Raw milk and cheese cause 840 times more illnesses than pasteurized products

Unpasteurized milk and cheeses made from it are responsible for nearly all foodborne illnesses caused by contaminated dairy products. And the growing popularity of and access to these products threaten to increase the number of disease outbreaks caused by these food items, a new study says.

Unpasteurized dairy products cause 840 times more illnesses and 45 times more hospitalizations than pasteurized products do, according to the article, which will be published in the June issue of the journal Emerging Infectious Diseases.

“Consumer demand for organic and natural foods… has been on the rise. However, in contrast to some perceptions, natural food products are not necessarily safer than conventional ones, as evidenced by higher rates of foodborne illnesses associated with unpasteurized dairy products,” wrote the authors, consultants for EpiX Analytics of Boulder, Colo.

There are roughly 760 reported cases of foodborne illness caused by unpasteurized milk and raw milk cheeses a year and on average 22 of those people require hospitalization, the study said.

Those figures are likely the tip of a much larger iceberg, said Kirk Smith, who is supervisor of the foodborne, waterborne, vectorborne, and zoonotic sector of the Minnesota Department of Health. Smith said the database from which the figures were drawn captures outbreaks. Individual cases of illness typically don’t come to the attention of these kinds of detection systems.

“Outbreaks get all the press. But really the non-outbreak associated cases probably really dwarf the number of outbreak-associated cases,” said Smith, who was not involved in this study.

Unpasteurized or raw milk and raw milk cheeses can be contaminated with a number of different bacteria that can make people sick, including E. coli, salmonella, listeria, and Campylobacter. These bacteria can trigger vomiting and diarrhea, but can cause more severe illnesses as well.

Campylobacter infection can lead to Guillain-Barré syndrome, a form of progressive paralysis from which most but not all people recover. Some strains of E. coli can cause hemolytic uremic syndrome, which can lead to kidney failure. Listeria infections in pregnancy can result in miscarriage, and people with severe listeria infections can die.

“Raw milk is a risky product and is linked to a lot of outbreaks,” said Megin Nichols, who works on raw milk related issues in the Centers for Disease Control and Prevention’s division of foodborne, waterborne, and environmental diseases. “Especially states that allow the legal sale of raw milk for human consumption, those states have more raw milk related outbreaks of illnesses than states that do not allow the sale of raw milk legally.”

The Food and Drug Administration prohibits distribution of raw milk across state lines if it has been packaged for sale to the public. Raw milk can only cross state lines if it is en route to a pasteurization facility or is slated to be made into aged cheese.

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