July 2026
NCCID Disease Debriefs provide Canadian public health practitioners and clinicians with up-to-date reviews of essential information on prominent infectious diseases for Canadian public health practice. While not a formal literature review, information is gathered from key sources including peer-reviewed literature, the Public Health Agency of Canada (PHAC), the USA Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO).
Questions, comments and suggestions regarding this debrief are most welcome and can be sent to nccid@umanitoba.ca
What are Disease Debriefs? To find out more about how information is collected, see our page dedicated to the Disease Debriefs.
Questions Addressed in this debrief:
- What are important characteristics of cyclosporiasis?
- What measures should be taken for a suspected cyclosporiasis case or contact?
- What is the current risk for Canadians with cyclosporiasis?
What are important characteristics of Cyclosporiasis?
Characteristics & Cause:
Cyclosporiasis is an intestinal disease caused by Cyclospora cayetanensis, a protozoan parasite. Transmission occurs via ingestion of sporulated oocysts in contaminated food or water (fecal‑oral route). It is not typically spread directly from person to person.
Cyclospora can be found in sewage and untreated water. It is found worldwide, but is most commonly found in tropical and subtropical areas, such as:
Peru, Cuba, India, Nepal, Mexico, Guatemala, Southeast Asia, Dominican Republic
Cyclospora cavetanensis is not common in food and is not in drinking water in Canada. However, food can be a source of cyclosporiasis for Canadians when imported from countries where it is common. Foods imported to Canada that have been linked to the Cyclospora parasite include basil, cilantro, raspberries, blackberries, mesclun lettuce, snow and snap peas, and pre-packaged salad mix.
CDC – Parasite – Cyclosporiasis
Cleveland Clinic – Cyclosporiasis
California Department of Public Health – Cyclosporiasis
Signs & Symptoms:
Cyclosporiasis infects the small intestine and typically causes watery diarrhea with frequent, sometimes explosive, bowel movements. Other symptoms may include:
- abdominal bloating and gas
- fatigue (tiredness)
- stomach cramps
- loss of appetite
- weight loss
- mild fever
- nausea
It may take 7 to 14 days for symptoms to appear after intake of contaminated food or water.
If left untreated, the illness may persist for a few days to a few months. Most people have symptoms for 6 to 7 weeks. Sometimes, symptoms may go away and then return in a remitting-relapsing course. Although cyclosporiasis is usually not life-threatening, reported complications have included malabsorption, cholecystitis, and reactive arthritis.
CDC – Clinical Overview of Cyclosporiasis
Cleveland Clinic – Cyclosporiasis
California Department of Public Health – Cyclosporiasis
Epidemiology
Cyclospora is endemic in tropical and subtropical regions. In non‑endemic countries, cases are often linked to imported fresh produce (e.g., berries, leafy greens, herbs). Seasonal outbreaks have been reported in North America, with increased detection during warmer months when produce supply chains are active.
Cleveland Clinic – Cyclosporiasis
California Department of Public Health – Cyclosporiasis
Transmission & Risk Factors
Transmission: ingestion of contaminated food or water containing sporulated oocysts. Risk factors include consumption of raw produce, travel to endemic areas, and exposure to contaminated water or sanitation breakdowns.
Imported foods that have been linked to outbreaks of cyclosporiasis include basil, cilantro, raspberries, blackberries, mesclun lettuce, snow and snap peas, and pre-packaged salad mix
Canadians at the greatest risk of getting cyclosporiasis are travellers to high-risk countries who:
- eat fresh produce
- drink untreated water
Populations at higher risk for a longer or more severe illness include:
- young children
- older adults
- persons with a weakened immune system (cannot fight disease easily)
PHAC – Risks of cyclosporiasis (Cyclospora)
CDC – Clinical Overview of Cyclosporiasis
Cleveland Clinic – Cyclosporiasis
California Department of Public Health – Cyclosporiasis
Prevention & Control
Prevention focuses on food safety: washing produce, safe handling, and preventing contamination at production and distribution points. Public health measures include outbreak investigation, traceback, and recall of contaminated products.
When travelling to a country where Cyclospora is found, people can reduce their risk by:
- avoiding food that has been washed in local drinking water
- drinking water from a safe source
- eating cooked food only, or fruit peeled by the person eating it.
It can be hard to prevent cyclosporiasis. This is because washing produce does not always get rid of the Cyclospora parasite that causes the illness. Risk can be reduced by following safe food handling practices, consuming produce grown in Canada, and cooking produce imported from countries where Cyclosporiasis is found
PHAC – Prevention of cyclosporiasis (Cyclospora)
CDC – Cyclosporiasis prevention
Diagnosis & Testing
Diagnosis is typically confirmed by identification of the Cyclospora oocyst in:
- duodenal aspirates
- small bowel biopsies
- fresh or iodine-preserved stool
With acid-fast or safranin O staining, oocysts can be seen as 10 µm spheres with clusters of refractile globules. Diagnosis can be performed using modified Ziehl-Neelsen (MZN) and auramine-rhodamine stains.
