Cyclosporiasis, an intestinal infection caused by the Cyclospora cayetanensis parasite, has sickened thousands across the United States this summer, with health officials tracking clusters in over 30 states. According to the Centers for Disease Control and Prevention (CDC) and state health departments, the infection is typically linked to contaminated produce or water, though investigators have not yet identified a single, definitive source for the current multi-state surge.
Tracking the Cyclospora Surge
As of mid-July, reports indicate roughly 5,000 cases of cyclosporiasis, with the CDC officially confirming 843 cases and 86 hospitalizations since the May 1 start of the season. Michigan currently reports the highest impact, with 3,309 cases and 44 hospitalizations according to the Michigan Department of Health and Human Services (MDHHS). Ohio, New York, North Carolina, and Illinois have also reported hundreds of cases each.
Experts remain divided on whether these clusters are linked. While the CDC has noted no evidence of a single, multi-state outbreak, Donald Schaffner, Ph.D., a professor of food microbiology at Rutgers University, suggests the possibility of “multiple unrelated outbreaks” occurring simultaneously. Dr. Trevor Suslow of the University of California, Davis, concurs, stating that “parallel pathways” for infection are a more likely explanation than one central source.
Did you know?
The Cyclospora parasite requires one to two weeks to mature outside the human body before it becomes infectious. This maturation period makes person-to-person transmission highly unlikely, according to Kali Kniel, Ph.D., a professor of microbial food safety at the University of Delaware.
Potential Sources and Investigative Challenges
Investigators are prioritizing fresh produce in their search for the origin of the parasite. In Michigan, health officials identified lettuce or salad greens as a potential culprit, though they cautioned that other food items have not been ruled out. Historically, past outbreaks have been tied to cilantro, basil, raspberries, and various salad greens.
The investigation is complicated by the parasite’s long incubation period. Symptoms—most notably sudden, watery, “explosive” diarrhea—can take up to 10 days to appear. Dr. John Torres, an NBC medical contributor, notes that by the time a patient is diagnosed and interviewed by an epidemiologist, they often struggle to recall specific food consumption patterns from weeks prior. Furthermore, Schaffner points out that since the CDC made testing for Cyclospora optional in its surveillance network in July 2025, the ability to track these clusters may be impacted.
Safety Recommendations for Consumers
Despite the rise in cases, food safety experts emphasize that the vast majority of fresh produce remains safe. “Almost all servings of fresh fruits and vegetables that you can buy on the market today are not linked to this outbreak,” says Schaffner.
For those in affected areas, health departments suggest specific precautions to reduce risk:
- Choose whole heads: Buy whole heads of lettuce rather than pre-washed, bagged greens.
- Remove layers: Discard the outer two to three layers of leaves.
- Rinse thoroughly: Wash inner leaves under running water.
- Cook greens: Heating greens to at least 158 degrees Fahrenheit is the most effective method to neutralize the parasite.
- Hygiene: Wash hands thoroughly before and after handling raw produce and use a produce brush to scrub fruits and vegetables.
Pro Tip:
If you suspect you have contracted cyclosporiasis, prioritize hydration and seek medical care. While most healthy individuals recover on their own, the infection can be treated effectively with a specific combination antibiotic.
Frequently Asked Questions
What are the primary symptoms of cyclosporiasis?
The hallmark symptom is sudden, watery, and often “explosive” diarrhea. Other gastrointestinal symptoms may accompany the infection, which can persist for several weeks if untreated.
Is it safe to eat fresh fruits and vegetables?
Yes. Experts like Dr. Schaffner maintain that there is no reason to remove raw produce from your diet. The risk is limited to specific, currently unidentified contaminated batches, and produce remains a vital part of a healthy lifestyle.
Can washing produce kill the parasite?
Washing reduces risk but does not guarantee the removal of the Cyclospora parasite. Cooking produce to 158 degrees Fahrenheit is a way to protect yourself.
Have you or someone you know been affected by the recent rise in gastrointestinal illnesses? Share your thoughts in the comments below or subscribe to our health newsletter for the latest updates on food safety alerts.
