Excerpts on the Influenza and Pneumonia Pandemic of 1918
ANNUAL REPORT OF THE SURGEON GENERAL
FOR FISCAL YEAR 1919
VOLUME I
INFECTIOUS DISEASES
II. INFLUENZA, PNEUMONIA, AND COMMONRESPIRATORY
DISEASES
CONTENTS
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1. STATISTICAL DISCUSSION.
The respiratory disease group, including lobar and broncho-pneumonia, influenza with its various complications, and the common respiratory diseases, classed here as "other respiratory" (including bronchitis, acute coryza, acute tonsillitis, acute pharyngitis, and acute nasopharyngitis, laryngitis, and pleurisy), were the most important diseases with which the Medical Department of the Army as well as the civil authorities of this country and of the entire world, had to contend with in the year 1918. The one disease of this class which was of particular importance in this country, as well as elsewhere on account of the numerous deaths which it, together with its complications caused, was influenza. Never before, at least not since the Civil War, had the Army such a scourge of respiratory diseases to combat. Before considering in detail these diseases for the year 1918, it is of interest to review the history of them since the year 1862.
Tables 370 and 371 and figure 99 give the figures and show the comparative rates for common respiratory diseases, influenza, and pneumonia, with the total for this class of diseases both for admissions and deaths for the years 1862-1918, inclusive. In comparing the rates
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for the earlier years it is probable that the death rates are more reliable than the admission rates. Many cases of admission were apparently not reported unless they were serious cases.
In considering the rates for pneumonia during the Civil War it is to be recalled that many cases of pneumonia which resulted from attacks of measles or other infectious diseases were charged to primary pneumonia. This was due to the inability to connect the cases in general hospital with those at the original place of admission and so connect the diagnosis of final disease with the primary disease. Consequently the death rate for primary pneumonias was higher than the cases warranted. The admission and death rates for pneumonia as well as "other respiratory diseases" increased during the Civil War, though not in proportion to the total rates for the admissions or deaths. As is stated elsewhere, the one great class of disease that caused so many admissions and so many deaths during the Civil War was the gastro-intestinal.
In the year 1862 the death rate for total respiratory disease was 8.40 per 1,000. It was practically stationary in 1863, showing a slight decline, with a considerable increase in 1864 to 10.28. After this year the rate began to decline, it was 9.17 in 1865, 5.04 in 1866,and 2.20 in 1867. After the year 1866 no death rate for total respiratory diseases reached a point of 2 per 1,000 until the year 1918. Following 1867 the highest death rates for total respiratory diseases was in the following year 1868, when it was 1.66 and in1890 when it was also 1.66.
Influenza, or epidemic catarr b (as it was thus called), which was reported as a cause of admissions during the Civil War, was reported each year from 1862until the present time. No deaths were attributed to influenza or epidemic catarrh from the year 1865 until the year 1890 with the exception of one case in1873. Between 1890 and the present time there was a number of years when no deaths were charged to this disease. The death rates reached a lower level than they had during the `60s and earlier `70s in the year 1873. From that year forward we find that the total death rates were markedly influenced by the death rates for pneumonia and respiratory diseases. The rise in admission rates for pneumonias or respiratory diseases were not always followed by an increased death rate. During these years the Army was small and scattered in small frontier posts. In 1880 the death rate for pneumonias rose to 1.33. In the preceding year it had been 0.75. The death rate for total respiratory diseases was 1.42, whereas in the preceding year it had been 0.92. The total admission rate for disease for the year 1880 showed a slight increase over that for the preceding year. After this year there was a decline in the death rate for respiratory diseases with also some decline in the admission rate which varied from year to year. It was in 1888, before it was recognized that influenza was epidemic in the United States (1889 or 1890 epidemic), that a marked rise occurred in the death rate for pneumonia. This rate for 1887 for respiratory diseases had increased to 1.02 from 0.77 in the preceding year. In 1888 it showed further increase to 1.50, of which 1.42 was attributed to pneumonia. In these two years preceding the historic influenza epidemic of 1889 and 1890 there was an increase in the admission rates for ordinary respiratory disease with an
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increase in the admission rate for pneumonia, but a decrease in the admission rate for influenza. In 1889, the first historic influenza year, the death rate for respiratory diseases declined from 1.50 of the preceding year to 0.74. There was also a decline in the admission rate for common respiratory diseases and for pneumonia, while the admission rate for influenza was practically stationary. It was 1890 that it was first recognized that the epidemic of this period was present in the Army. Consequently the admission rate for influenza increased from 27.63 of the preceding year to 189.44 for 1890. There was at the same time some decrease in the admission rate for ordinary respiratory diseases and some decrease in the admission rate for pneumonias. The death rate for respiratory diseases for this year showed a slight increase over that of the preceding year, being 0.82 as compared with 0.74. In this year 14 deaths with a rate of 0.52 were charged to pneumonia and 6 deaths with a rate of 0.22 to influenza. The most marked increase occurred in the death rate in 1891. This year the admission rate for influenza declined from what it had been in the preceding year, 189.44, to 155.61. The admission rate for common respiratory diseases increased as, did the rate for pneumonia. The total rate for all respiratory diseases was practically stationary, being 306.22 in 1890 and 305.30 in 1891. Of the 44 deaths reported in 1891 with a rate of 1.66, 20 were charged to primary pneumonia with a rate of 0.76 and 22 to influenza with a rate of 0.83. After 1891 the death rate as well as admission rate for respiratory diseases declined.
