CO129-562-12 Dysentry epidemic- recommendation to enforce compulsory pasteurization of milk 7-6-1937 - 17-8-1937 — Page 39

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158. We have discussed the two methods whereby it has been suggested that the interests of producer-retailers might be reconciled with those of public health. We have shown that the first, namely, the removal of cows yielding tuberculous milk by periodic clinical examinations, can only effect a moderate reduction of the infection of milk with tuberculosis; and that it is unlikely that this reduction would be associated with a comparable decrease in the infection of man by the consumption of milk. The possibilities of the bacterio- logical examination of samples of bulked milk, though a valuable For these additional safeguard, do not affect this conclusion.

are satisfied that clinical inspection alone is not a satisfactory alternative to pasteurisation in those areas where the latter is practicable.

reasons we

159. Secondly, milk sold by producer-retailers could be made safe by the eradication of tuberculosis from their herds. If this could be effected economically it would be a satisfactory solution of the problem. Indeed, most witnesses who recommended compulsory pasteurisation recognised that milk from tuberculosis-free herds should be excepted from the general rule, though others, impressed by the danger of other milk-borne diseases, objected even to this exception. But difficulty arises from the fact that until a sufficient supply of tuberculosis-free animals has been secured by eradication in breeding herds, eradication among producer-retailers whose herds are generally recruited by purchases from outside sources is not practicable. Eradication might, in such circumstances, prove at least as onerous to these herd owners as pasteurisation. If, however, eradication in breeding herds is vigorously pursued, this will in time be a satisfactory alternative.

160. To sum up, there is, in our view, no policy which at the outset satisfies the interests of public health, and safeguards the position of producer-retailers in large towns. Taking a longer view, however, we consider that a policy giving producer-retailers the alternative of pasteurising their milk or of freeing their herds from tuberculosis, would be compatible with both these interests as soon as a sufficient supply of tuberculosis-free dairy cattle was available from which they could recruit their herds. We explain later (part 3) the legislative and administrative measures necessary to give effect to such a policy.

(b) Compulsory pasteurisation in areas where milk already undergoes some form of heat-treatment.

161.

The objections to pasteurisation which we have just considered are relevant only to the question of making obligatory the pasteurisation of milk now sold raw. But most of the milk at present sold in towns large enough to render the adoption of compulsory pasteurisation practical, is to-day either pasteurised or

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undergoes one of the forms of heat treatment which though often incorrectly spoken of as pasteurisation do not comply with the terms of the milk (special designations) order. We may summarise the evidence which we have received on this point as follows:-

(i) Most of the milk which undergoes heat treatment is treated in unlicensed plants, and is consequently free from any inspection other than that required by the milk and dairies orders for premises where milk is stored. This cannot secure that the milk treated (a) is not damaged from the nutritional point of view by the process it undergoes, and (b) is in any way improved hygienically.

"

(ii) Milk so treated, as well as milk treated in licensed plants,

is often sold as milk" or even

raw milk without any indication to the purchaser that the milk has under- gone heat treatment in any form.

(iii) The inspection of licensed plants is unsatisfactory. It is not uniform between districts. It does not prevent occasional gross errors in the construction of plants. It does not secure the proper operation of plants.

(iv) Milk sold from licensed pasteurising plants, and, still more, milk sold from plants where other forms of heat-treatment are carried out, is not infrequently found to be infected with tubercle bacilli.

162. We consider this is a sufficiently disturbing situation. No milk should be permitted to undergo any form of heat treatment which is not approved by the Ministry of Health or the Department of Health for Scotland, for the purposes of the milk (special designations) orders,* with the exception of sterilised milk, which should be sold as such. All milk, except sterilised milk, which has undergone heat treatment should be sold as pasteurised. All plants for the heat treatment of milk should be regularly inspected and the standard of inspection should be raised and made uniform throughout the country.

168. We have seen that pasteurisation is designed to raise the milk to a temperature high enough, and to hold it there long enough, to destroy the tubercle bacillus and other micro-organisms, without appreciably detracting from the nutritional value of the milk. The margin of safety is narrow. Every particle of the milk must be held for at least thirty minutes at a temperature neither below 145° F. nor above 150° F. lest bacilli should survive in some little pocket. In this matter no minority of failures can be accepted as negligible. Witnesses before us have expressed this by saying that in the day- to-day working of commercial plants a full laboratory standard of exactitude must be maintained. This gives rise to mechanical problems of some difficulty. In some of the earlier plants these

*

At present the only method approved by these departments is the holder method, to which paragraph 163 relates.

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