Twelve deaths have been reported as part of an outbreak of Listeria monocytogenes infections linked to frozen supplemental shakes, the US Food and Drug Administration said Monday. At least 38 people in 21 states had been infected,

Recalled supplemental shakes were distributed to hospitals and long-term care facilities nationwide, federal officials say.

An ongoing listeria outbreak credited with 11 deaths is linked to frozen supplemental shakes. Here’s what you should know: The shakes, sold in 4-ounce cartons under the brands Lyons ReadyCare and Sysco Imperial, were made by Prairie Farms Dairy at its Fort Wayne, Indiana, facility.