PURITY OF MILK

Manawatu Standard, Volume LVI, Issue 260, 1 October 1936, Page 6

PURITY OF MILK

NECESSITY STRESSED. I ADDRESS BY MR W. Ml. WEBSTEI | Convened by tlic Palmerston Norl I branch of the Plunket Society, a publi meeting was hold in the City Counc Chambers, yesterday afternoon, n which the speaker was Mr W. M. AVel ster, M.11.0.V.5., of the vetorinar pathology department, Massey College his subject being “The Necessity for Tubercular-Free Milk Supply.” Tlier ! was a large attendance, various wc ! men’s organisations being well repre iseated. At the conclusion of the address th following resolution .was passed:—“Tim this meeting, representing the Plunke Society, and various other women’s or ganisations, recognising that a tuber eular-free milk supply is essential ii the interests of health, strongly urge the Palmerston North City Council ti introduce by-laws on lines similar ti those in force in Napier, rendering i an offence to supply milk and crean for human consumption unless it is cer tifiecl free from tubercular disease.” Miss M. McLagnn who presided, ir introducing Mr Wooster stressed tin importance of the subject. INCIDENCE OF THE DISEASE. “Many medical authorities have published data showing the relative incidence of the human and bovine types of tubercle bacillus isolated from cases of tuberculosis in man,” said Mr Webster. “Perhaps the most authoritative are the findings of the British Royal Commission on Tuberculosis, published in 1922. According to this report, which covered data collected from 1901 onwards, 87.5 per cent, of tuberculosis of the neck glands and abdominal organs in children under five years of age was of bovine origin. In tuberculosis of the bones, joints and skin the bovino type of bacillus was found in from 35 per cent, to 50 per cent, of cases, whilst 41.3 per cent, of children dying from tuberculosis showed the same type of infection. As age increases the incidence of bovine tuberculosis in man decreases and among adults the majority of cases are of the human type. Reports from other sources show a similar relative incidence and various authorities state that the bovine type of bacillus is responsible for from 35 per cent, to 50 per cent, of all cases! of noil-pulmonary tuberculosis. “Unfortunately the cow is particularity prone to suffer from tuberculosis. The disease may attack any organ of the body including the udder. When the latter organ is the sent of the tubercular disease, as not infrequently j happens, the milk produced by that animal will be infected with tubercle bacilli. Furthermore, according to the Royal Commission’s report: ‘Tubercle bacilli may also be present in the inilk of tubercular cows presenting no evidence whatever of disease of the udder even when examined post-mor-tem.’ “British veterinary authorities estimate that some 34 per cent, of all dairy cows in the United Kingdom are tubercular, whereas the recent Dairy Commission Report estimates tha about 9 per cent, of New Zealand dair cows are diseased. Lest these figure should be unduly alarming, it shoul be emphasised that in the majority c infected cows tho lesions are small local and inactive, and whilst in thi stage they do not constitute any rea menace. Nevertheless, the fact remain that between 1 per cent, and 2 po cent, of the samples of milk retnilee in New Zealand for human consump tion are infected with virulent tubercb bacilli and as such constitute a menaci to our children in particular. Retwcei 700 and 800 cases of non-pulmonan tuberculosis pass through our hospital: every year. Unfortunately, no statistic: are available to show the relative inei deuce of the bovine and human strain: in New Zealand cases, but since tin relative incidence does not differ greatly in other parts of the world where it has been studied, one can oidy assume that it is probably very simihu here; in other words somewhere between 250 and 400 cases of human tuberculosis every year in New Zealand are of bovine origin.

DAIRYMEN NOT TO BLAME. “The dairyman who retails his milk for human consumption cannot bo justly blamed for this state of affairs. All dairies producing milk for domestic use are registered and are subjected t to regular inspection and one can satcJy assort that probably nowhere else in li 11lie world is such a high standard of u general cleanliness and freedom from I disease attained as in New Zealand, t : Experience shows that the average -! dairyman is extremely careful of the 7 j quality of his product and is quick to , ■■ report to the authorities any cow which i he suspects is diseased. The difficulty s and danger lies in the fact that tubor- - culosis is so slow and insidious in its - onset that it is only in its advanced stages that it becomes clinically re--3 cognisable, and ere this stage is reached t it may have caused irreparable harm, fc “There is only one way in which this - potential menace to human health and - wellbeing, can be overcome, viz., by 1 testing the dairy cows and eliminat- ; ing all those found to be diseased. The > tuberculin test is an extremely accu- ’ rate and delicate biological test which ; is comparatively simple and cheaply 1 applied, and will detect any case of ■ tuberculosis even in its earliest and slightest stages.” After quoting the national cam--1 paign carried out in the United States to eliminate tho disease from dairy herds, Mr Webster said that tuberculin testing had gone on on a stupendous scale and at present they were testing some 16,000,000 cows annually. A number of States in the Union were now declared free from the disease and the percentage of reactors had been reduced to less than 1.5 per cent. The most striking ; result had been the spectacular fall in the incidence of non-pulmonary . tuberculosis amongst the population. 1 Between 1900 and 1917 the annual < death rate from these forms of the • disease was more or less constant at ' about 2.5 per 10,000 population. By * 1926 it had dropped to 1 and at pre- < sent it had reached the phenomenally ’ low level of 0.58 per 10,000. Up to c 1917 the average annual New Zea- 1 'land rate was 1.57. It first 101 l be- J low I per 10,000 in 1925, and reached . its lowest level of o.'? in 1931. Since J. then there had been a slight tendency g to rise again. Ever since the na- c tions agreed to keep a standardised j, form of vital statistics New Zoaland a had occupied pride of place as having r] one of the lowest tuberculosis death j rates in the world. However, as far as the non-pulmonary type was con- r eerned she had definitely lost that . c happy position. However, a much more disturbing feature was the fact 11 that the reduction in mortality just j a noted in New Zealand was not paral- i e leled in the gross incidence of non- | pulmonary tuberculosis. The hospital j admissions 20 years ago were aetu- *- ally lower than they were within the past few years. Thus tho decline in mortality must bo attributed to a higher standard of medical skill in treating the cases, since it was important to realise that the non-pumon-ary types of tuberculosis were essentially crippling and disabling rather than fatal in tho majority of instances and were often amenable to surgical treatment.

