Frozen shakes served at hospitals and nursing homes are being recalled after they were linked to a deadly outbreak of listeria, the U.S. Food and Drug Administration said. The agency said in an update Monday that 12 people have died.

The frozen shakes were served at hospitals and long-term care facilities, sickening 38 people and resulting in 11 deaths in 21 states, according to the FDA.

The supplemental shakes are labeled under the brands Lyons ReadyCare and Sysco Imperial and were sold to institutional customers, including hospitals and long-term care facilities, officials said.