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Cyclospora Infections (Cyclosporiasis)

Cyclospora cayetanensis is a parasite that causes a diarrheal illness. Cyclosporiasis is not usually a serious illness but can persist for several weeks.

This parasite is not usually found in BC. Most infections in BC residents occur during travel to tropical countries. However, outbreaks can occur in BC in the spring and summer from importation of contaminated produce such as fresh herbs, lettuce and berries.

Information for Health Professionals


Cyclospora cayetanensis is a parasite that infects the small intestine. When a person gets sick from this infection it is called cyclosporiasis. 

Most infections are acquired during travel to countries where this parasite is endemic such as in Central and South America and Asia. However, nearly every year in the spring and summer, BC residents are affected by outbreaks of Cyclospora infection. These local outbreaks have been linked to eating contaminated, imported fresh produce, especially leafy green vegetables (e.g. lettuce), fresh herbs (e.g. basil and cilantro) and berries (e.g. raspberries and blackberries).

 
Cyclosporiasis usually causes:
  • frequent watery, often explosive, diarrhea 
  • abdominal cramps
  • nausea
  • vomiting
  • loss of appetite
  • weight loss
  • fatigue
  • and occasionally fever.

Symptoms start approximately 1 week after exposure to the parasite. A person can be infected and have no symptoms. In some cases, symptoms may continue for more than a month and can sometimes return even after you have started to feel better.


People who are immune-compromised may experience prolonged diarrhea.

Cyclospora are spread by the fecal-oral route, meaning through the consumption of food or water contaminated by human feces. The parasite is not spread from person-to-person because it is not infectious when it is passed in the stools of an infected person. It must remain in the environment, outside the host, for a number of days to become infectious. 

Contaminated fruits and vegetables are the main source of cyclospora infections. Produce may become contaminated when watered with or washed in water containing the parasite, or when handled by infected workers. 

Untreated, cyclosporiasis will cause prolonged diarrhea, with relapses, especially in people whose immune systems are compromised.

Diagnosis is made by microscopic examination of one or more stool samples.

If you think you have a Cyclospora infection, see your family doctor for testing, advice and treatment.

Antibiotics are used to treat cyclospora infections. Your doctor will decide which treatment is right for you. People with cyclospora infections are usually advised to drink plenty of fluids to prevent dehydration from diarrhea.

It is important to wash fruits and vegetables as thoroughly as possible before eating them, however, washing produce will not completely remove the possibility of infection. When traveling to developing countries, avoid any fruits and vegetables that cannot be peeled or cooked. 

Do not drink untreated surface water from a spring, stream, river, lake, pond or shallow well. When traveling to a developing country make sure that you drink bottled water from a reputable supplier, or boil untreated surface water that is used for: 
  • drinking
  • making ice cubes
  • washing uncooked fruits and vegetable
  • making baby formula
  • brushing teeth and
  • washing dentures.

Boil for at least 1 minute at a rolling boil. At elevations above 2000 m (6562 ft), boil for at least 2 minutes. Cyclospora are resistant to chlorine, so boiling water is the best way to disinfect it.


Wash your hands before handling food and eating.

SOURCE: Cyclospora Infections (Cyclosporiasis) ( )
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