The South Dakota Department of Agriculture says listeria showed up in a sampling of bottled raw milk from Jerseydale Farms.

Listeriosis is a serious infection caused by eating food contaminated with the bacterium Listeria monocytogenes. It is especially risky for the elderly, pregnant women, newborns, and adults with weakened immune systems and that is why the Centers for Disease Control warns the public about consuming unpasteurized milk.

Despite the health risks, buying and sell raw milk is legal in South Dakota. As with conventional dairy farming, the government does inspections annually and dairies must also submit samples monthly for bacteria and residue testing and it was during that test the listeria was discovered. They say the milk products should be discarded or returned.