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SCIENCE AND INDUSTRY. 
Bovine Tuberculosis and its Repression 
[The following statement is a summary of a lecture given at the 
Royal Society of New South Wales recently by Professor Douglas 
Stewart, of the Veterinary School, University of Sydney. Some time 
ago the Institute appointed Special Committees in each State’ to inquire 
into the prevalence of tuberculosis in live stock, and the different reports —— ~ 
are now being prepared with a view to their publication as a bulletin. 
Professor Douglas Stewart was Chairman of the New South Wales 
Committee. Apart from the monetary loss to the Commonwealth from 
this disease, there is the more important consideration of conserving 
public health. The danger to the community from the existing methods 
of supervision followed in New South Wales is readily apparent. Tn 
one or two of the other States, where there is practically no expert 
supervision, the danger is intensified.] : 
After explaining, with the aid of a number of lantern slides, the 
actual cause and the morbid conditions produced by the disease, 
Professor Stewart referred to the different pathogenic effects of the 
three recognised types of tubercle bacillus, and described the manner 
in which the disease is disseminated. Infection occurs, as a rule, 
during extra-uterine life, and in the vast majority of cases it is acquired 
through the medium of contaminated inhaled air or ingested food. 
Inhalation is the more certain method of infection, and the danger of 
keeping a tuberculous animal on the farm, even though it is not being 
milked, was stressed. In food ingestion, raw milk plays an important 
part. Not only is the milk from cows with evident tuberculous 
symptoms dangerous, but milk from. apparently healthy tuberculous 
cows may contain tubercle bacilli derived from deep-seated udder lesions, 
or contaminated discharges from the uterus or bowels soiling the ‘hind- 
quarters. Further, the milk of perfectly healthy cows may become 
contaminated by dust containing infective tubercular matter voided by 
another member of the herd. Apart from bacteriological findings, 
there is ample evidence of the infectivity of raw milk from an infected 
herd in the prevalence of tuberculosis in pigs fed on it and the marked 
decline in the incidence of the disease among these animals when: fed 
on milk that had been pasteurized. 
Professor Stewart pointed out that, apart from the necessity of 
controlling bovine tuberculosis to prevent the heavy monetary losses 
it is responsible for, and which have been estimated by a Special Com- 
mittee appointed by the Federal Institute of Science and Industry to 
amount to about £250,000 per annum in New South Wales alone, the 
repression of the disease is indispensable to. any complete scheme 
- adopted for the protection of public health. While the great majority 
of fatal cases of tuberculosis in man are caused by tubercle bacilli of 
the human type, there is now abundant evidence that the bovine type S 
of tubercle bacillus is responsible for much tubercular infection of 
human beings, commonest during infancy, particularly of neck glands 
and alimentary tract. Official returns from different countries were 
compared, showing the striking agreement between the prevalence of 
tuberculosis in dairy cows and the existence of neck and abdominal 
tuberculosis in children. ; ¢ 
604. ‘ 
