Very early in the course of our study of throat cultures at Camp Pike, the great frequency of abundant growths of B. influenzæ was observed. Consequently, the throat cultures of all measles patients examined from September 15 to October 20 were studied for the identification of B. influenzæ. In all cases identification was based on the cultural, staining and morphologic characteristics. Tests for growth on hemoglobin free media were not made as a routine.
Relation of Measles and Pneumonia Following Measles to the Influenza Epidemic.—The influenza epidemic at Camp Pike was recognized on September 23 because of an alarming increase of hospital admissions. It ran its brief course, and ten days later, October 3, the decline began. The first four days of October rank highest in admissions of patients with pneumonia following influenza. The onset of 20 scattered cases of measles occurred before September 25, and later the number slowly increased reaching its height about the middle of October; after this time a gradual decline began, and continued during about three weeks before the preepidemic level was reached. During this period of six weeks following September 25, 709 cases of measles occurred.
| Table LVIII | ||
|---|---|---|
| Onset of Measles and of Pneumonia Following Measles by Weeks from September 11 to December 11, 1918 | ||
| DATES | MEASLES | PNEUMONIA FOLLOWING MEASLES |
| Sept. 11 to 17 | 18 | 0 |
| Sept. 18 to 24 | 20 | 0 |
| Sept. 25 to Oct. 1 | 74 | 0 |
| Oct. 2 to 8 | 143 | 13 |
| Oct. 9 to 15 | 178 | 9 |
| Oct. 16 to 22 | 158 | 16 |
| Oct. 28 to 29 | 100 | 6 |
| Oct. 30 to Nov. 5 | 56 | 3 |
| Nov. 6 to 12 | 38 | 4 |
| Nov. 13 to 19 | 23 | 1 |
| Nov. 20 to 26 | 29 | 1 |
| Nov. 27 to Dec. 3 | 22 | 1 |
| Dec. 4 to 10 | 8 | 1 |
| Dec. 11 | 0 | 1 |
Pneumonia following measles began to appear on October 5, and within the week following 16 cases occurred. An equal number of cases appeared each week during about three weeks and fewer scattered cases occurred throughout November and December. Table LVIII shows date of onset of measles and measles pneumonia cases.
Chart 3 presents the occurrence of measles and of the pneumonia following measles by weeks of onset compared with that of epidemic influenza.
Chart 3.—Shows the relation of the epidemic of measles to that of influenza at Camp Pike, and the relations of the pneumonia following measles to both measles and influenza. The large incomplete curve represents influenza; the intermediate curve, measles; the small curve, pneumonia following measles.
It will be noted from the overlapping of the two curves in Chart 3 that a considerable portion of the measles cases appeared before the influenza had subsided in Camp Pike. This occurrence of the two epidemics at the same time makes it impossible to separate the parts played by each disease in producing the pneumonias and other complications following measles. Analysis of the chart, however, shows that the pneumonia with measles occurred in large part during the first half of the measles epidemic. This is of particular significance since it was during this period that the effects of the influenza wave were felt most severely.
In Table LIX the cases of measles are grouped into fifteen day periods according to their dates of onset and the pneumonias arising from each group are tabulated. This tabulation shows very clearly that the pneumonia complications developed in large part in patients with measles entering the hospital during the influenza period, that is, late in September and during the first half of October.
| Table LIX | ||||||
|---|---|---|---|---|---|---|
| Patients with Measles and with Subsequent Pneumonia | ||||||
| DATES | TOTAL CASES OF MEASLES DURING INTERVALS OF 15 DAYS | TOTAL CASES PNEUMONIA FROM SAME | OF PER CENT INCIDENCE OF PNEUMONIAS | |||
| Sept. 11 to 30 | 86 | 433 | 14 | 42 | 16.28 | 9.7% |
| Oct. 1 to 15 | 347 | 28 | 8.07 | |||
| Oct. 16 to 31 | 270 | 434 | 8 | 14 | 2.96 | 3.2% |
| Nov. 1 to 15 | 91 | 2 | 2.2 | |||
| Nov. 16 to 30 | 56 | 4 | 7.15 | |||
| Dec. 1 to 15 | 17 | 0 | ||||