Southeast Michigan is dealing with a confirmed cyclospora outbreak in 2026. The Michigan Department of Health and Human Services (MDHHS) has reported more than 300 cases since late June, a number that is well above expected seasonal levels. With no common food source identified yet, the outbreak continues to spread. If you have experienced persistent watery diarrhea, abdominal cramping, or unusual fatigue over the past few weeks, you may have been exposed to Cyclospora cayetanensis.
This post explains what Cyclospora is, what symptoms to watch for, how it is diagnosed, and what treatment looks like. Walk-in testing is available at MI Express Urgent & Primary Care locations throughout Southeast Michigan.
Cyclosporiasis cases in Michigan typically number around 50 per year. In June and July 2026, that figure was surpassed many times over, with Southeast Michigan counties, especially those near the Ohio border, accounting for the bulk of cases. The MDHHS and local health departments are actively investigating to identify a potential common food or water source.
For the most current public health updates, you can review the official MDHHS outbreak advisory. Cases have also been reported across 18 states nationally, making this one of the most significant Cyclospora outbreaks in recent U.S. history.
Cyclospora cayetanensis is a microscopic, single-celled parasite that infects the small intestine. It is found most commonly in tropical and subtropical regions but reaches the United States through contaminated fresh produce. Previous U.S. outbreaks have been linked to fresh herbs such as cilantro and basil, as well as raspberries, snow peas, and mixed salad greens consumed during the summer months.
One important fact that often surprises people: Cyclospora is not contagious from person to person. You cannot catch it from a coworker, a family member, or anyone else who is infected. The parasite spreads only when someone ingests food or water that has been contaminated with Cyclospora oocysts.
Symptoms of cyclosporiasis typically begin two to fourteen days after exposure, with most people feeling ill within about one week. The most common symptoms include:
One characteristic that sets cyclosporiasis apart from a standard stomach virus is its relapsing pattern. Many people begin to feel better, only to have symptoms return days later. If you have had diarrhea that improves and then comes back, that relapsing course is worth discussing with a provider.
Without antibiotic treatment, cyclosporiasis may persist for several weeks to a month or longer. The relapsing pattern described above can extend the illness considerably. Fatigue in particular may linger after the digestive symptoms have passed. Treatment shortens the duration of illness and reduces the likelihood of relapse. If you have had GI symptoms lasting more than a few days, seeking care is the right call, not waiting it out.
This is a critical point that patients and some providers may not be aware of. A standard stool ova and parasite (O&P) test does not automatically check for Cyclospora. The parasite's oocysts require specific staining and must be explicitly requested on the lab order. If the provider does not know to ask for it, the test will miss it.
The preferred diagnostic approach right now is multiplex PCR testing, such as the BioFire GI panel. This test is highly sensitive, detects Cyclospora along with other GI pathogens in a single specimen, and produces results faster than traditional methods. When you come in, be specific about your symptoms: how long they have lasted, whether they have relapsed, and any recent consumption of fresh produce.
For clinical testing guidance, the CDC clinical care page for cyclosporiasis provides up-to-date information on preferred diagnostic methods. You can also explore our full list of conditions we evaluate and treat.
The only recommended antibiotic treatment for cyclosporiasis is trimethoprim-sulfamethoxazole (TMP-SMX), sold under the brand names Bactrim, Septra, or Cotrim. A standard treatment course runs for approximately 10 days. Because a prescription is required, you will need to be seen by a provider to receive treatment. Urgent care and primary care providers can both prescribe TMP-SMX without a referral.
If you have a known allergy to sulfa drugs, discuss alternatives with your provider. Do not attempt to treat cyclosporiasis with over-the-counter antidiarrheal medications alone. While these may provide temporary symptom relief, they do not eliminate the parasite, and symptoms will return.
You do not need a scheduled appointment or a referral to be seen for GI illness at MI Express Urgent & Primary Care. Walk-in visits are welcome at all locations. If your symptoms match the description above, or if you have had diarrhea lasting more than a few days, come in to speak with one of our providers. We can order the appropriate stool testing and, if indicated, prescribe treatment the same day.
Find your nearest location: Urgent care in Ann Arbor and Urgent care in Canton.
No. Cyclospora does not spread through contact with an infected person. It spreads only through food or water contaminated with the parasite's oocysts. Person-to-person transmission has not been documented.
Symptoms typically begin two to fourteen days after exposure. Most people notice illness within about one week of consuming contaminated food or water.
Cyclospora may eventually resolve without treatment, but the illness often lasts a month or longer and frequently relapses. Antibiotic treatment significantly shortens duration and reduces relapse risk.
Cyclosporiasis tends to last longer than a typical viral stomach illness and commonly follows a relapsing pattern, where symptoms improve briefly and then return over days or weeks.
U.S. outbreaks have previously been linked to fresh herbs like cilantro and basil, raspberries, snow peas, and mixed salad greens, particularly produce consumed raw during summer months.
