Microbiological risks of the consumption of raw milk and raw milk dairy products

The Scientific Committee of the Belgian FASFC has published several opinions where the objective was to assess the risks and benefits of the consumption of raw milk and raw dairy products (from multiple species), based on an elaborate literature study and expert opinion. Raw milk In Belgium, the most relevant microbiological hazards related to the consumption of raw cow, sheep and goat milk are Campylobacter, Salmonella and human pathogenic verocytotoxin producing E. coli (VTEC). Raw donkey and horse milk generally has a high microbial quality. A risk assessment at an European level identified the same hazards and included also Brucella spp. in sheep milk, Mycobacterium bovis in cow milk and tick-borne encephalitis virus in milk from several species. As potential emerging hazards, Coxiella burnetii and Mycobacterium avium subsp. paratuberculosis (MAP) were identified. Raw dairy products In Belgium, the risks of raw dairy products (especially (semi-)soft cheeses) are mainly linked to Listeria monocytogenes, VTEC, Staphylococcus aureus, Salmonella and Campylobacter. Dairy products from cows with subclinical mastitis may contain high numbers of L. monocytogenes and S. aureus. L. monocytogenes, VTEC and S. aureus have been identified as microbiological hazards in raw milk butter and cream albeit to a lesser extent because of a reduced growth potential of these pathogens compared to cheese. In endemic areas in Belgium or abroad, raw dairy products may also be contaminated with Brucella spp., Mycobacterium bovis, the tick-borne encephalitis virus, C. burnetii and MAP. Based on the health threat due to the possible presence of human pathogens, it is stated that heat treatment of milk before consumption and dairy production is important to insure the safety of such products. Concerning so-called beneficial (nutritional and health) effects attributed to raw milk consumption, it was concluded that there is no scientific evidence that, with the exception of an altered organoleptic profile, heating raw milk would substantially change its nutritional value or other hypothesized benefits. The benefits of probiotic and lactic acid bacteria are not relevant due to low numbers encountered in raw milk