In early 2024, the U.S. Centers for Disease Control and Prevention (CDC) and the U.S. Food and Drug Administration (FDA) solved a decade-long foodborne illness outbreak, linking a nationwide string of Listeria monocytogenes infections to queso fresco and cotija cheeses produced by Rizo Lopez Foods Inc.

On October 8, 2024, the U.S. District Court for the Eastern District of California entered a consent decree of permanent injunction against Rizo Lopez Foods and the company’s co-owners, Edwin Rizo and Tomas Rizo. Among other stipulations, the consent decree prohibits Rizo Lopez Foods from manufacturing and selling any food products, excluding prepackaged foods, at or from its facilities until the company complies with Federal Food, Drug, and Cosmetic Act regulations and other requirements. The consent decree requires the defendants to make corrective actions and receive FDA approval before resuming operations.

Rizo Lopez Foods was linked to the outbreak after the Hawaii State Department of Health’s Food and Drug Branch collected a retail sample of cotija cheese produced by the company, which tested positive for L. monocytogenes. Through whole genome sequencing (WGS), the positive cheese sample was matched to clinical isolates identified by CDC. Subsequently, FDA matched the same strain of L. monocytogenes in Rizo Lopez’s production facility. In February 2024, Rizo Lopez Foods voluntarily recalled its entire inventory of dairy products.

Spanning 11 states, a total of 26 illnesses, 23 hospitalizations, two deaths, and one miscarriage were associated with this outbreak. The earliest onset of illness occurred in 2014 and the latest onset of illness was recorded in 2023.

Since 2020, a significant number of foodborne illness outbreaks have been attributed to fresh, soft, queso fresco-type cheeses made from pasteurized milk, which have been contaminated by L. monocytogenes after pasteurization, as explored in this article written by CDC and FDA officials for Food Safety Magazine.

In this context, FDA has developed a Listeria prevention strategy for soft, queso fresco-type cheeses.