EPIDEMIOLOGY OF PNEUMONIA 477 



From evidence like this, we conclude that in the sanitation of 

 pneumonia it would be dangerous to lay too great proportionate stress 

 upon mere transmission, but to remember that the average resistance 

 to pneumococcus infection of the lung is fairly high among human 

 beings, and that sanitary precautions must include a very rigid atten- 

 tion to the factors of warmth, ventilation in sleeping quarters, ade- 

 quate food, dryiiess of feet, and avoidance of overwork. In. communi- 

 ties like those of South Africa, the prevention of transmission alone 

 cut short the epidemic, but we have already pointed that the 

 susceptibility factor was unusually high in these communities. 



It will rarely be necessary for sanitarians working in civilized 

 communities to be called upon to prevent epidemics of primary pneu- 

 monia. They will develop under such conditions as those prevailing 

 in military camps, and which might well be imagined as possible in 

 badly managed industrial communities, schools, labor camps, etc., 

 where laborers are forced to sleep in ill-ventilated barracks are 

 crowded during working hours, or in mines, and crowded institutions. 

 Such conditions may occur among civilian populations at times of 

 famine, and penury incident to war. Primary pneumonia epidemics 

 will occur only when crowding, coincident with generalization of mild 

 respiratory infections increases the distribution of bacteria and when, 

 at the same time, the community suffers from insufficient shelter and 

 is perhaps under-nourished and overworked. The most important 

 factor in the prevention of such outbreaks, therefore, is attention to 

 the ventilation of sleeping quarters, sufficient number of blankets on 

 beds, dry feet, warm and plentiful food, and opportunities for reason- 

 able rest. If this is combined with isolation of coughing and sneezing 

 individuals, at least during indoor life, if spitting is stopped and care- 

 ful supervision of the cleansing of eating utensils, sterilization of 

 handkerchiefs, etc., is enforced, such epidemics should yield readily. 



Cases which have been diagnosed as lobar pneumonia should be 

 reportable, like other infectious diseases. This has already been intro- 

 duced by a number of health departments. In hospitals pneumonia 

 cases should be treated as communicable, the cases isolated, at least 

 by maintaining proper distance between beds, screening between beds, 

 and care in the collection and disposition of sputum and other secre- 

 tions. Care of eating utensils and general cleanliness should be car- 

 ried out with proper consideration of the possibilities of communica- 

 tion that have been spoken of above. In view of the probability of 

 persistence of the carrier state for four weeks or longer after con- 



