- FDA reanalyzed a positive test and deemed it a false positive, yet interviews and traceback still point to Taylor Farms shredded iceberg lettuce.
- Taylor Farms voluntarily removed central Mexico iceberg lettuce; its products reach major retailers and restaurants nationwide, causing industry and consumer impacts.
- Officials advise choosing whole heads, rinsing outer leaves, and pregnant or immunocompromised people to avoid raw salads; cooking to 158°F kills Cyclospora.
The Food and Drug Administration's investigation into the Cyclospora outbreak took an unexpected turn this week after the agency revealed that a laboratory test that initially appeared to detect the parasite in shredded iceberg lettuce from Taylor Farms was actually a false positive.
At first glance, that might sound like the investigation moved back to square one. But that's not what happened: Despite the lab error, federal health officials still believe shredded iceberg lettuce supplied by Taylor Farms is the most likely source of the outbreak, based on interviews with people who got sick and extensive traceback data.
While infections have been reported in 34 states, the current outbreak is centered in the Midwest. Michigan has reported the bulk of cases, followed by New York, Illinois, and Texas. If you’re not familiar with the parasite causing all this trouble, Cyclospora can lead to weeks of watery diarrhea, stomach cramps, nausea, and fatigue.
Here's what to know about the probe, where Taylor Farms products are sold, and what experts recommend if you're wondering whether it's safe to eat lettuce.
Is Taylor Farms responsible for the outbreak?
Investigators believe Taylor Farms lettuce is the likely source of the outbreak, but they have not definitively confirmed it. The top line of the notice on the FDA’s website continues to say, “Do not eat recalled iceberg lettuce from Taylor Farms de Mexico,” and the agency says its investigation is ongoing.
But the FDA's recent updates have made it harder to understand what's going on. On Saturday, the agency reported that a sample of Taylor Farms shredded iceberg lettuce had tested positive for Cyclospora. The following day, it walked back that finding, saying it should be considered a false positive after re-reviewing the laboratory data. The lettuce that was tested was not part of the original recall, and there are currently no confirmed food products that have tested positive for the parasite. The back-and-forth didn't end there: Taylor Farms said the FDA apologized for the false positive, but the agency later disputed that account.
After the reversal, the FDA clarified on Monday that the false positive does not change the basis of its investigation or the evidence linking the outbreak to shredded iceberg lettuce supplied by Taylor Farms. In a statement posted to X, officials said they would "continue to work with federal and state partners to investigate this multistate outbreak and ensure products implicated in this outbreak have been removed from the market."
Future testing could still detect the parasite in additional samples, but that isn't the only way investigators determine the source of an outbreak. Jennifer McEntire, a food safety expert who consults for companies including Taylor Farms, told The Wall Street Journal that Cyclospora is especially difficult to study. Unlike bacteria such as E. coli and Salmonella, it can't be grown in a lab to produce more genetic material, making it harder for scientists to connect individual cases to a common source. By the time illnesses are reported, contaminated lettuce has also often been eaten or thrown away before it can be tested. That's why investigators rely not only on laboratory testing but also on interviews with sick people and traceback data to identify the most likely source of the illnesses.
Taylor Farms, meanwhile, has maintained that its products were not contaminated but says it has fully cooperated with the FDA's investigation. As a precaution, the company voluntarily removed lettuce sourced from central Mexico from the U.S. market on July 17, while many of its other products remain on grocery store shelves.
Where are Taylor Farms products sold?
Taylor Farms is one of the largest fresh produce companies in North America. (It has also become a major political donor: Federal Election Commission records show the company has contributed more than $3.8 million to conservative-aligned groups this decade, including President Donald Trump's MAGA Inc. super PAC.)
It sells produce under its own brand and owns popular labels like Earthbound Farm. The company supplies lettuce and other fresh produce to major grocery chains, including Walmart, Safeway, Costco, Whole Foods, Kroger, Target, and Amazon Fresh, as well as restaurant chains such as Taco Bell, Chipotle, McDonald's and Subway. Through foodservice distributor Sysco, its products also end up in schools, hospitals, and sports venues.
The investigation has also had ripple effects for some of Taylor Farms' biggest customers. Taco Bell, for instance, has removed lettuce linked to the outbreak from its restaurants. According to The Wall Street Journal, citing Placer.ai data, visits to Taco Bell fell between 16.9 and 18.9 percent from Wednesday through Friday last week compared with the average for those weekdays between Jan. 1 and July 6. Chipotle saw traffic decline by 5.7 to 7.2 percent, while Panera experienced a 3.5 to 7.4 percent drop over the same period, suggesting some diners may have become more cautious about eating at restaurants that serve fresh produce.
What lettuce is safe?
Health officials aren't telling people to swear off lettuce altogether. But Michigan's chief medical executive, Natasha Bagdasarian, MD, told The New York Times that people who want to be extra cautious while the investigation continues should choose whole heads of lettuce over bagged or pre-cut salad mixes. Whole heads allow consumers to remove the outer leaves, trim away any damaged areas, and rinse the lettuce under running water before eating it.
As for other greens, that's a harder question to answer. Dr. Bagdasarian cautioned that the investigation is still unfolding, so it would be premature to rule out other products entirely. Cross-contamination can also occur when different leafy greens are processed together. So while there's currently no evidence linking romaine, spinach, kale or other roughage to the outbreak, health officials aren't ready to give them the all-clear just yet.
"We are seeing exposure potentially across diverse settings," she told the newspaper, adding, "I think it could be premature to say that we believe this is just one product."
People who are pregnant, immunocompromised, older, or very young may want to take extra precautions while the investigation continues. Some food safety experts recommend skipping raw salads and opting for cooked vegetables instead. According to the CDC, washing alone can't guarantee the removal of Cyclospora. Cooking produce to at least 158°F is the only reliable way to kill the parasite.
