A multistate outbreak of Cyclospora infections tied to contaminated iceberg lettuce has grown to 6,358 laboratory-confirmed illnesses across 15 states, according to the Centers for Disease Control and Prevention, making it the largest cyclosporiasis outbreak on record in the United States. At least 278 people have been hospitalized, and two deaths have been reported in Michigan among patients with underlying health conditions.
Investigators at the CDC and the Food and Drug Administration traced the source to iceberg lettuce grown in central Mexico and distributed by Taylor Farms de Mexico. The company issued a voluntary recall on July 17 covering lettuce sold at retail — including Marketside-brand salads and shredded lettuce at Walmart — with best-if-used-by dates spanning July 18 through August 3. Recalled foodservice lettuce was also distributed to restaurants in 29 states, including Taco Bell locations; the FDA's investigation summary notes that 90% of interviewed patients who ate at affected Taco Bell restaurants reported eating iceberg lettuce there.
Illness onset dates run from June 22 through July 31, and the case count has climbed steadily as more states report infections. The outbreak began in five states — Indiana, Kentucky, Michigan, Ohio and West Virginia — before expanding in early August to include Arkansas, Iowa, Missouri, Nebraska, New Hampshire and North Carolina, among others.
A parasite that hides in produce
Cyclospora cayetanensis is a single-celled parasite that spreads when food or water becomes contaminated with feces containing the organism's oocysts, often through contaminated irrigation water or handling during harvest and processing. Unlike many foodborne bacteria, it cannot be killed by simply rinsing produce, and symptoms — watery diarrhea, loss of appetite, cramping, nausea, fatigue and sometimes weight loss — can take about a week to appear after exposure and may persist for weeks or relapse if untreated.
The FDA is advising consumers, restaurants and retailers who received recalled lettuce from Taylor Farms de Mexico to "discard it immediately and not consume it." Because iceberg lettuce has a limited shelf life, health officials say most of the originally recalled product should now be out of circulation, but they caution that new illnesses linked to the earlier exposure window may still be reported as lab confirmations catch up with case counts.
The investigation remains open, and the CDC has said additional states or cases could still be identified as public health labs complete testing on backlogged samples. Health officials are urging anyone who ate iceberg lettuce in the affected window and has since developed prolonged gastrointestinal symptoms to contact a healthcare provider, since cyclosporiasis requires a specific antiparasitic treatment — trimethoprim-sulfamethoxazole — rather than standard antibiotics, and can otherwise drag on for weeks.
