DISCUSSION ON TUBERCULOSIS. 709 



Dr. CuMPSTON, Medical Officer of Health of Western Aus- 

 tralia, said : — 



We have heard a good deal this morning about the frequency 

 with which human beings are invaded by tuberculosis ; and Dr. 

 Mills has stated that every man has been invaded by the bacillus of 

 tuberculosis, but has successfully resisted this invasion. Dr. Mills, 

 however, laid stress upon the fact that the dosage of tubercle 

 bacillus had been great enough to confer upon each of us a definite 

 degree of immunity. This statement that every man has at some 

 time had a slight degi-ee of tuberculosis has been repeated so often 

 that it is now accepted as fact. It may be true for England, 

 France, or Germany, but there is not, so far as I am aware, any 

 evidence available that this general statement is true for Australia. 

 I am not aware of any records of pathologists dealing with this 

 matter, and until such are forthcoming there is no justification for 

 the application to Australia of the sweeping statement that every 

 man has had tuberculosis. 



I do not propose to discuss the question of human and bovine 

 tuberculosis and their relative importance, beyond simply stating 

 that I definitely register my adhesion to the principles of the 

 resolution of the International Congress held at Washington in 

 September, 1909, and believe that the most important factor in 

 the production of human tuberculosis is pre-existing human tuber- 

 culosis. Bovine tuberculosis probably plays its part, most likely 

 in the production of tuberculosis in children and adolescents ; but 

 our problem to-day is the suppression of adult pulmonary tuber- 

 culosis, and here there seems to be an unanimous opinion that 

 pre-existing pulmonary tuberculosis of the infectious type is 

 the principal factor at work. 



While agreeing with this general statement, I am inclined to 

 go one step further and say that it is not the incidental and occa- 

 sional exposure to infection that is important, but that a repeated 

 exposure to infection is necessary. I am not at one with those 

 who clamour of the danger of spitting in the streets, of travelling 

 in trams, and other similar hypothetical exposures to infection, for 

 I do not think these play much part. It is the repetition of fairly 

 large doses of bacilli that is the danger, and I would go so far as 

 to say that the probability of any person becoming infected is 

 directly proportional to his continued proximity to an infectious 

 consumptive. Prof. Pannwitz, in addressing the Tuberculosis 

 Congress at Washington, put this fact neatly: "But it must be 

 stated emphatically that exposure must occur repeatedly before 

 infection can take place. A single exposure is almost without 

 danger, hence panic fear of infection is unfounded." 



The logical deduction, then, from this necessity for continued 

 exposure to infection is that the one single measure to which the 

 greatest importance must be attached is effective segregation. 

 Many may hold the opinion that segregation may be effective in 



