Iceberg lettuce from Taylor Farms is still the likely source of the massive cyclosporiasis outbreak, according to the Food and Drug Administration.

The agency said on July 19 that a sample of Taylor Farms lettuce that tested positive for cyclospora—the parasite that causes cyclosporiasis—was actually a false positive. But health officials have since said they still think Taylor Farms supplied the contaminated lettuce based on epidemiologic and traceback data.1

On July 24, the lettuce was linked to outbreaks in four additional states—Illinois, Kansas, Oklahoma, and Pennsylvania—on top of the five states already identified: Indiana, Kentucky, Michigan, Ohio, and West Virginia.2

Here’s everything you need to know.

Why Was There a False Positive?

The first announcement of a potential source of the cyclosporiasis outbreak—which has now climbed to an estimated 7,000 cases nationwide—identified shredded lettuce served at Taco Bell.34

From there, health officials identified the supplier of the contaminated lettuce as Taylor Farms. In response, Taylor Farms voluntarily recalled all iceberg lettuce sourced from central Mexico.

Then came the false positive. According to Donald Prater, the FDA’s acting deputy commissioner for food, the agency initially publicized the positive cyclospora test result on July 18 due to the urgency of the outbreak.

“At that time, it was important for us to communicate that result,” he said in a press call. “This is in the face of an ongoing outbreak that was making people sick.”

But on July 19, quality testing found the mistake. Prater said several factors make cyclospora difficult to detect. Only a small number of the parasite’s microscopic oocysts may be present on contaminated produce, and it can take weeks for symptoms to appear after someone eats it. Because iceberg lettuce has a short shelf life, the contaminated product is often gone by the time people become sick.

“Test results are difficult to obtain,” Prater added. “Most of the time, our tracebacks and epidemiologic information are what allow us to determine the source of an outbreak.”

Despite the false positive, Prater confirmed that “the outbreak data continue to converge on shredded iceberg lettuce from Taylor Farms locations in central Mexico.”

Which Lettuce Was Recalled?

Most of the recalled lettuce from Taylor Farms was distributed to foodservice providers, but two products were sold at Walmart under the Marketside brand:5

• Iceberg Salad, sold in sizes: 12 oz and 24 oz, with best-if-used-by dates: 7/18/2026 to 8/3/2026
• Shredded Lettuce, sold in sizes: 8 oz and 16 oz, with best-if-used-by dates: 7/18/2026 to 8/3/2026

The recalled lettuce was sold at Walmart stores in 15 states: Alabama, Arkansas, Florida, Georgia, Indiana, Kansas, Kentucky, Louisiana, Missouri, Mississippi, Oklahoma, Tennessee, Texas, Virginia, and West Virginia.

The affected lettuce at foodservice providers was distributed to 27 states: 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, and Wisconsin.

A full list of affected products is available in the FDA’s announcement.

What You Should Do

Check your fridge for the recalled lettuce. If you have it, throw it away and contact your local store for a refund.

The FDA is also advising consumers not to eat affected lettuce at Taco Bell and to ask the restaurant if you’re unsure of the source of its lettuce.

If you think you have eaten contaminated lettuce, monitor for symptoms of cyclosporiasis, including watery diarrhea—the hallmark of the illness—as well as nausea, fatigue, abdominal cramps, flu-like symptoms, and loss of appetite.4

Contact a healthcare provider if you experience symptoms. They can issue a stool test to confirm the infection and treat it with an antibiotic.