Listeria Outbreak: CDC Warns of Contaminated Supplement Shakes

The Centers for Disease Control and Prevention (CDC) is investigating a multistate outbreak of Listeria infections linked to frozen supplement shakes distributed to long-term care facilities and other institutional settings. As of May 16, 2025, the outbreak has affected 42 people across 21 states, leading to 41 hospitalizations and, tragically, 14 deaths. While the outbreak strain of Listeria has been circulating since 2018, a significant number of illnesses have occurred in 2024 and 2025, prompting renewed investigation and a recall.

Understanding Listeria and the Outbreak

Listeria monocytogenes is a bacterium that can cause a serious infection called listeriosis. While most healthy people experience mild symptoms like fever, muscle aches and tiredness, the infection can be particularly dangerous for certain populations: pregnant women, adults 65 years or older, and individuals with weakened immune systems. For these groups, Listeria can lead to invasive listeriosis, where the infection spreads beyond the gut and causes severe complications, including pregnancy loss, premature birth, and even death. The CDC provides detailed information about Listeria on their website.

The current outbreak was traced to supplement shakes manufactured by Lyons Magnus LLC, which initiated a recall on February 22, 2025. The recalled products were distributed to food service operators and long-term care facilities nationwide. Importantly, these shakes were not available for purchase by the general public.

How the Investigation Unfolded

Identifying the source of this outbreak proved challenging. The CDC had investigated this particular strain of Listeria on several previous occasions but lacked sufficient information to pinpoint a specific food source. It wasn’t until this year, through a combination of epidemiologic data, laboratory analysis, and environmental testing, that the connection to the supplement shakes was established. The CDC’s investigation update provides further details on the process.

The investigation revealed that the majority of individuals affected by this outbreak resided in long-term care facilities or were hospitalized prior to becoming ill. This highlights the vulnerability of these populations and the importance of stringent food safety measures in institutional settings.

Symptoms and What to Do

Symptoms of listeriosis typically appear within two weeks of consuming contaminated food, although they can range from the same day to as late as 10 weeks after exposure. Symptoms vary depending on the individual. Pregnant women may experience fever, muscle aches, and fatigue. Others may develop headaches, a stiff neck, confusion, loss of balance, or seizures.

If you suspect you may have been exposed to the recalled supplement shakes, or are experiencing symptoms of listeriosis, the CDC recommends the following:

• Do not consume any recalled products.
• Dispose of any recalled products immediately.
• Thoroughly clean and sanitize refrigerators, containers, and surfaces that may have come into contact with the recalled products.
• Contact a healthcare provider if you develop symptoms, especially if you are pregnant, 65 or older, or have a weakened immune system.

What Businesses and Facilities Should Do

Facilities that received the recalled supplement shakes should immediately remove them from service and follow the CDC’s guidance on cleaning and sanitizing potentially contaminated areas. It’s crucial to review food safety protocols and ensure that staff are trained on proper handling and storage procedures to prevent future outbreaks.

The Importance of Ongoing Surveillance

This outbreak underscores the critical role of ongoing surveillance in identifying and responding to foodborne illness outbreaks. The CDC, in collaboration with state and local health departments, continuously monitors foodborne illness trends and investigates potential outbreaks. This surveillance allows for the rapid identification of contaminated food products and the implementation of control measures to protect public health. The FDA provides updates on outbreak investigations.

The CDC has stated that this outbreak is now considered over, but continues to emphasize the importance of vigilance and adherence to food safety practices. Public health officials will continue to monitor for any further cases and will update guidance as needed. The process of investigating foodborne illness outbreaks is complex and often requires collaboration between multiple agencies and organizations.

If you have questions about cases in a particular state, please contact that state’s health department.