t SCOPE OF TESTING. y Proceeding, Mr "Webster said:— j “There are some 5000 registered dairyf men in New Zealand retailing their milk in cities, boroughs and towns, yet ’ the maximum number of samples tested ] for the presence of tubercle bacilli in j any one year is between 500 and GOO. , Up to 1930 the annual total was in I the vicinity of 300 per annum and the incidence of tuberculosis was less than , 1 per cent. Since then the number of ' samples tested has increased, but so ' has the incidence of tubercular infection, which now approaches 2 per cent. Te fault does not lie with the dairy- ’ man since, as explained earlier, the disease is so insidious that it cannot be detected clinically except in the advanced stages. “.Milk vendors can request the authorities to test their herds with tuberculin and it is an encouraging sign that ol recent years an increasing number are doing so. A. few years ago only a few thousand cows were tested annually, but last year the total had reached 14,423, with 7.9 per cent, reactors. This figure does not refer to registered dairy herds, however, but to alt cows in the Dominion and many tests were applied to country herds in which the disease was suspected lo have a firm hold. Consequently, this incidence is higher than it would probably lie had I testing been confined to registered dairy i herds. At the present time Napier, Christchurch, Timaru, .Masterton and Gisborne have for practical purposes already a completely tuberculosis tested milk supply. Napier has the honour of being tile first progressive borough in the Dominion to pass a by-law prohibiting the sale of any milk unless it is derived from tubercular tested cows. It is also encouraging to note that other municipalities are considering a move in the same direction. The position of the country dweller is still more unsatisfactory since there can be no organised system of inspection. Registered dairies are confined to town districts. The total population of tile latter is in the vicinity of 9UU,000 so that the remainder of the residents of the country have not even the benefit of this ; very limited amount of tuberculosis control, which is in vogue amongst the leg- ] istered town supply dairies. “Before concluding, 1 wish to emphasise the tact that I do not wish to l>e regarded as an alarmist or one- who is raising an unnecessary scare. Tlia.t is definitely not the case. I wish to emphasise again that although bovine tuberculosis has what appears to be a widespread hold in the Dominion, when 1 judged on a comparative standard with ' other countries where the incidence is often three or four times as high, we !

must regard ourselves as fortunately situated. Similarly our annual death rate from tuberculosis is about the lowest in the world-—again a matter for congratulation. On the other hand, unless much more energetic steps are taken to deal with the problem we may not always occupy such a favourable position in international statistical summaries in the future. “The recent Commission which sat to enquire into the position of the dairy industry strongly recommended that the country should Undertake a comprehensive scheme of tuberculosis eradication. Their object in making that recommendation was a purely mercenary one, viz., that owing to the low incidence of the disease in our dairy herds we would be in a position to eliminate it at an earlier date than other competitors in the export market could hope to do so. As a result we would secure a valuable advertising asset for our export products. COST OF ERADICATION. “I Wish to strongly urge the necessity ot a national seneme of tuberculosis eradication on humanitarian grounds. it is established beyond dispute that a large proportion of nonpuunonary tuberculosis, particularly in children, is of bovine origin. Tins type of infection is crippling and disabling rather than iutai in the majority of cases, but anything we can do to reduce the risk our children run should be undertaken without hesitation. The estimated cost is not un:luly heavy. The Dairy Commission went into the matter very fully and considered that it would require approximately £1,000,000 spread over a period of three years to test the whole of the dairy cows (approximately 1,000,000) in tin's country. There vould, of course, be a recurrent annual charge to cover the cost of revesting at intervals. However, when me sees the amount of money made ivailable for expenditure in other diections a cost of only 10s per cow is urely a nominal insurance to pay in u'der to avoid the risk of contracting his disease. Such a policy will unloubtedly come in the future. There nay be, and probably are, practical iifliculties in obtaining the necessary, rained staff to carry out the work inmediately on a Dominion-wide asis. Therefore, the first step is to ecure a tubercle-free milk supply in ur towns. What other cities and orougjhs have done we should do here 1 nd I would like to suggest that this leeting pass a motion urging the 'almerston North City Council to ass a by-law on similar lines to that ecently enforced by the Napier muniipality.” Various questions were answered by lie speaker at the conclusion of his ddress, and the motion already quoti was then passed. On the motion of Miss McLagan, Mr Webster was accorded a vote of tanks.