(NEXSTAR) – A listeria outbreak tied to supplement shakes is now linked to at least 12 deaths and 38 cases across 21 states, according to the Centers for Disease Control and Prevention (CDC).

The listeria strain, responsible for at least 37 hospitalizations, has been traced back to Lyons ReadyCare and Sysco Imperial Frozen Supplemental Shakes manufactured by Prairie Farms Dairy, Inc., according to the Food and Drug Administration (FDA).

The Fort Wayne, Indiana-based dairy company has recalled potentially affected shakes that were distributed nationwide to long-term care facilities. The shakes were not sold to the general public.

Cases involving the listeria monocytogenes strain date back to 2018, but investigators say more than half of the people sickened in the outbreak got sick in 2024 or 2025.

“It is common for Listeria outbreaks to last several years because it is an incredibly hardy germ that can survive on surfaces for long periods of time,” according to the CDC.

While the CDC had managed to trace the strain to long-term facilities, it wasn’t until this year that investigators were able to identify the source of the outbreak using whole genome sequencing.

See the full list of recalled products below:

Common listeria symptoms include fever, muscle aches, tiredness, confusion, loss of balance, seizures, a stiff neck and headaches, according to the CDC.

The bacteria can be especially dangerous for pregnant women, as listeria can cause a pregnancy loss, premature birth or a potentially-deadly infection in the newborn.

People 65 years or older, or those with weakened immune systems, are also especially at risk.

According to the CDC, symptoms usually begin within two weeks after consuming contaminated food but may not start until as late as 10 weeks after.

Anyone who has the recalled shakes should throw them away or return them, then clean any surface that they might have touched. “Listeria can survive in the refrigerator and can easily spread to other foods and surfaces,” the CDC warns.

Anyone who starts feeling symptoms after consuming one of the products should contact their healthcare provider.