Symptoms and Signs of Cyclospora Infection (Cyclosporiasis)

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Medically Reviewed on 2/26/2022

Doctor's Notes on Cyclospora Infection (Cyclosporiasis)

Cyclospora cayetanensis is a single cell microscopic parasite that causes cyclosporiasis, an infection of human intestinal tract cells. It mainly occurs in semitropical and tropical regions. Signs and symptoms of a Cyclospora infection include

Some individuals develop low fevers and vomiting. If not treated, the symptoms and signs may last for weeks to months.

C. cayetanensis is the cause of cyclosporiasis. The parasite has a complicated life cycle that needs to develop (oocysts) in human intestinal cells; after development, the non-sporulated oocysts are shed in human feces into the environment where they mature (sporulate) and contaminate food and water sources where they can start their life cycle again by infecting humans.

What Is the Treatment for Cyclospora Infections?

People with a healthy immune system may recover without treatments. It may last a few days to a month (or more) as the disease may relapse. However, Cyclospora treatment is simple. Trimethoprim/sulfamethoxazole is the most used and effective antibiotic to treat this infection. No alternative antibiotics or antiparasitic drugs are as effective.


Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.