Of the first group, those cases of epidemic influenza not showing pulmonary lesions, we will have very little to say, in as much as the pathological investigations of them is impossible, or nearly so, during the height of the disease.
Such cases apparently do not die at this period. I am willing to admit that individuals without pulmonary involvement may succumb, but I question whether their death has been due to the result of the influenzal lesions, be it in nose, pharynx, larynx or trachea, or be it in the intestine, but rather that the fatal termination occurred later in the course of this complex disease, when distant vital organs became involved or incapacitated in a toxemia or secondary bacterial invasion. We must clearly distinguish these cases from the clear-cut ones of epidemic influenza, looking upon the new circumstances as complications aside from the original disease. Such, for example, is the case we have mentioned where a fatal streptococcus bacteriæmia followed in the wake of an otitis media. In our experience we have not had a fatal case of the acute epidemic disease in which the lung was not involved.
In types of epidemic disease such as we have just had, where the epidemic wave has passed over in a period of four or five weeks, there is always much to be regretted which has been left undone. We tried as far as possible to gain all the information available at the time of collecting our materials and of laying aside such of the work which could be accomplished at a subsequent date. The materials were collected from divergent sources in the cadaver, and the more perishable substances were analyzed immediately. During the period of the epidemic 32 autopsies were performed and as much use as possible was made of each for a thorough comprehension of the lesions.
Materials
During the period of our work 639 patients were admitted to the hospital suffering from clinical influenza. The cases varied in type from the very mild to the extremely ill. The majority of the cases were of the type of “three-day fever.” Clinically 81 cases developed pneumonia, and of these, 35 died. It would, of course, be impossible to say how many other individuals had a pulmonary involvement which could not be recognized clinically. In fact, some of the cases which did come to autopsy were only recognized as having a pulmonary involvement when the lungs were examined outside of the body. The physicians freely admitted that the physical signs were quite unusual and unlike those of the ordinary forms of pneumonia. In fact, except for the fact that we were living in the midst of an epidemic of respiratory infections, there was nothing to make the clinician suspect that many of these cases had a pulmonary involvement. Obviously, when the recognized signs of different types of pneumonia made their appearance, the clinician did not fail to make proper interpretation of the lung involvement. This, as we shall discuss later, is an event superadded to a lung condition which pathologically must be recognized as pneumonia (inflammation) and which differs so decidedly from what we know of as croupous or lobar pneumonia, as well as ordinary broncho-pneumonia that it would be incorrect to include them under this heading, although the distribution of the lesion may have lobar, bronchial or lobular characters.
TABLE I
| Date 1918 | Patients Admitted | Patients Discharged | Cases in Hospital | Deaths | |
|---|---|---|---|---|---|
| October | 5 | 65 | 0 | 65 | 0 |
| 〃 | 6 | 23 | 0 | 88 | 0 |
| 〃 | 7 | 61 | 0 | 149 | 0 |
| 〃 | 8 | 77 | 0 | 225 | 1 |
| 〃 | 9 | 42 | 1 | 266 | 0 |
| 〃 | 10 | 35 | 1 | 300 | 0 |
| 〃 | 11 | 9 | 0 | 307 | 2 |
| 〃 | 12 | 2 | 16 | 290 | 3 |
| 〃 | 13 | 10 | 0 | 298 | 2 |
| 〃 | 14 | 1 | 18 | 278 | 3 |
| 〃 | 15 | 4 | 13 | 266 | 3 |
| 〃 | 16 | 9 | 23 | 248 | 4 |
| 〃 | 17 | 10 | 19 | 235 | 4 |
| 〃 | 18 | 16 | 34 | 217 | 0 |
| 〃 | 19 | 38 | 29 | 225 | 1 |
| 〃 | 20 | 27 | 0 | 252 | 0 |
| 〃 | 21 | 37 | 43 | 245 | 1 |
| 〃 | 22 | 33 | 7 | 270 | 0 |
| 〃 | 23 | 14 | 20 | 263 | 2 |
| 〃 | 24 | 20 | 17 | 266 | 0 |
| 〃 | 25 | 27 | 21 | 272 | 0 |
| 〃 | 26 | 10 | 29 | 250 | 0 |
| 〃 | 27 | 18 | 3 | 265 | 1 |
| 〃 | 28 | 10 | 31 | 243 | 3 |
| 〃 | 29 | 6 | 16 | 231 | 0 |
| 〃 | 30 | 11 | 27 | 215 | 1 |
| 〃 | 31 | 2 | 15 | 202 | 2 |
| November | 1 | 2 | 18 | 185 | 0 |
| 〃 | 2 | 4 | 18 | 170 | 1 |
| 〃 | 3 | 5 | 1 | 174 | 0 |
| 〃 | 4 | 2 | 19 | 156 | 1 |
| 〃 | 5 | 5 | 0 | 161 | 0 |
| 〃 | 6 | 4 | 16 | 149 | 0 |
| Admissions. | 639 | 35 | |||
The individuals admitted to this hospital were obtained from the two military camps at the University of Pittsburgh and the Carnegie School of Technology. All of them were enrolled in the army service and ranged from the ages of 18 to 30. They were vigorous individuals, who had passed their physical examinations for the army. The epidemic made its appearance in these camps on October 2, rapidly ascending from a report of two ill on October 2, four on October 3, eight on October 4, to 65 on October 5. On October 11 there were 307 cases in the hospital.
Of these cases 35 died, the day of death being indicated in the following table.
TABLE II