Date: Thu 17 Apr 2014
Source: Svenska Yle [in Swedish, machine transl., edited]
The 1st results from milk samples at a farm in Askola, Finland taken 7 Apr 2014 revealed _Yersinia pseudotuberculosis_ and _Campylobacter jejuni_.
The number of people who drank milk from Uljaan tilamaito and experienced symptoms has increased in Porvoo and in the neighbouring municipalities (Askola, Lovisa, Borgnas and Sipoo). There are now 19 confirmed cases of yersiniosis. Campylobacteriosis has so far been isolated from a total of 8 people. Investigations are still on-going for about 20 people.
Uljaan tilamaito pulled away all unpasteurized milk from the shops in early April 2014.
[In 2013, a review of the issue of raw milk ingestion was addressed (Claeys WL, Cardoen S, Daube G, et al: Raw or heated cow milk consumption: Review of risks and benefits. Food Control 2013; 31(1): 251-62). The paper is available at: <http://dx.doi.org/10.1016/j.foodcont.2012.09.035
The abstract, introduction, and conclusions are given below with the citations removed.
In the context of the prevailing trend toward more natural products, there seems to be an increasing preference for raw milk consumption as raw milk is associated with several perceived health benefits that are believed to be destroyed upon heating. However, many human pathogens can be isolated from raw cow milk. The prevalence of foodborne pathogens in raw cow milk varies, but their presence has been demonstrated in many surveys and foodborne infections have been repeatedly reported for _Campylobacter_, _Salmonella_ spp. and human pathogenic verocytotoxin-producing _Escherichia coli_ [VTEC]. In industrialized countries, milk-borne and milk product-borne outbreaks represent 2-6 percent of the bacterial foodborne outbreaks.
The aim of this review is to present scientifically sound data regarding the risks and benefits related to the consumption of raw and heated cow milk. Both microbiological aspects (such as, the prevalence of milk-borne pathogens, pathogen growth inhibition by antimicrobial systems and by lactic acid producing bacteria, probiotic bacteria, etc.) and nutritional or health aspects (nutritional value, immunity, allergies, lactose intolerance, diabetes, milk digestibility, etc.) are considered.
As such, it is demonstrated that consumption of raw milk poses a realistic health threat due to a possible contamination with human pathogens. It is therefore strongly recommended that milk should be heated before consumption. With the exception of an altered organoleptic profile [taste], heating (in particular ultra high temperature and similar treatments) will not substantially change the nutritional value of raw milk or other benefits associated with raw milk consumption.
The consumption of raw milk is not well-documented, but in the context of the current trend toward "consuming natural" and "purchasing locally", raw milk consumption is becoming more popular. This is nourished by the perception that heating destroys the nutritional and health benefits of milk, and can even induce some detrimental effects. However, due to its high nutritional value together with the neutral pH and high water activity [content?], raw milk serves as an excellent growth medium for different micro-organisms, whose multiplication depends mainly on temperature and on competing micro-organisms and their metabolic products. In order to guarantee its microbial safety and to prolong its shelf-life, milk is heat treated.
The impact of milk pasteurization on public health can be clearly illustrated by means of historical data. Before 1938, an estimated 25 percent of all foodborne and waterborne disease outbreaks in the USA were associated with milk, whereas nowadays, the percentage of such outbreaks associated with milk is estimated to be below 1 percent. Between 1880 and 1907, 29 milk-borne outbreaks were reported on average each year in the USA. With the adoption of pasteurization in 1938, milk-borne diseases dropped to only 46 outbreaks during the 19-year period from 1973 to 1992, corresponding to an average of 2.4 outbreaks each year. A recent report of the USA CDC indicates that the vast majority of milk-borne outbreaks in the USA are in states that permit the sale of raw milk. In England and Wales, the great majority of milk-borne outbreaks during the 1980s were attributed to the consumption of raw milk. In Scotland, a similar situation existed until the sale of unpasteurized milk was prohibited in 1983, which led to a significant drop of the incidence of diseases related to liquid milk consumption.
