Oh Great, a Parasite That Causes Explosive Diarrhea Is Spreading Right Now

https://gizmodo.com/oh-great-a-parasite-that-causes-explosive-diarrhea-is-spreading-right-now-2000780106

Oh Great, a Parasite That Causes Explosive Diarrhea Is Spreading Right Now
Clusters of cyclosporiasis have been reported in multiple states, and several people have been hospitalized.
By Ed Cara
Published July 1, 2026, 1:15 pm ET

If there was one word you wouldn’t want to hear in front of the word “diarrhea,” it’d be “explosive.” Unfortunately, it’s a combination that some Americans are personally experiencing right now, thanks to ongoing outbreaks of a parasitic foodborne disease called cyclosporiasis.

According to the Centers for the Disease Control and Prevention, there have been nearly 150 cases of cyclosporiasis reported across 17 states since early May, with close to two dozen people needing hospitalization as a result. The true toll of cases is almost certainly higher, though, and no clear food source behind these outbreaks has been identified as of yet.

Cyclosporiasis is caused by various species of the microscopic parasite Cyclospora, though it’s predominantly Cyclospora cayatenensis.

It usually takes about a week to feel sick after being infected, and the main symptom of cyclosporiasis, according to the Cleveland Clinic, is “loud, watery (explosive) diarrhea.” Joy. The infection can also cause fatigue, loss of appetite, and vomiting, though some people infected with the parasite are fortunate enough to avoid any symptoms at all. People generally feel better after a week or two without the need for treatment, though symptoms can last up to a month. While the infection is rarely fatal, people with weakened immune systems are more vulnerable to severe illness.

Cyclosporiasis is a nationally notifiable disease in 47 states, meaning doctors and testing labs are obligated to report any confirmed cases to their local or state health departments. According to the CDC, cases of cyclosporiasis in the U.S. tend to increase during the warmer months, and this year is no exception. Between May 1 and June 16, there have been 145 domestically acquired cases in 17 states reported to the CDC; of these, 20 people have been hospitalized, though no deaths have been recorded. There have also been 45 reported cases associated with travel (meaning they were likely infected outside of the U.S.).

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