Publisher’s Platform: You could not have picked a worse food item to contaminate with Listeria

Illnesses linked to supplement shakes date back to August 2018. Thirty-eight people sick and twelve dead.

As the CDC reported (welcome back), as of February 21, 2025, 38 people infected with the outbreak strain of Listeria monocytogenes have been reported from 21 states. The 21 States with Cases are: Alabama, California, Colorado, Connecticut, Florida, Illinois, Indiana, Maryland, Michigan, Minnesota, Missouri, North Carolina, Nevada, New York, Ohio, Oklahoma, Pennsylvania, Tennessee, Texas, Washington and West Virginia.

Sick people’s samples were collected on dates ranging from August 17, 2018, to January 23, 2025. Of 38 people with information available, 37 have been hospitalized. Twelve deaths have been reported from California, Illinois, Indiana, Michigan, Minnesota, North Carolina, New York, Tennessee, Texas, and Washington. 

Most people in this outbreak reported living in long-term care facilities or were hospitalized prior to becoming sick.

The elderly are particularly vulnerable to Listeria infections due to several factors related to aging and health.

As people age, their immune systems naturally become less effective at fighting off infections. This immune senescence means older adults have a decreased ability to mount a strong immune response against pathogens like Listeria monocytogenes.

Many elderly individuals have one or more chronic health conditions, such as diabetes, cardiovascular disease, or kidney disease, which can further compromise the immune system and increase susceptibility to infections.

Aging can impact gastrointestinal function, including changes in stomach acidity and digestive enzyme production. This can make it easier for Listeria, which can survive in less acidic environments, to colonize and infect the host.

Elderly individuals are more likely to be in hospitals or nursing homes, environments where Listeria outbreaks can occur. They may also undergo medical procedures that increase infection risk.

Older adults may have less varied diets, sometimes due to dietary restrictions or decreased appetite, potentially leading to deficiencies in important nutrients that support immune health. Additionally, they may consume more ready-to-eat foods, which can sometimes be a source of Listeria contamination.

The elderly often use medications that can affect the immune system, such as corticosteroids or treatments for autoimmune diseases and cancer, making them more susceptible to infections.

Epidemiologic, laboratory, and traceback data show that supplement shakes manufactured by Prairie Farms are contaminated with Listeria and are making people sick.

CDC investigated this outbreak in 2018, 2021, and 2023. Epidemiologic evidence in previous investigations identified that sick people were residents in long-term care facilities and nursing homes and the likely source was a food served in those types of institutions, but there was not enough information to identify a specific food. CDC reopened the investigation in October 2024 after six new illnesses were reported. In February 2025 after traceback identified a product of interest, the outbreak strain was found in environmental samples from Prairie Farms.

State and local public health officials are interviewing people about the foods they ate in the month before they got sick. Of 38 people with information, 34 (89%) reported living in long-term care facilities or were hospitalized before becoming sick. Eight people reported mechanical soft diets, like supplement shakes. Records reviewed from facilities indicated supplement shakes were available to residents. 

Public health investigators are using the PulseNet system to identify illnesses that may be part of this outbreak. CDC PulseNet manages a national database of DNA fingerprints of bacteria that cause foodborne illnesses. DNA fingerprinting is performed on bacteria using a method called whole genome sequencing (WGS). WGS showed that bacteria from sick people’s samples are closely related genetically. This suggests that people in this outbreak got sick from the same food.

FDA traced food records from long-term care facilities. These records showed that supplement shakes made by Prairie Farms were a common food served to people. On February 4, 2025, FDA collected environmental samples at Prairie Farms for testing. On February 19, 2025, WGS showed that the Listeria in the environment are closely related to bacteria from sick people.

On February 22, 2025, Lyons Magnus LLC recalled supplement shakes. CDC is advising people not to eat, sell, or serve recalled products.

Because Listeria can lead to severe illnesses such as meningitis, septicemia, and encephalitis, it’s important to take preventive measures, like proper food safety practices and avoiding high-risk foods, to protect vulnerable populations such as the elderly.

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Source: https://www.foodsafetynews.com/2025/03/publishers-platform-you-could-have-not-picked-a-worse-food-item-to-contaminate-with-listeria/