Raw-milk cheeses: What are the associated health risks and what preventive measures can be taken?
Salmonella, enterohaemorrhagic E. coli, Listeria monocytogenes – a wide range of bacteria can be found in the raw-milk cheeses and other raw-milk dairy products we consume. These are sometimes involved in cases of food poisoning, leading them to be recalled or withdrawn from the market. In order to further improve the control of these risks, ANSES has identified the types of raw-milk cheeses on which efforts should focus as a priority.
ANSES received a request from the Directorate General for Food to identify and classify the main bacterial hazards associated with the various types of raw-milk cheeses and other dairy products made from raw milk. The aim was also to assess the main sources of contamination and the means implemented to control the associated risks.
The main microbiological hazards in raw-milk cheeses and dairy products
In France over the last decade, 34%, 37% and 60% of outbreaks of salmonellosis, listeriosis and enterohaemorrhagic E. coli (EHEC) infections respectively have been linked to the consumption of raw-milk cheeses. While some bacteria can cause gastroenteritis symptoms (Salmonella spp. and Staphylococcus aureus), others can have much more serious consequences such as kidney failure (EHEC) or even death (L. monocytogenes, EHEC).
The main sources of these hazards are soft cheeses with a surface mould (such as Camembert, Brie and Crottin) and short-ripened uncooked pressed cheeses (such as Morbier, Reblochon and Saint-Nectaire). Next come soft washed-rind cheeses such as Munster and Maroilles.
Continue efforts to prevent microbiological risks, from farm to consumer
The means implemented to control microbiological risks in the main dairy sectors (cattle, sheep, goats), from the rearing stage to the consumption stage, were studied by the Agency. It concluded that:
- at farm level, good animal husbandry and hygiene practices are well known in the various sectors. The efforts already well under way in terms of hygiene during milking and the management of mastitis should be continued;
- at the production stage, levels of risk control are also very high; the Agency recommends continuing to implement good hygiene practices and to carry out self-checks in order to best anticipate any risk of an outbreak;
- at consumer level, in order to avoid a foodborne infectious disease, it is essential to comply with the information on the packaging or that given by the seller concerning the temperature at which the cheese should be stored in the refrigerator and its use-by date. Lastly, ANSES reiterates its recommendation that pregnant women, immunocompromised individuals, people over the age of 65 and young children should avoid consuming raw-milk cheeses, with the exception of hard pressed cheeses such as Gruyère and Comté.
“For several years now, we have been seeing a strong commitment on the part of the various raw-milk cheese sectors to preventing microbiological risks. Thanks to the actions taken, levels of hygiene and risk control are now very high on farms. The self-checks implemented at the processing stage are able to identify a large number of problematic batches. However, there is still a residual risk and it is important to identify new ways of optimising the current control measures. For example, this could involve improving epidemiological investigations, identifying poor hygiene practices at an earlier stage, or communicating more with consumers", explains Laurent Guillier, who coordinated ANSES's expert appraisal.
Did you know?
Contrary to popular belief, removing the rind from a raw-milk cheese is not enough to protect yourself against bacteria, as these can be found everywhere in the cheese.
On the other hand, when raw-milk cheeses are well cooked, as in an oven-baked recipe, they no longer pose a health risk.
A new forthcoming expert appraisal
This work to classify raw-milk cheeses was a first step in responding to the formal request. The expert appraisal work is continuing, to evaluate the effectiveness of the various health measures such as the sorting of milk at farm level and self-checks at the production stage. The next step will be to identify priority work areas for further reducing microbiological risks.