The organisms associated with influenzal pneumonia are the so-called “mouth organisms.” They are not only found in the mouths and upper air passages of the influenza patients, but also in those of normal individuals. This points to the fact that the bacteria of the mouth have gained access to the lung, probably already injured by a primary agent, in sufficient numbers to bring about a serious inflammatory process. In this connection it is of interest to note the relatively high frequency of the mouth organisms, pneumococcus, Types III and IV, in influenzal pneumonia as compared to the less frequent mouth inhabitants, Types I and II, which are responsible for two-thirds of the cases of true lobar pneumonia (5, 45, 92, 121).
Only the eighty-two cases at the New Haven Hospital are included in the following report. Routine post-mortem cultures were taken from blood, lung, serous fluid wherever present, and exudates from the trachea and bronchi in the later cases. Blood and serous fluids were cultured into neutral infusion broth and plated on blood agar after twelve to thirty-six hours’ incubation. Lung and bronchial cultures were streaked on blood agar plates and for the last third of the series on Avery’s oleate media. Cultures were examined on each successive day and were discarded only after one week. Undoubtedly, we have failed to find B. influenzæ in many of the earlier cases because of lack of familiarity with the organism, of variations in its morphology (33), and of unsuitable culture media. The organisms tabulated below include only those determined by cultural methods; those found by direct smears or in histopathological preparations are not considered. (See Table No. [I].)
B. THE RELATION OF THE TYPE OF ORGANISM TO PLEURAL INVOLVEMENT
The hemolytic streptococcus has been found frequently in association with purulent pleural effusions in influenza, Thomas (146), Stone and Swift (138), Ely et al (37); and Goodpasture (48) has suggested an etiologic relationship between the type of effusion and the infecting organism in influenza, as has been brought forward for the similar post-measles empyema in the army camps. At the New Haven Hospital the Streptococcus hemolyticus was found frequently in non-fatal empyema. However, at post-mortem examination the frequency of this organism in pleural effusions of various types was no greater than that of several other organisms, but it occurred in the only two cases of frank empyema of this series. (See Table No. [II].)
C. THE RELATION OF DIFFERENT ORGANISMS TO THE TYPE OF PNEUMONIA
Various observers have emphasized the types of organism associated with different gross and microscopic manifestations of influenzal pneumonia. Pfeiffer described the peribronchial type with purulent bronchitis, from which the influenza bacillus was isolated, and the same association has been noted by MacCallum (92), Wolbach (162), Wegelin (156), Dietrich (34), and others. Opie et al (110), however, in a series from which B. influenzæ was isolated in over eighty-five per cent of the necropsies rarely found this picture. Wolbach states that the gross anatomical picture in influenzal pneumonia is similar to that following measles, from which a hemolytic streptococcus has been isolated in a high percentage of cases. MacCallum (93) classified this type as interstitial pneumonia. It is interesting to note that interstitial pneumonia has been rare in many localities where the hemolytic streptococcus has been prevalent during the past year. Stone and Swift (138) state that “despite the prevalence of the streptococcus at necropsy, only eight instances of so-called interstitial pneumonia were found in a series of fifty-five cases,” and Goodpasture (48) failed to find a single example in a series of sixteen cases. The pneumococci Types I and II, frequently encountered in the usual forms of lobar pneumonia, have been found exceptionally in this epidemic. Type II, however, has been reported (67, 107) present in about the same proportion as in true lobar pneumonia (5). Chickering and Park (25) described a series of cases of pneumonia due to the staphylococcus characterized by multiple miliary abscesses. Necrotization and abscess formation, however, have been striking features of the pathology of this epidemic, even when the staphylococcus has not been demonstrable. Recently Wadsworth (154) demonstrated experimentally that organization in pneumonia does not result from the pneumococcus or the staphylococcus alone, but only follows when both organisms are associated. On the contrary, Blanton and Irons (12) found that “there was no difference to be made out in the nature of the process caused by the streptococcus, pneumococcus, or influenza bacillus.”
FIG. XLVII. AUTOPSY NO. 100. PROLIFERATION OF THE ALVEOLAR EPITHELIUM IN A PORTION OF THE LUNG ONLY SLIGHTLY INVOLVED BY THE ACUTE INFLAMMATORY PROCESS. COMPARE FIGURES [IV], [XI], [XLVIII], AND [XLIX].
