Michigan health officials said today that lettuce or salad greens may be the source of the Cyclospora outbreak that has now sickened more than 3,000 people across Michigan and Ohio, the first time investigators have pointed to a specific food category since the outbreak began in late June.
Michigan's Department of Health and Human Services announced on July 13, 2026 that its investigation, which involved more than 1,000 patient interviews conducted by state health workers, has pointed to lettuce as a food that "regularly comes up" in those interviews. The state immediately qualified the finding: no specific type of produce, grower, or supplier has been identified as the source, and other food items cannot be completely ruled out.
"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," Dr. Natasha Bagdasarian, Michigan's chief medical executive, said in a July 13 MDHHS statement. "Early information has shown lettuce as a common product that regularly comes up during the investigation."
As of Monday morning, Michigan has reported 2,640 confirmed cases, including 44 hospitalizations. Ohio has reported 361 cases since June 1. An NBC News tally of state health departments put the national total above 4,000 as of July 13, though the CDC's confirmed count — last updated July 9 — stood at 843 cases across 31 states, reflecting a multi-week lag in federal reporting.
No food recall has been issued. There is no specific brand, supplier, or product for consumers to look up or discard.
Why This Matters
The lettuce finding changes the practical guidance for millions of Americans in a meaningful way — not because a recall has been issued, but because it gives consumers a specific food category to treat more carefully while the investigation continues.
Pre-washed packaging does not guarantee safety, and rewashing bagged lettuce is unlikely to remove Cyclospora. The parasite produces oocysts — protective shells — that cling to produce surfaces and cannot be dislodged or killed by water alone, however thoroughly applied. The standard food-safety step most Americans rely on — running produce under tap water before eating — provides no protection against Cyclospora.
This makes the outbreak structurally different from most bacterial foodborne outbreaks, where washing, thorough cooking, and refrigeration offer meaningful protection. For Cyclospora, the only reliable kill step is heat: cooking to at least 158 degrees Fahrenheit (70°C).
Anyone who has eaten salad, salad kits, or fresh lettuce in Michigan, Ohio, or another affected state in the past two to four weeks and has developed persistent diarrhea should contact a health-care provider — and specifically request Cyclospora testing.
What We Know So Far
This outbreak has grown to a size that exceeds all historical norms for Cyclospora in the United States. Michigan typically sees approximately 50 cases of cyclosporiasis annually. The 2026 total — 2,640 cases in Michigan alone — represents more than 50 times the annual average. The 2026 outbreak has already surpassed all of 2025, when the United States recorded approximately 2,700 cyclosporiasis cases for the entire season.
The investigation is complicated by several structural factors Dr. Bagdasarian identified in her statement. Produce may have been grown in other parts of the country or internationally, processed elsewhere, and then distributed by suppliers serving multiple grocery stores and restaurant chains. Cyclospora also has a one-to-two-week incubation period, meaning patients are being asked to recall meals from two to six weeks ago. Genomic matching — the technique used to rapidly link Salmonella and E. coli cases across states — is not yet as well developed for Cyclospora.
Michigan confirmed there is currently no evidence linking recreational water activities to this outbreak. Investigators continue to focus on contaminated produce as the likely source.
Surveillance data have also been weakened by a policy change. Before July 1, 2025, the CDC's Foodborne Diseases Active Surveillance Network (FoodNet) collected data on eight pathogens, including Cyclospora. It now collects data on only two — Salmonella and E. coli — making the national surveillance net less robust for this pathogen. Former CDC Director Dr. Robert Redfield told CNN on Monday that "surveillance is sort of the key to early identification" and that cutting these programs is not in the country's interest.
Where the Risk Is Highest
Michigan has the most confirmed cases of any state — 2,640 as of July 13. Ohio has reported 361 cases since June 1, with at least 46 hospitalizations. The CDC's July 9 update confirmed 31 states reporting domestic cases, though federal officials acknowledged the count significantly lags state totals.
Previous U.S. and Canadian Cyclospora outbreaks have been linked to bagged salad mixes, fresh cilantro, fresh basil, raspberries, snow peas, and green onions. Any of those foods — as well as lettuce — should be treated with extra caution while the investigation continues.
Some restaurants have voluntarily pulled certain fresh ingredients from their menus while the investigation continues. Those measures are voluntary and were confirmed by Dr. Bagdasarian. No mandatory recall or removal order has been issued.
What Doctors and Experts Say
Dr. Natasha Bagdasarian urged the public on July 13 to request national coordination: "We really need that kind of coordination to happen at the national level. As soon as other states get their numbers to the CDC, we hope they can take a broader look to see whether these outbreaks are related."
Dr. Kiran Joshi with the Cook County Department of Public Health described the hallmark symptom as diarrhea that "can be really frequent, pretty severe"— including what patients describe as explosive diarrhea — accompanied by abdominal symptoms such as loss of appetite, nausea, vomiting, and sometimes a low-grade fever.
Jennifer McEntire, a microbiologist and CEO of Food Safety Strategies, told CNN that tracing Cyclospora is far harder than tracing bacterial pathogens because the genomic sequencing tools that work efficiently for bacteria are far less developed for this parasite. She compared the difficulty to reading "War and Peace" versus a children's book.
