| Influenza and Pneumonia Mortality in the United States Registration Area for Each Year Since 1900. | |||
|---|---|---|---|
| Year. | Annual death rates per 100,000. | ||
| Pneumonia. | Influenza. | Combined diseases. | |
| 1900 | 158.6 | 22.8 | 181.4 |
| 1901 | 133.5 | 32.2 | 167.7 |
| 1902 | 124.7 | 10.1 | 134.8 |
| 1903 | 122.6 | 18.5 | 141.1 |
| 1904 | 136.3 | 20.2 | 156.5 |
| 1905 | 115.7 | 18.8 | 134.5 |
| 1906 | 110.8 | 10.3 | 121.1 |
| 1907 | 120.8 | 23.3 | 144.1 |
| 1908 | 98.8 | 21.3 | 120.1 |
| 1909 | 96.3 | 13.0 | 109.3 |
| 1910 | 147.7 | 14.4 | 162.1 |
| 1911 | 133.7 | 15.7 | 149.4 |
| 1912 | 132.3 | 10.3 | 142.6 |
| 1913 | 132.4 | 12.2 | 144.6 |
| 1914 | 127.0 | 9.1 | 136.1 |
| 1915 | 132.7 | 16.0 | 148.7 |
| 1916 | 137.3 | 26.4 | 163.7 |
At best our information for these years is unsatisfactory. It is greatly to be desired that individuals who have access not only to the current medical literature, but also to the vital statistics and other records for all countries possessing reliable records, and who are versed in the newer mathematical methods of demography, establish definitely the influenza prevalence and distribution during these interpandemic years. The difficulty in this work is that mortality statistics are unreliable and morbidity statistics are lacking.
Influenza in 1915–1916.—Until the end of 1915 there was no widespread distribution in the United States similar to that of 1900 and 1901, but at that time there developed a widespread epidemic in this country of similar or possibly slightly greater severity than that of fifteen years previously. Reference to the last table will show that during 1916 the annual death rate from influenza as reported in the United States Vital Statistics reached the rate of 26.4 per 100,000. According to V. C. Vaughan the literature of that time shows that this epidemic originated in the West, first attracting attention at Denver, and gradually spread over the country.
Dr. Dublin of the Metropolitan Life Insurance Company gives the following table in which the deaths from influenza and pneumonia during the months of December, 1914, and January, 1915, are compared with deaths from the same cause during the months of December, 1915, and January, 1916:
| Name of city | Deaths reported as due to influenza. | Deaths reported as due to pneumonia. | ||
|---|---|---|---|---|
| In 1915–16. | In 1914–15. | In 1915–16. | In 1914–15. | |
| Baltimore | 57 | 12 | 219 | 101 |
| Cincinnati | 81 | 2 | 105 | 84 |
| New Orleans | 97 | 44 | 35 | 29 |
| New York | 494 | 62 | 2,067 | 1,207 |
| Philadelphia | 324 | 62 | 564 | 272 |
| Providence | 38 | 3 | 31 | 31 |
| Total | 1,091 | 185 | 3,021 | 1,724 |
Dublin states that the Industrial Department of the Metropolitan Life Insurance Company, covering the entire country and embracing ten millions of people, had deaths in the periods above mentioned, as follows:
| In December, 1914, and January, 1915, the number of deaths attributed to influenza was | 165 |
| While in the corresponding months of 1915–1916 the deaths attributed to influenza were | 957 |
| The deaths attributed to pneumonia in December, 1914, and January, 1915, were | 1,468 |
| While the number of deaths attributed to the same cause in December, 1915, and January, 1916, were | 2,563 |
Coffey and others have reported an epidemic of influenza at Worcester, Mass. during the first three weeks of January, 1916. During the first three weeks of January, 1915, there were reported in that city twenty-two deaths from respiratory diseases, making a total of 14.9 per cent. of the total deaths. In the same period of 1916 there were reported ninety-three deaths from acute respiratory diseases in the same population.
Two of the more complete descriptions of the epidemic of the year 1915–16 are those by Mathers, and by Capps and Moody. Mathers reports that: “During the winter of 1915–1916 the United States was visited by a severe epidemic of acute respiratory infections which resembled in every detail the great epidemic of 1890. This outbreak was apparently first noticed in the Middle Western States, and it spread rapidly over the entire country, taking a heavy toll of human life. December and January were the months in which these infections were most prevalent, and the epidemic had almost completely lost its impetus by March, 1916. During the height of this epidemic in Chicago, sixty-one cases of the disease were studied bacteriologically, and the results form the basis of this paper.”
Mathers found hemolytic streptococci in forty-six instances, in all of which they predominated. Green producing streptococci were found thirty times, with one pure culture, and pneumococci thirty times with four pure cultures. Staphylococci were isolated in fifty cases; Micrococcus catarrhalis in six, and Friedländer’s bacillus in one case. The influenza bacillus was found in only one instance, and then in small numbers. The majority of the patients were studied early in the course of the disease, and in the earliest, hemolytic streptococci were almost constantly found, especially in the throat. In the atypical pneumonia which followed many of the attacks of grip, hemolytic streptococci predominated. In none of these was the Bacillus influenza found.