Cyclosporiasis: Preventing The Spread Of The ‘Explosive Diarrhea’ Parasite

Headlines about the parasite causing “explosive diarrhea” in several states, including Indiana, may make some parents nervous or question what’s safe to eat, but a Franciscan Health infectious disease doctor says simple steps make the difference in preventing the spread of cyclosporiasis.

Franciscan Health infectious disease expert Erica West, MD, who helped write the American Medical Association’s information page on Cyclospora, discusses how we can best prevent the spread of the Cyclospora parasite, symptoms of an infection and treatment options. 

Key Takeaways: Cyclosporiasis Symptoms, Treatment & Prevention

• Thorough handwashing and washing of produce and utensils can prevent the spread of the Cyclospora parasite.
• It takes about a week for GI symptoms to begin, and for most people, symptoms may end within a week. Others may have symptoms that last for weeks and may need antibiotics as part of their treatment.
• Cyclosporiasis treatment at home includes staying hydrated.

What Is Cyclosporiasis?

Cyclosporiasis, known in the media as an illness involving “explosive diarrhea,” is caused by the parasite, Cyclospora cayetanensis. A multi-state outbreak, including Indiana and surrounding states, made the news in summer 2026.

How Is Cyclospora Spread?

Cyclospora is spread when people eat food or water that has been contaminated with feces (poop) that contains the parasite. Previous outbreaks, which often occur between May and July, have been linked to fresh produce.

“The way Cyclospora causes infection is that we ingest from the contaminated produce little oocytes," explained Dr. West, who practices at Franciscan Health Dyer in northwest Indiana. "Those oocytes, once we ingest them, take about a week - it sounds gross - but it's going to sporulate in your body and that's what actually releases the parasite and causes the infection.”

According to the Indiana Department of Health, person-to-person spread of cyclosporiasis is unlikely.

What Is My Risk Of Getting Cyclosporiasis?

Dr. West says the general risk of you becoming infected is low. Typically, the U.S. has between 10 and 15 outbreaks per year, resulting in between 200 and 1,000 illnesses.

“I don't want people to use these types of outbreaks as a reason to cut off all eating of anything green, leafy or from a tree,” Dr. West said. “There are still a lot of benefits to eating fruits and vegetables. So as long as you are washing them, using those little vegetable scrubbers to make sure you get a clean surface, your risk is going to be really low. “

People more at risk

“People who are especially prone to dehydration are the ones who tend to get the sickest,” Dr. Kaufman West said.

Those groups include:

• Infants, toddlers and small children
• Older adults
• Having certain underlying illnesses or taking diuretics

What Are Symptoms Of Cyclosporiasis?

Cyclosporiasis symptoms are typically gastrointestinal in nature. They include:

GI symptoms

• Watery diarrhea. It’s been often described in the media as “explosive diarrhea.”
• Loss of appetite
• Stomach pain or cramps
• Bloating
• Gas
• Nausea
• Vomiting

Other symptoms of cyclosporiasis

• Body aches
• Headache
• Fever
• Flu-like symptoms

Cylosporiasis symptoms vs. stomach bugs

“There's not that much difference when you talk about diarrheal illnesses,” Dr. Kaufman West said. “This one they tend to call ‘explosive.’ There's a lot of intestinal inflammation that goes along with cyclosporiasis. It hits you fast, and you don't have a lot of time to get to the bathroom. Most stomach flus, as people call them, are going to be upper GI where it's a lot of nausea, vomiting and not wanting to eat.”

Cyclospora infects the intestines, not the stomach, leading to lower-GI symptoms, gas, cramping and diarrhea.

Cylosporiasis symptoms vs. IBS flares

While GI symptoms can happen with IBD flares, Dr. West notes one key difference.

“Some people that have inflammatory bowel disease can get bloody diarrhea. This should not be bloody,” she said. “It causes inflammation, but it doesn't necessarily cause an invasive sort of response like that. So if you do see bloody diarrhea, I would definitely go get it checked out because that's not commonly associated with Cyclospora.”

How Long Do Cyclosporiasis Symptoms Last?

