US Cyclosporiasis Outbreak Linked to Taco Bell Lettuce Sickens 1947, Yum Brands Shares Fall 5%

The U. S. Food and Drug Administration linked the parasitic outbreak to lettuce supplied to Taco Bell, causing double-digit declines in the chain's average daily foot traffic. Yum Brands' shares fell 5% over the same period, reducing its market capitalization to about $42 billion. As of last Friday, data from the U. Centers for Disease Control and Prevention showed the outbreak had sickened at least 1947 people, with 98 hospitalized and no deaths reported. Federal health authorities identified iceberg lettuce from Taylor Farms as the suspected source.

Taco Bell is one of Yum's "dual engines," together with KFC's international business, supporting the company's profit and revenue. The Mexican-style chain has long been a core brand in Yum's portfolio, with a loyal customer base and same-store sales growth amid a consumer shift toward value. Yum also owns Habit Burger, but that brand is smaller with fewer than 400 stores. Yum recently spun off Pizza Hut, which had been struggling for more than a decade. The spin-off means more attention is focused on Taco Bell, and the outbreak has come at a critical time.

Taco Bell removed the affected iceberg lettuce from its stores on July 17. Five days later, Chief Executive Officer Sean Tresvant issued an open letter pledging to put safety first and remain transparent. The same day, the chain sold Enchirito and nacho fries for $1; on July 28, it sold its highly sought-after Mexican Pizza for $1. On social media, some consumers expressed brand loyalty, posting supportive comments on Taco Bell's Instagram.

The outbreak is still spreading, with daily new cases in Michigan continuing to rise. Secretary of Health and Human Services said the outbreak is "under control," but the CDC has not yet declared it over. Between 2015 and 2018, Chipotle Mexican Grill suffered at least five foodborne illness outbreaks, leading to double-digit same-store sales declines from the fourth quarter of 2015 through the fourth quarter of 2016. Chipotle ultimately recovered by replacing its CEO, strengthening employee training, and enhancing its food safety program. In late 2024, McDonald's saw a sharp drop in U. store traffic due to an E. coli outbreak, but sales began to recover within weeks after the CDC declared the outbreak over, and fully rebounded in the second quarter of 2025. McDonald's also cut ties with Taylor Farms.