246 PATHOGENIC BACTERIA IN MILK 



marked decrease in deaths due to Tabes inesenterica, and in chil- 

 dren under one year a notable increase of deaths due to this latter 

 disease.^ Deaths from phthisis occur mostly between the ages 

 of twenty and forty years, and from Tabes mesenterica in children 

 under two years. Such returns admittedly vary according to 

 variations in divi^-^o^xs, post-mortem examinations, medical opinion, 

 and other unknown quantities. There is also the difficulty of 

 forming correct opinions as to whether or not the condition was 

 primary or secondary, and due to alimentary or other infection. 

 In this connection it should be remembered that it is compara- 

 tively rare to find the mesenteric glands affected in phthisis. The 

 result of recent special inquiries by post-mortem examination by 

 a number of workers has crystallised the deductions to be drawn 

 from the reports of the Registrar-General, and has added emphasis 

 to the view that a considerable amount of alimentary tuberculosis 



tuberculosis in children, it is a matter of extreme difficulty to determine which 

 was, in fact, the primary channel of infection, and this must be taken into 

 consideration in estimating the significance of the frequency in the above figures. 

 Further, owing to the fact that children swallow their pulmonary expectoration, 

 secondary infection of the intestine may rapidly follow primary infection of the 

 lungs. Hence it comes about that, in many cases, the intestine and mesenteric 

 glands are affected, and yet such a condition cannot be taken as evidence of 

 the infection by food. Dr Still concludes that (a) the commonest channel of 

 infection with tuberculosis in childhood is through the lung ; {b) infection 

 through the intestine is less common in infancy than in later childhood ; 

 {c) milk, therefore, is not the usual source of tuberculosis in infancy ; and {d) 

 inhalation is much the commonest mode of infection in the tuberculosis of child- 

 hood and especially in infancy. Dr Still has placed on record five cases of 

 tuberculous ulcer of the stomach in children. 



It would seem, therefore, that the evidence in support of the theory that 

 children commonly contract their tuberculosis from milk is not conclusive, but 

 rather the reverse. The first Royal Commission on Tuberculosis and Sir Richard 

 Thome ^ may be said to have laid the chief emphasis upon the milk theory of 

 infantile tuberculosis. But later researches have thrown some doubt upon 

 some of the conclusions of the Commission, and with others we have, for long, 

 thought that the facts emphasised by Sir Richard Thorne bear, in part, another 

 interpretation than that to which he drew attention. Further exact research 

 and careful inquiry is needed to obtain necessary data upon which to base any 

 reliable conclusions respecting this matter. But we are satisfied that, in any 

 event, there is evidence to show that tuberculosis can be conveyed to man by 

 means of milk, and that milk for sale containing the bacilli of tubercle is being 

 sold, not alone to the prejudice, but also to the risk, of the purchaser. 



^ Reports of Registrar-General, Somerset House ; The Administrative Con- 

 trol of Tuberculosis (Sir Richard Thorne), 1899, pp. 5-9 and 28-32. 



2 The Administrative Control of Tuberculosis {Yi&vh&n Lectures), 1899, pp. 

 5-7, and 28-32. 



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