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Cyclosporiasis is an intestinal illness caused by the microscopic parasite Cyclospora cayetanensis. The parasite can infect people when they ingest something—such as food or water—that was contaminated with feces (stool). CDC scientists and partners are using Advanced Molecular Detection (AMD) methods to develop DNA fingerprinting to distinguish among same or similar C. cayetanensis that cause cyclosporiasis. These tools could help link cases to each other and to particular food products, and help public health officials investigate and prevent further cases and outbreaks of Cyclospora infection.


Key Facts

  • Cyclospora cayetanensis is a microscopic parasite that causes an intestinal infection called cyclosporiasis.
  • In the United States, foodborne outbreaks of cyclosporiasis have been linked to various types of imported fresh produce.
  • Cyclosporiasis has been reported in many countries but is most common in tropical and subtropical areas.
  • The majority of U.S. cases occur in warmer months. Outbreaks have been identified nearly every year since the mid-1990s.


Woman holding stomach
Feeling Sick?

A person with cyclosporiasis may begin to feel sick about 7 days after eating contaminated food. Symptoms may include watery diarrhea (most common), loss of appetite, weight loss, cramping, bloating, increased gas, nausea, and fatigue. Since these may be similar to those of other intestinal illnesses, cyclosporiasis can only be diagnosed by a doctor.

Lettuce being washed in sink
Food Safety Importance

To prevent cyclosporiasis, try to avoid food or water that may have been contaminated with stool. If traveling, follow safe food and water habits. At home, wash all fruits and vegetables thoroughly under running water before eating, cutting, or cooking. Fruits and vegetables that are labeled “prewashed” do not need to be washed again.

Slide of Cyclosporiasis
Troublesome Parasite

Cyclospora cayetanensis is a parasite composed of one cell, too small to be seen without a microscope. This parasite causes an intestinal infection called cyclosporiasis.

Scientist holding DNA sheet
Developing Detection Tools

AMD methods help CDC and other agencies distinguish different infections or contaminations of food by Cyclospora parasites based on their DNA. These tools could help link cases of cyclosporiasis to each other and to particular types of food, and help public health officials investigate and prevent cases and outbreaks of cyclosporiasis.

Prevention Tips

  • Travelers to cyclosporiasis-endemic areas (such as tropical and subtropical regions) should be aware that treatment of water or food by routine chemical disinfection or sanitizing methods is unlikely to kill the Cyclospora parasite.
  • See your healthcare provider if you think you have cyclosporiasis. A specific test for the parasite is required to diagnose the infection.

It is also important to follow these food safety precautions:

  • Wash your hands with soap and water before and after handling or preparing fruits and vegetables.
  • Wash all surfaces with soap and water between preparing raw meat, poultry, and seafood products and preparing fruits and vegetables that will not be cooked.
  • Scrub firm fruits and vegetables, such as melons and cucumbers, with a clean produce brush. Cut away any damaged or bruised areas on fruits and vegetables before preparing and eating.
  • Refrigerate cut, peeled, or cooked fruits and vegetables as soon as possible, or within 2 hours. Store fruits and vegetables away from raw meat, poultry, and seafood.