US officials trace Taco Bell parasite outbreak to shredded lettuce

US officials on Friday linked a foodborne parasite outbreak tied to Taco Bell locations in five states to shredded iceberg lettuce used by the fast food chain.

A federal investigation by the Food and Drug Administration traced the contamination to a single supplier of iceberg lettuce from Mexico, according to a statement from the Centers for Disease Control and Prevention. The lettuce was used by Taco Bell locations in Indiana, Kentucky, Michigan, Ohio and West Virginia.

The CDC said more than 1,644 people in those five states were confirmed to be infected with cyclosporiasis and linked specifically to the Taco Bell outbreak. The agency said there had been no deaths and 94 hospitalizations related to the outbreak. It said the number does not include all cyclosporiasis infections from other causes.

Federal officials warned people in the five affected states not to eat shredded iceberg lettuce from Taco Bell.

The CDC did not name the supplier. The Washington Post, citing unnamed sources familiar with the investigation, reported that Taylor Farms sold the lettuce.

Taco Bell said it had taken immediate action to voluntarily remove potentially affected lettuce from a supplier in select states. The company said the affected ingredient from its supplier was being removed indefinitely from its supply chain nationwide and would be replaced within 24 hours in select states. Taco Bell said it believes public health is a shared responsibility among restaurants, suppliers and authorities.

Cyclosporiasis can cause diarrhea and other symptoms. The CDC statement cited in the report said it can cause "explosive diarrhea." Untreated, the illness can last more than a month. It is generally not life-threatening, but can cause dehydration.

Past cyclosporiasis cases have been linked to foods including bagged salad mixes, fresh cilantro, fresh basil, raspberries, snow peas and scallions. Officials recommend thoroughly washing produce or cooking it, because heat above 158 Fahrenheit, or 70 Celsius, kills the parasite.

Michigan has been particularly affected by cyclosporiasis this year, with state authorities reporting more than 5,000 cases. The FDA cautioned that state data can differ from national surveillance numbers because states often include probable as well as confirmed cases. It also said reporting and national data updates can lag.