Dr. Ambreen Malik, an infectious disease specialist at the University of Michigan Health Sparrow, noted that the size of the national food distribution network compounds the tracing challenge significantly.
What the Evidence Shows and What It Does Not
MedicalDaily Consumer Alert Check
- Confirmed cases as of July 13: Michigan 2,640 (44 hospitalizations); Ohio 361; NBC News national tally above 4,000
- CDC confirmed cases (July 9 data): 843 across 31 states — acknowledged undercount due to reporting lag
- Suspected food vehicle: Lettuce or salad greens (preliminary, based on patient interviews — not confirmed by laboratory testing of specific product)
- Specific type, grower, or supplier identified: No
- Recall issued: No
- Water contamination link: No — investigators have ruled out recreational water
- What the evidence does not yet prove: Which specific lettuce product, supplier, or distribution chain is contaminated; whether the Michigan and Ohio outbreaks are part of the same source as the broader national outbreak
- What readers should do: Treat all fresh lettuce and salad greens with increased caution using the specific steps below
Who Faces the Greatest Risk?
All residents of Michigan, Ohio, and neighboring states who have recently consumed fresh salad greens or lettuce are at potential exposure risk. Groups facing the most severe illness if infected include:
- Older adults and young children, who face higher rates of dehydration from prolonged diarrhea
- Organ transplant recipients and people undergoing chemotherapy
- People with weakened immune systems who may develop more severe or prolonged illness
- People without convenient access to primary care, who may not receive the specific diagnostic test required
Symptoms and Warning Signs to Watch For
Symptoms typically appear one to two weeks after exposure. The hallmark symptom is frequent, watery diarrhea — sometimes described as explosive — that may continue for weeks without treatment. Additional symptoms include loss of appetite, abdominal cramps, bloating, nausea, vomiting, and low-grade fever. Unlike many intestinal illnesses, cyclosporiasis does not resolve quickly without antibiotic treatment.
Seek medical evaluation and specifically request Cyclospora testing for:
- Diarrhea lasting more than three days
- Signs of dehydration: dizziness, dry mouth, decreased urination, dark urine
- Severe abdominal cramping or inability to keep fluids down
- Symptoms returning after initial improvement — relapse is common without treatment
Standard stool panels and cultures will not detect Cyclospora. Tell your doctor you are concerned about Cyclospora and request modified acid-fast staining or PCR testing specifically.
What You Can Do Now
- Buy whole heads of lettuce rather than pre-washed bagged lettuce or pre-mixed salad kits. Michigan health officials issued this recommendation directly today. Whole heads reduce the risk of cross-contamination from processing.
- Discard the outer two to three layers of leaves from a whole head of lettuce before preparation, and wash the inner leaves thoroughly under running water.
- Cook greens when possible. Heating lettuce or other greens to at least 158°F (70°C) kills Cyclospora — the only reliable kill step available.
- For herbs such as cilantro, basil, and green onions , separate leaves and wash thoroughly; trim the root end of green onions and peel back the outer layer before washing.
- If you have recently eaten fresh salad greens or lettuce and develop persistent watery diarrhea , contact your health-care provider and specifically request Cyclospora testing — not a standard stool culture.
- Monitor the CDC's Cyclospora surveillance page and the FDA's outbreak investigations table for any product recall or consumer advisory.
- Do not use dish soap or produce wash on fresh produce — residual chemicals can cause gastrointestinal irritation.
Cost and Access: What Patients Should Know
Cyclosporiasis is treated with the antibiotic trimethoprim-sulfamethoxazole (Bactrim or Septra). Generic versions are widely available and typically cost under $20 for a standard course with a prescription. Patients who are allergic to sulfa drugs should consult an infectious disease specialist.
For patients without insurance, Federally Qualified Health Centers offer sliding-scale care — find one at findahealthcenter.hrsa.gov. Michigan residents can contact the MDHHS at 1-888-535-6136. Ohio residents can contact the Ohio Department of Health at 1-800-282-5616.
What Happens Next
Michigan state workers will continue patient interviews and laboratory testing to narrow the produce source. The FDA is conducting traceback investigations as data are compiled. If a specific supplier or product is identified, a public consumer advisory and voluntary or mandatory recall would follow.
The CDC's Cyclospora surveillance season runs through August 31, with peak activity expected through mid-summer. The official case count is expected to rise sharply when the next federal update is published. MedicalDaily will update this article immediately when a specific product source is identified or a recall is issued.
The Bottom Line
Michigan health officials today named lettuce or salad greens as the suspected food vehicle in the worst Cyclospora outbreak the United States has seen in decades — based on more than 1,000 patient interviews. No specific product has been identified, no recall has been issued, and other foods cannot be ruled out. But consumers in Michigan, Ohio, and all 31 affected states now have actionable guidance for the first time: buy whole heads of lettuce instead of pre-washed bags, discard outer leaves, cook greens when possible, and seek Cyclospora-specific testing if you develop persistent watery diarrhea.
