Cyclosporiasis Handout
You Can't Wash Away Cyclospora — Here's What Actually Works
Cases are running high this summer, and the food safety advice most people reach for doesn't touch this parasite.
The short version
Cyclospora is a microscopic parasite that hitchhikes on fresh produce. Swallow a few, and you can end up with weeks of watery diarrhea, cramping, and exhaustion — the kind that seems to clear up, then comes roaring back.
Here's the uncomfortable part: the two things most people do to protect themselves don't work on this one. Rinsing your produce won't reliably remove it. Keeping food cold won't kill it. Heat kills it, and awareness protects you. That's the list.
This summer is a bad one. As of July 9, 2026, CDC has confirmed 843 cases acquired in the U.S. across 31 states, with 86 hospitalizations and no deaths — plus more than 1,500 additional cases still being analyzed. Because there's roughly a six-week lag between someone getting sick and the case reaching the CDC, those numbers are expected to climb.
Why washing isn't the answer
Cyclospora is wrapped in a tough shell called an oocyst. It grips into microscopic crevices on leaves and skins, and it doesn't rinse off cleanly. CDC notes that routine chemical disinfection or sanitizing is unlikely to kill it — and that goes for commercial produce washes, vinegar soaks, and chlorine rinses too.
This is not permission to stop washing your produce. CDC still recommends rinsing fruits and vegetables under running water, scrubbing firm items like melons, and cutting away bruised spots. Those steps protect you from a long list of other pathogens. Just don't mistake a good rinse for a force field against this particular parasite.
Why the fridge won't save you either
"Don't leave it out at room temperature" is bacteria logic. Salmonella multiplies in food; Cyclospora doesn't. Time on the counter doesn't make produce more contaminated with it, and chilling or freezing doesn't kill it.
Refrigerate cut produce within two hours anyway — CDC advises it, and it matters. It just isn't the lever that stops Cyclospora.
And you won't catch it from a sick family member
Not directly. The parasite needs days to weeks outside the body before it becomes infectious, so it doesn't spread person-to-person the way norovirus does. It comes from contaminated food or water.
So what does work?
Heat. Cooking, boiling, or blanching breaks down the oocyst wall. It's the only reliable kill step — which is exactly why nearly every Cyclospora outbreak traces back to something eaten raw.
Beyond that, your protection comes from knowing what to watch and when:
Know the usual suspects. Outbreaks repeatedly involve fresh cilantro, basil, salad and lettuce blends, spinach, berries, and snow/snap peas — especially imported products in spring and summer.
Watch your state health department. CDC says it outright: states may have more timely information than the national numbers. States report probable cases that CDC doesn't count yet, so your state is often weeks ahead of the federal picture. Search "[your state] health department cyclospora."
Follow recalls. Sign up for FDA and USDA alerts at foodsafety.gov. If a product you have is named, throw it out — don't try to wash it clean.
Be careful traveling. In tropical and subtropical regions, stick to cooked food and treated or bottled water. Chemical treatment won't kill this parasite.
Know the symptoms — and say the word out loud
Symptoms usually start about a week after exposure (range: 2 days to 2+ weeks): frequent watery diarrhea, stomach cramps, nausea, loss of appetite, fatigue, weight loss, sometimes a low-grade fever.
The telltale sign is relapse — symptoms seem to clear up, then return. Untreated, it can drag on for a month or more.
Here's the part worth repeating to readers: Cyclospora doesn't show up on a standard stool test. A provider has to order testing for it specifically. If diarrhea has lasted more than a few days, say the word "Cyclospora" out loud at the appointment. Once identified, it's treatable with a common antibiotic.
The bottom line
You can't wash your way out of Cyclospora, and the fridge won't save you. Heat kills it. Awareness protects you. Know the risky foods, monitor your state health department during outbreak season (CDC counts it as May 1 through August 31), and if diarrhea lasts more than a few days, ask your doctor to test for it by name.
Download the free handout below to share with clients, patients, or staff.
