What to know about 'explosive diarrhoea' parasite outbreak in US

July 9, 2026

A parasitic outbreak causing cyclosporiasis has affected thousands of people across more than a dozen US states, with Michigan reporting approximately 1,000 cases within just two weeks. The infection, transmitted through contaminated food or water, causes severe watery diarrhea and can last from several days to over a month if left untreated. Although 20 people required hospitalization, no deaths have been reported from this outbreak.

Who is affected

Thousands of people across 17 US states (including Michigan, Illinois, New York, Texas, and Ohio)
Nearly 1,000 people in Michigan specifically (within a two-week period)
141 people in Illinois
177 people in Ohio
20 people hospitalized nationwide
Restaurants and kitchens preparing or serving raw produce

What action is being taken

The US Centers for Disease Control and Prevention (CDC) is tracking and sharing data on reported cases
State public health departments are reporting increasing numbers of infections
Michigan's health department is recommending restaurants and kitchens thoroughly wash greens, cook raspberries and leafy greens when possible, and remove outer layers of lettuce and green onions

Why it matters

This outbreak is significant because it has spread rapidly across multiple states with unusually high infection numbers (described as "higher-than-average" in Illinois). While not typically life-threatening, the illness causes severe symptoms that can last over a month if untreated and may return after appearing to resolve. The unknown source of contamination creates ongoing public health risks, particularly since the actual number of infected people is likely higher than reported as many recover without seeking medical care or testing.

What's next

The BBC has asked the CDC for more up-to-date figures
Health officials are conducting traceback investigations to identify the specific produce type, grower, or supplier responsible for the outbreak
People experiencing diarrhea are urged to contact healthcare providers and ask about possible infection

Read full article from source: BBC