Cyclospora infection (Cyclosporiasis)

Cyclosporiasis is a diarrheal illness caused by a parasite called Cyclospora cayetanensis. You can become infected with Cyclospora by drinking water or eating food that is contaminated with the parasite.

Outbreaks in North America have been traced to imported fresh produce such as raspberries and cilantro. Cyclosporiasis is not spread directly from one person to another. When passed in an infected person's stool, the parasite may require days to weeks in the environment before becoming infectious.


Symptoms usually appear one week after exposure. Symptoms include:

  • Watery diarrhea and frequent bowel movements
  • Loss of appetite and weight loss
  • Bloating, increased gas and stomach cramps
  • Nausea and vomiting
  • Tiredness
  • Muscle aches
  • Low-grade fever

Symptoms may subside and then return. If untreated, the illness may last a few days to a month or even longer. Some people who are infected do not develop any symptoms.


Infection can be prevented by avoiding water or food that may be contaminated with stool.

  • Practice good hand hygiene: Wash your hands with soap and warm water before handling food, or after using the toilet or changing diapers.
  • Avoid food that may be contaminated: Thoroughly wash uncooked fruits and vegetables.
  • Avoid water that may be contaminated: Do not drink water directly from streams, lakes, springs or swimming pools. If you must drink from these sources, make sure to boil water for at least one minute or to use a filter with a pore size of one micron or smaller.
  • Take extra care when traveling: When traveling to countries with poor water treatment or food sanitation, avoid raw fruits and vegetables, unboiled tap water, ice and food from street vendors.

Diagnosis and Treatment

Health care providers can detect cyclosporiasis through stool tests.

Most people who have healthy immune systems will recover without treatment. The recommended medicine for treatment is trimethoprim-sulfamethoxazole. This can be prescribed by a health care providers.

Infected people with diarrhea should rest and drink plenty of fluids. Patients should speak to their health care providers before taking medicine to limit their diarrhea.

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