The Outbreak Is Expanding Fast
A Cyclospora parasite outbreak has infected people across 34 U.S. states since May, with nearly 7,000 confirmed or probable cases now reported, a figure far beyond anything seen during the same period in recent years. The CDC issued a Health Alert Network notice on July 15 confirming 1,645 lab-verified cases and more than 5,100 additional probable cases under investigation, all in people who ate contaminated food in the United States.
No specific food product, grower, retailer, or restaurant chain has been confirmed as the source. No recall has been issued as of July 15, 2026. The investigation is ongoing.
Why This Matters
Cyclosporiasis is caused by the microscopic parasite Cyclospora cayetanensis, and it spreads when people consume food or water contaminated with human fecal matter containing the parasite's infectious form. It does not spread directly from person to person, which means the sustained rise in cases points to a contaminated food supply that continues to circulate.
The CDC confirmed that the 1,645 lab-verified cases represent a six-fold increase over the 249 confirmed cases reported nationally by the same date in 2025. When the more than 5,100 probable cases are included, the 2026 total is roughly 27 times higher than last year's comparable figure — what CDC officials publicly described as a "very big shift" from previous seasons.
If you have consumed fresh produce recently, especially salad greens or items eaten raw, and developed prolonged watery diarrhea, you may want to speak with a clinician who can order the specific test needed to detect this parasite.
What We Know So Far
According to the CDC's active surveillance page, all 1,645 confirmed domestic cases are in individuals who became ill after eating in the United States and reported no international travel in the 14 days before their symptoms began. Sick individuals range in age from 2 to 95 years, with a median age of 44. Of the confirmed cases, 141 — approximately 9% — required hospitalization. No deaths have been reported.
The CDC's Health Alert Network notice identifies at least one confirmed multistate cluster involving more than 400 cases across Michigan, Ohio, West Virginia, and Kentucky. Investigators are simultaneously examining several other clusters in additional states, as well as cases that have not yet been linked to any cluster.
Cyclospora season typically runs from May 1 through August 31, with case counts rising through the summer. CDC officials have noted two potential peaks in illness onset dates — one around June 25 and another around July 7 — which investigators say may point to two separate contaminated food events.
Where the Risk Is Highest
Michigan has been hit hardest, with the Michigan Department of Health and Human Services reporting more than 3,300 cyclosporiasis cases as of July 13, according to Today.com reporting. The state has interviewed more than 1,000 patients and said preliminary results point to lettuce or salad greens as a potential source for the Michigan cluster — though officials emphasized they have not ruled out other foods or suppliers.
New York State reported approximately 394 cases since May 1, according to state health officials. Ohio confirmed at least 364 cases as of July 10, with more than 171 occurring since late June. North Carolina confirmed 240 infections since May.
The fact that cases are concentrated in the Midwest but spread broadly across 34 states suggests a widely distributed food product — one that reaches grocery stores, restaurants, and food service operations across the country.
What Doctors and Experts Say
Dr. Kawsar Talaat, a physician at Johns Hopkins Hospital board-certified in pediatrics, internal medicine, and infectious diseases, told NPR that cyclosporiasis can present with a distinctive pattern. "If the diarrhea goes away and comes back, that's another sign of a potential Cyclospora infection," Dr. Talaat said. She also warned that standard stool tests for diarrheal illness cannot detect the parasite — clinicians must specifically request a Cyclospora test.
Dr. Gwen Biggerstaff, deputy director of the CDC's Division of Foodborne, Waterborne, and Environmental Diseases, told reporters this is "much, much higher than what we've seen last year or the year before" and called the pattern "a very big shift" from typical cyclosporiasis seasons.
Dr. Brian Kaminski, vice president of medical affairs at ProMedica Health System in Michigan and Ohio, described how the case surge first became apparent clinically: "When we started seeing cases of persistent diarrhea showing up, we knew there's something going on."
What the Evidence Shows and What It Does Not
Cyclospora outbreaks are consistently linked to fresh produce consumed raw — previous outbreak investigations have identified raspberries, fresh herbs, and salad greens as sources in past seasons, according to CDC historical outbreak data. However, the current outbreak source has not been confirmed.
Michigan's suggestion of lettuce or salad greens is preliminary and based on patient interviews, not product testing or traceback confirmation. No food product from any grower, supplier, or distributor has been identified. Public health officials have not issued any food safety guidance specifically telling people to avoid a particular item.
Cyclospora investigations are known to be especially difficult, because there is typically a weeks-long lag between when someone gets sick and when the case is reported. By the time a cluster is identified, the contaminated product may have already been consumed, sold out, or discarded.
