Michigan health officials have identified lettuce and salad greens as the potential source of a cyclosporiasis outbreak that has sickened 2,640 people and caused 44 hospitalizations. According to a Monday news release from state officials, these figures represent a 69 percent increase in cases since the previous Friday and mark the highest annual total ever recorded in Michigan.
Did you know? Michigan typically records only 40 to 50 cases of cyclosporiasis per year. The current surge exceeds that average by more than 50 times.
National Surge in Cyclospora Infections
While Michigan is currently reporting the most cyclospora infections in the country, the Centers for Disease Control and Prevention (CDC) notes that other states are also seeing abnormal spikes. Higher-than-typical case numbers are appearing in New York, Ohio, Illinois, Indiana, and Kentucky.
The CDC has confirmed at least 843 illnesses across 31 states and 86 hospitalizations. However, health experts suggest these figures are an undercount due to the time required for state reporting and agency confirmation. The New York Times independently confirmed at least 4,800 cases so far this year.
Caitlin Rivers, an epidemiologist at the Johns Hopkins Bloomberg School of Public Health, is tracking the data. Rivers stated that this year is “on track to be the biggest year on record” for cyclosporiasis in the United States, especially when compared to the CDC’s reported average of 2,800 cases per year since 2016.
Comparing Current Outbreaks to Past Foodborne Events
Lettuce and salad mixes are frequent culprits in parasite outbreaks, but they aren’t the only risks. According to the CDC, previous outbreaks have also been linked to raspberries, basil, cilantro, fruit mixes, snow peas, and snap peas.
The scale of current infections mirrors previous major events. In 2020, the CDC linked an outbreak to Fresh Express bagged salads containing iceberg lettuce, red cabbage, and carrots, which sickened 701 people across 14 states. In 2022, the CDC linked a Florida outbreak to bagged salads, including Caesar salad kits with romaine lettuce.
Pro Tip: To reduce risk, Michigan health officials recommend avoiding pre-mixed salad kits. Instead, buy whole heads of lettuce, discard the outer two to three layers of leaves, and wash the inner leaves thoroughly under running water.
Identifying Symptoms and Treatment Options
Cyclospora is a parasite transmitted through food or water contaminated with feces. The resulting illness, cyclosporiasis, typically causes watery diarrhea and frequent, sometimes “explosive” bowel movements. Other symptoms include nausea, fatigue, bloating, cramping, and loss of appetite.
The CDC stated on Friday that those experiencing these symptoms should seek a health care provider for testing. While serious complications are rare, symptoms can persist for months if left untreated. The illness is treatable with antibiotics.
How to Prepare Produce Safely
Because washing does not completely remove the parasite, health officials recommend a multi-step approach to food safety:
- Wash everything: Rinse all fresh produce under running water to reduce the number of parasites.
- Peel: Remove the skin from produce that has a removable peel.
- Heat: Cook produce to at least 158 degrees, a temperature that kills the parasite.
Cyclosporiasis FAQ
What is the most likely source of the current Michigan outbreak?
Michigan health officials pointed to lettuce or salad greens as the potential source, though they noted other food items have not been ruled out.
How does this year’s outbreak compare to previous years?
Nationally, the CDC averages 2,800 cases per year. This year is on track to be the biggest on record, with the New York Times confirming at least 4,800 cases.
Can you prevent cyclosporiasis by washing lettuce?
Washing under running water reduces the risk and the number of parasites, but health officials warn it will not remove them completely.
Are you monitoring your food sources or changing how you prep your salads? Share your thoughts in the comments or subscribe to our newsletter for more public health updates.
Update (July 14, 2026)
According to detroitnews.com, state health workers have interviewed more than 1,000 people who contracted the parasite in an effort to find a conclusive source. While lettuce has been identified as a common product in the investigation, the Michigan Department of Health and Human Services noted that no specific type of produce, grower, or supplier has been identified as the source.
Natasha Bagdasarian, the state's chief medical executive, stated, “Although we do not have a definite product identified as the source of the outbreak, we want to let Michiganders know what we have learned so far so they can take steps to protect their families.” State officials added that given the extent of the outbreak, it will take some time for agencies to complete their investigation.
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