Cyclospora: What to Know About the Parasite Sweeping the Nation

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Key tips for getting through an outbreak if you or your loved ones get sick. Read the full article on Health Lab.

Resources

Homemade Oral Rehydration Solution Recipe

Cyclosporia: Comprehensive Guide for Clinicians

Michigan Department of Health & Human Services: Infectious Disease Outbreaks

USDA Food Safety Basics

Transcript

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Welcome to Health Lab, your destination for news and stories about the future of healthcare.

In recent weeks, people across the country have had to solve an unfortunate riddle: What is small, causes “explosive diarrhea" and has been striking fear into the hearts of produce shoppers across the United States?

That’s right. You know it, you don’t love it, but its reputation precedes it - we’re talking about Cyclospora, the tiny parasite responsible for the huge wave of persistent diarrhea and gastrointestinal distress sweeping the nation.

The name for the disease caused by Cyclospora is cyclosporiasis - which scores of Americans have recently learned firsthand causes recurring diarrhea, nausea, stomach cramps and fever.

But other than giving lettuce and berries the sideeye, what can we do if Cyclospora pays us a house call? 

Today on Health Lab, we’re sharing expert tips on how to take care of yourself and others if cyclosporiasis unfortunately ends up on the menu.

Public health detectives in Michigan and other states have used clues from some infected patients to figure out that the infections stemmed from contaminated lettuce supplied to many restaurants and stores.

But even as the investigation continues into the origin of the outbreak, and the suspected lettuce is recalled or expires, many more people could still get sick.

This is because Cyclospora’s hard microscopic cells can take weeks to “hatch” in your gut, before they start wreaking havoc, and it can take weeks to get rid of, even with antibiotic treatment.

Mark Ealovega, M.D., and other primary care clinicians across University of Michigan Health have helped hundreds of patients cope with cyclosporiasis in recent weeks, and they expect more to come.

Dr. Ealovega, who is a member of the faculty in U-M Medical School’s Division of General Medicine in the Department of Internal Medicine, shared key insights for anyone affected by the cyclosporiasis outbreak so far.

Here are 8 experts tips about cyclosporiasis:

1. If you have symptoms that might be cyclosporiasis

Dr. Ealovega says, “While frequent, watery diarrhea is the most notorious symptom, cyclosporiasis can also cause abdominal cramping, low grade fever, and nausea.” He goes on, “Most cases will eventually get better on their own, but the symptoms can last for a month or longer if untreated.”

That prolonged misery is reason enough to reach out for care for any child or adult who develops symptoms.

But Dr. Ealovega emphasizes that the infection can be especially dangerous for people who are older, immunosuppressed or immunocompromised, pregnant, or have other chronic health problems.

And reporting symptoms can also help with tracking the size of this outbreak.

So, no matter what the person’s age or health status, call the person’s primary care doctor's office, by phone, to report the symptoms as soon as possible.

Calling is better than sending a patient portal message, which can take longer to get an answer.

The clinic will guide you on whether they will want to see the patient in person or virtually, to get a stool (poop) test kit, if the patient qualifies for antibiotics even before a test is done, or if they need to go to an urgent care center or emergency department.

2. Which symptoms of possible cyclosporiasis should make you seek emergency care?

If it’s hard to reach a primary care clinic by phone during nighttime hours or a weekend, or if the person doesn’t have a regular primary care provider, Dr. Ealovega says, it can be difficult to know what to do.

“You should seek emergency care if you or your loved one have severe symptoms such as very bad abdominal pain, high fever, or signs of severe dehydration such as severe dizziness or passing out,” he says.

3. Cyclospora poop tests must be handled carefully

To find out if Cyclospora is the cause of a person’s diarrhea, as opposed to some other cause, doctors can send a sample of the person’s poop to a clinical laboratory, such as Michigan Medicine’s MLabs, to be tested.

MLabs, for instance, runs tests for many clinics and health systems, and can detect Cyclospora’s genetic material through sophisticated rapid tests.

But these tests only work if the poop sample is in a special container that comes from the doctor’s office, is sterile until it is opened to put the sample in, and if it contains a substance that stabilizes the poop until it can be examined in the lab.

It is very important that you do not bring a stool sample to your clinic in any container other than one you were given for that purpose.

If your clinic gives you a poop test kit, follow the instructions carefully and make sure to handle the sample meticulously according to instructions, including the instructions on how to get it back to the clinic within the time limit.

If multiple people in your home are sick and are giving stool samples, make sure each person uses the kit with their name on it.

If your clinic doesn’t order a stool test for you, that’s OK – the outbreak is so widespread that many doctors have started assuming that most people with diarrhea lasting more than 48 hours have cyclosporiasis.

