Predisposing Causes of Consumption
By N. S. Davis
THAT the specific cause or causes of tubercular disease exist now, and have existed for many generations in nearly all the inhabited parts of America and Europe, is conceded by all who have investigated the subject. Consequently there are but few persons of adult age in any part of our country who have not been repeatedly in contact with the tubercle bacillus on the streets, in public conveyances, public assemblies, in family and social circles, etc.; and yet a very large majority of the people live, and die from other causes, giving no sign of tubercular disease. No other evidence is needed to demonstrate the fact that the healthy living human body possesses a natural vital resistance or immunity to the influence of the tubercle bacillus sufficient to enable a large majority of people to go through life unaffected by it.
If this is true, then the question, Why do the minority yield to its influence? becomes of great importance. What are the causes or conditions that so far impair their natural immunity as to enable the bacillus to find in them not only lodgment, but a ground for multiplication, and ultimately to bring destructive consequences? Of course this is only another mode of stating the old and familiar question, What are the predisposing causes of tuberculosis? And the equally familiar answer comes, Living and working in overcrowded, ill-ventilated rooms; neglect of outdoor exercise; insufficient or badly adjusted clothing; persistent depressing mental emotions, as grief or anxiety; and the habitual use of alcoholic drinks or other anæsthetic and narcotic drugs. In other words, these conditions greatly diminish the individual’s natural immunity or vital resistance to the action of the specific cause of tubercular disease.—N. S. Davis, M. D.