MedicalDaily Evidence Check
- Outbreak source: Under active investigation by CDC, FDA, and state health departments
- Lab-confirmed cases: 1,645 in 34 states as of July 13, 2026
- Additional probable cases under investigation: More than 5,100
- Hospitalizations: 141 (approximately 9% of confirmed cases)
- Deaths: None reported
- No food product has been recalled or identified as the source
Who Faces the Greatest Risk
Most healthy adults who contract cyclosporiasis will recover without medical treatment, but the illness can be prolonged and serious in vulnerable individuals. Health officials say the groups at greatest risk for severe outcomes include:
- Older adults and people over 65
- People with weakened immune systems, including those living with HIV, cancer patients receiving chemotherapy, or transplant recipients
- People with chronic gastrointestinal conditions
- Children under five
- Pregnant people, for whom severe dehydration and nutritional loss pose additional risks
For otherwise healthy adults, illness is often self-limited, but it can last for weeks if untreated, with a characteristic pattern of diarrhea that temporarily improves only to return.
Symptoms and Warning Signs to Watch For
Symptoms of cyclosporiasis typically begin approximately one to two weeks after exposure to the parasite. The CDC describes the most common symptoms as:
- Watery diarrhea, sometimes frequent and explosive
- Loss of appetite
- Weight loss
- Bloating and gas
- Nausea
- Fatigue
- Low-grade fever (less common)
- Vomiting (less common)
Without treatment, symptoms can follow a pattern of improving and then worsening repeatedly over a period of days to more than a month. Anyone experiencing prolonged watery diarrhea combined with fatigue or loss of appetite should contact a clinician, especially if symptoms have persisted for more than a few days.
Seek prompt medical attention for high fever, inability to keep fluids down, signs of dehydration, or symptoms that are worsening rapidly.
What You Can Do Now
- If you have symptoms, ask your doctor specifically about Cyclospora testing. Standard stool tests will not detect this parasite. Clinicians must order a specific test for Cyclospora cayetanensis .
- Wash all fresh produce thoroughly under running water before eating or cooking it, including packaged items labeled "pre-washed." The FDA notes that cooking produce to 158°F or higher kills Cyclospora, but most produce linked to past outbreaks was eaten raw.
- Monitor the CDC's active investigation page for updates on whether a specific food product is identified. If a recall is issued, check whether items in your home are affected.
- Do not attempt to self-diagnose or self-treat with over-the-counter diarrhea medications if symptoms persist — the effective treatment for confirmed cyclosporiasis is the prescription antibiotic trimethoprim/sulfamethoxazole (brand names Bactrim or Septra).
- Check your local or state health department for county-level case counts and any local guidance.
- Seek urgent care for symptoms of severe dehydration, including very dark urine, dizziness, confusion, or inability to retain liquids.
Cost and Access: What Patients Should Know
Cyclospora testing requires a stool sample sent to a laboratory capable of detecting the parasite — which is not all facilities. Patients who see a primary care provider or urgent care clinic and receive a standard stool culture may be told the results are negative, when Cyclospora has not actually been tested for.
For patients without insurance or with high deductibles, community health centers and federally qualified health centers (FQHCs) typically offer diagnostic services on a sliding-fee scale. The Health Resources and Services Administration maintains a searchable directory of low-cost clinics.
If cyclosporiasis is confirmed and you cannot afford the antibiotic treatment, pharmaceutical patient assistance programs or generic pricing through discount pharmacy programs such as GoodRx may provide significant cost reductions on trimethoprim/sulfamethoxazole.
What Happens Next
The CDC says investigators are combining detailed patient interviews with targeted genotyping of Cyclospora from stool samples to identify clusters of related cases. FDA traceback teams are working in parallel. Case counts will continue to rise over the coming weeks due to the known six-week reporting lag between symptom onset and confirmed case reporting.
A CDC press briefing held July 14 included FDA Acting Deputy Commissioner Donald Prater, indicating the investigation has elevated priority at the federal level. Taco Bell confirmed on July 15 that it removed some ingredients from its menu at certain locations as a precaution — though public health officials have not confirmed any connection to that chain or any specific supplier.
MedicalDaily will update this story as new cases are confirmed and as source identification progresses.
The Bottom Line
This is a real and active food safety emergency affecting all 50 states' food supply chains. The fact that no source has been identified means there is no specific product to avoid — which makes general food safety practices the only available protection for now. If you or a family member develops prolonged, recurring watery diarrhea and have eaten fresh produce recently, contact a clinician and ask specifically about Cyclospora testing. Monitor the CDC's outbreak investigation page for updates and follow your local health department for any regional guidance.
