Cyclospora infection (cyclosporiasis)

Cyclospora infection (cyclosporiasis)

Last Updated: November 24, 2023
HealthLinkBC File Number: 121
Download PDF

What is cyclosporiasis?

Cyclosporiasis is a foodborne intestinal infection caused by Cyclospora parasites.

What are the symptoms?

Symptoms of Cyclospora infection include:

  • Frequent watery (often explosive) diarrhea
  • Abdominal cramps and bloating
  • Nausea
  • Flatulence (gas)
  • Occasional fever
  • Loss of appetite
  • Fatigue
  • Weight loss

The intensity of symptoms may change during the course of the illness. Dehydration can also occur.

Symptoms usually occur within one week and last two weeks to 2 months. People with a weak immune system may experience an even longer illness.

A person can be infected and have no symptoms.

How is cyclosporiasis spread?

The disease is spread through the "fecal-oral" route.

Parasite eggs are shed in the stool of infected people. The eggs must remain in the environment for a number of days to become infectious. People are infected by eating contaminated food or water. The parasite is not spread directly from person to person.

The parasite does not exist normally in B.C. or Canada. Most infections occur during travel to countries where this parasite is common, such as in Central and South America and Asia.

However, nearly every year in the spring and summer, B.C. residents are affected by outbreaks of Cyclospora infection. These outbreaks have been linked to eating contaminated, imported fresh produce. High-risk foods include leafy green vegetables, fresh peas, fresh herbs and berries.

Produce may become contaminated when watered with or washed in water containing the parasite, or when handled by people infected with cyclosporiasis.

How do I prevent cyclosporiasis?

  • Wash your hands before, during and after preparing food
  • Wash fruits and vegetables as thoroughly as possible before eating them. However, washing may not eliminate the risk
  • Be aware that eating fresh produce imported from Central and South America and Asia into B.C. in the spring and summer will increase your risk of Cyclospora infection
  • To reduce your risk of infection, it is recommended to eat cooked or locally sourced high-risk foods like leafy green vegetables (such as lettuce), fresh herbs (such as basil and cilantro) and berries (such as raspberries and blackberries)
  • When traveling to developing countries, avoid eating fruits and vegetables that cannot be peeled or cooked
  • Do not drink untreated water when travelling

How is cyclosporiasis treated?

If you have prolonged or severe diarrhea, see your health care provider. Cyclosporiasis is diagnosed by testing a stool sample.

Your health care provider may prescribe antibiotics if you have a severe case of cyclosporiasis or a weak immune system.

For more information

For more information, see the following HealthLinkBC Files:

For information on the use of antibiotics, visit: