CDC Expands Cyclospora Outbreak Tied to Taco Bell Lettuce to 20 States, Nearly 11,500 Illnesses

Federal health officials said Thursday that a multistate outbreak of cyclosporiasis linked to iceberg lettuce served at Taco Bell restaurants has grown to at least 11,458 confirmed illnesses across 20 states, one of the largest foodborne-parasite outbreaks recorded in the United States. The updated case count, hospitalization total and list of affected states appear in an outbreak investigation page maintained jointly by the Food and Drug Administration, which was refreshed with Thursday's figures. Three states, Georgia, Tennessee and Texas, were added to the case list since the prior update on August 20.

The outbreak has been traced to shredded iceberg lettuce grown and processed in central Mexico by Taylor Farms de Mexico, a subsidiary of the Salinas, California-based produce giant Taylor Farms. The company recalled all iceberg lettuce sourced from the region on July 17, more than five weeks ago, but new illnesses have continued to surface because Cyclospora infections often take a week or longer to produce symptoms and further time to be diagnosed and reported to health departments.

The scope, so far

At least 495 people have been hospitalized and two have died, both in Michigan, according to the federal tally. Illness onset dates now range from June 14 through August 15. When the outbreak was first announced in mid-July, it was confined to five states, Indiana, Kentucky, Michigan, Ohio and West Virginia, with roughly 1,600 reported illnesses, according to reporting at the time. The case count has since grown more than sevenfold as testing and epidemiological investigation caught up with infections that had already occurred. Michigan alone accounts for the largest share of confirmed cases, at one point reporting more than 5,000 illnesses on its own, state health data cited in national coverage showed. The FDA has said the outbreak may extend beyond the states currently reporting illness, since many people with cyclosporiasis recover without seeking medical care or being tested for the specific parasite.

Cyclospora cayetanensis, the single-celled parasite responsible for the illness, causes watery diarrhea that can persist for weeks if untreated, along with loss of appetite, weight loss, bloating, nausea and fatigue. It is treated with the antibiotic combination trimethoprim-sulfamethoxazole. Unlike bacteria such as E. coli or Salmonella, Cyclospora oocysts are not infectious immediately after leaving a host; they require days to weeks in the environment to mature, which means the illness does not spread directly from person to person and instead points investigators back toward a contaminated food source, in this case fresh produce.

How the parasite reached the supply chain

Traceback work led by the FDA, using loyalty-card and purchase records from Taco Bell locations, identified a single Taylor Farms de Mexico facility in Guanajuato as the common link among early cases. The company's recall notice, filed with the FDA, covered foodservice and limited retail iceberg lettuce, including Marketside-brand bags sold at Walmart, distributed from late June through mid-July. In its own account of the response, Taylor Farms has said it suspended all iceberg lettuce sourcing from central Mexico for the remainder of the growing season, idled the implicated facility and hired outside experts to review its food-safety protocols, on top of the roughly $200 million the company says it spends annually on food-safety measures.

Food-safety attorneys who have litigated past produce outbreaks say the source of contamination is almost always upstream of the processing plant. William Marler, the Seattle-based attorney whose firm has sued both Taylor Farms and Taco Bell on behalf of sickened customers, said in a statement distributed through PR Newswire that consumers should not assume produce can be made safe simply by rinsing it.

"No rinse, no chlorine wash and no post-harvest process in commercial use will remove Cyclospora from lettuce. The only place to stop it is upstream, in the water," Marler said.

That assessment does not contradict the guidance federal officials gave consumers when the outbreak first surfaced. Gwen Biggerstaff, deputy director of the CDC's Division of Foodborne, Waterborne, and Environmental Diseases, told reporters in July that washing hands and produce under running water remains good general practice, and that heating food to at least 158 degrees Fahrenheit is effective at killing the parasite, a step that raw, ready-to-eat lettuce by definition never undergoes.

Who is affected

Confirmed illnesses have now been reported in Arkansas, Georgia, Iowa, Illinois, Indiana, Kansas, Kentucky, Massachusetts, Maine, Michigan, Missouri, Nebraska, New Hampshire, North Carolina, Ohio, Oklahoma, Pennsylvania, Tennessee, Texas and West Virginia. The recalled lettuce itself reached a wider footprint, distributed to roughly 30 states before the recall, though the FDA has said the affected products' best-by dates have now passed and none should remain on shelves or in restaurant kitchens. Taco Bell has said it removed the Taylor Farms-supplied lettuce from its entire domestic supply chain within a day of being notified, not only the restaurants in states where illnesses were first confirmed.

The financial and legal fallout has extended beyond the health toll. Multiple lawsuits have been filed against both Taco Bell and Taylor Farms on behalf of sickened customers, and Taco Bell's parent company has acknowledged the outbreak weighed on sales at franchise locations in the hardest-hit markets over the summer.

What happens next

The FDA and CDC say the investigation remains active, and officials expect the reported case count to keep climbing for some time even though the contaminated product is long off the market, because reporting of cyclosporiasis cases lags well behind actual infection dates. Investigators have used genetic sequencing, known as genotyping, to confirm that the parasite strains found in patients across the expanding list of states are closely related, which the agencies say is additional evidence pointing to a single, common source rather than several unrelated incidents. Taylor Farms has said it will not resume sourcing iceberg lettuce from central Mexico until the current growing season ends and its outside food-safety review is complete. For consumers, both agencies' current guidance is unchanged from when the recall was announced: the specific recalled lettuce should already be gone from stores and restaurants, but anyone who develops prolonged watery diarrhea after eating shredded lettuce in recent weeks is advised to contact a healthcare provider and specifically request testing for Cyclospora, since standard stool tests do not always detect it.