You think you've got a bad case of food poisoning. You ate some fresh, healthy salad, and a few days later, your stomach starts churning. What follows isn't just a quick 24-hour bug. It is a grueling, weeks-long ordeal of relentless, watery, and often explosive diarrhea.
If you are living in the United States right now, there is a strong chance you aren't dealing with typical food poisoning. You might be host to Cyclospora cayetanensis, a microscopic parasite that is currently tearing through the country in a historic surge.
Health officials are sounding the alarm. By mid-July 2026, the Centers for Disease Control and Prevention (CDC) reported over 1,600 laboratory-confirmed domestic cases of cyclosporiasis, with thousands more under investigation. To put that in perspective, we have already blown past typical seasonal numbers, with states like Michigan seeing massive, unprecedented clusters.
This isn't a problem you can easily wash away under the kitchen faucet. Here is what is actually going on, why our food supply is vulnerable, and how you can protect your gut.
The Parasite Behind the Panic
To understand why this outbreak is so frustrating, you have to understand the parasite itself. Cyclospora is a single-celled pathogen. It is not a bacteria like Salmonella or E. coli, nor is it a virus like norovirus. It's a protozoan.
It spreads through the fecal-oral route. Basically, someone gets infected, the parasite leaves their body in their stool, and that stool somehow contaminates food or water that another person consumes.
In many developing countries where the parasite is common, water treatment infrastructure isn't robust. But in the US, we usually see seasonal spikes during the spring and summer. This happens when imported fresh produce, or domestic crops irrigated with contaminated water, make their way onto grocery store shelves and restaurant plates.
Here is the weird part: you can't catch Cyclospora directly from another person. When the parasite is first passed in stool, it is in an immature, non-infectious state called an oocyst. It needs to sit in the environment—usually in warm, moist soil or water—for one to two weeks to mature and become active. That means you won't get it from shaking hands with an infected coworker or caring for a sick family member. It almost always comes down to what you eat.
The 2026 Outbreak by the Numbers
This year is shaping up to be exceptionally bad.
The CDC and state health departments are tracking active infections in more than 30 states. Michigan is currently the epicentre, recording thousands of cases alone—a massive jump for a state that typically sees only about 50 infections in an entire year. Neighboring Ohio, West Virginia, and Kentucky are also reporting significant, interconnected clusters.
Why the sudden explosion? Experts point to two main factors:
- Climate shifts: Warmer, longer summers create the perfect incubator for the parasite to mature quickly in soil and agricultural runoff.
- Better diagnostic tools: Historically, doctors didn't test for Cyclospora because standard stool tests for food poisoning bypass it. Newer, multi-pathogen DNA tests make it much easier to identify, meaning we are finally seeing the true scale of the problem.
Foods to Watch Out For
The biggest challenge with Cyclospora is that it loves healthy food. You can't cook it out of a raw salad.
While investigators haven't pointed to a single, nationwide brand or supplier for the current outbreak, local health departments have raised flags. Michigan officials, for example, have identified lettuce and leafy greens as highly suspect.
Historically, outbreaks in the US have been traced back to fresh, raw, imported produce:
- Bagged salad mixes and pre-washed leafy greens
- Fresh herbs like cilantro and basil
- Berries, particularly raspberries
- Snow peas and green onions
If these items are irrigated or washed with contaminated water on the farm, the microscopic parasites cling tightly to the rough surfaces of the leaves and fruit.
Symptoms That Just Won't Quit
If you swallow a Cyclospora oocyst, you won't feel sick right away. It typically takes about a week for the parasite to set up shop in your small intestine and start causing havoc.
Once it kicks in, the primary symptom is watery, frequent, and sometimes explosive diarrhea. It is often accompanied by:
- Extreme, bone-deep fatigue
- Severe bloating, gas, and stomach cramps
- Loss of appetite and subsequent weight loss
- Nausea and occasionally vomiting
- A low-grade fever
What makes this infection particularly brutal is its longevity. A typical stomach bug wraps up in a few days. Cyclospora can persist for weeks, or even months, if left untreated. It is also notorious for relapsing. You might think you're finally over it, only for the symptoms to come roaring back a week later.
What to Do If You're Sick
If you've had watery diarrhea for more than a few days, do not just wait it out.
First, get tested. Go to your healthcare provider and specifically ask for a stool test that screens for parasites, including Cyclospora. Standard PCR panels often cover this now, but it's always smart to double-check with your doctor to make sure they are ordering the right test.
If you test positive, the standard treatment is a specific course of antibiotics. The go-to option is trimethoprim-sulfamethoxazole (commonly known as Bactrim or Septra). If you have a sulfa allergy, let your doctor know immediately, as they will need to explore alternative treatments.
While you are recovering, hydration is your absolute priority. Losing that much fluid over weeks can quickly lead to dehydration, requiring medical intervention. Skip the sugary sports drinks and opt for oral rehydration solutions or water mixed with electrolytes.
How to Protect Yourself in Your Kitchen
You can't completely eliminate the risk of foodborne illness, but you can drastically lower the odds of bringing Cyclospora into your home.
Here is what you should do right now:
- Wash and scrub: Wash all fresh produce under running water. Even if you plan to peel a fruit or vegetable, wash it first so you don't transfer pathogens from the skin to the flesh with your knife.
- Don't rely on "triple-washed" labels: If you are using bagged salads, wash them again anyway. While commercial washing reduces bacteria, it isn't always 100% effective at stripping away stubborn parasites.
- Cook when in doubt: Cyclospora cannot survive high heat. If you are concerned about an outbreak in your area, stick to cooked vegetables and cooked meals rather than raw salads and fresh, unpeeled berries for a few weeks.
- Keep it cold: Store your fresh produce in the refrigerator. While cold won't kill the parasite, it prevents other bacteria from multiplying and making a bad situation worse.
- Check local alerts: Keep an eye on local health department updates. If they identify a specific brand of greens or herbs linked to cases in your city, throw those products out immediately. Do not risk eating them.
