Health officials are investigating an explosive diarrhea parasite outbreak caused by Cyclospora. Learn the symptoms, affected states, and how to stay safe.
Michigan has seen one of the largest surges, along with Ohio and North Carolina.
Health officials are investigating a growing explosive diarrhea parasite outbreak after cases of a gastrointestinal illness caused by the parasite Cyclospora cayetanensis were reported in multiple states. While the source of the outbreak has not yet been identified, the U.S. Centers for Disease Control and Prevention (CDC) says the illness is seasonal and often linked to contaminated fresh produce.
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The illness, known as cyclosporiasis, affects the small intestine and can leave people dealing with weeks of unpleasant digestive symptoms if left untreated.
The outbreak is being caused by Cyclospora cayetanensis, a microscopic parasite that spreads through food or water contaminated with human feces. Unlike many stomach bugs, Cyclospora is not typically spread from person to person because the parasite needs time to mature in the environment before it becomes infectious.
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According to the CDC, investigators are working alongside state health departments and the U.S. Food and Drug Administration to determine whether the recent illnesses are connected to a single contaminated food source or several separate outbreaks. So far, no specific product has been identified.
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Historically, Cyclospora outbreaks have been linked to fresh produce, including cilantro, basil, raspberries, lettuce, and bagged salad mixes.
The most commonly reported symptom is watery diarrhea with frequent — and sometimes explosive — bowel movements, but the parasite can cause a range of gastrointestinal issues.
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@cbsnewsSince June 22, Michigan has reported more than 170 cases of cyclosporiasis, an illness that mostly originates from contaminated food and water and can cause severe gastrointestinal symptoms, like explosive diarrhea. CBS News' Ash-har Quraishi has more information on the spiking cases, what they could mean for the rest of the U.S. and how to prevent yourself from getting it this holiday weekend. #news #michigan #sick #fourthofjuly #gastrointestinal
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Other symptoms may include:
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Symptoms usually begin about one week after exposure, although they can appear anywhere from a few days to two weeks later. Without treatment, the illness can last for several weeks or even longer, and symptoms may temporarily improve before returning.
While most healthy adults recover, dehydration can become a concern, particularly for older adults, young children, and people with weakened immune systems.
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The CDC has confirmed cases across multiple states, with health officials noting that the true number of infections is likely higher than reported because many people never seek medical care or testing.
Michigan has seen one of the largest surges, with hundreds of confirmed cases reported in recent weeks. Other states, including Ohio and North Carolina, have also reported increases as investigators continue tracking the outbreak.
— Complex (@Complex) June 30, 2026There is a parasite outbreak that is causing explosive diarrhea in the U.S 😳
The CDC says at least 145 people in 20 states have gotten sick from the parasite Cyclospora, with 20 people hospitalized and no reported deaths.
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Because investigators have not yet identified the source of the outbreak, there is no way to avoid one specific food item. However, health experts recommend taking a few basic precautions:
If you develop persistent watery diarrhea, especially after eating fresh produce or traveling, health experts recommend contacting a healthcare provider. Cyclosporiasis can often be treated with prescription antibiotics, and early treatment may help shorten the illness and reduce the risk of complications.