A listeria outbreak back in 2014 has been traced to raw milk from an organic farm, according to the U.S. Centers for Disease Control and Prevention.

On Friday, the agency said that raw milk produced by Miller’s Organic Farm in Bird-in-Hand, Pennsylvania tested positive for listeria and is likely the outbreak's source. The bacteria causes listeriosis, an infection affecting the gastrointestinal tract, and like salmonella, E.coli, and Campylobacter, can result in foodborne illnesses.

The 2014 outbreak involved two persons, one from California and one from Florida, who were from ages 73 to 81 and contracted the illness after they drank raw milk, said their families. The patient from Florida, who had bought raw milk from the brand, according to family members, died from the incident.

The cause of the two illnesses in 2014 remained undetermined until Jan. 29, when the Food and Drug Administration told the CDC that genome sequencing showed that the raw milk's bacteria appeared closely genetically related to listeria samples from the two victims.

Raw milk comes from cows and other animals, but it has not been pasteurized to kill dangerous bacteria.

The CDC report recommended consuming only pasteurized dairy, including cheese and yogurt products, where the milk is heated to a high enough temperature to kill bacteria.

“This is especially important for people at higher risk for foodborne illness: children younger than 5, pregnant women, adults 65 and older, and people with weakened immune systems,” reminds the health agency. The CDC also expressed concern over the continued sale of potentially contaminated raw milk and raw dairy from the company.

Miller’s Organic Farm works as a private club where its members can purchase a range of products from animal milks and fresh produce to meats and oils. CNN sought a comment from the company, but received no response.

In November 2015, its chocolate milk tested positive for the same bacteria after the FDA obtained a sample during a raw milk testing in California and informed the CDC. Its link to the 2014 outbreak was then established.

In early March, despite no health cases being reported, a Starbucks supplier recalled breakfast sandwiches after a routine test showed the presence of Listeria monocytogenes in the production facility. Aside from the sandwiches, Starbucks’ Cheese & Fruit Bistro Boxes were also voluntarily pulled out due to potential allergens undisclosed on the label.

Photo: Rebecca Siegel | Flickr

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