For the past few weeks, headlines about the “explosive diarrhea” parasite have been seemingly everywhere, causing widespread concern about how to avoid cyclosporiasis, which is typically spread through foods, like fresh produce
Cyclosporiasis, a gastrointestinal infection with the parasite cyclospora, isn’t new and usually ramps up in the U.S. in the summer. However, multiple states are seeing large clusters of cases at numbers higher than expected for this time of year
“The very quick uptick and high numbers of cases, I would say, is unusual,” Kali Kniel, Ph.D., professor of microbial food safety at the University of Delaware, tells TODAY.com
The parasite spreads through contaminated food or water, and past outbreaks have been linked to raw produce. So, what’s driving the latest spike — and is it safe to enjoy fresh fruits and vegetables this summer?
Health officials are still investigating a potentialrently unclear if the outbreaks in different states are connected, the U.S. Centers for Disease Control and Prevention previously told NBC News
What Is the ‘Diarrhea Parasite’ Going Around?
Cyclosporiasis is caused by Cyclospora cayetanensis, a microscopic parasite carried in human feces. People become infected by consuming food or water contaminated with particles of feces from an infected person, Kniel explains
When ingested, cyclospora infects the small intestine and causes severe gastrointestinal upset. The most common symptom of cyclosporiasis is sudden, watery, “explosive” diarrhea, which may persist for weeks, TODAY.com reported previously
It’s usually not life-threatening, and people can recover on their own, Kniel says. However, treatment with a combination antibiotic is highly effective
After the parasite is shed in stool, it takes one to two weeks living outside the body to mature and become infectious, says Kniel, which makes direct, person-to-person spread highly unlikely
The parasite can get into produce if it’s grown in soil or washed with water contaminated with feces, for example. Fresh fruits and vegetables are common culprits, says Kniel
Where Are Cyclosporiasis Cases Surging?
As of July 13, at least 4,202 cases of cyclosporiasis have been reported in more than 30 states, according to reports from state health departments confirmed to TODAY.com and NBC News
Additionally, the CDC has confirmed reports of 843 cyclosporiasis cases and 86 hospitalizations May 1, which is considered the start of cyclosporiasis season in the U.S
Michigan is being hit the hardest. As of July 13, the state has reported 2,640 cyclosporiasis cases and 44 hospitalizations, per the Michigan Department of Health and Human Services
Ohio, New York, North Carolina and Illinois are also seeing cases surge into the hundreds
There’s no evidence that there is a single, multi-state outbreak and it’s unclear if these clusters are connected, the CDC says
“There may be multiple unrelated outbreaks going on at the same time,” Donald Schaffner, Ph.D., professor of food microbiology in the Department of Food Science at Rutgers University, tells TODAY.com
The true number of cyclospora infections in the U.S. is likely higher than the numbers currently being reported. That’s because many people who get sick with diarrhea do not go to a doctor or get tested for cyclospora, per the CDC
What Food Is Driving the Rise in Cyclospora Cases?
The cause of the recent cyclosporiasis outbreaks is still unknown
The CDC is working with the U.S. Food and Drug Administration to investigate a potentialon food
Currently, the spotlight is on fresh fruits and vegetables. That’s because past cyclosporiasis outbreaks in the U.S. have been linked to contaminated salad greens, cilantro, basil and raspberries, per the CDC
However, the experts emphasize that food isn’t the only culprit, and that water could potentially be to blame
Water contaminated with feces can be used to irrigate produce crops, for example. People can also become infected from drinking or swimming in untreated water
“I think there’s a good chance that water may be contaminated, especially with the rise of cases in Michigan,” says Kniel
In Michigan and Ohio, the surges are happening in counties that border Lake Erie. “These cases seem to me to be more a waterborne outbreak rather than a foodborne outbreak because of the geographical clustering,” says Schaffner
So far, theHHS
“Much more likely, there are multiple parallel pathways for people to become infected,” Dr. Trevor Suslow, an expert on food safety and professor at University of California, Davis, tells TODAY.com
Tracking Cyclospora Outbreaks
Cyclospora is a challenging parasite to track, food safety experts tell TODAY.com
Symptoms may not appear for up to 10 days, and confirming the diagnosis investigate can take weeks. By then, the person isn’t likely to remember what they consumed that could’ve caused the symptoms
As a result, only a small portion of cases every year get traced back to a particular food item, Dianna Blau, acting chief of the CDC’s Parasitic Disease Branch, told NBC News
It’s also worth noting that, in July 2025, the CDC’s foodborne surveillance network made testing for cyclospora optional, which could be impacting the response, Schaffner says
Should You Avoid Certain Produce?
The only way to prevent cyclosporiasis to avoid food and water that may be contaminated with feces. And because nokeep off your grocery list — but the experts caution people not to panic
“Almost all servings of fresh fruits and vegetables that you can buy on the market today are not linked to this outbreak, and are not any more likely to cause illness because of the outbreak,” says Schaffner
So, currently there’s no reason to cut out raw produce, especially during peak season for so many delicious fruits and vegetables, the experts say
“We know that fresh (produce is) part of a healthy diet, and I certainly don’t want to discourage that,” adds Schaffner, who still plans to enjoy his favorite fresh produce this summer
How to Prevent Cylospora
“There are ways to be proactive,” says Kniel
Heat is the most effective way to destroy the cyclospora parasite, so cooking food to least 158 degrees Fahrenheit is one way to protect yourself
Freezing can also kill the parasite, but it’s not guaranteed, NBC News reported previously
Washing produce thoroughly can reduce the risk of foodborne illness, but it won’t eliminate cyclospora entirely, Suslow notes
State health departments offer a few more tips to prevent cyclospora infection:
- Wash your hands with soap and hot water before and after handling raw produce.
- Scrub all fresh fruits and vegetables with a produce brush under clean, running water. Do not use soap.
- Remove the outer layer of leaves or the peel, if possible.
- Cut or peel off damaged areas of produce before eating.
People with weakened immune systems may need to take extra precautions and should consult their doctor about how to avoid foodborne illness, Kniel
“We are seeing hospitalizations, so if you do get sick, good hydration is critical, and so is getting clinical care because this can be treated,” says Kniel
If you develop symptoms of cyclosporiasis, contact your doctor
