The frozen supplemental drinks have been linked to an outbreak of listeria that has killed at least 11 people and hospitalized 37.

An outbreak of listeria infections linked with frozen supplemental shakes has made at least 38 people ill in 21 states, with 37 hospitalizations and 11 deaths, the U.S. Food and Drug Administration said Friday.

In the outbreak, 38 people were infected across 21 states, including Pennsylvania, the FDA said. Most of them lived in long-term care facilities or were hospitalized prior to getting sick.