As of July 10, 2026, health officials across 31 states are investigating a significant surge in cyclosporiasis, a foodborne parasitic infection causing severe, watery diarrhea. With nearly 3,000 cases reported nationwide, the outbreak has hit Michigan particularly hard, prompting a multi-state investigation by the Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA) to identify potential contaminated food sources. According to the CDC, 86 people have been hospitalized as a result of the illness.
Dr. Natasha Bagdasarian and Michigan Infection Rates
Michigan and Midwest Outbreak Escalation
The current surge in cyclosporiasis has centered on the Midwest, with Michigan experiencing an “unusually high” number of infections. Michigan reported 1,562 cases as of Friday, a stark contrast to the state’s typical annual average of 40 to 50 infections. Dr. Natasha Bagdasarian, the chief medical executive of Michigan, described the rapid rise as “highly unusual.” Laboratories in the state are currently scrambling to sequence the genome of the bug to track its origin. “We can see if isolates are closely related, meaning that there was likely a common source, and then we can potentially go back and look for the source of that contamination,” Dr. Bagdasarian stated.
Neighboring states are also seeing elevated numbers. The Ohio Health Department listed 177 cases as of July 2, with 28 people hospitalized, but those numbers are expected to climb, as the Toledo-Lucas Health Department reported 306 cases this past week. Meanwhile, Illinois health officials have confirmed 141 cases statewide. According to the Illinois Department of Public Health, of the 141 cases, 62 reported travel outside the U.S., 59 were domestically acquired, and 20 cases are pending investigation to determine travel status. New York has also reported 394 cases. An NBC News tally of state health department data shows 2,912 cases have either been reported or confirmed nationwide.
For more on this story, see Historic Cyclosporiasis Outbreak Surges Across 17 States.
Dianna Blau and Federal Challenges in Identifying Contaminated Food
CDC and FDA Investigation Status
Federal agencies are working to determine if the clusters across 31 states are linked to a common, yet-to-be-identified food item. Dianna Blau, acting chief of the CDC’s Parasitic Disease Branch, explained that investigations are inherently difficult because symptoms often appear a week or more after exposure, making it hard for patients to recall specific meals. “In an average year, there’s a small proportion of cases that actually get traced back to one particular food item,” she said. The CDC noted that the numbers represent a “sharp rise” compared to this time last year, when there were approximately 2,700 cases nationally.
The CDC has confirmed 843 of the current cases, all acquired in the U.S., and is still investigating more than 1,500. No deaths have been reported. While the Food and Drug Administration remains “actively engaged” with state partners, no specific product recalls have been issued to date. In July of last year, the CDC made tracking cyclospora optional as it scaled back its Foodborne Diseases Active Surveillance Network, a move that food safety experts worried would make it harder to identify and respond to outbreaks.
This follows our earlier report, Norton Healthcare Reports Cyclosporiasis Spike in Kentucky Amid National Outbreak.
Kristin Gustashaw and Clinical Treatment for Cyclospora cayetanensis
Symptoms and Clinical Guidance
Cyclosporiasis is caused by the parasite Cyclospora cayetanensis, which is typically found in food or water. The illness can begin with flu-like symptoms, such as severe fatigue and body aches. What sets the symptoms apart is explosive, watery diarrhea that is sometimes uncontrollable. Patients may also experience unusually bad gas, stomach cramps, and nausea, often leading to a loss of appetite. Low-grade fevers are rare.
The infection is treated with an antibiotic, usually Bactrim. If left untreated, symptoms can linger for weeks. According to Dianna Blau, on average, 10% of patients need to be hospitalized, often due to dehydration. Young children, older adults, and those with compromised immune systems are at the highest risk. While test results usually take about 24 hours, increased demand for testing has lengthened turnaround times to two to three days in some areas. Clinical dietician Kristin Gustashaw of Rush advised that the illness can be contracted by consuming food or water contaminated with feces.
Read also: Cyclospora Outbreak: Parasite Contaminating Produce Across Multiple States.
Fresh Produce Handling Protocols for Seasonal Parasite Peaks
Prevention and Seasonal Trends
The CDC defines the peak season for cyclosporiasis as May 1 through August 31. Because the parasite is often associated with fresh produce—such as raspberries, bagged lettuce, salads, cilantro, and basil—health departments are urging extra caution. The parasite clings to these items, making them difficult to rinse away.
To reduce the risk of infection, health officials recommend the following:
- Scrub firm produce like melons and cucumbers with a clean brush.
- Cut away bruised or damaged areas before eating.
- Clean and sanitize utensils and food-prep surfaces before and after use.
- Sanitize display cases and refrigerators used to store fresh produce.
- Clean and sanitize cutting boards and tools used with fresh produce.
- Refrigerate cut, peeled, or cooked fruits and vegetables promptly.
As of July 2026, health authorities continue to monitor the situation, noting that while the parasite is rarely waterborne, it is generally not transmitted directly from one person to another.
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