Читать книгу Epidemic Respiratory Disease - Thomas M. Rivers - Страница 11
Pneumonia
ОглавлениеThe opportunity presented for a correlated study of the clinical features, bacteriology, and pathology of pneumonia following influenza throughout the period of the epidemic at Camp Pike from September 6, 1918, to December 15, 1918, made it evident that this pneumonia could be regarded as an entity in only one respect, namely, that influenza was the predisposing cause. Clinically, bacteriologically, and pathologically it presented a very diversified picture ranging all the way from pneumococcus lobar pneumonia to hemolytic streptococcus interstitial and suppurative pneumonia with the picture modified to a varying extent by the preceding or concomitant influenzal infection.
One hundred and eleven consecutive cases in which careful clinical and bacteriologic studies were made form the basis of the material presented. Of these cases, 38 came to necropsy so that ample opportunity was presented to correlate the clinical and bacteriologic studies made during life with the pathology and bacteriology at necropsy. It has seemed advisable to group the cases primarily on an etiologic basis with secondary division according to clinical features in so far as this can be done. Bacteriologic studies showed that at the time of onset these pneumonias were either pneumococcus pneumonias or mixed pneumococcus and influenza bacillus pneumonias in nearly all instances. Certain of these cases later became complicated by a superimposed hemolytic streptococcus or a staphylococcus infection. In a few instances hemolytic streptococcus pneumonia directly followed influenza without an intervening pneumococcus infection. B. influenzæ was present in varying numbers in nearly all cases. In only 2 instances however, was it found unassociated with pneumococci or hemolytic streptococci, once alone and once with S. viridans.
Clinically the cases fell into four main groups: (1) Lobar pneumonia; (2) lobar pneumonia with purulent bronchitis; (3) bronchopneumonia (pneumococcus); (4) bronchopneumonia (streptococcus). It should be borne in mind, however, that the picture was a complex one and that correct clinical interpretation was not always possible, since many cases did not conform sharply to any one type and superimposed infections during the course of the disease often modified the picture.
Pneumococcus Pneumonia Following Influenza.—Bacteriologic examination of selected and washed specimens of sputum coughed from the lungs at time of onset of pneumonia showed the various immunologic types of pneumococcus to be present in 105 cases. The incidence of the different types is shown in Table XIV.
| Table XIV | ||||
|---|---|---|---|---|
| Types of Pneumococcus in 105 Cases of Pneumococcus Pneumonia Following Influenza | ||||
| LOBAR PNEUMONIA | BRONCHOPNEUMONIA | TOTAL | PER CENT | |
| Pneumococcus, Type I | 8 | 0 | 8 | 7.6 |
| Pneumococcus, Type II | 3 | 1 | 4 | 3.8 |
| Pneumococcus, II atyp. | 12 | 7 | 9 | 18.1 |
| Pneumococcus, Type III | 3 | 3 | 6 | 5.7 |
| Pneumococcus, Group IV | 32 | 36 | 68 | 64.8 |
The most noteworthy feature of the figures in Table XIV is the high proportion of pneumonias due to types of pneumococci found in the mouths of normal individuals, 93 cases or 88.6 per cent, being caused by Pneumococcus Types II atypical, III, and IV. This is in harmony with the results generally reported and is in all probability due to the fact that in patients with influenza pneumococci, which under normal conditions would fail to cause pneumonia, readily gain access to the respiratory tract and produce the disease. It is also of interest that with one exception the highly parasitic pneumococci of Types I and II were associated with pneumonias clinically lobar in type.
Superimposed infection of the lungs with other types of pneumococci than those primarily responsible for the development of pneumonia occurred not infrequently in this group of cases either during the course of the disease or shortly after recovery from the first attack of pneumonia. Pneumococcus Type II infection was superimposed upon or shortly followed pneumonia caused by Group IV pneumococci in 4 instances, by Pneumococcus II atypical in 1 instance. In 1 case pneumonia due to Pneumococcus II atypical occurred three days after recovery from a Pneumococcus Type I pneumonia, in another case Pneumococcus Type III infection was superimposed upon a pneumonia originally due to a pneumococcus of Group IV. These cases are presented in detail in another section of this report, and in several instances were shown to be directly due to contact infection from patients in neighboring beds.
In a similar manner, superimposed infection with S. hemolyticus at some time during the course of the pneumonia occurred in 13 cases in this group, with fatal result in all but one. Streptococcus infection occurred in pneumonia due to Pneumococcus II atypical once, to Pneumococcus Type III once, and to pneumococci of Group IV eleven times. Nine of these cases were free from hemolytic streptococci at the time of onset of the pneumonia, 4 showed a very few colonies of hemolytic streptococci in the first sputum culture made.
