Shares of Yum Brands were down nearly 4% on Tuesday

Taco Bell pulled some ingredients from menus "due to a nationwide recall," some news outlets reported last week.

Yum Brands' Taco Bell chain reportedly faces an investigation into whether some of its locations were linked to an outbreak of a parasite that has sickened more than 3,000 people in Michigan and appeared in other states.

The news of the investigation was reported by the Washington Post, which said federal and state health officials were looking into the matter. Last week, news outlets reported that notices were posted at some Taco Bell locations in the Detroit area, saying those restaurants were unable to sell items like lettuce, pico de gallo and guacamole "due to a nationwide recall."

"Any items ordered that normally come with these items WILL NOT contain them," the notices read.

According to the Michigan Department of Health and Human Services, there were 3,309 cases in the state involving the outbreak of cyclosporiasis, an intestinal illness caused by a parasite that can lead to diarrhea and what the Centers for Disease Control described as "sometimes explosive bowel movements."

Some people who had gotten sick "told investigators they had eaten at Taco Bell," the Post reported, citing a person familiar with the matter. But others who had fallen ill hadn't eaten there, "suggesting the outbreak extends beyond the chain," the Post said.

No precise source of the outbreak has been identified. Yum Brands did not immediately respond to a request for comment.

Shares of Yum Brands (YUM) were down 3.9% on Tuesday, at last check, though the stock was still up 3.3% so far this year. Shares were trading at around $156, off of highs reached in February.

The Michigan Department of Health and Human Services said that while an investigation into the source of the outbreak continues, "available information indicates that lettuce or salad greens may be a potential source of this outbreak. However, other food items cannot be completely ruled out."

"No specific type of produce, grower or supplier has been identified as the source," the agency noted. As of July 9, 44 of Michigan's reported cases indicated they were hospitalized.

The CDC said that without treatment, people with the parasite can stay sick for anywhere from a few days to more than a month, though the parasite usually isn't life-threatening. Treatment generally involves antibiotics, according to the Cleveland Clinic.

Cyclosporiasis cases become more common in the spring and summer, according to the CDC. But experts have said the exact source of any outbreak can be difficult to identify due to the time it takes for people to start feeling sick - anywhere from two days to upwards of two weeks.

Still, some parts of the country are reporting higher cases when compared with the same period a year ago, the CDC said. Concerns have grown that funding cuts to programs that monitor such outbreaks could make the investigation more difficult.

But at least as of last week, some Wall Street analysts expressed confidence that the restaurant industry had gotten better at keeping outbreaks in check.

"Having covered the sector for nearly 20 years and experienced multiple food-safety issues including McDonald's in October 2024 and Chipotle in 2015, we believe the industry has figured out how to contain and limit the risk of these food-safety issues," BTIG analyst Peter Saleh said in a note Thursday.

-Bill Peters

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July 14, 2026 13:28 ET (17:28 GMT)

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