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Federal and state authorities in the U.S. have been investigating cases of illness from an intestinal parasite.
Cyclospora is a microscopic parasite that contaminates food that has come into contact with human feces, such as when produce is irrigated or washed with contaminated water.
Cyclosporiasis, the infection caused by the parasite, most commonly causes diarrhea, but some people can experience other gastrointestinal symptoms and dehydration. Symptoms usually start within a week of ingesting the parasite, doctors say.
The illness usually does not spread from person to person.
As of July 20, more than 30 states have reported illnesses, with about 100 hospitalizations to date and no deaths. The true number of infections is likely much higher given that many people recover without seeking medical treatment and that there is lag between when symptoms start and reporting.
Public health officials say they are not currently investiagting any Cyclospora outbreaks in Canada.
The parasite can stick in the nooks and crannies of berries, food scientists say. (Frannyanne/Shutterstock)
Foods imported to Canada that have been linked to the Cyclospora parasite include:
- Basil.
- Cilantro.
- Raspberries.
- Blackberries.
- Mesclun lettuce.
- Snow and snap peas.
- Pre-packaged salad mix.
This is how the current outbreak south of the border unfolded and how Canadian health officials reacted.
May 13, 2026
The U.S. Food and Drug Administration (FDA) says this is when the first illnesses from the Cyclospora parasite started.
June 30
Michigan state health officials say as of this date, more than 170 cases have been reported across several counties compared with around 50 cyclosporiasis cases per year typically.
July 8
The Public Health Agency of Canada says it is not investigating any Cyclospora outbreaks in Canada and tells CBCNews the parasite is not commonly found on food and is not in drinking water here.
"In the spring and summer, there is usually an increase in Cyclospora infections linked to consuming fresh fruit and vegetables imported from other countries," a spokesperson for PHAC said in an email.
July 16
The FDA and U.S. Centers for Disease Control and Prevention (CDC), in collaboration with state and local partners, investigate a multi-state outbreak of Cyclospora illnesses linked to shredded iceberg lettuce served at Taco Bell locations in Indiana, Kentucky, Michigan, Ohio and West Virginia.
WATCH \| A food scientist explains Cyclospora:
What is cyclospora? A diarrhea-causing parasite
A diarrhea-causing parasite has led to a growing outbreak in the United States that has sickened more than 1,000 people and sent dozens to hospital. As of Wednesday, multiple states had reported cyclospora infections, which can cause watery diarrhea, bloating, fever and nausea. While cases are common in the spring and summer, the current outbreak has led to an unusually high number, making it one of the largest the country has seen. No deaths have been reported.
Illnesses start occurring between May 13, 2026, and July 13, 2026. Michigan analyzes food exposure details from 190 of the cases of people who reported eating at Taco Bell and shared these findings with CDC.
The FDA says its traceback investigation to try to find the source converged on a single supplier of iceberg lettuce from Mexico used by Taco Bell locations where sick people ate before becoming ill.
Meanwhile, health officials in Alberta say they're investigating an uptick in cyclosporiasis. But the province said no connection has been made between the Alberta illnesses and the American outbreak.
July 17
Taylor Farms de Mexico, which provided shredded iceberg lettuce used by Taco Bell locations where sick people ate before becoming ill, is flagged by the FDA as a supplier. The company announces that it is voluntarily removing all iceberg lettuce sourced from central Mexico from the U.S. market.
Health officials in Quebec say that since the beginning of the year, 85 cases of cyclosporiasis have been reported, compared to 30 cases in 2025 for the same period (average of 32 cases annually between 2022 and 2025).
"As in previous years, most Quebec cases are thought to be linked to travel exposure, primarily in Mexico," a spokesperson for Quebec's Ministry of Health and Social Services said in an email.
No Quebec cases appear to be associated with the outbreak in Michigan, they said.
July 18
On July 17, the FDA said Taylor Farms de Mexico, based in Guanajuato and also known as Taylor Fresh Foods, announces that it is voluntarily removing all iceberg lettuce sourced from central Mexico from the U.S. market.
A recall notice put out by Taylor Fresh Foods includes Marketside-brand iceberg lettuce products available at Walmart in the U.S.
July 19
The FDA points to the complexity of detecting Cyclospora, saying its laboratory experts concluded a new sample of shredded lettuce from Taylor Farms de Mexico tested positive for Cyclospora during import examination at the U.S.-Mexico border. This ended up being a false positive, the FDA said.
July 20
On social media, FDA officials clarify there is still "overwhelming epidemiological data" supporting a large voluntary recall by Taylor Farms.
The Public Health Agency of Canada says is still not currently investigating any Cyclospora outbreaks in Canada.