CDC, FDA zero in on potential source of diarrhea outbreak

Lettuce served at Taco Bell restaurants has been linked to an ongoing cyclosporiasis outbreak that has sickened more than 1,600 people in in five states, federal health officials say.

An investigation by the Centers for Disease Control and Prevention, the Food and Drug Administration and state health officials has linked shredded iceberg lettuce served at Taco Bell locations in Indiana, Kentucky, Michigan, Ohio, and West Virginia to an outbreak of the stomach-churning parasitic infection that causes diarrhea and nausea across several states.

The FDA's traceback investigation has identified a single supplier of iceberg lettuce from Mexico used by these Taco Bell locations, the agencies said late Thursday, July 16.

Across the U.S., the CDC is also investigating other outbreaks and illnesses of the stomach-churning parasitic infection that causes diarrhea and nausea that are unrelated to this five-state outbreak, the agency said. The infection, caused by the parasite Cyclospora cayetanensis, can cause frequent, watery diarrhea or explosive bowel movements, nausea, cramps, bloating and low-grade fever.

The outbreak has especially hit Michigan hard. The state health department there on Thursday, July 16, reported 4,312 cases statewide of the fast-moving gastrointestinal illness. At least 102 people in the state have been hospitalized since June 22, according to the Michigan Department of Health and Human Services. Infections have escalated in 34 states as well.

Lettuce identified as possible link to cyclosporiasis outbreak

Public health officials in Michigan analyzed food exposures from 190 of the cases who reported eating at Taco Bell and shared these findings with the CDC, officials said. About nine out of 10 of those (90%) reported eating iceberg lettuce.

The FDA is working with the supplier to determine if more potentially contaminated shredded iceberg lettuce remains on the market, the agency said. The FDA is working with state health departments to collect additional samples and is also increasing screening "at the border for products implicated in the outbreak," the FDA said in an update late Thursday.

Earlier in the week, health officials in Michigan said lettuce could be a possible source but weren't yet ruling out other items.

Then, on Thursday, July 16, Taco Bell saidit had removed lettuce from one of its suppliers in select states after reports linked the ingredient to the growing cases of the stomach-churning parasitic infection that causes diarrhea and nausea across several states.

"Based on ongoing conversations with public health officials, and out of an abundance of caution, Taco Bell has taken immediate action to voluntarily remove potentially impacted lettuce from a supplier in select states," the company said in a statement.

The lettuce supplied by the vendor would be "indefinitely removed" from its supply chain nationwide and replaced within 24 hours in affected states, according to Taco Bell. The company did not identify the supplier or specify which states were affected by the removal.

A day earlier, Taco Bell said it had removed ingredients from some stores in what the fast food chain said was a precautionary move.

Taco Bell's statement hinted that it wouldn't be the last restaurant to make a lettuce move.

"While no official advisory has been issued, we believe public health is a shared responsibility among restaurants, their suppliers, and authorities, and we are proud to have consistently acted quickly and proactively to protect our guests," read the company statement. "Taco Bell has taken precautionary action, and we encourage all relevant restaurants, retailers, and foodservice operators to do the same."

Contributing: Melina Khan, Sara Moniuszko, and Kristen Jordan Shamus, USA TODAY; Reuters

This article originally appeared on USA TODAY: CDC, FDA zero in on potential source of diarrhea outbreak

Reporting by Mike Snider and Thao Nguyen, USA TODAY / USA TODAY

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This story was originally published July 17, 2026 at 8:30 AM.