ASHLAND — You don’t have to hop on a plane to get traveler’s diarrhea.
Hundreds of Americans, including more than 170 Ohioans, have come down with cases of cyclosporiasis — an intestinal illness caused by a microscopic parasite. That’s probably a microscopic number compared to those who haven’t reported the ailment but are afflicted with it.
Cyclosporiasis outbreaks aren’t unprecedented in the United States, but are more common in tropical or subtropical parts of the world, according to the Cleveland Clinic.
The illness is not usually life-threatening and in some cases, infected people don’t even experience symptoms, according to the CDC.
Nevertheless, cyclosporiasis can be unpleasant. Those who are affected tend to experience watery diarrhea with “frequent and sometimes explosive bowel movements.”
Other symptoms may include bloating, cramping, loss of appetite, fatigue, low-grade fever, nausea and vomiting.
The parasite spreads when people eat food or drink water that was contaminated with feces. Symptoms usually appear about one week after becoming infected, but can begin as early as two days or upwards of two weeks.
Symptoms may regress and then relapse once or more, the CDC states. People can get infected with cyclosporiasis more than once.
How to reduce your risk
Public health officials haven’t been able to pinpoint the source of the latest outbreak. But fresh produce has been linked to cases in the past.
The most common culprits of outbreaks in the U.S. have included raspberries, basil, salad mixes, cilantro, berry or fruit mixes, lettuce and snap peas, per reporting from CNN.
To reduce your risk of cyclosporiasis, wash your hands with soap and water before and after handling raw fruit and vegetables.
Wash fresh fruits and vegetables thoroughly under warm running water. Scrub firm produce, like melons, with a clean produce brush. Wash all food prep surfaces, dishes and utensils with hot water and soap after use.
Cut, peeled or cooked fruits and vegetables should be eaten or promptly refrigerated.
One of the hardest-hit states in the latest wave of cyclosporiasis is Michigan, where public officials have urged the public to take extra precautions around leafy greens.
“While the investigation is ongoing, current results point to lettuce or salad greens as a potential source for this outbreak, although other food items cannot be completely ruled out,” the state health department announced via press release on Monday.
No specific type of produce, grower or supplier has been identified as the source, the release stated.
The Michigan Department of Health and Human Services recommended cooking produce whenever possible, as heating food to at least 158 degrees Fahrenheit kills cyclospora.
Other tips included discarding the outer layers of lettuce heads and purchasing whole heads of lettuce rather than pre-washed bagged lettuce or pre-mixed salad kits.
What to do if you suspect you’re infected
Most people with healthy immune systems will recover from cyclosporiasis without treatment, while people in poor health or those who are immunocompromised may be at a higher risk for severe or long illness, according to the CDC.
But that doesn’t mean you shouldn’t call your doctor. Left untreated, cyclosporiasis may last between a few days to more than a month.
Cyclosporiasis can be treated with antibiotics, according to the Ohio Department of Health, which may make symptoms go away sooner. Longer bouts of cyclosporiasis can increase a person’s risk for dehydration, according to the Cleveland Clinic.
As with most stomach bugs, it’s important to get plenty of rest and stay hydrated. Avoid caffeinated beverages and alcohol and eat food however you can.
Cyclosporiasis case rates are higher than normal this year
The Ohio Department of Health is reporting 177 cyclosporiasis cases in the state in 2026, according to a July 8 press release. Of those, 171 cases occurred in June, mostly since June 20.
Twenty-eight Ohioans have been hospitalized as a result.
“Fortunately, there have been no deaths in Ohio, as is consistent with our past experiences with this illness,” said ODH Director Bruce Vanderhoff.
“Nevertheless, this is a serious illness that can cause dehydration and require people to seek emergency medical care, and it should be taken seriously.”
Cyclosporiasis cases tend to rise during the spring and summer months, but this summer’s wave appears to be an unusual uptick. So far this year, multiple states have reported an increase in cases in the last two weeks compared to the same period in 2025, the CDC reports.
There were 843 confirmed domestic cases of cyclosporiasis reported to the CDC between May 1 and July 10. Those cases were spread across 31 states, resulting in 86 hospitalizations.
The CDC is also aware of more than 1,500 suspected cases requiring additional analysis, according to a July 10 bulletin on the agency’s website.
Not all cases appear to be homegrown. The CDC also reported that, as of July 9, there have been an additional 343 cases contracted by U.S. residents while traveling abroad.
Cyclospora is one of eight food borne micro-organisms that has been monitored by FoodNet, a collaboration between the CDC, USDA, FDA and ten state health departments, for decades.
Reporting for all but two of them (salmonella and E. coli) became optional last year.
A disclaimer on FoodNet’s website states that “no recent changes have been made to how CDC and our federal, state, and local partners detect and investigate outbreaks through existing epidemiologic or laboratory systems.”
