Cyclospora Outbreak: Symptoms, Causes and What U.S. Consumers Should Know

A multistate Cyclospora outbreak in the United States has prompted a federal investigation after health officials linked illnesses to iceberg lettuce sourced from central Mexico. The outbreak has drawn attention because thousands of people reported illnesses after eating at Taco Bell locations, while recalled lettuce was distributed through restaurants, foodservice operations and retail stores.

The U.S. Food and Drug Administration says the investigation involves Cyclospora infections associated with recalled iceberg lettuce from Taylor Farms de Mexico. The FDA’s July 24 update reported 1,947 people infected with Cyclospora who reported Taco Bell exposure across nine states, with at least 98 hospitalizations and no deaths. The FDA cautioned that case numbers could continue to rise because it can take as long as six weeks to determine whether a sick person is part of the outbreak.

What Is Cyclospora?

Cyclospora is a microscopic parasite known scientifically as Cyclospora cayetanensis. When people consume food or water contaminated with the parasite, they can develop an intestinal infection called cyclosporiasis.

Unlike bacteria such as Salmonella, Cyclospora is a parasite. It has an unusual life cycle that helps explain why direct person-to-person transmission is considered unlikely. After the parasite is passed in stool, it generally needs time in the environment before it becomes infectious. The CDC says Cyclospora typically requires at least one to two weeks outside the body to become infectious.

The parasite primarily affects the small intestine and can cause prolonged gastrointestinal illness. Some infected people may have no symptoms, while others can experience significant diarrhea and fatigue.

What Happened in the 2026 Cyclospora Outbreak?

In July 2026, the FDA and CDC began investigating a multistate outbreak associated with shredded iceberg lettuce served at Taco Bell restaurants. Initially, the investigation involved five states: Indiana, Kentucky, Michigan, Ohio and West Virginia.

The investigation expanded to nine states: Illinois, Indiana, Kansas, Kentucky, Michigan, Ohio, Oklahoma, Pennsylvania and West Virginia.

According to the FDA, epidemiological information showed that 1,947 people with Cyclospora reported exposure to Taco Bell across those nine states. Illness onset dates ranged from June 22 through July 20, 2026. At least 98 people had been hospitalized, and no deaths had been reported in the FDA’s July 24 update.

The FDA said the outbreak represents only a subset of Cyclospora infections identified nationwide. In other words, not every Cyclospora infection reported in the United States is necessarily connected to the lettuce or Taco Bell investigation.

How Was Iceberg Lettuce Linked to the Outbreak?

Investigators used epidemiological information and traceback work to identify a common ingredient among affected consumers.

The FDA said its traceback investigation converged on Taylor Farms de Mexico, which supplied shredded iceberg lettuce used by Taco Bell locations where people reported becoming ill. The agency also said Michigan officials analyzed food-exposure information from affected people and found that 90% of 190 interviewed cases reported eating iceberg lettuce.

Based on the available epidemiological and traceback evidence, Taylor Farms de Mexico voluntarily removed iceberg lettuce sourced from central Mexico from the U.S. market beginning July 17.

The FDA has continued to investigate the outbreak and has said that the recalled products should be avoided.

Which Lettuce Products Were Recalled?

The recall included iceberg lettuce sourced from central Mexico and distributed through retail and foodservice channels.

Among the retail products identified by the FDA were Marketside-brand products sold at select Walmart stores. These included 12-ounce and 24-ounce Iceberg Salad products with Best if Used By dates from July 18, 2026, through August 3, 2026. The recall also included 8-ounce and 16-ounce Shredded Lettuce products with dates ranging from July 18 through August 3.

The FDA also identified recalled products distributed through foodservice channels. Distribution was confirmed across numerous states, including Alabama, Arkansas, Connecticut, Florida, Georgia, Iowa, Illinois, Indiana, Kansas, Kentucky, Louisiana, Massachusetts, Maryland, Michigan, Missouri, Mississippi, North Carolina, New Hampshire, New Jersey, Ohio, Oklahoma, Pennsylvania, South Carolina, Tennessee, Texas, Virginia, Wisconsin and West Virginia.

Because food distribution can be complex, consumers should not assume that a product is safe simply because they live outside one of the states where illnesses were reported. The FDA has warned that recalled products may have reached additional locations.

What Are the Symptoms of Cyclospora?

Watery diarrhea is the most common symptom of cyclosporiasis. Unlike some short-lived stomach illnesses, Cyclospora infection can persist for weeks if it is not treated.

According to the CDC and FDA, symptoms can include frequent watery bowel movements, loss of appetite, weight loss, stomach cramps or abdominal pain, bloating, increased gas, nausea and fatigue. Some people may also experience vomiting, body aches, headaches or a low-grade fever.

Symptoms usually begin about one week after infection, although the incubation period can range from approximately two days to two weeks or more.

One of the most frustrating characteristics of cyclosporiasis is that symptoms may appear to improve and then return. The CDC notes that untreated illness can last from several days to a month or longer, and relapses can occur.

Some infected people do not develop noticeable symptoms at all. This means that people cannot always determine whether they were exposed simply by how they feel.

Who Is Most at Risk?

Anyone can become infected with Cyclospora, but certain people may experience more serious or prolonged illness.

The FDA identifies children, older adults and people with weakened immune systems as groups that can be at higher risk of complications. Immunocompromised people may experience longer-lasting illness and may require closer medical attention.

Dehydration is one of the major concerns when diarrhea is severe or prolonged. People who are unable to drink enough fluids or who have persistent diarrhea should seek medical advice.

