Diarrhea, Stomach Cramps, and Fatigue — Could It Be Cyclospora?
Medically Reviewed by Paul Richardson, MD, Chief Medical Officer & Vice President of Graduate Medical Education
In this article:
You may have seen it trending in the news under a headline that isn’t exactly appetizing — the “explosive diarrhea parasite.” It sounds dramatic, but this summer, cyclospora is a very real concern, and it’s already showing up in South Carolina.
Here’s what you need to know about the illness it causes, how to protect yourself, and when your symptoms mean it’s time to seek care at CMC.
What is Cyclospora?
Cyclospora cayetanensis is a microscopic parasite — too small to see with the naked eye — that infects the small intestine and causes a gastrointestinal illness called cyclosporiasis. It’s most commonly spread through contaminated food or water, particularly fresh produce like leafy greens and fruit.
This summer, a multistate outbreak linked to contaminated shredded iceberg lettuce has been confirmed by the CDC across nine states, with a voluntary recall of affected lettuce issued in mid-July 2026. Nationally, an estimated 18,000 people have developed cyclosporiasis so far this summer — a number that far exceeds the typical annual case count of fewer than 4,000. Two deaths linked to the outbreak were reported in Michigan.
Closer to home, the South Carolina Department of Public Health has confirmed 43 cases of cyclosporiasis in the state as of July 28, 2026. While South Carolina’s cases have not been officially linked to the national lettuce outbreak, state health officials are actively investigating.
If you have purchased shredded or bagged iceberg lettuce recently and are unsure whether it is subject to a recall, check the FDA’s recall database and when in doubt, throw it out. State public health officials have been clear: do not wash and keep recalled lettuce — discard it.
Experiencing severe stomach symptoms that came on suddenly? If your symptoms are intense, accompanied by dehydration, or not improving, the Conway Medical Center Emergency Department is open 24/7 with expert providers ready to evaluate and treat you. For emergencies, call 911. For urgent concerns, visit our Emergency Department.
What Are the Symptoms?
Symptoms of cyclospora infection typically appear about one week after exposure, though the window can range from two days to two weeks or more. The most common symptoms include:
- Watery diarrhea, which can be frequent and explosive
- Loss of appetite and unintended weight loss
- Stomach cramping and bloating
- Increased gas
- Nausea and vomiting
- Fatigue and muscle aches
- Low-grade fever
- Dehydration — one of the most significant concerns, especially in older adults and those with underlying conditions
One of the more frustrating aspects of cyclospora is that if untreated, it can last anywhere from a few days to a month or longer — and symptoms may appear to improve before coming back (relapse). Some people who are infected experience no symptoms at all, which is part of why it can spread quietly.
People with weakened immune systems or poor overall health are at higher risk for a more severe or prolonged illness.
How Do You Get It?
Cyclospora is spread through the consumption of food or water that has been contaminated with infected stool. It is not spread directly from person to person — the parasite requires one to two weeks outside the body before it becomes capable of infecting someone, so you cannot catch it simply by being around someone who is sick.
Outbreaks have repeatedly been linked to fresh produce — particularly:
- Leafy greens (especially lettuce and spinach)
- Herbs such as cilantro and basil
- Berries and other fresh fruits
- Contaminated water sources, particularly in tropical and subtropical regions
The current outbreak tied to shredded iceberg lettuce underscores how challenging it is to detect this parasite in food. Standard washing and chemical disinfection do not reliably eliminate cyclospora — which is why food source identification and recalls are the primary containment tool once an outbreak is identified.
How to Protect Yourself
While there is no vaccine for cyclospora, the following steps reduce your risk significantly:
- Throw away any recalled iceberg lettuce — do not wash and keep it; discard it immediately. Check the FDA’s recall database at fda.gov for the most current list of affected products, and when in doubt, throw it out.
- Wash your hands thoroughly before and after handling any fresh produce.
- Wash all fruits and vegetables before eating, even those with peels you don’t eat.
- Avoid water that may be contaminated, particularly if traveling internationally to tropical or subtropical regions, where cyclospora is more commonly found.
- Be cautious with produce at restaurants — if you’re concerned, it’s reasonable to ask about produce sourcing or opt for cooked menu items during an active outbreak.
Important Note:
If you are traveling internationally to an area where cyclospora is endemic, standard water disinfection methods — including chlorine and iodine tablets — are not effective against this parasite. Use bottled water and be selective about raw produce consumption when traveling abroad
When to See a Doctor — And When to Go to the ER
See your primary care provider if:
- You have watery diarrhea that lasts more than three to four days
- You are experiencing significant fatigue, cramping, or loss of appetite that isn’t improving
- You know you may have consumed recalled produce and develop any of the symptoms above
- Your symptoms improve and then return — cyclospora relapse is common
Your provider can order a stool test specifically for cyclospora. It’s important to tell your doctor if you have recently traveled internationally or if you may have consumed produce linked to an active outbreak, as cyclospora requires specific testing that isn’t included in standard stool panels.
Treatment is available — the antibiotic trimethoprim/sulfamethoxazole (sold under names like Bactrim or Septra) is the standard therapy. Be sure to mention any sulfa drug allergies so your provider can discuss alternatives.
Go to the Emergency Department immediately if you or someone you know experiences:
- Signs of severe dehydration — extreme thirst, very dark urine, dizziness, confusion, or rapid heartbeat
- Inability to keep any fluids down
- Symptoms that are rapidly worsening
- High fever (above 103°F)
- Blood in the stool
Dehydration from prolonged diarrhea is the most serious complication of cyclospora infection and can become dangerous quickly, especially in children, older adults, and those with underlying health conditions.
CMC Primary Care can evaluate your symptoms, order the right tests, and prescribe treatment. If you’re experiencing persistent GI symptoms or think you may have been exposed, don’t wait it out. New patients: call 843-347-8000 or schedule online. Find a CMC Primary Care location near you at conwaymedicalcenter.com/locations.
