
Topics: Health, US News, Food and Drink
A parasite that causes severe, ‘explosive’ diarrhoea is spreading across multiple US states, prompting health experts to urge the public to watch for other symptoms.
Hundreds of cases of cyclosporiasis, an infection caused by a microscopic parasite, have been reported across 31 states. It has affected many people in Michigan, with the state reporting on Friday (12 July) that more than 1,000 people were diagnosed in just two weeks.
People can become infected by eating food or water that contains the parasite. The main symptom is frequent, water and explosive diarrhoea.
No deaths have been reported and the source of the spread is yet to be identified. It usually takes about one week after infection before the person becomes sick.
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The US Centers for Disease Control and Prevention (CDC) has been monitoring the situation and has shared that it received reports of 145 cases of cyclosporiasis acquired in the United States in people who became sick from May 1, 2026, through June 16, 2026.
However, with it now being mid-July, it’s likely that these aren’t the most up-to-date figures.
In addition to severe diarrhoea, Cleveland Clinic says suffers may also experience:
Some people may not experience any symptoms.
It is not yet known how or where the current outbreak started. Previous outbreaks in the US and Canada have been linked to bagged salads, fresh cilantro, fresh basil, raspberries, snow peas and green onions, the BBC reports.
Experts are advising that, since a source is yet to be pinned down, washing fruit and veg thoroughly is important.
Dr. Maryrose Laguio-Vila, an infectious disease physician at Rochester General Hospital, told Spectrum Local News: "This parasite can live on the surfaces of particularly raw fruits and vegetables. And so even when we buy it from the grocery stores, it is still good practice to wash thoroughly.”

Dr. Jim McDonald, commissioner of the New York State Department of Health, warned that the scale of the outbreak ‘points to a common source’.
He explained: “This speaks to its probably something that is commonly eaten in 29 states.”
While the parasite is not spread from person to person, according to Dr Caitlin Rivers of the Johns Hopkins Center for Health Security, anyone experiencing diarrhoea is urged to contact a healthcare provider and ask whether they should be tested for a possible infection, officials said.