensis as of this writing. While CDC has not identified a specific source of this outbreak, the CDC, public health and regulatory officials are collecting data as part of the investigation. Previous cases of cyclosporiasis in the U.S. have been caused by produce items including raspberries, basil, cilantro, snow peas, and lettuce. Consumers should be aware that rinsing and/or washing contaminated produce with sanitizers or disinfectants are unlikely to kill this parasite. The CDC recommends thorough rinsing of all produce to remove the organism, including those packaged foods labeled as pre-washed, with clean water to reduce your risk of becoming ill with cyclosporiasis, even though rinsing may not fully remove the parasite. For surfaces CDC and FDA recommend standard sanitization and disinfection using EPA registered products following thorough cleaning.
There are currently no EPA registered products with demonstrated efficacy against Cyclospora for water, food, or surface treatment. There is also no EPA approved test method to assess efficacy in these uses against this parasite. EPA does have a testing protocol for Microbiological Water Purifiers that includes Cryptosporidia and Giardia (810.2600) which may offer a place to start for water treatment method development, but significant method research will be needed to create a valid protocol with all necessary controls. Protocols for surface, water or food treatment against this parasite will need to route through the EPA New Protocol Process (PRIA A521 or 522) and receive agency approval before GLP product testing may be conducted to support the addition of use directions and label claims related to Cyclospora cayetanensis.
We are not aware of FDA registered products for pre- or post-harvest produce treatment for this parasite either. SRC anticipates any future produce treatments and test methods specific to Cyclospora will likely be a joint effort between the FDA and EPA.
Although this is a developing situation, CDC recommends continuing thorough rinsing of produce with clean water, frequent hand washing with warm soapy water, and utilizing safe food handling practices to reduce your risk of food-borne illnesses.
References:
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US CDC. Health Alert Network: Domestically Acquired Cyclosporiasis Cases in Multiple US States, 2026. https://www.cdc.gov/han/php/notices/han00531.html. July 14, 2026.
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