Illinois has confirmed 240 cases of the diarrhea-causing illness cyclosporiasis, the state’s public health department confirmed Wednesday.
Cyclosporiasis is not considered a deadly disease and is more of an inconvenience that in rare cases could have complications, said Dr. Emily Landon, an infectious diseases specialist at UChicago Medicine. In Illinois, 21 people have been hospitalized so far, according to the Illinois Department of Public Health. Most in Illinois who contracted the illness had traveled recently — 105 people internationally and 111 domestically. It’s unclear if the other 24 traveled.
Higher numbers of cyclosporiasis are typically reported in the summer months, but this year has seen an especially high number, health officials said.
The increase in Illinois is part of a larger number of cases in most states. Across 34 states, 1,645 cases have been reported, according to the Centers for Disease Control and Prevention.
Here’s what you need to know about cyclosporiasis in Illinois.
What is cyclosporiasis?
Pronounced sigh-klo-spore-EYE-uh-sis, cyclosporiasis is an intestinal illness caused by the microscopic parasite cyclospora. Infection often comes after eating fresh fruits and vegetables, and can lead to watery diarrhea, stomach cramps, gas and nausea.
The heat-loving parasite infects the bowels and spreads through feces. In the past, people have been infected by consuming fruits or vegetables that were exposed to feces-contaminated irrigation water.
What is causing cyclosporiasis in Illinois?
No definitive source has been identified for the current outbreak, but past outbreaks have been linked to imported fresh produce, like bagged salad kits and berries, according to IDPH.
Cyclosporiasis is not transmitted from person to person, Landon said. Even if a person becomes sick, people don’t usually contaminate objects in their house enough to spread it to someone else.
How long does it take to recover?
People should talk to their doctor about getting tested if they have symptoms, so health officials can continue to track the outbreak, said Gwen Biggerstaff, the CDC’s Deputy Director of Foodborne, Waterborne, and Environmental Diseases.
Most who contract the illness recover in one to two weeks, according to the CDC. Many can recover with rest and plenty of fluids, but some may need antibiotics.
People can experience bloating, gas and even dehydration but rarely have more complications.
“The problem with this disease is it can be kind of persistent,” Landon said. “And you can feel pretty sick and then you can be starting to get better and then the diarrhea can come back again.”
Should I stop eating fresh fruits and vegetables?
If a person is immunocompromised or has an underlying medical condition, they should take more precautions, Landon said. That’s especially true, for example, for those undergoing surgery soon or cancer treatments.
Everyone can follow typical food safety guidelines like washing hands and thoroughly washing and scrubbing fresh produce. Illinois health officials also suggest:
- Incorporate more fruits and vegetables with peels or outer layers.
- Eat canned fruits and vegetables.
- Keep produce separate from raw meat and seafood.
- Refrigerate cut, peeled, or cooked fruits and vegetables within two hours.
- Refrigerate perishable produce.
- Cook vegetables to at least 158 degrees Fahrenheit
Is it safer to buy produce from my local Illinois farmers market?
Fruits and vegetables coming from a smaller, local producer are likely to have less of a risk for contamination than food from massive manufacturers, Landon said. That’s especially true if an outbreak is centered around a certain product, but officials this time around don’t know if that’s the case.
So you shouldn’t assume there’s zero risk in buying from a local vendor because any farm can become contaminated especially because of the current weather, Landon said.
Vendors at Chicago farmers markets haven’t seen a decline in sales so far but have gotten more questions from customers.
“We are quite confident that it is not coming from our farm or any of the other local family farms around us,” said Christina Gelder of Ellis Family Farms. She added that they are in close contact with Michigan State University to track research related to the cyclosporiasis outbreak.
Chelsa Moore shopped for produce at the Pullman Farmers Market after going down a “rabbit hole” searching for best practices to avoid getting sick. She’s avoiding prepackaged food and triple rinsing produce at home.
“I’m kind of leaning toward the side of just like not buying anything from the big stores and going to the local farmers market,” she said. “And then even doing even more with prepping and cleaning.”
How is Illinois tracking the cases?
The Illinois Department of Public Health is working with local health officials to collect data on the cases. They are also working with the CDC to investigate a potential source causing the illness.
The CDC has identified one common source linked to outbreaks in Michigan, Ohio, West Virginia and Kentucky, and the agency is tracking other cases to identify likely sources. Michigan has reported 3,762 cases as of Wednesday, which is more than the total national figure the CDC has reported.
But several states — including Illinois — have reported cases unrelated to that cluster, said Biggerstaff, of the CDC. The federal agency also is investigating other outbreaks that could be connected.
The number of cases locally and across the country could be higher, Landon said. That’s because testing for cyclosporiasis is expensive and some insurance may not cover it. But as cases of cyclosporiasis are more in the news, doctors will likely start testing more patients or prescribe antibiotics to treat it if the person has symptoms.
If a person is confirmed to have cyclosporiasis, Landon said it’s important to cooperate with the local health department to detail everything they ate so officials can pinpoint the outbreak source.
Are federal cuts impacting the outbreak?
Last summer, the federal government scaled back a program, known as the Foodborne Diseases Active Surveillance Network, that monitored foodborne illnesses, NBC News previously reported. As part of the changes, reporting for cyclospora parasites became optional in 2025, according to the program’s website. The government had previously collected that data since 1997.
The scaled-back federal program worked with the FDA to proactively test certain foods to check if recalls were necessary, Landon said.
It’s hard to assess how much changes on the federal level are playing a role in the current outbreaks, Landon said. But it’s something health officials across the country should consider.
“It’s a combination of the nature of the illness, the fact that it’s happening at a time when there’s other sporadic cases and then the lack of infrastructure and resources available for testing does matter,” Landon said, summing up the factors driving the outbreak.