The parasite sheds intermittently, so you might miss it the first time
Each summer, the invisible world of microscopic parasites reminds us how intimately our health is bound to the food we eat and the care taken in its preparation. This season, a parasitic illness called cyclosporiasis has spread to 843 people across 31 states, with two cases confirmed in New Hampshire — a quiet but telling signal that public health vigilance is never truly at rest. The culprit is cyclospora, a parasite that travels through unwashed produce and wages a prolonged campaign of gastrointestinal suffering on those it reaches. The CDC continues to trace the outbreak's origins, while doctors urge those with lingering symptoms to seek care rather than wait.
- An 843-case surge of cyclosporiasis across 31 states has put the CDC and local health departments on heightened alert in the middle of summer produce season.
- Patients face days or weeks of watery diarrhea, crushing fatigue, nausea, and dehydration — symptoms that can persist indefinitely without antibiotic treatment.
- Diagnosis is frustratingly elusive: the parasite sheds intermittently, forcing doctors to collect multiple samples over several days before a confirmed result is possible.
- New Hampshire, which typically records only a handful of cases per year, has already confirmed two infections, prompting local physicians to sharpen their awareness of the illness.
- Antibiotics are effective when administered early, and doctors are urging anyone with several days of gastrointestinal symptoms — especially after eating unwashed produce — not to wait it out alone.
A parasitic illness called cyclosporiasis has spread with unusual reach this summer, drawing the attention of the CDC and public health officials nationwide. As of early July, 843 infections have been confirmed across 31 states, including two cases in New Hampshire — a state that normally sees only a small handful each year.
The illness is caused by a parasite called cyclospora, typically contracted through contaminated, unwashed produce. Once inside the body, it triggers watery diarrhea, fatigue, nausea, vomiting, and severe dehydration. Left untreated, symptoms can drag on for weeks; with antibiotics, recovery comes far sooner.
What distinguishes this outbreak is less the disease itself than its scale and the medical community's sharpened attention to it. Dr. Dilip Yarabothu of Southern New Hampshire Health Immediate Care noted that while cyclosporiasis is not new, clinicians are now watching for it more carefully than before.
Detection presents its own challenge. Cyclospora doesn't appear on standard parasite screens and sheds inconsistently from the body, meaning physicians may need to collect samples on multiple occasions over two to three days to confirm a diagnosis. The symptoms, too, come and go — complicating both detection and timely treatment.
Doctors are advising anyone who experiences several days of diarrhea, cramping, or dehydration to seek care promptly rather than waiting for symptoms to resolve on their own. The CDC's investigation into the contamination source is ongoing as the outbreak continues to unfold.
A parasitic infection spread across the country this summer in a way that caught the attention of public health officials and doctors alike. The Centers for Disease Control and Prevention has been tracking cyclosporiasis cases since early July, documenting 843 infections across 31 states. New Hampshire, a state that typically sees only a handful of cases each year, confirmed two residents with the illness.
Cyclosporiasis is an intestinal disease caused by a parasite called cyclospora, which enters the body through contaminated food—most commonly unwashed produce. Once infected, a person experiences a cascade of unpleasant symptoms: watery diarrhea, fatigue, nausea, vomiting, and severe dehydration. The illness is treatable with antibiotics, but without treatment, symptoms can persist for weeks.
What makes this outbreak noteworthy is not that cyclosporiasis is new. The New Hampshire Department of Health and Human Services has documented between two and nine cases annually over the past five years. Rather, what's different this year is the scale and the heightened awareness. Dr. Dilip Yarabothu, the Medical Director of Southern New Hampshire Health Immediate Care, noted that while the illness itself is not unusual, the medical community is paying closer attention to it now. "We deal with all kinds of illnesses all the time," he said. "It's just one that has shown up, and now we're being more hypervigilant of it."
The challenge in identifying cyclosporiasis lies in the nature of the parasite itself. Unlike many infections that show up on standard parasite screening tests, cyclospora requires specific testing. The parasite does not shed consistently from an infected person's body—it sheds intermittently. This means a doctor may need to ask a patient to provide samples three times over the course of two to three days to confirm the diagnosis. The symptoms themselves are also intermittent, adding another layer of difficulty to detection and treatment.
Doctors are advising people to seek medical attention if they experience several days of diarrhea, abdominal cramping, or signs of dehydration. Waiting weeks to see if symptoms resolve on their own is not advisable. The infection responds well to antibiotics, but early intervention prevents prolonged suffering and reduces the risk of serious complications from dehydration. For anyone who has consumed unwashed produce or eaten at a restaurant where produce handling may have been questionable, paying attention to gastrointestinal symptoms over the coming weeks is prudent. The outbreak is still unfolding, and the CDC continues to track cases as the investigation into the source of contamination proceeds.
Notable Quotes
We deal with all kinds of illnesses all the time. It's just one that has shown up, and now we're being more hypervigilant of it.— Dr. Dilip Yarabothu, Medical Director of Southern New Hampshire Health Immediate Care
If you're having several days of diarrhea and abdominal cramping and becoming dehydrated, it's reasonable to seek medical attention before it's weeks.— Dr. Dilip Yarabothu
The Hearth Conversation Another angle on the story
Why is this outbreak happening now, in the middle of summer? Is there something seasonal about it?
Cyclospora thrives in warm, moist conditions, so summer is when we typically see these cases spike. But the real question is the source—where the contaminated produce is coming from. That's what the CDC is trying to pin down.
Two cases in New Hampshire sounds small. Why should people care?
Two cases is small in isolation, but it's part of 843 across 31 states. That's a coordinated outbreak, which means there's likely a common source—probably a specific farm or distributor. If you live in one of those states, you could be eating the same contaminated food right now.
What's the hardest part about treating this?
Getting the diagnosis in the first place. A patient comes in with diarrhea, and a doctor runs standard tests. Nothing shows up. If the doctor doesn't specifically think to test for cyclospora, the patient goes home thinking it's a stomach bug and waits it out for weeks.
So the parasite is hiding?
Not hiding exactly—it's shedding unevenly. Imagine trying to catch something that only appears intermittently. You might miss it the first time you look. That's why doctors need multiple samples.
Is this dangerous?
It's not usually fatal, but untreated, it can make you very sick for a long time. Dehydration is the real risk, especially for older people or anyone with a compromised immune system. That's why doctors are saying don't wait—get checked if symptoms persist.
What should someone actually do if they think they have it?
If you've had diarrhea and cramping for more than a few days, go to a doctor and specifically ask them to test for cyclosporiasis. Don't assume it's food poisoning that will pass. And in the meantime, wash your produce thoroughly, even if it's labeled pre-washed.