The study, which was headed by the Pennsylvania Department of Health (PADOH), examined last year’s raw milk-associated outbreak of Campylobacter, which sickened 148 people across Pennsylvania, Maryland, West Virginia, and New Jersey.
The outbreak was among the largest linked to unpasteurised milk in Pennsylvania in the US in recent years, according to the report.
Pennsylvania-based The Family Cow store was identified as the source of the outbreak. It held a Pennsylvania Department of Agriculture (PDA) unpasteurised milk permit, and only “minimal deficiencies” were found during a recent inspection.
These seemingly reassuring factors “demonstrate the on-going hazards of unpasteurised dairy products,” according to the report, which was published in Clinical Infectious Diseases journal.
Outbreak demonstrates “importance of pasteurisation”
“This outbreak demonstrates the importance of pasteurisation and the on-going need for consumer education to specifically highlight the risk of serious illness from unpasteurised dairy products and the need to avoid these products,” said the report.
The US Food and Drug Administration (FDA) prohibits the interstate sale or distribution of unpasteurised milk products for human consumption. However, many US states permit the sale of these products within their borders.
A total of 12 US states, including Pennsylvania, California, Nevada, New Mexico and New Hampshire, allow the sale of unpasteurised milk products in any retail store. Another 17 US states permit the sale of raw milk products for human consumption on farms.
The number of dairies permitted to sell raw milk products within these states is on the up, the report added.
“The number of dairies legally permitted to sell unpasteurised dairy products in Pennsylvania has grown from 26 in 2002 to 153 in 2013, driven by consumer demand and the higher milk prices obtained by unpasteurised milk producers (PDA, unpublished data),” it said.
“This trend is not unique to Pennsylvania and will likely result in a growing number of outbreaks related to unpasteurised dairy products in the United States.”
Consumers can never be assured raw milk “pathogen-free”
Farms that hold the PDA unpasteurised milk permit are currently subjected to annual inspections, and twice-monthly testing. According to the report, officials in the state could consider additional regulations, but this may still not be enough.
“State official should consider additional regulation, such as monthly pathogen testing,” said the report.
“However, while it might be possible to reduce the risks associated with unpasteurised milk consumption with further testing, consumers can never be assured that certified unpasteurised milk is pathogen free, even when from a seemingly well-functioning dairy.”
“The only way to prevent unpasteurised milk-associated disease outbreaks is for consumers to refrain from consuming unpasteurised milk," the study added.
Allison H Longenberger, Aimee J Palumbo, Alvina K Chu, Mària E Moll, André Weltman, and Stephen M Ostroff Campylobacter jejuni Infections Associated With Unpasteurized Milk—Multiple States, 2012 Clinical Infectious Diseases 2013: cit231v2-cit231.