The Centers for Disease Control and Prevention confirmed Friday that the largest multistate cyclosporiasis outbreak recorded in the United States this year has expanded to nine states, with 1,947 people infected after eating at Taco Bell restaurants in the affected areas.
The four newly added states — Illinois, Kansas, Oklahoma, and Pennsylvania — join Indiana, Kentucky, Ohio, West Virginia, and Michigan, which has been the hardest-hit state in the outbreak.
Cyclospora is a microscopic parasite transmitted through contaminated food or water. Infection causes cyclosporiasis, a gastrointestinal illness marked by symptoms that can include severe diarrhea. Patients can require hospitalization, though no deaths have been reported in connection with the current outbreak.
The scale of this year's outbreak far exceeds historical norms. The U.S. typically records roughly 200 to 1,000 cyclosporiasis cases annually; this year's count has already reached thousands of illnesses nationwide, with the CDC's federal tally running behind totals reported by individual states.
Illnesses tied to the outbreak began on June 22 and have continued through July 20, the CDC said. The earliest cases began showing symptoms in mid-May.
Federal health and food regulators have focused their investigation on shredded iceberg lettuce supplied by Taylor Farms, specifically from the company's facility in Guanajuato, Mexico. The Food and Drug Administration previously identified Taylor Farms de Mexico as the likely source of the outbreak, and last week the agency said the company had supplied the shredded iceberg lettuce to Taco Bell locations where patients had eaten before becoming ill.
Taylor Farms subsequently issued a voluntary recall covering all iceberg lettuce sourced from its Guanajuato facility, and Taco Bell removed the affected lettuce from its restaurants.
Mexican health authorities complicated the picture Thursday, saying that samples of lettuce and water taken from the Taylor Farms plant in central Mexico tested negative for cyclospora. The FDA, however, said that result does not disprove its earlier identification of the facility as the likely source, noting that the long incubation period for infection means the crop responsible would have been distributed weeks before testing.
The FDA also found itself in a dispute with Taylor Farms over a reported false positive on lettuce samples. After the agency disclosed the error on Sunday, Taylor Farms issued a statement on X claiming that the FDA had apologized. The FDA later clarified that it had issued no such apology. Taylor Farms subsequently deleted the statement from X, though it remained posted on the company's website as of Friday.
Health experts have also criticized the company's recall notice, saying it used abbreviations and lacked enough detail for consumers to determine whether they had purchased or consumed a product at risk.
Taylor Farms supplies lettuce and other produce to major retailers including Walmart, Target, and Whole Foods, in addition to restaurant chains.
The FDA is separately investigating a second cyclosporiasis outbreak linked to an unidentified food product or products — an investigation proceeding in parallel with the Taco Bell-linked inquiry.
Investigators are working to contain the outbreak amid what experts describe as a more complicated response environment, shaped in part by staffing reductions that some say have made it harder to move quickly. With the federal case count still lagging behind state-level tallies and the source investigation ongoing, public health officials have not indicated when they expect the outbreak to be fully contained.