Column 16. Empyema.—The presence of the lesion is indicated by “E.”
Column 17. Bronchiectasis.—“B” indicates the lesion.
Column 18. Unresolved bronchopneumonia.—Presence of the lesion is indicated by the plus sign (+).
Column 19. Organizing bronchitis and bronchiolitis.—“O” indicates the lesion.
The lesions of columns 7 to 12 are acute inflammatory processes, columns 9 to 12 represent different types of bronchopneumonia. Columns 13 to 15 represent suppurative lesions. Columns 17 to 19 represent chronic lesions. A survey of the table shows the predominance of acute lesions in the early period of the study and the gradual increase of chronic lesions.
The last four columns of the table of autopsies give the bacteriology of the sputum during life and the bacteria found in the bronchi, in the lungs, and in the blood of the heart after death.
Mortality of Pneumonia Following Influenza.—From September 6 to December 15, 250 autopsies were performed on patients who had died with pneumonia at the base hospital at Camp Pike, and with few exceptions bacteriologic cultures were made from them. Although it was not possible to perform autopsies on all who died, those which were performed afford a fair index of all deaths, for throughout the epidemic of influenza and its outbreak of pneumonia approximately one half of all who died were examined after death. The relation of autopsies to deaths is shown by a comparison by weeks of the number of deaths and number of autopsies during the months of September and October.
| WEEK | DEATHS | AUTOPSIES |
|---|---|---|
| Sept. 1–7 | 1 | 1 |
| Sept. 8–14 | 1 | 1 |
| Sept. 15–21 | 4 | 3 |
| Sept. 22–28 | 15 | 14 |
| Sept. 29–Oct. 5 | 121 | 67 |
| Oct. 6–12 | 191 | 78 |
| Oct. 13–19 | 78 | 43 |
| Oct. 20–27 | 22 | 15 |
| Oct. 28–31 | 8 | 6 |
| 441 | 228 |
For most of these autopsies there is a record of the date of onset of the illness, namely, influenza, which finally resulted in pneumonia and death. Comparison of the number of cases of influenza which developed on any day with the number of fatal cases which had their onset on the same day will determine the mortality of influenza at different periods of the epidemic. Chart 1 shows the number of cases of influenza which had their onset on each day from September 1 to October 31 and the number of fatal cases with autopsy which had their origin on corresponding days. The comparison by weeks between autopsies and total number of deaths shows that the autopsies represent with considerable accuracy the deaths. If there is any error it occurs at the height of the outbreak of pneumonia from September 29th to October 5th and not at its beginning, or end. The chart shows that the highest mortality occurred among cases of influenza which had their origin at the beginning of the epidemic from September 21 to October 1, whereas after October 1, though the maximum number of cases of influenza occurred on October 3, very few developed fatal pneumonia.
Mortality from Pneumococcus and Streptococcus Pneumonias.—By referring fatal cases of streptococcus pneumonia back to their date of origin it is possible to determine what proportion of the cases of influenza, which developed on any day, died with infection by hemolytic streptococcus. The accompanying chart (Chart 1) shows that infection with hemolytic streptococci has been very frequent at the beginning of the epidemic of influenza (shown by area with double hatch in chart) that is, from September 20 to 30 and subsequently has gradually diminished so that few cases have had their onset in the second half of the epidemic from September 30 to October 15.