Consumers are up to 160 times more likely to contract a Listeria infection from soft-ripened cheese made from raw milk compared to the same cheese made with pasteurized milk, according to a joint risk assessment drafted by the U.S. Food and Drug Administration and Health Canada. “This finding is consistent with the fact that consuming raw milk and raw milk products generally poses a higher risk from pathogens than do pasteurized milk and its products,” an FDA media release read. On Monday, the FDA published a Federal Register Notice of the draft assessment for a public comment period ending April 29. The FDA’s assessment examined the mathematical probability of consumers in the U.S. and Canada contracting Listeria infection via either pasteurized or raw-milk camembert cheese. In the U.S., the FDA estimates that there is one case of listeriosis linked to raw-milk cheese for every 55 million servings eaten. For pasteurized soft cheese, that ratio is one listeriosis case for every 8.64 billion servings. For raw-milk cheese producers to reduce their Listeria risk to levels equal with pasteurized producers, they would need to test every raw-milk cheese lot for pathogens and remove any positive lots from the supply chain, the assessment concluded. Testing only some lots would not provide the same level of reduced risk. Whether from pasteurized or unpasteurized products, Listeria monocytogenes has some of the highest fatality and hospitalization rates among pathogenic bacteria. Health officials especially discourage children, the elderly, pregnant women, and those with weakened immune systems from consuming raw milk products due to the heightened risk of contracting Listeria or other harmful bacteria typically killed during the pasteurization process. Despite their mathematically lower risk, pasteurized soft cheeses have been recently tied to notable Listeria outbreaks. Between March and September 2012, at least 22 people in the U.S. fell ill from Frescolina Marte-brand ricotta solata cheese made from pasteurized sheep’s milk and imported from Italy. That outbreak resulted in 4 deaths and 20 hospitalizations. And right now, Australia is experiencing “the nation’s largest Listeria outbreak,” with at least 26 people sickened — including 3 dead — after eating cheeses produced with pasteurized milk by Jindi Cheese. Read the draft assessment here, a summary here, and internal peer-review responses here.