If someone develops prolonged watery diarrhea after eating potentially contaminated food or after travel to an area where Cyclospora is common, it is important to tell a healthcare professional about the possible exposure.

How Is Cyclospora Diagnosed?

Cyclospora can be difficult to diagnose because it is not always detected through routine stool testing.

The CDC says healthcare providers may need to specifically request testing for Cyclospora when the patient's symptoms and exposure history suggest the infection. In some situations, more than one stool sample collected on different days may be necessary.

Diagnosis matters because the symptoms of cyclosporiasis can resemble other gastrointestinal infections. A laboratory-confirmed diagnosis can help healthcare providers choose appropriate treatment and can also provide valuable information to public-health investigators monitoring outbreaks.

How Is Cyclospora Treated?

Cyclosporiasis is treatable. The CDC identifies trimethoprim-sulfamethoxazole as the standard treatment.

People with symptoms should speak with a healthcare professional rather than attempting to diagnose themselves. Treatment decisions can depend on a person's health status, symptoms, medical history and other factors.

Maintaining hydration is also important, particularly for people experiencing frequent diarrhea. People who are immunocompromised may need closer monitoring because infection can be more severe or prolonged.

Consumers should not assume that an ordinary over-the-counter anti-diarrheal medication will treat the underlying parasite. Anyone with persistent or severe symptoms should seek medical guidance.

How Does Cyclospora Spread?

Cyclospora generally spreads when people consume food or water contaminated with fecal material containing the parasite.

Fresh produce has been associated with several previous U.S. outbreaks. Past investigations have involved products such as leafy greens, herbs, raspberries, basil, cilantro, parsley, broccoli and other fresh produce.

Direct transmission from one person to another is considered unlikely because Cyclospora needs time outside the body to become infectious. This makes food and water contamination particularly important in understanding outbreaks.

The parasite can also be acquired during international travel, especially in tropical and subtropical regions where cyclosporiasis is more common.

Can Washing Lettuce Prevent Cyclospora?

Consumers should wash fresh fruits and vegetables thoroughly under clean running water, but washing does not guarantee that Cyclospora will be removed.

The FDA notes that Cyclospora parasites are resistant to standard chlorine-based sanitizers. Consumers should not use soap or bleach to wash produce.

For leafy greens, the FDA recommends discarding outer layers when possible and rinsing the remaining produce under clean running water. However, if a specific product has been recalled, washing it is not an appropriate substitute for following the recall.

Consumers should discard recalled products rather than trying to make them safe through washing or cooking.

What Should Consumers Do With Recalled Lettuce?

If consumers have recalled iceberg lettuce identified in the FDA advisory, they should not eat it.

The safest action is to throw the recalled product away or follow the recall instructions provided by the retailer or manufacturer. Consumers should also clean and sanitize surfaces, containers and utensils that may have come into contact with the recalled food.

People who ate recalled lettuce do not automatically have Cyclospora infection. However, anyone who develops persistent watery diarrhea or other concerning symptoms should contact a healthcare provider and mention the possible food exposure.

People should pay particular attention to prolonged or recurring symptoms rather than assuming they have an ordinary short-term stomach bug.

Why the Outbreak May Continue to Produce New Cases

One important point about the 2026 Cyclospora investigation is that case numbers may continue increasing even after recalled lettuce has been removed from the market.

The FDA explained that it can take up to six weeks for public-health officials to determine whether a sick person belongs to the outbreak. That delay can occur because people may become ill after exposure, seek medical care later, undergo specialized testing and then have their cases linked to an outbreak through public-health investigations.

This means a rising case count does not necessarily mean that contaminated lettuce is still being sold. Some newly reported cases may reflect infections that occurred earlier.

What Consumers Should Watch Going Forward

Consumers should pay attention to updates from the FDA, CDC and their state health departments, particularly during the summer months.

The FDA says U.S. cyclosporiasis cases tend to occur between May and August. Fresh produce is a recurring focus of outbreak investigations, so consumers should continue practicing basic food-safety habits while also checking official recall announcements.

People who shop at large retailers, eat at restaurants or purchase prepared salads should pay attention to recall notices affecting specific products, brands, suppliers or dates.

It is also important to distinguish between confirmed recall information and social-media rumors. A product should not be considered unsafe merely because it resembles a recalled item. Consumers should compare the actual product information with the official FDA notice.

The Bottom Line

The 2026 Cyclospora outbreak is a significant U.S. food-safety investigation involving iceberg lettuce sourced from central Mexico. The FDA reported 1,947 illnesses across nine states among people reporting Taco Bell exposure, along with at least 98 hospitalizations and no reported deaths in its July 24 update.

The recalled lettuce was removed from the market after FDA traceback work converged on Taylor Farms de Mexico as a common supplier. Recalled products included certain Marketside iceberg salad and shredded lettuce products sold through select Walmart stores, along with products distributed through foodservice channels.

For consumers, the most important warning signs are persistent watery diarrhea, abdominal cramps, bloating, nausea, fatigue and possible weight loss. Symptoms often begin about a week after infection and can last much longer than an ordinary stomach illness.

Anyone who believes they may have been exposed should monitor their health and seek medical care for persistent or severe symptoms. Healthcare providers should be told about possible Cyclospora exposure because specialized testing may be required.

Most importantly, consumers should not eat products specifically listed in the recall. Washing recalled lettuce does not make it safe, and recalled food should be discarded according to official guidance.

As the FDA and CDC continue investigating the outbreak, consumers should rely on official updates for the latest information. Food-safety precautions, careful attention to recall notices and prompt medical advice when symptoms persist remain the best ways for U.S. consumers to reduce the risks associated with Cyclospora.