In the mid-20th century, the main illnesses associated with raw milk consumption were brucellosis and tuberculosis. These have been eradicated as milk-borne diseases in developed countries, mainly through herd certification programs which included culling of infected animals, the installation of refrigerated bulk tanks for milk collection on farms, and the introduction of pasteurization. In the past, pasteurization conditions were standardized based on the destruction of _Mycobacterium bovis_, a relatively heat-resistant non-sporogenic bacterium that formerly was among the most serious pathogenic bacteria present in milk. Pasteurization standards today are based upon the destruction of _Coxiella burnetii_ the most heat-resistant milk-borne zoonotic pathogen known. In the past 30 years, several previously unrecognized foodborne bacterial infections, including infection with _Campylobacter jejuni_, _Listeria monocytogenes_, and _Escherichia coli_ strain O157 (or more general verocytotoxin-producing pathogenic _E. coli_ [VTEC]), have emerged as significant causes of human morbidity and mortality. Pathogens mainly present in raw milk today are, among others, _C. jejuni_, _Salmonella_ spp., _Staphylococcus aureus_, _Listeria monocytogenes_, pathogenic _E. coli_ and _Yersinia enterocolitica_.
In Europe, the current regulatory microbial criteria for raw cow milk are less than or equal to 100 000 colony forming units (cfu)/ml for plate count (at 30 deg C/86 deg F) and less than or equal to 400,000 cfu/ml for somatic cells, as is stipulated in Regulation (EC) 853/2004 laying down specific hygiene rules on the hygiene of foodstuffs. In this Regulation, health requirements for production animals and hygienic requirements on milk production holdings (such as, regarding premises and equipment, hygiene during milking, collection, and transport, staff hygiene) are established as well. In general, raw milk intended for human consumption must meet the requirements of the General Food Law (Regulation (EC) 178/2002) and be free of pathogens. Even though improvements in hygiene resulted in routine production of raw cow milk with less than 20 000 cfu (total flora)/ml), this does not guarantee raw milk to be free of pathogens. In approximately 1-6 percent of the human outbreaks reported in developed countries, milk has been identified as the vehicle of infection. An overview of foodborne disease reports from different industrialized countries indicates that milk and milk products are implicated in 1-5 percent of the total bacterial foodborne outbreaks, with 39.1 percent attributed to milk, 53.1 percent to cheese, and 7.8 percent to other milk products.
Whereas milk quality and safety has been the topic of many research studies, raw milk still continues to be an issue for debate, which is primarily held on the internet where often non-scientifically based information circulates. Therefore, the aim of this study is to evaluate the risks and benefits related to the consumption of raw cow milk at one hand, and to evaluate the effect of heat treatments of milk on these risks and benefits on the other hand, considering the microbiological as well as the nutritional (health) aspects.
In this evaluation it is clearly demonstrated that the consumption of raw milk poses a realistic and unnecessary health threat because of its possible contamination with pathogenic bacteria. It is therefore recommended to heat [raw] milk before consumption, especially when served to young children, pregnant women, or any person suffering from a chronic disease or a suppressed immune system. In this context the attention is drawn to raw milk provided on farms to the general public (such as during a school visit) and raw milk distributors allowing the automatic supply of raw milk from a bulk reservoir to the consumer. >From a nutritional point of view, infants should only be given "infant formula" since unprocessed milk does not fulfill the nutritional needs of this age group.
Historical data show that the pasteurization of milk has led to improved public health and more recent data on occasional raw milk consumption indicate the hazard of bacterial infections, which could be avoided by a heat treatment. At present, thermal treatment remains the most frequently used and most effective method to increase the microbiological safety of milk without substantially changing the nutritional value of milk or other benefits associated with raw milk consumption. Table 4 [see original URL above] summarizes the main (claimed) benefits of raw milk consumption and the (claimed) detrimental effects of heating discussed in the present paper. Almost all arguments put forward by raw milk proponents for not heating milk, can be refuted, and the only substantial disadvantage of heating is the change in the organoleptic profile [taste] of milk. It is clear that this 'detrimental' effect of heating does not countervail the risk posed by raw milk consumption, namely of a milk-borne pathogen infection, which can have serious health consequences." - ProMed Mod.LL]
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