A microscopic parasite commonly associated with contaminated fresh produce has sickened at least 1,645 people across 34 states, setting off a multistate investigation into one of the largest U.S. cyclosporiasis surges in recent years.
The Centers for Disease Control and Prevention says the confirmed patients became ill after eating food in the United States and did not report international travel during the two weeks before their symptoms began. At least 141 people have been hospitalized, although no deaths had been reported as of July 13, 2026.
Health officials have not yet identified a single food, brand, farm or distributor responsible for the outbreak. The CDC and Food and Drug Administration are investigating several illness clusters and tracing possible produce exposures, but the available national numbers also include patients who may not be linked to one common source.
What Is Cyclospora?
Cyclospora cayetanensis is a microscopic parasite that infects the small intestine and causes an illness called cyclosporiasis.
People usually become infected by eating food or drinking water contaminated with human feces. Fresh produce has been connected to previous U.S. outbreaks because fruits, vegetables and herbs can become contaminated through water, soil, handling or processing before reaching consumers.
Cyclospora does not normally spread directly from one person to another. After leaving an infected person’s body, the parasite typically needs at least one to two weeks in the environment before it becomes infectious.
The current outbreak began during the normal U.S. Cyclospora season, which runs from May through August. The CDC says case totals are expected to continue rising because there can be a reporting delay of approximately six weeks between the beginning of a patient’s illness and the case reaching federal surveillance systems.
The Exact Produce Source Has Not Been Confirmed
The outbreak is strongly associated with foodborne transmission, but shoppers should be cautious about claims naming a specific product before regulators complete their investigation.
Previous U.S. Cyclospora outbreaks have been connected to raspberries, basil, cilantro, snow peas, lettuce and mixed salads. Those past links do not prove that any of those foods caused the current outbreak.
Investigators face a difficult task because a contaminated ingredient may appear in restaurant meals, salad kits, grocery-store products and prepared foods sold under multiple names. Patients may also struggle to remember every herb, garnish or vegetable they ate one or two weeks before symptoms began.
The CDC says its current total includes multiple clusters under active FDA traceback investigation, along with cases that have not yet been tied to a shared source.
Consumers should therefore continue checking official updates instead of avoiding an entire category of produce based on rumors.
Symptoms Can Last for Weeks
The most common symptom is frequent watery diarrhea, which the CDC says can sometimes involve sudden or explosive bowel movements.
Patients may also experience stomach cramps, bloating, gas, nausea, fatigue, reduced appetite, weight loss and a low-grade fever. Vomiting can occur but is less common.
Symptoms generally begin about one week after a person consumes the parasite, although the incubation period can range from two days to two weeks or longer.
Untreated illness may continue for several days, a month or even longer. Some people begin feeling better and then experience another round of symptoms, a pattern known as relapse.
The extended delay before symptoms and the possibility of recurring illness can make Cyclospora harder to distinguish from an ordinary stomach virus or brief case of food poisoning.
More People May Be Sick Than the Official Count Shows
The 1,645 confirmed cases represent people whose infections were reported to the CDC. The true number is likely higher.
Some patients recover without visiting a doctor. Others may not receive the special stool testing required to detect the parasite.
Cyclospora is not always included in routine gastrointestinal testing. The CDC says patients may need to provide multiple stool samples collected on different days because the parasite can be difficult to detect. Healthcare providers may also need to request a Cyclospora-specific laboratory test.
Anyone with persistent watery diarrhea should mention the possibility of Cyclospora to a clinician, especially when symptoms last longer than a typical stomach illness or return after briefly improving.
The Infection Is Treatable
Cyclosporiasis is generally treated with the antibiotic combination trimethoprim-sulfamethoxazole, commonly sold under names including Bactrim and Septra.
Patients who are allergic to sulfa medications should speak with a healthcare professional about possible alternatives. There is no equally established first-choice substitute suitable for everyone.
Rest and fluid replacement are also important because prolonged diarrhea can lead to dehydration. People who cannot keep fluids down, urinate much less than normal, become confused or feel faint should seek prompt medical attention.
Most otherwise healthy people eventually recover, but those with weakened immune systems or poor overall health may experience a longer or more severe illness.
Washing Produce Helps but Cannot Guarantee Protection
Consumers should wash fruits and vegetables thoroughly under clean running water before eating, cutting or cooking them. The CDC now recommends washing produce even when the package says it has already been washed.
Firm produce such as cucumbers and melons can be scrubbed with a clean produce brush. Damaged or bruised sections should be removed, and cut produce should be refrigerated within two hours.
Washing may reduce contamination, but it cannot guarantee that Cyclospora has been removed from every surface. The parasite can cling to delicate leaves, herbs, berries and produce with small crevices.
Routine chemical disinfectants and sanitizers are also unlikely to reliably kill Cyclospora. Alcohol-based hand sanitizer should not replace proper handwashing with soap and water.
Cooking is more effective than rinsing alone. Heating produce to at least 158 degrees Fahrenheit, or 70 degrees Celsius, can kill the parasite.
Shoppers Do Not Need to Stop Eating All Produce
Health officials are not currently advising Americans to avoid all fresh fruits and vegetables.
Produce remains an important source of fiber, vitamins and other nutrients. The safer response is to follow food-handling guidance, watch for official product warnings and avoid any item specifically named in a future recall or public-health advisory.
Choosing whole produce instead of pre-cut or mixed products may reduce the number of handling and cross-contamination opportunities, but it does not eliminate risk.
Consumers can also peel suitable fruits and vegetables, remove outer lettuce leaves and cook produce when practical. Surfaces, knives, cutting boards and hands should be cleaned before and after preparation.
Anyone in a high-risk medical group may wish to discuss additional precautions with a clinician while investigators continue searching for the source.
Why Cyclospora Outbreaks Are Difficult to Solve
Cyclospora investigations often take longer than bacterial foodborne-outbreak investigations.
The parasite’s incubation period means patients may need to remember meals eaten more than a week earlier. Produce ingredients may be mixed together, used as garnishes or sourced from several farms and distributors.
Unlike some bacteria, Cyclospora is also difficult to culture using standard laboratory methods. Public-health agencies are still developing and validating molecular tools that can connect patients and food samples more precisely.
Investigators may eventually identify several separate sources rather than one product responsible for every reported illness.
This is why national surveillance totals should not automatically be treated as one confirmed outbreak caused by one type of produce.
When to Contact a Doctor
A person should contact a healthcare provider when watery diarrhea continues for several days, becomes severe or returns after improving.
Medical advice is especially important when symptoms include dehydration, significant weight loss, persistent vomiting, fever, blood in the stool or severe abdominal pain. Young children, older adults and people with weakened immune systems may need earlier evaluation.
Patients should tell their clinician about recent produce consumption and ask whether Cyclospora testing is appropriate. Because routine stool tests may not detect the parasite, specifically mentioning cyclosporiasis can help guide diagnosis.
What Consumers Should Do Now
Shoppers should continue monitoring official CDC and FDA updates because the investigation is active and the suspected source could change as traceback work progresses.
Fresh produce should be washed under running water, firm items should be scrubbed and hands should be cleaned with soap and water before food preparation. Produce named in any future recall should be discarded rather than washed and eaten.
People experiencing prolonged or recurring watery diarrhea should contact a healthcare professional and ask about specific testing for Cyclospora.
The latest national case count and investigation status are available through the CDC’s Cyclosporiasis Surveillance page. Prevention advice can be found in the CDC’s Cyclospora safety guidance, while general information about the parasite and treatment is available through the CDC’s Cyclosporiasis overview.
