Largest-Ever U.S. Cyclospora Outbreak: 6,358 Sickened by Iceberg Lettuce Across 15 States

The U.S. Centers for Disease Control and Prevention (CDC) is investigating the largest known outbreak of cyclosporiasis in American history, with more than 6,300 confirmed illnesses across 15 states linked to contaminated iceberg lettuce imported from central Mexico. Health officials say the outbreak is still growing, and they are urging consumers to check their kitchens, restaurants and takeaway orders for recalled lettuce from Taylor Farms de Mexico.

As of the latest CDC update in early August 2026, the outbreak has sickened at least 6,358 people, resulted in 278 hospitalizations and been linked to two deaths. Six new states have joined the investigation, which began with illnesses reported as early as June 22, 2026. This is a developing public health alert, and the true number of cases is likely higher than reported because many people recover without seeking medical care.

What is Cyclospora and Cyclosporiasis?

Cyclospora cayetanensis is a microscopic parasite that causes an intestinal infection called cyclosporiasis. Unlike many foodborne bacteria, Cyclospora is not killed by typical washing — the parasite is protected by a tough outer shell and is most reliably destroyed by cooking produce to an internal temperature of at least 158°F (70°C).

People become infected by swallowing food or water contaminated with the parasite. In this outbreak, the source has been traced to iceberg lettuce grown in central Mexico and supplied by Taylor Farms de Mexico.

Key Facts About the Outbreak

• Cases: 6,358 reported illnesses across 15 states
• Hospitalizations: at least 278
• Deaths: 2 reported
• Source: iceberg lettuce from central Mexico supplied by Taylor Farms de Mexico
• Recall date: July 17, 2026 — all iceberg lettuce sourced from central Mexico
• Where sold: at least 27 states, including Taco Bell restaurants and Marketside-brand lettuce at select Walmart stores
• Illness onset: cases began June 22, 2026 and have continued through late July

The Recall: What Was Pulled From Shelves?

On July 17, 2026, Taylor Farms de Mexico recalled all iceberg lettuce sourced from central Mexico. The recall covers multiple lots and package types, including:

• Shredded and whole-head iceberg lettuce distributed to restaurants and retailers
• Marketside-brand lettuce products sold at select Walmart locations
• Lettuce served at Taco Bell restaurants supplied by Taylor Farms de Mexico

Investigators used traceback data to converge on Taylor Farms de Mexico as the single supplier of the shredded iceberg lettuce eaten by sick people before they became ill. The FDA has increased screening at the border for implicated products, and Taco Bell has stopped using lettuce connected to the investigation.

Because the best-by dates on these products have now passed, the recalled lettuce should no longer be on store shelves or restaurant menus. However, if you stored lettuce in your refrigerator or freezer and are unsure of its source, health officials advise throwing it away rather than risking illness. Wash any surfaces, cutting boards or containers that touched the recalled lettuce with hot, soapy water or in the dishwasher.

Symptoms of Cyclosporiasis

Symptoms typically begin about one week after infection, though the incubation period can range from two days to two weeks or longer. Common symptoms include:

• Watery diarrhea (the most common symptom)
• Fatigue and tiredness
• Loss of appetite
• Weight loss
• Cramping and bloating
• Increased gas
• Nausea

Without treatment, symptoms can last anywhere from a few days to more than a month, and they may come and go. People with weakened immune systems, older adults and young children are at higher risk of more severe or prolonged illness.

When to See a Doctor and How Testing Works

If you develop watery diarrhea that lasts more than a few days — especially if you ate at a Taco Bell or consumed iceberg lettuce from Mexico in the two weeks before you became ill — contact your healthcare provider. This is important for two reasons:

• Routine stool tests don’t always screen for Cyclospora. You may need to specifically request testing for this parasite.
• Cyclosporiasis is treatable. A course of prescription antibiotics is highly effective once the infection is confirmed.

Stay well-hydrated while ill, since diarrhea can cause significant fluid loss. Health officials may also contact you if you are sick, asking what you ate in the two weeks before symptoms began — answering these questions helps investigators identify and stop the outbreak at its source.

How to Protect Yourself

While this outbreak has been traced to Taylor Farms de Mexico lettuce, Cyclospora can contaminate many types of fresh produce. The CDC recommends these protective steps:

• Wash your hands thoroughly with soap and water before preparing or eating food
• Rinse all fresh produce under running water before cutting, cooking or eating — but remember washing alone cannot guarantee removal of Cyclospora
• Cook produce to at least 158°F (70°C) when possible, which kills the parasite
• Throw out recalled lettuce rather than eating it, even if it looks fresh
• Stay informed about current food recalls and outbreak alerts

Frequently Asked Questions

What should I do if I have recalled lettuce in my fridge?

Do not eat it. Throw it away or return it to the store, and wash any surfaces or containers that touched the lettuce with hot, soapy water.

Can washing lettuce remove Cyclospora?

No. Washing reduces but cannot guarantee removal of the parasite. Cooking produce to at least 158°F (70°C) is the only reliable way to kill Cyclospora.

How long after eating contaminated lettuce do symptoms appear?

Symptoms usually begin about one week after exposure, but can appear anywhere from two days to two weeks or more later.

Is cyclosporiasis contagious from person to person?

No. Cyclospora does not spread directly from person to person; infection requires swallowing contaminated food or water. However, the parasite can remain infectious in the environment for weeks or months.

How is cyclosporiasis treated?

Cyclosporiasis is treated with prescription antibiotics, which are highly effective. See your healthcare provider for diagnosis — and specifically request testing for Cyclospora, since routine stool tests don’t always detect it.

Which states are affected?

The CDC has confirmed cases in 15 states, including Illinois, Indiana, Kansas, Kentucky, Michigan, Missouri, Ohio, Oklahoma, Pennsylvania and West Virginia, with six additional states recently added to the investigation.

Bottom Line

This is the largest Cyclospora outbreak ever recorded in the United States, and it may not be over yet. The most important actions right now are simple: throw out any recalled lettuce, wash your hands and produce carefully, cook where possible, and seek medical care — with a specific request for Cyclospora testing — if you develop persistent watery diarrhea after eating lettuce from Mexico. Stay tuned to CDC and FDA updates as the investigation continues.