CDC Reports 145 people with cyclosporiasis
since May 1, 2026
#19,231
Every few years we see an outbreak of water and food borne illness here in the United States due to a pair of misery inducing parasites; cyclospora & cryptosporidium. A few past blogs:MMWR: More Tales From The Crypto (2019)
While Cyclosporiasis is currently making the rounds, Cryptosporidiosis still leads the pack, with an EID study published in early 2011 estimating 750,000 Crypto infections in the U.S. each year (see Foodborne Illness Acquired in the United States—Major Pathogens), although only about 8,000 are laboratory confirmed.
While fairly common in developing tropical, or sub-tropical countries, Cyclosporiasis – an infection usually acquired through consuming food or water contaminated with Cyclospora cayetanensis - is relatively rare in the United States.
This is because hosts infected with Cyclospora shed unsporulated (non-infective) cysts in their stool which require days or even weeks to mature into infectious agents. Infection is characterized by prolonged bouts of watery diarrhea, which may persist or reoccur over a period of weeks.
We tend to see non-travel acquired Cyclospora cases in the United States during the summer months, usually peaking in June or July.
In recent weeks several states have reported an uptick in Cyclosporiasis, as reported yesterday by the CDC.
Although it doesn't show up in yesterday's CDC's update (July 1st), Michigan's Department of Health and Human Services published a press release yesterday that more than doubles the CDC's count; announcing an additional 170 cyclosporiasis infections over the past 9 days.
Surveillance of Cyclosporiasis
For Public Health
July 1, 2026
Key points
- Cyclosporiasis is caused by several species of the microscopic parasite Cyclospora.
- Cyclosporiasis is a nationally notifiable disease.
- CDC has received reports of 145 cases of cyclosporiasis acquired in the United States of people who became sick from May 1, 2026, through June 16, 2026.
- There is currently no evidence of a single, multistate Cyclospora outbreak linking all cases. Rather, this is a surveillance count of cases across the United States. Investigations to identify potential clusters and potential sources of illness are ongoing.
Although it doesn't show up in yesterday's CDC's update (July 1st), Michigan's Department of Health and Human Services published a press release yesterday that more than doubles the CDC's count; announcing an additional 170 cyclosporiasis infections over the past 9 days.
Outbreak of cyclosporiasis occurring in Michigan
July 01, 2026
No cause identified for illnesses at this time; state offers prevention tips
LANSING, Mich. - The Michigan Department of Health and Human Services (MDHHS) and Michigan Department of Agriculture and Rural Development (MDARD), in partnership with several local health departments, are actively investigating a large and growing outbreak of cyclosporiasis, a diarrheal illness.
As of Tuesday, June 30, more than 170 cases have been reported in Monroe, Lenawee, Washtenaw, Wayne, Livingston, Shiawassee and Jackson counties in the past nine days. Typically, Michigan only identifies around 50 cyclosporiasis cases per year.
“Outbreaks of cyclosporiasis have been occurring across the United States and now here in Michigan,” said Dr. Natasha Bagdasarian, chief medical executive. “Based on the unusual number of cases we have identified in a little over a week, we anticipate additional cases of illness being reported. We recommend Michiganders contact their health care provider if they experience sudden, ongoing diarrhea and reach out to their local health department if additional members of their family are suffering from the same symptoms.”
Cyclosporiasis is caused by infection with the parasite Cyclospora cayatenensis, which is commonly found in developing countries and spread by food or water contaminated with feces. In recent years, outbreaks have occurred in the U.S. as a result of eating contaminated fresh produce, especially during the summer months. Cyclosporiasis is not known to spread from person to person. Symptoms occur two to 14 days after exposure and may include: Frequent watery diarrhea. Loss of appetite and weight. Abdominal cramps and bloating. Nausea (vomiting is less common). Low-grade fever.
Individuals experiencing sudden gastrointestinal illness are encouraged to be evaluated by a health care provider. Symptoms of cyclosporiasis can be significantly improved with antibiotic treatment. If untreated, the illness may last for a few days to a month or longer. Providers are urged to consider cyclosporiasis among patients presenting with acute gastrointestinal illness in southeast Michigan.
“MDARD is committed to ensuring food safety across the state and is working in partnership with local health departments to identify the source of the outbreak and keep consumers safe,” said Jennifer Bonsky, Director of the Human Food Division at MDARD. “In these moments, it becomes even more important to follow all of the essential food preparation guidelines, such as washing your hands before and after preparing food and washing produce before it is consumed.”
To help avoid any illness from cyclospora or other harmful bacteria or organisms, MDARD recommends the following: Wash all fruits and vegetables thoroughly under running water before eating, cutting or cooking. Scrub firm fruits and vegetables, such as melons and cucumbers, with a clean produce brush. Cut away any damaged or bruised areas on fruits and vegetables before preparing and eating. Refrigerate cut, peeled or cooked fruits and vegetables as soon as possible.
Not all cases identified in the last nine days may be connected to the outbreak and the public health investigation is ongoing. State and local officials are interviewing cases to try and identify a common exposure and prevent additional illness. Individuals diagnosed with cyclosporiasis are encouraged to talk to health department staff investigating these illnesses to help identify a potential cause. Additional information is available at About Cyclosporiasis | Cyclosporiasis | CDC.
Current case county by county as of Tuesday, June 30: Monroe: 70 Lenawee: 33 Washtenaw: 21 Wayne: 12 Jackson: 7 Shiawassee: 7 24 cases in 11 other counties and the City of Detroit.
Age Age range: 8 years to 84 years Average age: 44.3 years Median age: 41 years
Given the report from Michigan, it would not be surprising if we start hearing of more cases from other states.
In the meantime, to help prevent infection, the CDC recommends:
Prevention tips
People can take the following food and vegetable handling recommendations to prevent foodborne illness related to fresh produce:
Wash
- Wash hands with soap and water before and after handling or preparing raw fruits and vegetables.
Prepare
- Wash all fruits and vegetables thoroughly under running water before eating, cutting, or cooking.
- Fruits and vegetables that are labeled "prewashed" do not need to be washed again at home.
- Scrub firm fruits and vegetables, such as melons and cucumbers, with a clean produce brush.
- Cut away any damaged or bruised areas on fruits and vegetables before preparing and eating.
Store
- Refrigerate cut, peeled, or cooked fruits and vegetables as soon as possible (within two hours).
