December 23, 2014
1 min read

Outbreaks related to nonpasteurized milk have increased since 2007

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The number of infectious outbreaks associated with nonpasteurized milk in the United States increased between 2007 and 2012, according to recent findings.

Despite this, many state legislatures have considered loosening restrictions on the sale of nonpasteurized milk in response to increased demand, researchers said.

The researchers evaluated foodborne disease outbreaks reported to the CDC’s Foodborne Disease Outbreak Surveillance System between 2007 and 2012, in which nonpasteurized milk was the vehicle of transmission. They defined a foodborne disease outbreak as the occurrence of two or more cases of a similar illness resulting from consumption of a common food.

Between 2007 and 2012, a total of 81 outbreaks related to nonpasteurized milk were reported in 26 states. These outbreaks included 979 illnesses and 73 hospitalizations, but no deaths were reported. The causative agent was identified in all of the outbreaks. Of the 78 outbreaks with a common etiology, Campylobacter spp. was the most prevalent pathogen, causing 81% of outbreaks. This was followed by Shiga toxin-producing Escherichia coli (17%), Salmonella enterica serotype Typhimurium (3%), and Coxiella burnetii (1%). Three outbreaks originated from multiple pathogens.

There was an increase in outbreaks from 30 during 2007-2009 to 51 during 2010-2012. Approximately 2% of foodborne outbreaks in 2007-2009 were related to nonpasteurized milk consumption, and this percentage increased to 5% in 2010-2012. Additionally, there was an increase in the number of Campylobacter spp. infections, from 22 during 2007-2009 to 40 during 2010-2012.

For 68 (84%) of the outbreaks, data were reported on how the milk was acquired. Nonpasteurized milk was acquired from the following sources: dairy farms (71% of outbreaks); licensed or commercial milk sellers (13% of outbreaks); cow- or herd-share arrangements (12% of outbreaks); and other sources (4% of outbreaks).

Of all foodborne disease outbreaks reported from 2007 to 2009, 81% were reported in states where the sale of nonpasteurized milk was legal to some degree.

According to the researchers, outbreaks associated with nonpasteurized milk continue to pose a public health threat, which will likely only worsen with increased legalization of nonpasteurized milk sales.

“This possibility is especially concerning for vulnerable populations, who are most susceptible to the pathogens commonly found in nonpasteurized milk. Public health officials should continue to educate legislators and consumers about the dangers associated with consuming nonpasteurized milk,” they wrote.

Disclosure: The researchers report no relevant disclosures.