The Latest on the Cyclosporiasis Outbreak: An FDA False Positive Test, and What Treatment Looks Like

Update: The FDA announced an update regarding the sample of lettuce supplied by Taylor Farms de Mexico which was reported positive on July 18.

“Due to the complexity in detection of Cyclospora, FDA laboratory experts re-reviewed the sample results and have concluded that the finding does not represent true amplification and should be considered a false positive. Information about the sample has been removed from the July 18, 2026, update below. FDA has notified Taylor Farms and continues working with the firm to ensure product implicated in this outbreak has been removed from the market. FDA and state partners continue to collect and analyze product samples. As of July 19, 2026, there are no confirmed positive sample results for product testing for Cyclospora,” the FDA wrote on its site.

A statement from Taylor Farms:

“Today, FDA apologized to us.

Yesterday, FDA informed Taylor Fresh Foods that one of its iceberg lettuce products from central Mexico tested positive for cyclospora. Today, we were informed that FDA made a mistake, and this was a false positive. To be clear, at this moment, FDA has not identified a single positive product test result for Cyclospora.

Based on initial information provided by health officials, in an abundance of caution, we completed a voluntary recall of iceberg lettuce from central Mexico. Recalled product was limited to iceberg lettuce grown and processed in central Mexico.

All other Taylor Farms products, including all Taylor Farms brand products available for purchase, are not involved in the recall.

Our thoughts remain with everyone who has fallen ill in this outbreak. We are committed to working with public health authorities as the ongoing outbreak investigation continues.”

Original report: Investigators have determined lettuce served at Taco Bell is the source of the ongoing, multistate cyclosporiasis outbreak.¹

On July 17, Taylor Farms, a produce distributor for Taco Bell, initiated a recall of all iceberg lettuce sourced from central Mexico. The recall includes iceberg lettuce sold at retail stores and restaurants. It also includes other recalled products distributed to food service customers. A complete list of those products is included in the recall notice.¹

The incubation period for the food-borne illness can vary. Symptoms typically develop about 1 week after infection but can appear anywhere from 2 days to more than two weeks after exposure.² Unlike many viral gastrointestinal illnesses that resolve within a day or two, cyclosporiasis infections typically cause prolonged watery diarrhea that persists or returns after initially improving.

In terms of when to seek medical attention, Catherine O’Neal, MD, chief academic officer for the Franciscan Missionaries of Our Lady Health System, offers some guidance.

“Most diarrheal illnesses come and go. They leave us feeling a little weak, but we get over them and we go back to work. If yours is just sticking around, you need to call your doctor. Or maybe you had a diarrheal illness that you thought was getting better, and then this week it's back. So, a relapsing diarrheal illness is also a reason to call your doctor. Most of the time, a 24 or 48 hour bug that gives you a diarrheal illness is something you can stay home with—not call your doctor.”

O’Neal also noted that fever and vomiting are uncommon with Cyclospora infection.

She explained that diagnosis requires testing that specifically detects Cyclospora, as routine stool parasite testing may not identify the organism. If confirmed, treatment with trimethoprim-sulfamethoxazole, an antibiotic used for traveler’s diarrhea may be used, while hydration remains an important part of management for both outpatient and hospitalized patients.The latter patients are typically treated the same, but with more monitoring.

O’Neal encouraged consumers to be cautious with lettuce and other fresh produce as this is a large issue.

“The problem with bagged lettuce is that it says that it's washed, but you cannot right now ensure that it is…So buy heads of lettuce if you can. If you're buying lettuce, make sure you wash it well. If you're going to eat lettuce at a restaurant or at a gathering, it's important to ask about how that was prepared, or to avoid that when you're not sure how that preparation went.”

Reference
1.Cyclospora Outbreak Linked to Iceberg Lettuce in 5 States. CDC. July 18, 2026, 2024. Accessed July 20, 2026.
https://www.cdc.gov/cyclosporiasis/outbreaks/07-26/index.html
2.About Cyclosporiasis. CDC. September 4, 2024. Accessed July 18, 2026.
https://www.cdc.gov/cyclosporiasis/about/index.html