Читать книгу Epidemic Respiratory Disease - Thomas M. Rivers - Страница 16

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Influenza as observed at Camp Pike presented itself as a highly contagious infectious disease, the principal clinical manifestations of which were, sudden onset with high fever, profound prostration with severe aching pains in the head, back and extremities, erythema of the face, neck and upper chest with injection of the conjunctivæ, and a rapidly progressive attack upon the mucous membranes of the respiratory tract as evidenced by coryza, pharyngitis, tracheitis and bronchitis with their accompanying symptoms. In the majority of cases it ran a short self-limited course, rarely of more than four days’ duration, and was never fatal in the absence of a complicating pneumonia.

Bacteriologic examination in early uncomplicated cases of the disease showed the B. influenzæ of Pfeiffer to be present in all cases, often in predominating numbers. It was found more abundantly present during the acute stage of the disease than during convalescence in uncomplicated cases. No other organisms of significance were encountered by the methods employed.

Purulent bronchitis of varying extent developed in approximately 35 per cent of the cases and often prolonged the course of the illness to a considerable extent. Bacteriologic studies showed that it was invariably associated with a mixed infection of the bronchi with B. influenzæ and other bacteria, in most instances the pneumococcus, and indicated that it should be regarded as a complication rather than as an essential part of influenza. Its clinical features consisted of a mild febrile reaction, frequent cough with the raising of considerable amounts of purulent sputum, and the physical signs of a more or less diffuse bronchitis. It led to a varying degree of bronchiectasis in at least some instances.

Pneumonia complicating influenza presented a very diversified picture and appeared to have only one constant character, namely, that influenza was the predisposing cause. It may be best classified on an etiologic basis since the clinical features to some extent and the pathology to a much greater extent depended upon the infecting bacteria in a given case.

Bacteriologic examination showed that a very large proportion of the cases was due to infection with the different immunologic types of pneumococci or to a mixed infection with B. influenzæ and pneumococci. The types of pneumococci commonly found in normal mouths, namely, II atypical, III, and IV, comprised approximately 88 per cent of these, the highly parasitic Pneumococci Types I and II, but 12 per cent. A small number of cases were due to hemolytic streptococci or to mixed infection with B. influenzæ and S. hemolyticus. No certain evidence was obtained that pneumonia was due to B. influenzæ alone. This organism was present in varying numbers, however, in approximately 80 per cent of the sputums examined, and it seems fairly certain that it must have played at least a part in the development of the pneumonia in many of the cases in which it was found. Superimposed infections with other types of pneumococci than those primarily responsible for the development of pneumonia, with hemolytic streptococci and with Staphylococcus aureus occurred frequently in cases of pneumococcus or mixed pneumococcus and B. influenzæ pneumonia and undoubtedly contributed to a considerable extent in increasing the number of deaths.

Three clinical types of pneumococcus pneumonia following influenza occurred: lobar pneumonia, lobar pneumonia with purulent bronchitis, and bronchopneumonia. Lobar pneumonia was usually sudden in onset and ran the characteristic course of the primary disease. Lobar pneumonia with purulent bronchitis similarly ran the characteristic course of the primary disease but presented the unusual picture of lobar pneumonia with mucopurulent rather than rusty, tenacious sputum and numerous moist râles throughout the unconsolidated portions of the lungs. The cases of bronchopneumonia ran a very variable course from mild cases of a few days’ duration and meager signs of consolidation to rapidly progressive cases with signs of extensive pulmonary involvement. Purulent bronchitis was very frequently associated with bronchopneumonia.

Hemolytic streptococcus pneumonia following influenza presented the clinical picture of bronchopneumonia and was not readily distinguished on clinical grounds from pneumococcus bronchopneumonia except in those cases which developed a pleural exudate early in the disease. The advent of tertiary infection of the lower respiratory tract with hemolytic streptococci in cases of secondary pneumococcus pneumonia presented no symptoms sufficiently constant or certain to make clinical diagnosis easy. The development of empyema in pneumococcus bronchopneumonia usually meant streptococcus infection.

Pure B. influenzæ pneumonia, if such cases existed, presented no diagnostic features by which it could be distinguished from pneumococcus bronchopneumonia following influenza. It was impossible to determine on clinical and bacteriologic grounds alone what part the prevalent influenza bacilli played in the causation of the actual pneumonia.