B. influenzæ was found in the sputum coughed from the deeper air passages in the majority of cases, being present in 80, or 76.2 per cent, of the 105 cases. In the 58 cases of lobar pneumonia it was found 41 times, or 70.7 per cent, in the 47 cases of bronchopneumonia 39 times, or 82.9 per cent. The abundance of B. influenzæ in the sputum varied greatly in different cases. Microscopic examination of stained sputum films and direct culture of the sputum on blood agar plates showed that in general it was more abundant in the mucopurulent sputum from cases of bronchopneumonia than in the mucoid rusty sputum from cases of lobar pneumonia. This was by no means an invariable rule, however, since in the former the bacilli were sometimes very few in number, in the latter quite abundant. Whether B. influenzæ shared in the production of the actual pneumonia in these cases is difficult to decide and cannot be stated on the basis of the bacteriologic and clinical observations which have been made.
Clinical Features.—One of the most striking aspects of pneumococcus pneumonia following influenza was the diversity of clinical pictures presented. These varied all the way from the classical picture of lobar pneumonia to that of bronchopneumonia of all grades of severity from the rapidly fatal coalescing type to that of very mild character with very slight signs of consolidation. For this reason it is questioned whether there is any real justification for speaking of a typical influenzal pneumonia, an opinion that seems well supported by the diversified picture found at the necropsy table.
For purposes of presentation, pneumococcus pneumonia following influenza may be divided into three clinical groups: (1) Lobar pneumonia; (2) lobar pneumonia with purulent bronchitis; (3) bronchopneumonia. No accurate data are available as to the relative frequency with which these three types occurred at Camp Pike. In the group of 105 cases studied there were 58 cases of lobar pneumonia, 11 of which had purulent bronchitis, and 47 cases of bronchopneumonia. The majority of these cases, however, occurred during the early days of the epidemic of influenza and probably show a considerably higher proportion of lobar pneumonias than actually occurred in the total number of pneumonias throughout the epidemic. This is indicated by the fact that of 100 consecutive cases of influenza selected for observation at the height of the epidemic, 3 developed clinical evidence of lobar pneumonia and 12 of bronchopneumonia.
(1) Lobar pneumonia presenting the typical clinical picture with sudden onset, tenacious rusty sputum, sustained temperature, and physical signs of complete consolidation of one or more lobes occurred in 47 cases; 36 cases in this group definitely followed influenza. In 11 cases no certain clinical evidence of a preceding influenza was obtained, and it is probable that some of these represent cases of pneumonia occurring independently of the epidemic of influenza.
The onset of pneumonia in this group of cases occurred from four to nine days after the onset of influenza and with few exceptions was ushered in by a chill and pain in the chest. In several instances the patient had apparently recovered from influenza as evidenced by fall of temperature to normal. After twenty-four to seventy-two hours of normal temperature the patient would have a chill and develop lobar pneumonia. In the majority of cases, however, lobar pneumonia developed while the patient was still sick with influenza. The course of the disease, symptomatology and physical signs were quite characteristic of lobar pneumonia and require no special comment. Recovery by crisis occurred in 21 cases, by lysis in 8. Pneumococcus empyema developed in 3 cases, fibrinopurulent pericarditis in 3 and all but 1 of these 6 cases terminating fatally.
In Table XV 5 fatal cases of lobar pneumonia, which illustrate some of the unusual features of the disease when it follows influenza, have been summarized. The first 2 cases represent examples of recurring attacks of pneumonia which developed shortly after recovery from the first attack, in both instances being due to types of pneumococci different from those causing the first attack. The third case represents an example of superimposed infection of the lungs with hemolytic streptococci and staphylococci during the course of a pneumonia due to Pneumococcus IV and disappearance of the latter organism from the tissues so that it was not found at time of necropsy. The last 2 cases are examples of fulminating rapidly fatal cases of lobar pneumonia associated with mixed infections of pneumococci and hemolytic streptococci, the streptococci probably being secondary in both cases. Cases like the few examples cited above, which occurred not infrequently throughout the epidemic of influenza, serve to illustrate the difficulties which may be met in attempting to correlate the clinical, bacteriologic and pathologic features of pneumonia following influenza unless careful bacteriologic examinations are made both during life and at the necropsy table in the same group of cases.
