Latest updated map tracking 'explosive diarrhea' cases in the US
Health officials in several states are tracking new cases of cyclosporiasis, a foodborne infection caused by a parasite that leads to severe gastrointestinal symptoms, including intense diarrhea.
Wyoming has confirmed at least three cases of cyclosporiasis as of early July. Cases of cyclosporiasis, a parasitic infection known to cause severe diarrhea, have been reported in all but eight states, according to USA TODAY's reporting.
NBC News/Today's tally of state reports found more than 4,000 reported cases nationwide as of July 13, 2026, although those figures are not directly comparable to the Centers for Disease Control and Prevention's confirmed national surveillance count. Michigan has officially reported 2,640 cases to date. According to the CDC, there have been no deaths reported as of July 9.
Which states have identified cases of cyclosporiasis?
The actual number of cyclosporiasis infections is likely higher than reported, as many people recover without seeking medical care and therefore are never tested for cyclosporiasis.
According to NBC News reporting, Michigan, New York, Ohio, Illinois and North Carolina are among the states reporting the highest numbers of cases of the parasitic illness.
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How cyclosporiasis and other gastrointestinal illnesses differ and overlap
Cyclosporiasis can present with symptoms such as diarrhea, abdominal cramps, nausea and fatigue that overlap considerably with other gastrointestinal illnesses, making clinical diagnosis difficult without specific laboratory testing to identify the causative pathogen.
While cyclosporiasis has the public spotlight, other diseases such as E. coli/STEC and Salmonella are much more common in the United States and can cause severe gastrointestinal symptoms. Here's how they compare.
Guidance of dealing with foods
Cyclosporiasis cases have been linked to an assortment of fresh fruits, vegetables and herbs, including bagged salad mixes and kits, fresh cilantro, basil and parsley, raspberries, snow peas and green onions.
State health departments have issued guidance for avoiding the spread of cyclosporiasis, including:
- Avoid consuming food or water that may be contaminated with feces. Avoid drinking or cooking with untreated water.
- Wash your hands with soap and water after using the bathroom and before, during and after food prep.
- Wash all food prep surfaces, including utensils, cutting boards and countertops, before and after use.
- Wash and peel vegetables before eating them; scrub produce with skins like melons and cucumbers well; and cut away damaged or bruised areas on fruits and vegetables before preparing and eating them.
- Refrigerate prepared fruits and vegetables as soon as possible (within two hours).
- Cook your food when you can; heating food to 158 degrees Fahrenheit or higher kills cyclospora.
CONTRIBUTING: Mary Walrath-Holdridge, USA TODAY
This article originally appeared on USA TODAY: Latest updated map tracking 'explosive diarrhea' cases in the US
Reporting by Janet Loehrke, USA TODAY / USA TODAY
USA TODAY Network via Reuters Connect
Copyright Reuters or USA Today Network via Reuters Connect
This story was originally published July 13, 2026 at 2:22 PM.