Fast food chains have struggled for years to win back consumers fatigued with rising prices and unexciting menus -- and then there's Taco Bell.

The home of the Crunchwrap Supreme and Cheesy Gordita Crunch has kept on finding ways to grow, rolling out new offerings like Diablo Dusted Crispy Chicken Nuggets and Mountain Dew Baja Blast Pie, helping it outpace competitors in U.S. sales growth for at least six years.

A microscopic parasite now threatens Taco Bell's hot streak, potentially imperiling millions of dollars in sales and setting up a slog to win back consumers. Yum Brands, the chain's parent company, could have to contend with a standout brand not delivering the consistent sales growth that has powered its overall revenue and profit.

"We see risk that concerns about Taco Bell food safety could pose a measurable headwind," Baird restaurant analysts said Friday, particularly if consumers connect the problem more to the chain than its supplier.

Federal health officials said late Thursday that the outbreak of cyclosporiasis was linked to shredded iceberg lettuce served at Taco Bell locations in Michigan, Indiana, Ohio, Kentucky and West Virginia. They said that over 1,600 people who became ill in the outbreak reported eating at Taco Bell locations in those states.

Taco Bell said late Thursday that it had voluntarily removed potentially affected lettuce in select states. Yum Brands shares have fallen around 5% over the past five days, and Taco Bell's Instagram feed, which typically posts vibrant images of its sauce packets and Baja Blast drinks at the beach, has gone quiet.

The chain earlier this month pulled some fresh ingredients from regional menus in what it called a proactive move -- which raised alarm bells among some consumers. Taco Bell's business has slowed as the outbreak picked up steam, according to third-party data providers.

Placer.ai, which analyzes foot traffic at businesses, estimated that visits to U.S. Taco Bell locations were 2.3% higher than the day of week average on July 7, but by July 11, were 5.8% lower.

The chain's U.S. sales grew 4.2% for the week ended July 11, representing the slowest weekly increase since April, according to data firm Consumer Edge, which analyzes credit and debit transaction activity.

An Ohio man on Thursday sued a large Taco Bell franchisee, alleging he fell ill and tested positive for cyclospora after eating Taco Bell food in late June. Pacific Bells, the Washington-based operator that runs the Ohio restaurant, didn't immediately respond to requests for comment.

Bigger portion

Yum needs Taco Bell's strong run to continue, particularly now that its stable of brands is set to shrink. The Kentucky-based company struck a deal last month to sell its Pizza Hut chain to a private-equity firm after a long string of weak sales.

Taco Bell currently represents more than a fourth of systemwide sales for Yum, which also operates KFC and Habit Burger & Grill. Yum executives have frequently referred to Taco Bell as a "category of one brand" without comparison, and it represented around 38% of the company's operating profit before the Pizza Hut sale.

Fast-food chains have struggled to increase sales for years as consumers, navigating rising prices, have reconsidered how they spend on food. McDonald's and other chains have rolled out deals for the past two years, helping bring some customers back -- but not in droves.

Taco Bell has also pushed value offerings, but it has been able to draw diners and lift sales with "Luxe Boxes" sold across a broad price range, at $5, $7 and $9 dollars.

The chain reported a 6.5% increase in U.S. sales last year, compared with the limited-service sector's average of 3.1%, according to market-research firm Technomic. Taco Bell has beat the fast-food sector's performance at least since 2019, the firm said.

Led by former Nike marketing executive Sean Tresvant, Taco Bell has also cultivated its cool factor. At its Live Más Live event in March, Taco Bell televised its 2026 menu launch event at the Palladium in Hollywood, with rappers Vince Staples and Doja Cat toasting over new Refrescas and a Flamin' Hot Mini Taco Salad.

"Brands that break through speak to somebody specifically, and who we speak to is somebody we call the 'cultural rebel,' " Tresvant said during an interview last year.

Trust factor

McDonald's, Chipotle and other restaurant giants have also faced food safety crises, and have had to toil to regain customers' trust and business. After federal authorities said that slivered onions served on McDonald's Quarter Pounders were the likely source of an E. coli outbreak that sickened dozens in October 2024, the burger chain's U.S. same-store sales slumped for around six months.

In late 2006, Taco Bell also struggled with an E. coli outbreak. Its U.S. same-store sales dropped the following year, and it took around nine months for the chain's sales to stabilize.

Brands seeking to recover from a food-safety crisis often roll out buzzy menu items or new deals. The return of McDonald's Snack Wrap, along with more value deals, helped the burger chain's sales rebound.

In 2007, Taco Bell heavily advertised new products such as a Cheesy Beefy Melt, its value meals and a Major League Baseball promotion awarding free tacos. The chain was able to stabilize its sales by the end of the year.

Wall Street analysts have said they expect the outbreak to measurably depress Taco Bell's U.S. sales in the short term. Reclaiming its cool factor could take more time.

A Taco Bell X post last week riffing on the joys of "spiritually sitting in a taco bell parking lot at sunset" was met with poop emojis.

"I had a chalupa yesterday to celebrate taco Tuesday. It had lettuce on it. Do I now have Cyclospora parasite incubating in my body?" one commenter wrote.

Write to Heather Haddon at heather.haddon@wsj.com

(END) Dow Jones Newswires

July 17, 2026 11:58 ET (15:58 GMT)

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