Sources
CDC, Surveillance of Cyclosporiasis (updated July 10, 2026; case counts as of July 9, 2026)
Why the case numbers don't agree — and which one to trust
If you've been following this outbreak in the news, you've seen wildly different numbers. That's not sloppy reporting. It's two different instruments measuring two different things.
The CDC counts lab-confirmed cases only, and assumes a roughly six-week lag between someone getting sick and the case reaching them. States count every case reported during the outbreak investigation — confirmed and probable — and some update daily.
The result is genuinely strange: Michigan alone is reporting more cases than the CDC's entire national total. Both numbers are accurate. They just aren't measuring the same thing.
The reason the CDC is behind — and it's the real story
As of July 1, 2025, the CDC's FoodNet made Cyclospora surveillance optional. States are now required to track only two foodborne pathogens: Salmonella and Shiga toxin–producing E. coli. Some states, including Michigan, kept tracking Cyclospora voluntarily. Many did not. So the national picture is thinner than it used to be — by design. That is precisely why your state health department is the right place to look.
State by state, from the source
| Where | Cases | Hospitalized | As of | Source |
|---|---|---|---|---|
| Michigan | 2,640 | 44 | July 13 — updated daily | MDHHS dashboard |
| New York | 470 | — | July 2026 | NYS Dept. of Health |
| Ohio state figure |
177 | 28 | July 2 (published July 8) | Ohio Dept. of Health |
| Ohio county figure |
500+ incl. 306 in Lucas Co. |
— | July 9 | County officials, via AP / CIDRAP |
| National (CDC) | 843 confirmed +1,500 under analysis |
86 | July 9 | CDC Surveillance |
Look closely at the two Ohio rows. The state has confirmed 177 cases; county health departments were tracking more than 500 — including 306 in Lucas County alone — a week later. Both are legitimate. The state simply hadn't published yet. When a county number and a state number disagree, the county is usually ahead.
Michigan is the epicenter, concentrated in Southeast Michigan — Monroe, Lenawee, Washtenaw, and Wayne counties. MDHHS updates its count every weekday by 11 a.m. Eastern. It went from 170 cases on June 30 to 2,640 on July 13. For scale: Michigan normally sees about 50 cyclosporiasis cases in an entire year.
Where should I look for numbers I can trust?
Your state health department — not the national news, and not even the CDC.
Search "[your state] health department cyclosporiasis." If your state hasn't posted anything, check your county — throughout this outbreak, county health departments have consistently been ahead of both the state and the CDC. The CDC's official Health Department Directories will find yours.
Michigan's produce guidance is the best in the country
This is worth following no matter where you live. MDHHS went further than the CDC and issued item-by-item instructions for kitchens handling raw produce — the most practical guidance any agency has published on this outbreak:
| Lettuce & leafy greens | Buy whole heads rather than prewashed bagged lettuce or salad mixes. Discard the outer two to three layers of leaves, then wash the inner leaves under running water. Cook when possible. |
| Cilantro & basil | Separate the leaves and wash thoroughly under running water. Safest cooked. |
| Green onions | Trim the root end, remove the outer layer, and wash thoroughly under running water. Safest cooked. |
| Raspberries | The hardest one. That bumpy surface is nearly impossible to clean — the parasite hides in the tiny crevices. Safest cooked (pies, jams) or use frozen. Freezing may reduce, but does not eliminate, the parasite. |
| Snow & snap peas | Wash under running water while rubbing the surface. Safest cooked. |
Source: MDHHS Cyclosporiasis Outbreak guidance
Notice the through-line: every single item ends the same way — safest when cooked. Five different foods, five different washing techniques, one conclusion underneath all of them. That's not a coincidence. Heat is the only reliable kill step.
Case counts change daily during outbreak season. Figures above are as of July 13, 2026. Sources: Michigan MDHHS, New York State Dept. of Health, Ohio Dept. of Health, CDC, and CIDRAP (University of Minnesota).
