The US Food and Drug Administration and the Centers for Disease Control and Prevention said on Monday the agencies were investigating a multi-state outbreak of listeria infections linked to frozen supplemental shakes manufactured by Prairie Farms Dairy Inc.

As of February 24, 2025, a total of 38 people infected with the outbreak strain of listeria monocytogenes have been reported from 21 states, according to the FDA, which added that 37 people have been hospitalized and 12 deaths have been reported.

Prairie Farms Dairy did not immediately respond to a request for comment.

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The frozen supplemental shakes under brands Lyons ReadyCare and Sysco Imperial have been recalled, the FDA said. They were distributed to hospitals and long-term care facilities nationwide, according to the agency.

Listeria are bacteria that can contaminate many foods, with symptoms including fever, muscle aches and nausea.

Symptoms usually start within two weeks after eating food contaminated with listeria but may start as early as the same day or as late as 10 weeks after.

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As part of the investigation, the FDA conducted an onsite inspection and collected environmental and product samples at Prairie Farms in Fort Wayne, Indiana.

Three of the environmental swabs collected from the processing area tested positive for listeria monocytogenes, the FDA said.