Epidemic Respiratory Disease / The pneumonias and other infections of the repiratory tract accompanying influenza and measles

by Eugene L. Opie; Francis G. Blake; Thomas M. Rivers; James C. Small

Conclusions

1. Consideration of all the evidence available makes it seem highly probable that B. influenzæ is the specific etiologic agent of epidemic influenza, because (a) it is always present in early uncomplicated cases of influenza; (b) it is predominantly so during the acute stage of the disease in cases going on to rapid recovery without development of complications; (c) its presence in varying numbers in normal individuals and in other diseases of the respiratory tract is not valid evidence against its etiologic relationship to influenza, but on the contrary is quite in harmony with what should be expected from our knowledge of other bacteria known to be the etiologic agents of various respiratory diseases; (d) its rapidly increasing prevalence in normal individuals simultaneously with the progress of the epidemic indicates that actual dissemination of B. influenzæ readily occurs and is very widespread during pandemic times; (e) cultures of B. influenzæ freshly isolated from early acute cases of influenza are pathogenic for animals, and may produce in monkeys a disease closely resembling influenza.

2. Final proof of the exact relationship of B. influenzæ to influenza must depend upon (a) more definite knowledge of the immunology both of the organism and of the disease, and (b) knowledge of the pathologic lesions of influenza and the production of these lesions in animals by inoculation with B. influenzæ.

CHAPTER II
CLINICAL FEATURES AND BACTERIOLOGY OF INFLUENZA AND ITS ASSOCIATED PURULENT BRONCHITIS AND PNEUMONIA

Francis G. Blake, M.D., and Thomas M. Rivers, M.D.

The material presented in this section of the report consists of clinical and bacteriologic observations made during the course of an investigation of influenza and its associated bronchitis and pneumonia at Camp Pike, Ark., between September 6 and December 15, 1918, comprising part of a correlated study of the epidemiology, bacteriology, pathology, and clinical features of these diseases. The bacteriologic studies are in the main limited to those made during life, those made at necropsy being reported in another section of this report.

Methods.—All cases upon which the clinical and bacteriologic data presented are based, were examined by the authors and our own clinical histories and physical examinations were recorded. This was considered of special importance, since in studying a group of diseases in which secondary infection of the respiratory tract might supervene at any time, it was essential to determine as far as possible the exact clinical condition of the patient at the time when bacteriologic examinations were made. The bacteriologic methods employed were the direct culture of nose and throat swabbings and of selected and washed specimens of sputum on the surface of 5 per cent defibrinated horse blood agar plates, the intraperitoneal inoculation of white mice with specimens of sputum according to the method described by Blake[^[28]] for the determination of pneumococcus types, and in some cases the method of Avery.[^[29]] B. influenzæ pneumococci and hemolytic streptococci were identified by the methods described elsewhere. Note was made in most instances of the presence of other organisms such as members of the Gram-negative diplococcus group, staphylococci, diphtheroids, and members of the streptococcus viridans group, but no attempt was made to further isolate or identify them since they played no significant part in the cases studied except in rare instances.