4. Hydrate, hydrate, hydrate

“You can become dehydrated very quickly from Cyclospora infection, and it is very important to focus on excellent hydration,” says Dr. Ealovega.

The best drinks to choose are water, juice (diluting them with water), broth or sports drinks, he says.

For people whose diarrhea is especially frequent, an oral rehydration solution such as Pedialyte and Liquid IV may also be helpful.

It’s important to also keep in mind that sports drinks such as Gatorade aren’t the same as oral rehydration solutions.

You can also make a homemade oral rehydration solution using a recipe that will be linked in the show notes for this episode.

5. Don’t use anti-diarrheal medication for suspected or known cyclosporiasis unless a health care provider says it’s OK

If your clinician is ordering a stool test, some medications can interfere with the results of one type of test, which looks for signs of parasite cells.

Not only that, but diarrhea is your body’s way of getting rid of the parasite.

That’s why it’s important to call your healthcare provider when symptoms start to determine your course of action, and to “hold off on any anti-diarrheal medications unless instructed to take it by your healthcare provider,” says Dr. Ealovega.

If your doctor says it’s OK to take medications like loperamide (which is sold as Imodium or the store brand), bismuth subsalicylate (sold as Pepto-Bismol, Kaopectate or store brand), follow the instructions on the label carefully.

It is also worth noting that probiotic supplements have not been shown to help with diarrhea caused by an infectious parasite.

6. Antibiotics can help, but you must follow the instructions

Because of the cyclosporiasis outbreak, the U-M Health Infectious Disease Division has put together comprehensive guides for clinicians about testing and using antibiotics in children and adults with infectious diarrhea, which they’ve made available for any clinician to use.

In general, most children and adults with diarrhea during a cyclosporiasis outbreak can receive an antibiotic combination called Bactrim, or TMP/SMX.

Even though antibiotics are usually used against bacteria, not protozoa (which is what Cyclospora is), the drug combination works.

“TMP/SMX works by sequentially blocking the parasites’ ability to make folate, and since it can’t use the host’s folate, it dies,” explained Lindsay Petty, M.D., Clinical Associate Professor in the Division of Infectious Diseases.

If a health care provider prescribes Bactrim to you or a loved one, it is very important to take it for the entire seven days of the prescription.

Do not stop early, even if symptoms go away before the last dose, and do not share your pills with anyone else.

People who are immunocompromised may need to take Bactrim for more than seven days.

Children over the age of 1 and adults who are allergic to sulfa drugs, which Bactrim contains, can take a different antibiotic, which may be somewhat effective.

7. If you're contacted by a public health agency, answer the phone

The probable source of the summer 2026 cyclosporiasis outbreak was found because people who got sick answered calls and texts from ‘disease detectives’ at the state health department.

This kind of sleuth work is critical to tracing outbreaks to their source, so that food producers, distributors, restaurants and stores can pull the contaminated product and prevent more illness.

Michigan’s public health department was able to contact individuals because clinics like Ealovega’s, and hospitals, are required to report positive tests for cyclosporiasis to the health department in their county, and the counties are then required to report them to the state.

But if people don’t respond to calls and texts in outbreaks like this one, it can take longer to find the source of the problem.

The state health department continues to share updated data on cyclosporiasis cases every weekday, and county-level breakdowns weekly.

Although the source of this outbreak may be mostly solved, it is a good reminder of the importance of testing, reporting, and cooperation with public health “contact tracing” for all kinds of infectious diseases.

8. Don’t take food safety for granted

During the first weeks of this summer’s outbreak, before the source was traced, public health authorities could only say that past cyclosporiasis outbreaks had been linked to uncooked produce, especially leafy greens and berries.

That made many people, especially in Michigan, temporarily worried about eating all kinds of produce.

Cyclospora is an especially tough microbe to get rid of because of the hard “shell” of the parasite that can hitchhike on produce from a farm field all the way to your mouth.

“In general, the Cyclospora parasite can be very difficult to remove, even by thorough washing,” says Dr. Ealovega. Importantly, he adds that, “The parasite is not spread directly from person to person.”

But there also are plenty of people getting sick every day from more common foodborne microbes, like strains of E. coli, listeria and salmonella bacteria, and viruses like norovirus and hepatitis A.

This is why it is crucial for everyone who prepares food for themselves or others, at home or in stores and restaurants, to wash their hands thoroughly after using the bathroom, and before handling food.

It’s also important to store food at the right temperature, to cook meat and seafood thoroughly, to follow use-by dates for perishables, and to throw out leftovers after a few days.

The United States Department of Agriculture’s Food Safety Basics website has good information to follow, and will also be linked in the show notes for this episode.

A reminder that all Health Lab content including health news, best practices and research insights are for informational purposes only, and are not a substitute for professional medical guidance. Always seek the advice of a health care provider for questions about your health and treatment options.

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