“‘The epidemic of influenza in the spring was a very mild one, so far as we can judge. The disease did not last more than a few days in most cases. The recent epidemic (October, November, December and January) has been much more severe, often lasting two or three weeks.’
“Only one death, which occurred on May 14th, was reported from Hongkong in the spring. In the later epidemic the deaths reported were as follows: October, 70; November, 95; December, 67. The first of these deaths occurred on October 5th. The figures for January had not been compiled, but the disease was diminishing.
“Dr. C. W. McKenny of Hongkong has kindly furnished me with the following facts: ‘During the first five months of 1918 there were twenty-two admissions for influenza to the Civil and Tung Wa hospitals (3 in May). In June there were 269 cases with three deaths. In July, August and September, 43 cases; and during October-November, 130 cases with four deaths....
“‘The June epidemic in Canton appeared first at the Pui Ying School, then among the employees of the Post Office, the staff of the Canton Hospital, the Canton Christian College, and the Kung Yee Hospital. The other schools entirely escaped. Eleven days were taken by the disease to spread from one part of the city to the various other parts.’”
Plague appeared in the north of China in 1917, originating apparently in inner Mongolia. The spread extended over quite an area, and it is reported that this epidemic of pneumonic plague has been more extensive than any since that of 1910–11. The disease was first reported prevalent in Patsebolong December 6, 1917. The diagnosis was confirmed bacteriologically, and there can be little doubt but that the cases of plague reported in various parts of China even up to March 18th were true plague, and not unrecognized influenza.
SECTION III.
In the following section of our report we shall have frequent occasion to refer to a series of investigations conducted by the author in the City of Boston during the 1920 influenza epidemic. We will explain in some detail at this point the nature of the work done and the methods used, in order that the subsequent references will be readily intelligible.
An Investigation of Influenza in Boston During the Winter of 1920.
Following every widespread epidemic interest centers in the question as to how much havoc the disease has wrought, what proportion of the population fell victim, and how many of these died. With regard to influenza the vital statistics of all countries are decidedly insufficient in furnishing this information.
In nearly all countries influenza is not a reportable disease. Usually, as was the case in the United States in 1918, the disease was made reportable during the epidemic, but this took effect usually at least two weeks after the epidemic had started in a community. Further, there is probably not a single community in which the reported cases of influenza reach to anywhere near the total of actual cases. The question of diagnosis, which is not always easy even in the presence of a pandemic, causes some physicians to hesitate to report cases. Other physicians “play safe” and report nearly everything as influenza. Finally, in the period of an epidemic, the physicians are so pressed with caring for the sick that they very naturally neglect to report cases as they occur.