INTRODUCTION
Death from lobar pneumonia, bronchopneumonia and measles, fatal with few exceptions in consequence of complicating pneumonia, constituted in 1916 approximately one-sixth (16.8 per cent) of the mortality in the army,[[1]] whereas in 1917 the same diseases were responsible for nearly two-thirds (61.7 per cent) of all deaths. During the first half of 1918 the incidence of pneumonia steadily increased and in some army camps there were extensive outbreaks of unusually severe pneumonia.
In July, 1918, the Surgeon General assigned a group of medical officers to the study of the pneumonias prevalent in the army and stationed them at Camp Funston, Kansas. At the base hospital of this camp all cases of pneumonia occurring among troops assembled in the camp were studied, but during the month of August there were few cases of pneumonia and these were of mild type.
Pneumonia which occurred at Camp Funston during August was almost wholly limited to recently recruited colored troops from southern states (Louisiana, Mississippi). There was a low rate of mortality, and few complications. This pneumonia exhibited a noteworthy difference in etiology from that usually seen in civil life, for it was associated with a high incidence of those types of pneumococci which occur in the mouths of healthy men, namely, Pneumococcus atypical II,[[2]] Type III, and the group of microorganisms represented by Type IV. Pneumococcus Type I was encountered in only a few instances and Type II was not found, although these two microorganisms are responsible for two-thirds of the lobar pneumonia which occurs in civil life.
During the investigation at Camp Funston the Commission had the courteous cooperation of Major Willard Stone, Director of Medical Service, and received much valuable assistance from Lieutenant A. McGlory, Registrar of the Base Hospital.
A review of the accurately compiled records of the base hospital was made in order to obtain a history of the pneumonias and other respiratory diseases which had occurred throughout the existence of the camp, established in September, 1917. It soon became evident that a disease recognized as influenza had been prevalent throughout this period and its incidence had shown a close parallel with that of acute bronchitis. At the same time there had been much pneumonia and a high death rate from this disease. The chart[[3]] which was constructed showed that the disease which had been designated influenza assumed epidemic proportions in March, 1918. Any doubt that may have been entertained concerning the nature of the disease is dispelled by the characters of this epidemic which, beginning at the end of February, reached its height on March 12 and rapidly subsided; 1,127 men with influenza entered the base hospital between March 4 and March 29 and many more were treated in the infirmaries of the camp. In April there was a second wave of influenza and in May a third, each in large part limited to newly drafted men brought into the camp shortly before these outbreaks. Corresponding to the epidemic of influenza there was a great increase of pneumonia, reaching a maximum about one week after the height of the incidence of influenza; subsequently the incidence of pneumonia increased after each one of the secondary waves of influenza. Pneumonia following measles occurred throughout the history of the camp; in November and December, 1917, there was a severe outbreak of pneumonia following measles and the mortality was high. Our conclusions in regard to the pneumonias which occurred during the history of Camp Funston were as follows:
1. Pneumonia of a relatively stationary camp population, such as that which occurred among white troops during the period of our investigation, was in considerable part caused by Pneumococcus Types I and II and resembled the pneumonia of civil life.
2. Pneumonia of newly drafted colored troops from southern states during the period of our investigation was caused in great part by pneumococci of those types which occur in the mouths of healthy men, namely, Types IV, III and atypical II.
3. Pneumonia caused by influenza occurred after the epidemic of influenza which we have described. The report states: “With the information available it is not possible to draw a sharp line between (1) the pneumonia of the stable camp population, (2) the pneumonia of the newly drafted southern troops, and (3) the pneumonia following influenza. It is possible that influenza, in greater or less degree, also acts as a predisposing factor in the production of the first and second varieties.”
4. Pneumonia with measles was a frequent and unusually fatal type of the disease. The most important causes of pneumonia during the history of the camp were influenza and measles.