Listeria-tainted frozen shakes served at hospitals and long-term care facilities have sickened at least 38 people and resulted in the deaths of 12, the Food and Drug Administration said. The FDA’s investigation is ongoing.

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

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.