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,

The U.S. Food and Drug Administration (FDA) is working together with the Centers for Disease Control and Prevention (CDC) in collaboration with state and local partners to investigate illnesses in a multi-state outbreak of Listeria monocytogenes infections.

The cause of a long-running listeria outbreak has finally been determined to be frozen supplemental shakes, and Alabama is one of the states impacted.