Cyclosporiasis symptoms normally begin about a week after exposure and can last days or weeks. Some people may also experience a cycle where they feel sick, then feel better for a few days, and then start to feel sick again. Other infected people have no symptoms.

What Should I Do If I Have Cyclosporiasis Symptoms?

“If the illness lasts beyond several days, so if you're getting into week two of diarrhea, that's when you really want to go and get checked out,” Dr. West said. “Most viruses, like norovirus, that might cause similar-type symptoms, it's going to get through within about a week's time, and so you'll start to feel better.

“With Cyclospora, the symptoms can last for several weeks if untreated. So if you're finding yourself in week 2 and especially in week 3 and it's just not letting up, go in. When you have that prolonged illness, that's when you need to be concerned.”

How Is Cyclosporiasis Diagnosed?

Stool tests in a lab look for the DNA of the parasite.

“It's good from an epidemiologic standpoint to get tested, so that we can track if it's coming into a new area,” Dr. West said. “It's also important just from your own treatment perspective, making sure that you're getting on the right antibiotic for the right duration.”

How Is Cyclosporiasis Treated?

Some cyclosporiasis cases are treated with antibiotics containing sulfa, however many people with healthy immune systems can recover from cyclosporiasis without additional medical treatment.

How Can I Care For Myself At Home? 

Cyclosporiasis treatment at home focuses on staying hydrated. Make sure you are drinking extra fluids, as diarrhea can lead to your body becoming dehydrated faster.

Can I Prevent Cyclosporiasis?

While there is no vaccine to prevent cyclosporiasis, common-sense steps can help prevent the spread of the parasite.

“I wash all fruits and vegetables that come into my house, whether it's a grapefruit or carrots,” Dr. West said. “I also try to remember to wash all bagged green leafies. So if I buy a bag of baby spinach, for example, I'll put it in a colander, run water on it, give it a second to air out before I use it. Trying to wash all fruits and vegetables is really important, and then obviously trying to stay on top of hand hygiene. I do have children, so that's always difficult, making sure their hands are clean before they grab food and put it in their mouths. But those are the two main things that I focus on.”

Hand hygiene

Hand hygiene is an essential way to prevent transmission. Wash your hands when handling produce or after using the bathroom.

“If you're changing diapers, whether that's for the very young or the very old, hand hygiene's important regardless,” Dr. West said.

Food safety

Make sure hands, cutting boards, utensils and counters are clean when preparing food.

“Stay away from the produce that's been recalled and then, always, make sure that you're washing your produce,” Dr. West said. “You might think to wash the head of lettuce for example, but most people don't think to wash something like a banana or orange. But if you're going to cut through the peel, it’s important to wash. Make sure sure you wash all of your produce just to make sure that you're not getting this or any other infection that could be out there. If you've got a bruise on your produce, cut it off. You want to make sure that you cut all of the bruised areas off because that could be an indication that there's something going on in there.”

Refrigerate cut, peeled or cooked fruits and vegetables as soon as possible, or within two hours, to slow the spread of potential parasites.

Food items that have been recalled by the CDC should be disposed of.

“As long as you're checking that and making sure you're throwing out anything that is affected, I think the risk for most people is going to stay low,” Dr. West said.

Splash pads

“Things like splash pads are always a concern for multiple different bacteria,” Dr. Kaufman West said. “If you go to the splash pad and you see children in regular diapers, not those water-resistant diapers, that's going to be an issue, and you should be concerned about the potential spread of this or other illnesses.”

Dr. West said most publicly-managed pools do keep chemicals in balance to help keep bacteria levels low.

Travel

The Indiana Department of Health recommends using caution when traveling to countries with minimal sanitation systems and water treatment.

Work

If you work in healthcare, food handling, daycare or school settings, the Indiana Department of Health recommends that you not return to work or school after cyclosporiasis infection until approved by the local health department.

“We have really good food processing plants in the US, so these are not common occurrences, but every once in a while something does get contaminated,” Dr. West said. “I think that's probably why the heightened sense of urgency with this.”