Cyclospora Cases Appear in Canada as Major US Outbreak Raises Concern

Canadian health authorities are monitoring cases of the intestinal parasite Cyclospora in several provinces as a major outbreak continues in the United States, although investigators have not yet confirmed a direct link between infections reported in the two countries.

Cyclospora cayetanensis causes an intestinal illness known as cyclosporiasis. The parasite is most commonly transmitted through contaminated food or water, particularly fresh fruits and vegetables eaten without cooking.

Direct person-to-person transmission is considered unlikely because the parasite usually needs to remain outside the human body for approximately one to two weeks before it becomes infectious.

In Quebec, 107 cases had been reported by July 11, 2026, compared with 30 cases during the same period last year. Provincial health officials said most infections appeared to be travel-related, particularly involving travel to Mexico, while fewer than five patients reported recent travel to the United States.

British Columbia recorded 93 cases during the year. Health authorities said most infections are normally connected to international travel and that the number of cases remained within expected seasonal levels.

Six cases were also reported in Alberta, five laboratory-confirmed cases in Nunavut, one in Manitoba and two cases in Ontario earlier in the year.

Despite infections being recorded in several regions, the Public Health Agency of Canada said it was not currently investigating a national Cyclospora outbreak.

Canadian authorities have also not established a connection between domestic cases and produce imported from the United States.

Canada normally experiences a seasonal rise in cyclosporiasis cases during spring and summer. Previous infections have often been associated with fresh produce imported from countries where the parasite is more common.

The Canadian Food Inspection Agency has not announced broad restrictions on fresh agricultural imports from the United States. Health officials continue to review patients’ travel histories and food consumption records to identify possible common sources.

In the United States, the Centers for Disease Control and Prevention reported 1,645 laboratory-confirmed cases across 34 states by July 13. At least 141 patients were hospitalized, while no deaths were reported.

Health officials warned that the true number of infections could be higher because some patients are not tested and reporting may be delayed.

US investigators also linked an outbreak involving more than 1,600 illnesses to shredded iceberg lettuce served at Taco Bell restaurants in Michigan, Ohio, Indiana, Kentucky and West Virginia.

Supply-chain tracing indicated that the affected restaurants received lettuce from a single distributor using crops originating in Mexico. Investigators continued examining whether contaminated produce may have been supplied to other businesses.

The most common symptom of cyclosporiasis is frequent and sometimes severe watery diarrhea. Other symptoms may include loss of appetite, stomach cramps, bloating, increased gas, nausea, fatigue and weight loss.

Symptoms usually begin about one week after exposure, although they may appear within two days or take more than two weeks to develop.

Without treatment, the illness may last from several days to more than a month. Symptoms can disappear and later return.

Older adults, young children and people with weakened immune systems may face a greater risk of prolonged illness or dehydration.

Health authorities recommend washing hands carefully before and after preparing food and thoroughly rinsing fruits and vegetables under running water, even when packaging says the produce has been pre-washed.

Firm produce should be scrubbed with a clean brush, while peeled or cut fruits and vegetables should be refrigerated promptly.

However, washing may not completely remove Cyclospora from contaminated produce. Proper cooking can kill the parasite.

People experiencing persistent watery diarrhea or severe symptoms should contact a healthcare provider and mention the possibility of Cyclospora infection.

Routine stool tests do not always screen for the parasite, meaning a specific laboratory test may be required for diagnosis.