The Centers for Disease Control and Prevention (CDC) and state health officials are investigating a multistate Listeria monocytogenes outbreak that resulted in two cases and one death in 2014.

Raw milk/CDC
Raw milk/CDC

Two people infected with the outbreak strain of Listeria were reported from California (1) and Florida (1). Both illnesses occurred in 2014 in elderly individuals. Both people were hospitalized, and the ill person in Florida died as a result of listeriosis.

The investigation now links raw milk produced by Miller’s Organic Farm in Bird-In-Hand, Pennsylvania, as the likely source of this outbreak.

Federal health officials say although the two illnesses occurred in 2014, the source of these illnesses wasn’t known until January 29, 2016, when the U.S. Food and Drug Administration informed CDC that whole genome sequencing of Listeria bacteria from raw chocolate milk produced by Miller’s Organic Farm showed that it was closely related genetically to Listeria bacteria from the two ill people described above.

Because Listeria was recently found in raw milk produced by Miller’s Organic Farm, CDC is concerned that conditions may exist at the farm that may cause further contamination of raw milk and raw dairy products distributed by this company and make people sick.

The CDC notes that raw milk and raw dairy products can pose severe health risks, including death, especially for people at higher risk for foodborne illness, including children younger than 5, pregnant women, adults 65 and older, and people with weakened immune systems. They recommend that people drink and eat only pasteurized dairy products.