A multistate cyclospora food poisoning outbreak traced to recalled iceberg lettuce has officially ended, U.S. health authorities announced Friday.
The Centers for Disease Control and Prevention said consumers are no longer believed to be at risk of contracting cyclosporiasis from this outbreak, adding that officials are confident the implicated iceberg lettuce has been removed from stores and supply chains.
The U.S. Food and Drug Administration said the outbreak is over, but its inquiry is not. Investigators will continue examining cyclospora infections connected to iceberg lettuce grown in central Mexico and recalled by Taylor Farms de Mexico.
“FDA will continue to work with federal, state, and international partners to complete its investigation and will provide updates as they become available,” the agency said on Friday.
Federal officials say nearly 13,000 reported cyclospora cases across 21 states were linked to the lettuce outbreak, accounting for much of this year’s extraordinary rise in the parasitic diarrheal illness. As of Friday, FDA and CDC data showed more than 570 people had been hospitalized and two had died.
Still, the end of the outbreak leaves major unanswered questions, including how the contamination began. Cyclospora spreads through human feces, and investigators have not yet explained how sewage-related contamination could have reached enough food to cause illnesses on such a large scale.
“This contamination can happen if produce is grown in soil or comes into contact with water that has been contaminated,” said Ellen Shumaker, director of outreach for Safe Plates, a North Carolina State University food safety program.
Since May 1, health officials have received reports of nearly 20,000 laboratory-confirmed cyclospora infections — more than 16 times the number logged during the same period last year. Authorities have also recorded more than 6,100 suspected cases.
Before this year, the highest annual U.S. total came in 2019, when roughly 4,700 cyclospora illnesses were reported nationwide.
The sharp increase this year was driven largely by the 21-state iceberg lettuce outbreak, though thousands of additional cyclospora cases have not been connected to that cluster.
Michigan was the hardest-hit state, reporting the most cases as well as the two U.S. deaths associated with the outbreak.
Cyclospora is a microscopic, round parasite that typically causes watery diarrhea, including “frequent and sometimes explosive bowel movements,” the CDC says. Outbreaks are most commonly reported in late spring and summer.
The illness, called cyclosporiasis, is less common than foodborne illnesses caused by other germs, including salmonella and E. coli. Many cases are never linked to a specific food or other source.
In this outbreak, investigators initially zeroed in on lettuce served at Taco Bell. Federal officials subsequently focused on Taylor Farms as the source of the lettuce, and the company recalled iceberg lettuce grown in central Mexico.
The Taylor Farms recall involved thousands of packaged salad products combining iceberg lettuce with other vegetables. The products were shipped to major U.S. restaurant chains, including Yum Brands, which owns Taco Bell, Pizza Hut and KFC.
The FDA has ended its on-site inspections and sample collection at iceberg lettuce growers and the processing facility in Mexico, the agency said Friday. Samples from the on-site inspections are pending analysis, the FDA said.
The outbreak cast a spotlight on a worsening problem: U.S. regulators are conducting fewer international inspections to catch contaminated produce before it lands on American plates.