Key facts
- What it is: Cyclospora cayetanensis, a microscopic parasite that infects the small intestine.
- How you get it: contaminated fresh produce or water — not person-to-person.
- Hallmark symptom: prolonged, watery, often relapsing diarrhea.
- The testing catch: routine stool microscopy frequently misses it; PCR panels detect it.
- Recovery: the gut can stay irritated after the parasite clears — where retesting helps.
A large Cyclospora outbreak — and the current outbreak numbers have put this parasite in the headlines across North America. This guide pulls together what actually matters if you or someone you know may be affected: what Cyclospora is as a parasite, the signs of a Cyclospora infection, how Cyclospora is diagnosed (and why standard tests miss it), Cyclospora treatment and the recovery timeline, and how to think about rebuilding your gut afterward. If you are in Canada, start with Cyclospora risk in Canada.
What is Cyclospora?
Cyclospora cayetanensis is a single-celled protozoan parasite. When swallowed in contaminated food or water, it infects the lining of the small intestine and causes cyclosporiasis. Because the oocysts a person passes are not immediately infectious — they need about a week or two in the environment to mature — the parasite does not spread directly from person to person. Read the full biology on what Cyclospora cayetanensis is.
The 2026 outbreak at a glance
Health authorities have reported a substantial outbreak of cyclosporiasis. Because these numbers change frequently, we maintain them in a dated, sourced snapshot rather than stating a single figure here. See the full Cyclospora outbreak tracker; the live snapshot below aggregates CDC (U.S.) and PHAC/CFIA (Canada) reporting.
Symptoms & when to see a doctor
The classic picture is watery, frequent diarrhea that can come and go, along with fatigue, loss of appetite, weight loss, cramping and nausea. Some warning signs mean you should be seen promptly. Use the educational explainer below, then read the full signs of Cyclospora infection.
How you get it: contaminated food & water
Cyclospora reaches North America largely on imported fresh produce — historically raspberries, basil, cilantro, snap peas and leafy greens — and through travel to regions where it is common. Washing lowers risk but cannot guarantee removal. See how it spreads through produce and how to reduce your risk.
How Cyclospora is diagnosed — and why routine stool tests miss it
This is the part most coverage gets wrong. Ordinary ova-and-parasite (O&P) microscopy frequently fails to detect Cyclospora unless the lab is specifically asked to look and uses special staining; molecular (PCR) panels detect it far more reliably. Our money page explains how Cyclospora is diagnosed in depth. The comparison below shows how it stacks up against other common gut bugs.
The GI-MAP™ detects Cyclospora by qPCR alongside 85+ other markers from one at-home sample.
Order Your GI-MAP™ Test → How it worksTreatment & recovery timeline
Cyclosporiasis is usually treated with a prescription antibiotic, and symptoms often improve within a few days of starting it. Full recovery of the gut can take longer. See Cyclospora treatment and the recovery timeline. The interactive timeline below sets general expectations.
Rebuilding your gut after an infection
A parasite can leave behind inflammation and an imbalanced microbiome, and post-infectious IBS is a recognised outcome after gastrointestinal infections. The measure-adjust-remeasure workflow — where a follow-up test confirms clearance and checks gut-health markers — is covered in rebuilding your gut afterward.
Cyclospora in Canada
Search interest in Canada is high, but the situation there differs from the U.S. See Cyclospora risk in Canada for current status, regional notes, and testing options.
Frequently asked questions
What is Cyclospora and what does it do?
Cyclospora cayetanensis is a microscopic parasite that infects the small intestine and causes cyclosporiasis, an illness marked by prolonged, watery diarrhea. It spreads through contaminated food or water, not from person to person.
Is cyclosporiasis contagious?
Not directly. The oocysts a person sheds need about one to two weeks outside the body to become infectious, so it does not pass person-to-person.
How long does a Cyclospora infection last?
Untreated, symptoms can persist and relapse for several weeks. Provider-prescribed antibiotics usually shorten the illness.
How is it diagnosed?
Through stool testing — but routine microscopy often misses it, so a PCR panel or special staining is needed. The testing guide explains the options.
Can GI-MAP detect Cyclospora?
Yes — by quantitative PCR, as one of more than 30 parasites on its panel.
Is Cyclospora in Canada?
It is not commonly found on Canadian food or water; most Canadian cases relate to travel or imported produce. See the Canada guide.
Sources & further reading
- U.S. Centers for Disease Control and Prevention — Cyclosporiasis (Cyclospora).
- CDC — Cyclosporiasis outbreak investigations & surveillance.
- Public Health Agency of Canada — Cyclosporiasis (Cyclospora).
- Canadian Food Inspection Agency — Food safety & imported-produce surveillance.
- Mayo Clinic Laboratories — stool parasite testing (why routine O&P can miss Cyclospora).
Outbreak figures reflect the named authorities as of the dates shown and should be re-verified against the current CDC and PHAC data.