(Max Sinsheimer, Duke University) – On March 9th the Centers for Disease Control and Prevention (CDC) issued every cheesemaker’s nightmare: a multistate Listeria outbreak advisory. The outbreak was traced to Ouleout, a raw milk (unpasteurized) cheese made by Vulto Creamery in Walton, New York. Six people across four states became ill, and two died, including an infant. The deaths, and Vulto’s recall of Ouleout and three similar soft cheeses, were covered in the New York Times.
Listeria outbreaks are all too common in the United States; listeriosis, the disease caused by the pathogenic strain of Listeria (L. monocytogenes) sickens about 1,600 people per year and kills nearly twenty percent of them. It is particularly virulent in pregnant women and newborns, the elderly, and the immunodeficient. And unlike most human pathogens, L. monocytogenes has adapted to refrigeration conditions, posing a stubborn public health challenge. In 2016, more than a quarter of the 764 food recalls were for Listeria contamination, in everything from sunflower seeds to frozen fruits and vegetables. Listeria and other bugs, like E. Coli, threaten the entire food industry.
But artisan cheesemakers, who are the only game in town when it comes to raw milk cheeses, are in a uniquely precarious position regarding the microbial safety of their food. That is not because eating a raw milk cheese is any more dangerous than eating deli meats. Rather, it is because government regulators want to do away with raw milk cheeses entirely, citing a public health risk. Outbreaks like the one that just occurred at Vulto Creamery fit their narrative.
You can see evidence of the CDC’s hardline stance on raw milk cheeses quite clearly on its website, which displays a video called “Real Stories About the Dangers of Raw Milk.” And it is discernible too in the CDC’s outbreak advisories. But is there anything different between the recent Vulto Creamery advisory and those issued, for example, for Crave Brothers Farmstead Cheeses (WI) and Karoun Dairies (CA)? The Vulto Creamery advisory is the only one that states whether the cheese used raw or pasteurized milk; as it happens, the other two were outbreaks that occurred in pasteurized cheeses.
Here’s the dirty secret: Listeria outbreaks occur in pasteurized cheeses slightly more often than in raw milk cheeses. And most Listeria outbreaks occur as a result of post-process contamination, which negates the safety impact of pasteurizing milk. Dairy post-process contamination, according to The Oxford Companion to Cheese, is “when microorganisms capable of causing harm to product quality or safety are found in pasteurized milk or cheeses made from pasteurized milk” (583). Aaron Foster, a cheese shop owner who has helped develop food safety programs, wrote to me that pasteurization may even provide a false sense of security: “you might use pasteurized milk to make your cheese, but then not maintain rigorous cleaning protocols on the pipes that carry that milk to the cheese plant. It’s already clean and pasteurized, so why constantly scrub the pipes?”
If anything, the risk dichotomy should be between hard and soft cheeses, not between raw vs. pasteurized cheeses. In general, the more moisture in a cheese, the more at-risk it is for Listeria contamination. But even soft cheeses are perfectly safe if sanitation protocols and testing procedures are in place at every step of processing and product distribution. It is too early to know yet whether Vulto Creamery was employing industry-standard sanitation and hazard analysis measures.
Rather than demonizing raw milk cheeses, Dr. Catherine Donnelly, a Professor of Nutrition and Food Science at the University of Vermont who is widely considered one of the world’s leading experts on Listeria, thinks that the FDA should follow Europe’s more holistic regulatory regime. There, Donnelly told me, “Governments spend extensive resources to educate cheesemakers and fund research stations to assist cheese manufacturers with contamination control. During an outbreak of listeriosis linked to Vacherin Mont d’Or cheese that occurred between 1983 – 1987, the epidemiologist investigating the outbreak, Dr. Jacques Bille, expressed concern that ‘we must save this magnificent cheese.’”
The Mont d’Or outbreak was ultimately traced to contaminated aging caves, and the Swiss Research Institute started a program to help cheesemakers monitor aging caves and establish other controls to eliminate Listeria. By contrast, the FDA seems intent on banning raw milk cheesemaking and criminally prosecuting companies responsible for Listeria outbreaks, as permitted under the Supreme Court’s Park Doctrine. Mateo Kehler, the founder of The Cellars at Jasper Hill in Greensboro, VT, an award-winning raw milk cheesemaker, put his frustration bluntly in the Foreword to The Oxford Companion to Cheese: “I used to believe that the greatest threat to our business was a microbiological threat, but have learned the microbiological risk can be managed. I now believe the biggest risk to the cheeses that are the foundation of our business is a regulatory risk.”
Max Sinsheimer worked for seven years at Oxford University Press as an editor responsible for overseeing a series of food encyclopedias, including The Oxford Companion to Cheese (2016). He moved to Chapel Hill in the Fall of 2016 to begin Duke’s Graduate Liberal Studies (GLS) program, while also opening a literary agency with a particular focus on food- and drink-related titles.