Cyclosporiasis is a disease caused by infection with Cyclospora cayetanensis, a pathogenic apicomplexan protozoan transmitted by feces or feces-contaminated food and water.

After incubation, the infected person begins to experience severe watery diarrhea, bloating, fever, stomach cramps, and muscle aches.

[citation needed] There is no vaccine to prevent cyclosporiasis in humans at present, but one is available for reduction of fetal losses in sheep.

[4] In addition to other extra-intestinal reports, cyclosporiasis might be involved in either reversible neuronal damage or other unknown mechanisms to lead to Guillain-Barré syndrome or Bell's palsy.

[5] The researchers found that openly defecated human stool samples around the swimmer's living quarters and near the swimming pool were positive for Cyclospora.

In one study, Tirth Raj Ghimire, Purna Nath Mishra, and Jeevan Bahadur Sherchan collected samples of vegetables, sewage, and water from ponds, rivers, wells, and municipal taps in the Kathmandu Valley from 2002 to 2004.

[12] Although it was initially thought that Cyclospora was confined to tropical and subtropical regions, occurrences of cyclosporiasis are becoming more frequent in North America.

[18] On July 31, 2018, the United States Department of Agriculture (USDA) issued a public health alert for certain beef, pork and poultry salad and wrap products potentially contaminated with Cyclospora.

In June 2020, the CDC and other regulatory bodies began investigating an outbreak of Cyclosporiasis in the Midwestern United States linked to bagged salad mix.