A years-long mystery has been finally solved. A deadly Listeria outbreak that has sickened 38 people and killed 12 across 12 states since 2018, is now traced back to frozen supplement shakes distributed to long-term care facilities, the U.S. Center for Disease Control and Prevention (CDC) revealed.
Investigators determined that the outbreak was due to contaminated supplement shakes manufactured by Prairie Farms. The products are now recalled by Lyons Magnus, who supplied them.
Though cases stretch back to 2018, 20 of them occurred in 2024 and 2025, as Listeria, a resilient bacterium, can survive for years in contaminated products. This food-borne infection mostly becomes severe or fatal in pregnant women, people aged 65 and older, and those with weakened immune systems.
“CDC has investigated this strain several times but never had enough information to identify a food source, beyond something being served in long-term care facilities. Environmental testing and whole genome sequencing helped solve the outbreak this year,” the CDC said in a news release.
The patients affected by the infection were between the ages of 43 and 101 years. The fatalities were reported from California, Illinois, Indiana, Michigan, Minnesota, North Carolina, New York, Tennessee, Texas, and Washington.
The patients were infected after being provided with the now-recalled nutritional shakes as part of a medically necessary soft diet while admitted to institutional settings like long-term care facilities. These products are not available to the general public.
“The true number of sick people in this outbreak is likely higher than the number reported, and the outbreak may not be limited to the states with known illnesses. This is because some people recover without medical care and are not tested for Listeria,” the CDC news release stated.
The officials caution people to discard or return recalled products and clean any surfaces they touched, as Listeria can survive in refrigerators and spread easily.
The symptoms of Listeria infection can occur on the same day or within two weeks of consuming the contaminated product. Most people develop fever, muscle aches, and fatigue. Pregnant women may experience only mild flu-like symptoms, but this can even lead to pregnancy loss, premature birth, or life-threatening infections in newborns. In some cases, Listeria can cause severe neurological issues, including headaches, a stiff neck, confusion, loss of balance, and even convulsions.
