What is Cyclospora?
Is it a type of bacteria? A virus? Actually, it’s neither.
Cyclospora is a tiny parasite responsible for an intestinal illness known as cyclosporiasis. It spreads when food or water becomes contaminated with human waste.
The parasite, Cyclospora cayetanensis, is often associated with fresh produce that people typically consume raw, such as fruits, leafy greens, and herbs. Past incidents in the U.S. have linked outbreaks to items like basil, cilantro, berries, and parsley.
There are several ways contamination can occur, usually happening long before the food reaches consumers. Cyclospora may be introduced if produce is irrigated or cleaned with tainted water, or if food handlers contaminate it due to poor hygiene.
During processing, fresh produce is washed to get rid of dirt, but it isn’t sterilized. Unlike foods that are cooked at high temperatures, fresh fruits and vegetables don’t go through treatments that can effectively kill parasites. Since Cyclospora isn’t visible to the naked eye, it can cling to small spaces in the produce, which makes washing insufficient.
Is Cyclospora contagious?
Unlike the viruses that cause stomach flu or norovirus, Cyclospora usually isn’t spread directly from one person to another.
Cyclospora cayetanensis needs time to develop after being shed in human feces. If that waste contaminates food or water, the parasite must sit in the environment for days or even weeks to become infectious—a process called sporulation.
This means it’s pretty unlikely for someone with Cyclospora to directly pass it on to others through everyday interactions.
How serious is Cyclospora?
For most healthy individuals, a Cyclospora infection isn’t life-threatening and remains rare. Nevertheless, more than 20 Americans have been hospitalized since May 1, 2026, as identified by the Centers for Disease Control and Prevention’s latest multistate investigation.
North Carolina has recorded at least 110 Cyclospora cases since May 1, 2026, but no hospitalizations had been reported up to July 6, 2026.
If left untreated, symptoms can linger for days or even weeks. Some individuals infected during a 2024 outbreak with over 130 cases in Wake County reported experiencing diarrhea that lasted for a month.
Severe diarrhea can also lead to dehydration.
People with weakened immune systems, older adults, and others more susceptible to dehydration could be at higher risk for severe illness.
How do you know if you have Cyclospora — or something else?
The only definitive way to confirm a Cyclospora infection is through a stool test. Depending on the lab and the tests, your healthcare provider may need to specifically request Cyclospora testing, as it’s often not included in standard U.S. stool tests.
A single negative test might not rule out a Cyclospora infection entirely. Some people may intermittently shed the parasite, so one sample could miss it. In certain instances, multiple stool samples are requested to enhance detection likelihood.
The North Carolina Department of Health and Human Services has reported cases in individuals of all ages.
What are the symptoms of a Cyclospora infection?
The symptoms of Cyclospora can resemble other intestinal infections, making it tricky to diagnose based solely on symptoms. Symptoms generally begin about a week after consuming contaminated food or water, but they can show up anywhere from two to 14 days later—or even longer.
The most common symptom is frequent, watery diarrhea, which many describe as severe or explosive.
Other symptoms may include:
• Severe abdominal cramping
• Bloating and increased gas
• Loss of appetite
• Nausea
• Body aches
• Fatigue
• Low-grade fever
• Weight loss in some cases
How common is Cyclospora?
Cyclospora is deemed an uncommon foodborne illness in the U.S., although the Food and Drug Administration notes that individuals traveling to tropical or subtropical regions may face a higher risk of infection.
Cyclospora cases are reported annually in the U.S., with spikes often occurring during spring and summer. The CDC designates “Cyclospora season” from May 1 to August 31, aligning with the highest imports of fresh produce usually linked to the parasite.
Why is Cyclospora so hard to trace?
Even when many individuals become ill, health investigators might struggle to pinpoint the contaminated food or drink connected to a cluster of Cyclospora cases.
One reason is the lengthy sporulation period of the parasite, along with the time it takes for symptoms to appear. By the time symptoms manifest, patients often can’t recall what they ate weeks earlier, where they purchased it, or if it could be the source.
Cyclospora has also been associated with herbs like cilantro and parsley, which can be easily forgotten when patients are asked about their food histories.
Timing is another issue. Contaminated produce can quickly disappear from store shelves, making it hard for health investigators to identify it. Many fruits, vegetables, and herbs that have been linked to Cyclospora have short shelf lives, leading them to be consumed or discarded before testing can occur.
Moreover, fresh produce is distributed widely. A single shipment of tainted herbs, leafy greens, or berries might be divided among various distributors, grocery stores, and restaurants across multiple states, making tracing illnesses back to one source even more challenging.
Can you prevent Cyclospora?
The best way to prevent foodborne illnesses like Cyclospora is through thorough cooking. However, many foods commonly linked to Cyclospora outbreaks—like berries, basil, cilantro, parsley, and leafy greens—are generally consumed raw.
Health experts advise washing fresh fruits and vegetables under running water prior to eating, cutting, or cooking them, even if they claim to be prewashed. While washing can remove dirt and some pathogens, it doesn’t consistently eliminate Cyclospora if contamination occurred earlier in the food supply.
Since contamination usually happens during growing, harvesting, or processing, preventing Cyclospora infections also relies on safe farming, hygiene, and food handling practices before the produce reaches consumers.
Additionally, keep an eye on public health alerts and recalls. If health authorities connect a food to a Cyclospora outbreak, it’s wise to avoid eating it and to dispose of any related products you might have at home.
If you suspect you have Cyclospora, reach out to your healthcare provider. They can help determine if you need treatment and arrange for the necessary stool test.
