602 PATHOGENIC MICROORGANISMS 



of immense importance in tuberculosis. In no disease is prevention so 

 intimately influenced by general sociological and economic improve- 

 ment as in tuberculosis. 



Wernicke 36 in a study of the relationship of diseases to social 

 conditions shows an almost direct relationship between the provision 

 of air space and parks in cities to tuberculosis. The statistics of the 

 influence of the war upon tuberculosis have not yet become avail- 

 able for study, but it is important to note that at the present writing 

 we are informed by sanitarians who have returned from Europe that the 

 sanitary problem in the European States is very largely one of tuber- 

 culosis, and that the effects of prolonged undernutrition, especially 

 upon children during the war years has resulted in an enormously 

 increased tuberculosis rate. 



The question of the inheritance of tuberculosis has frequently been 

 raised, and a large literature on this subject has accumulated, but an 

 analysis of this literature seems to show that inheritance must be 

 regarded as predisposition rather than as a method of direct infection. 

 Children of tuberculous parents are likely to be more susceptible to 

 tuberculosis and, of course, are expos3d to tuberculosis more intimately 

 during the early years of life than are children of normal parents. 

 There is no direct proof that tuberculosis is transmitted from mother to 

 the foatus. 



Prevention. As to preventive measures, we must refer the reader 

 to special books on the subject since the problem is too large to be 

 dealt with briefly with anything like completeness. The following 

 summary of preventive measures is based largely upon the conclusions 

 reached in Kober's discussion of this subject: 



We may assume, as premises for prevention, that tuberculosis can be 

 transmitted at all periods of life and that foci acquired in youth may 

 be arrested but light up under conditions of general undernutrition, 

 malnutrition, etc., etc., in later years. Infection may be direct from 

 person to person, indirect through contaminated food, fomites, flies; 

 through dust, and in childhood through milk from infected cattle. 

 The most common manner of acquiring tuberculosis is by inhalation 

 and, next to that, probably through the digestive tract. 



The most important factor in the prevention of tuberculosis is 

 education. This must elucidate the method of infection and the im- 

 portance of the economic and sociological factors as they effect habits 

 of food, sleep and fresh air. 



36 Wernicke, quoted from Kober. 