Several stool samples may be required due to intermittent shedding.
PHAC – For health professionals: Cyclosporiasis (Cyclospora)
CDC – Clinical Overview of Cyclospora
Treatment & Clinical Management
Trimethoprim-sulfamethoxazole (TMP‑SMX) is the first-line treatment, with symptom resolution usually reported within 2-3 days of therapy. No highly effective alternative antibiotic regimen has been identified yet for patients who:
- have a sulfa allergy, or
- do not respond to the standard treatment
Supportive care includes hydration and electrolyte replacement. Immunocompromised individuals may experience longer or more severe illness.
Care precautions
Treatment in pregnancy
Trimethoprim-sulfamethoxazole (TMP-SMX) is a pregnancy category C drug. TMP-SMX should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. TMP-SMX should be avoided near-term because of the potential for hyperbilirubinemia and kernicterus in the newborn.
Pregnancy Category C: Studies in both animals and humans have revealed adverse effects on the fetus (teratogenic or embryocidal, or other), and there are no controlled studies in women or studies in women and animals are not available. Drugs should be given only if the potential benefit justifies the potential risk to the fetus.
Treatment during lactation
Trimethoprim-sulfamethoxazole (TMP-SMX) is excreted in breast milk. TMP-SMX generally is compatible with breastfeeding of healthy, full-term infants after the newborn period. However, TMP-SMX generally should be avoided by women when nursing infants who are premature, jaundiced, ill, or stressed, or who have glucose-6-phosphate dehydrogenase deficiency.
Treatment in pediatric patients
The safety of trimethoprim-sulfamethoxazole (TMP-SMX) in children has not been systematically evaluated. Use in children under 2 months of age is generally not recommended.
PHAC – For health professionals: Cyclosporiasis (Cyclospora)
CDC – For Health Care Providers – Clinical Care of Cyclosporiasis
Cleveland Clinic – Cyclosporiasis
Case Definition
Only confirmed cases of cyclosporiasis should be notified nationally.
Confirmed case
Laboratory confirmation of infection in a person with or without clinical illness from an appropriate clinical specimen (e.g., stool, intestinal fluid, small bowel biopsy), with demonstration of:
Cyclospora spp. oocysts;
or
Cyclospora spp. nucleic acid (e.g., by polymerase chain reaction (PCR) or other nucleic acid test (NAT)).
Probable case
Clinical illness in a person who is epidemiologically linked to a confirmed case
Note:
Probable case definitions are provided as guidelines to assist with case finding and public health management and are not for national notification purposes.
The disease is not endemic in Canada; therefore, cases should be investigated as most likely associated with imported food or travel.
Direct person-to-person transmission is unlikely to occur.
What measures should be taken for a suspected cyclosporiasis case or contact?
Cyclosporiasis is a nationally notifiable disease in all provinces and territories.
Cases are reported to provincial or territorial departments of health and the federal government, if they meet the national case definition.
PHAC – Surveillance of Cyclosporiasis (Cyclospora)
Canada monitors food-borne illness using data from a number of surveillance systems to estimate food-borne illness, relying on information provided by the local public health authorities and laboratories as well as provincial and territorial public health ministries and authorities. These surveillance systems include:
- Canadian Notifiable Disease Surveillance System (CNDSS)
- National Enteric Surveillance Program (NESP)
- Enhanced National Listeriosis Surveillance
- FoodNet Canada
- Provincial and Territorial Reportable Disease Surveillance System
- National Studies on Acute Gastrointestinal Illness (NSAGI)
Other important surveillance systems for food-borne illness in Canada include:
- PulseNet Canada
- Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS)
PHAC – Surveillance of food-borne illness in Canada
What is the current risk for Canadians with Cyclosporiasis?
As of July 11, 2026, 107 cases have been reported in Quebec compared to 30 cases in 2025. In British Columbia (BC), 93 cases have been reported this year. Seven cyclosporiasis cases have been reported in Alberta, of which four cases were associated with recent travel to Mexico. Nunavut health officials confirmed five lab-confirmed cases this year, but there is no evidence to suggest that the cases identified in Nunavut are linked to any ongoing foodborne outbreak or to imported fruits or vegetables from the United States. In addition, in March of 2026, two cases were reported to Public Health Ontario, and Manitoba has also reported one case.
Between 2004 and 2023, an average of 298 cases of cyclosporiasis were reported annually through the Canadian Notifiable Diseases Surveillance System.
According to the Centers for Disease Control and Prevention, as of July 14th, 2026, nearly 7000 cyclosporiasis cases have been reported in the US.