Cyclosporiasis - Fact Sheet


What is cyclosporiasis?
Cyclosporiasis is an intestinal illness caused by Cyclospora cayetanensis, a one-cell parasite. The majority of cases are seen in the warmer months. In the last several years, outbreaks of the illness have been reported in the United States and Canada.

Where are Cyclospora parasites found?
Cyclospora is only known to be found in infected humans. The parasites are passed in the stool of an infected person.

How does this parasite spread?
Cyclospora is spread by people ingesting food or water that was contaminated with infected stool. Outbreaks of cyclosporiasis have been linked to various types of fresh produce. The parasite needs days or weeks after being shed in stool to become infectious, so it is unlikely that Cyclospora is passed directly from one person to another.

Who gets cyclosporiasis?
People of all ages are at risk for Cyclospora infection. In the past, cyclosporiasis was usually found in people who lived or traveled in developing countries. More recently, it is known that people can be infected worldwide, including the United States.

What are the symptoms of cyclosporiasis?
Cyclosporiasis infects the small intestine and usually causes watery diarrhea, with frequent (sometimes explosive) bowel movements. Other symptoms may include loss of appetite, weight loss, bloating, gas, stomach cramps, nausea, vomiting, muscle aches, low-grade fever, and fatigue. Some infected persons may not have any symptoms.

How soon do symptoms appear?
The symptoms generally appear about a week after becoming infected.

How long can an infected person carry Cyclospora?
Generally, infected people can pass the parasite in their stool for a few days to a month or longer.

What is the treatment for cyclosporiasis?
A combination of two antibiotics is used to treat cyclosporiasis. People who have diarrhea should rest and drink plenty of fluids.

How can cyclosporiasis be prevented?

  • Thoroughly wash hands after toilet visits and before eating or handling food.
  • Wash all fruits and vegetables thoroughly, especially those that will not be cooked; however, this practice may not completely eliminate the risk of Cyclospora.
  • Avoid consuming improperly filtered water from rivers, lakes, water parks, or swimming pools.



This fact sheet is for informational purposes only. It should not be used for self-diagnosis or as a substitute for consultation with a health care provider. If you think that you may have this infection, or have questions about the disease described above, you should consult your health care provider.


For additional information on this disease, visit the Centers for Disease Control and Prevention website.





To contact the Epidemiology and Emerging Infections Program, please call 860-509-7994.