U.S. cyclospora outbreak hits 1,645 cases across 34 states; Canada monitoring but not yet affected
The parasite outbreak linked to fresh produce has caused 141 hospitalizations with zero deaths. A Toronto infectious disease specialist explains the risk to Canadian travellers and what to watch for.
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An outbreak of cyclospora—a microscopic parasite that causes explosive diarrhea—has sickened over 1,600 people across 34 American states, with investigators still searching for the source of contamination.
As of July 13, the U.S. Centers for Disease Control and Prevention reported 1,645 lab-confirmed cases linked to food consumed in the United States, with 141 hospitalizations and zero deaths. The CDC is investigating Taco Bell and various lettuce suppliers as potential sources, though no specific food item has been confirmed.
Canada is not currently investigating any cyclospora outbreaks, according to the Public Health Agency of Canada. Isaac Bogoch, an infectious diseases specialist at Toronto General Hospital, said that while wealthy countries like Canada and the United States see small outbreaks from time to time—usually related to imported fresh produce—an outbreak of this magnitude is rare.
"The reason is because the parasite has to have about six or seven days outside of a human host in the right environment to fully develop before it can be infectious," Bogoch explained. Most cases of cyclospora diarrhea spread through eating contaminated food rather than person-to-person transmission.
Symptoms typically appear seven to 14 days after consuming contaminated food or water and include watery diarrhea, abdominal bloating and gas, fatigue, stomach cramps, loss of appetite, weight loss, mild fever, and nausea. If left untreated, symptoms can last from days to a few months, though most people experience them for six to seven weeks. A prescription antibiotic can improve symptoms within two to three days.
For Canadian travellers visiting affected U.S. states—particularly Michigan and Ohio—Bogoch recommends following the adage "boil it, cook it, peel it, or forget it." This means peeling back the outside layer of fruits and vegetables, cooking produce over high heat, or avoiding uncertain items altogether. Young children, older adults, and those with weakened immune systems face higher risk of more severe illness.
By the numbers
How many cyclospora cases have been confirmed in the U.S. outbreak as of July 13, 2026?
As of July 13, 2026, the U.S. Centers for Disease Control and Prevention reported 1,645 lab-confirmed cyclospora cases linked to food consumed in the United States, with 141 hospitalizations and zero deaths.
How long after exposure do cyclospora symptoms typically appear?
Symptoms of cyclospora typically appear seven to 14 days after consuming contaminated food or water.
How long does cyclospora diarrhea usually last if treated?
If left untreated, cyclospora symptoms can last from days to a few months, but a prescription antibiotic can improve symptoms within two to three days.