HELIOTYPE CO. BOSTON
| TABLE I. | |||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Post Mortem Bacteriology. | |||||||||||||||||
| Acute Fulminating (34 cases) | Necrotizing (36 cases) | Organizing (12 cases) | Total All Types (82) | ||||||||||||||
| Blood | Lung | Pleural fluid | Trachea and Bronchi | Total Cases | Blood | Lung | Pleural fluid | Trachea and Bronchi | Total Cases | Blood | Lung | Pleural fluid | Trachea and Bronchi | Total Cases | Total | Per cent. | |
| Strep. hemolyticus | 8 | 12 | 7 | 2 | 12 | 8 | 9 | 3 | 1 | 9 | 7 | 8 | 5 | 3 | 8 | 29 | 35.4 |
| Strep. non-hemolyticus | 7 | 7 | 2 | 5 | 1 | 5 | 5 | 0 | 12 | 14.6 | |||||||
| Strep. “viridans” | 0 | 2 | 1 | 2 | 2 | 0 | 2 | 2.4 | |||||||||
| Strep. mucosus capsulatus | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 1.2 | |||||||||
| Pneumococcus Type II | 3 | 4 | 3 | 1 | 4 | 3 | 4 | 1 | 2 | 4 | 1 | 3 | 1 | 3 | 11 | 13.4 | |
| Pneumococcus Type III | 4 | 4 | 3 | 4 | 2 | 1 | 2 | 1 | 1 | 1 | 7 | 8.6 | |||||
| Pneumococcus Type IV | 4 | 6 | 2 | 3 | 6 | 6 | 11 | 2 | 5 | 11 | 1 | 1 | 1 | 18 | 22. | ||
| Pneumococcus (Type undetermined) | 2 | 3 | 3 | 3 | 2 | 5 | 5 | 0 | 8 | 9.7 | |||||||
| B. influenzæ | 1 | 4 | 2 | 5 | 1 | 12 | 0 | 4 | 12 | 1 | 1 | 2 | 19 | 23. | |||
| Staphylococci | 3 | 2 | 2 | 4 | 1 | 9 | 3 | 4 | 9 | 6 | 2 | 6 | 19 | 23. | |||
| B. mucosus capsulatus | 1 | 1 | 1 | 2 | 1 | 1 | 2 | 0 | 3 | 3.7 | |||||||
| M. catarrhalis | 2 | 1 | 2 | 2 | 2 | 2 | 0 | 4 | 4.9 | ||||||||
| Diphtheroids | 1 | 1 | 0 | 1 | 1 | 1 | 2 | 2.4 | |||||||||
| Enterococcus | 1 | 1 | 0 | 0 | 1 | 1.2 | |||||||||||
| TABLE II. | ||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Bacteriology of Pleural Exudates. | ||||||||||||||||||||||
| Acute Fulminating (34) | Necrotizing (36) | Organizing (12) | Total (All Types) (82) | |||||||||||||||||||
| Fibrinous | Serofibrinous | Serofibrinopurulent | Empyema | Total | Fibrinous | Serofibrinous | Serofibrinopurulent | Empyema | Total | Fibrinous | Serofibrinous | Serofibrinopurulent | Empyema | Total | Fibrinous | Serofibrinous | Serofibrinopurulent | Empyema | Total | Total number of cases with positive cultures | Effusion present percent. | |
| Strep. hemolyticus | 1 | 5 | 2 | 8 | 3 | 2 | 1 | 6 | 1 | 1 | 3 | 2 | 7 | 5 | 8 | 6 | 2 | 21 | 29 | 55% | ||
| Strep. non-hemolyticus | 1 | 2 | 3 | 1 | 2 | 1 | 4 | 0 | 2 | 2 | 3 | 7 | 12 | 42% | ||||||||
| Strep. “viridans” | 0 | 1 | 1 | 2 | 0 | 1 | 1 | 2 | 2 | 50% | ||||||||||||
| Strep. mucosus capsulatus | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 100% | ||||||||||||||
| Pneumococcus Type II. | 2 | 1 | 1 | 4 | 2 | 1 | 1 | 4 | 1 | 1 | 2 | 4 | 2 | 3 | 1 | 10 | 11 | 54% | ||||
| Pneumococcus Type III. | 2 | 1 | 3 | 2 | 2 | 0 | 2 | 3 | 5 | 7 | 71% | |||||||||||
| Pneumococcus Type IV. | 1 | 2 | 2 | 5 | 5 | 4 | 2 | 11 | 1 | 1 | 2 | 6 | 7 | 4 | 1 | 18 | 18 | 67% | ||||
| Pneumococcus (Type undetermined) | 0 | 1 | 1 | 2 | 4 | 0 | 1 | 1 | 2 | 4 | 8 | 37.5% | ||||||||||
| B. influenzæ | 1 | 1 | 2 | 4 | 5 | 4 | 2 | 11 | 1 | 1 | 2 | 7 | 5 | 5 | 17 | 19 | 52% | |||||
| Staphylococci | 3 | 3 | 3 | 3 | 3 | 9 | 1 | 1 | 1 | 1 | 4 | 4 | 4 | 7 | 1 | 16 | 19 | 63% | ||||
| B. mucosus capsulatus | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 2 | 3 | 67% | ||||||||||||
| Number of cases of pleurisy | 3 | 12 | 6 | 21 | 13 | 7 | 10 | 30 | 1 | 1 | 5 | 2 | 9 | 17 | 20 | 21 | 2 | 60 | ||||
| Percent of cases showing excess of Pleural fluid. | 53% | 47% | 67% | 52.4% | 52.4% | |||||||||||||||||