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Fig. 101. Influenza By Camps, 1918, Ration per 1000
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Fig. 102. Pneumonia, Influenza and Other Respiratory Dis. By Camps, 1918, Ratio per1000
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Table 296.- Influenza uncomplicated, 1918.
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Table 297.- Influenza with broncho-pneumonia, 1918.
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Table 298.- Influenza with lobar pneumonia, 1918.
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Table 299.- Influenza with other complications, 1918.
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Table 300.- Broncho-pneumonia, 1918.
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Table 301.- Lobar pneumonia, 1918.
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Table 302.- Pneumonia (all)-(Broncho-pneumonia, lobar pneumonia), 1918.
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Table 303.- Other respiratory diseases, 1918.
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In the annual reports of the Surgeon General of this period there are many comments of much interest. In the discussion for the year 1887 there was some remark relative to the prevalence of the respiratory diseases. It was recorded that bronchitis was the cause of admissions in 1,643 cases, or 60 percent of the admissions for the diseases of the respiratory tract and that pneumonia was charged with 99 cases, of which 26 percent proved fatal. The next year, while it was not recognized that an epidemic of influenza existed, still it was recognized that the respiratory diseases were above the average, and more space is devoted to the discussion of these diseases. It is stated that catarrh and bronchitis troubles occasioned in the Army an admission rate of 104.62.
One remark that is of especial interest was:
Attention is invited to the fact that but for the exceptional occurrence of so many cases at Fort Robinson, the preponderance of cases of this dangerous disease (pneumonia) occurred at the recruiting depots; and the lesson to be learned from this is the same that has already been taught by the study of the statistics for the year, that if we desire to have a healthy Army we must look after the well-being of the recruit.
It was recognized in 1890 that the epidemic of influenza was present. We find recorded in the discussion of the sickness for this year that-
The epidemic of this disease, the so-called grippe, was developed in Boston and New York during the last week of December, 1889, and thence it spread with few exceptions to our military stations during the course of January and February, 1890. The epidemic reached its height at a given place on an average of 12 days from its invasion and lasted about 30 days. During the visitation from 5 to 90 percent, average about 33 percent, of each affected command suffered, but it prevailed as extensively among the camp attaches and in the neighboring civilian settlements as at the posts. At a few of the stations the medical officers did not recognize the presence of this disease. At some of these stations the medical officer is positive in his assertion that no epidemic of influenza was felt. Nevertheless it is possible that the disease may have visited some of the posts mentioned without leaving its mark upon the records. The note worthy symptoms affecting the nervous system were frontal headache, lumbar pains, aching in the lower limbs, insomnia, and prostration. Nasal, laryngeal, pharyngeal, or bronchial catarrhs were essentials; an accelerated action of the heart was followed by depression. Temperature ranged from 100oF. to 104.6o, and in one case, with secondary pneumonia, to 105.8o. Anorexia, nausea; vomiting, and constipation were generally present. The complications were bronchitis, pleurisy, pneumonia, inflammation of the middle ear, and erysipelas of the head. Relapses or recurrences were not uncommon. Convalescence was often protracted. Early in the year, and while the details of the epidemic were fresh in memory, a call was made by this office for special reports from every military station; and that the reports might be susceptible of comparison one with the other certain points were presented for special investigation and report.
Among the theories relative to the spread of the disease was the following:
The disease traveled westward notwithstanding a west wind and its invasion was later in the season in proportion to the length of stage travel to reach the post. The more distant posts escaped the epidemic entirely. An epidemic wave was wholly inconsistent with the facts and the propagation could be explained only on the assumption of a personal contagion carried from place to place by rail oro ther means of personal transportation.
For 1891 it is reported that-
The epidemic subsided during the warmer months but reappeared in November and December.
At some of the posts the cases were milder and others more severe than those of 1890. It will be noted that this was the year that the highest death rate occurred.
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From Fort Sidney, Nebr., it was reported that-
Epidemic influenza, or catarrh, did not reach us until last March. Its visit was of short duration (from the 16th of March until the 8th of April), and on the whole quite mild in character, the majority of the patients being incapacitated but a few days. It was complicated with lung troubles in only four cases, two of pneumonias terminating favorable and two of capillary bronchitis were both fatal. The symptoms in the main were intense headaches of a congestive character, pains in all the limbs, in the back and groins, and a temperature of about 103o of 36 or 48 hours` duration, and in many cases after convalescence was established a severe pain in the region of the spleen which frequently lasted for over a week. The tongue was generally clean and the bowels natural in character. Great prostration followed in all well-defined cases.
A number of reports were furnished which were quoted in the annual reports of that period describing the symptoms in detail, which were almost identical with those quoted in the two preceding quotations. Most of them mentioned the occurrence of complicating pneumonia though the proportion of cases so complicated was apparently small.
The surgeon from Fort Missoula, Mont., reported that-
There occurred five cases of pneumonia among the adults in the post and two in the vicinity. The pneumonia was croupous but markedly different from the affection as usually seen. Four in the post and two outside were markedly light in all respects; only one, fatal, was severe. In the light cases constitutional disturbance was slight, fever not going above 103o,usually 101 1/2o or 102o, Rusty or blood-streaked tenacious sputum was expectorated by the second day, quickly changing in all but one case, to a whitish frothy muco-pus. The consolidated areas presented marked variations. In each case there was but one part of a lobe affected and there was a band or zone of consolidation about 2 inches thick and about 2 inches above the base. In three cases the signs were found posteriorly, and yet anteriorly no adventitiouss ounds whatever could be heard. In one an area of consolidation 2 inches wide across the right chest, inclosing the nipple, was very marked, but posteriorly every sound was normal. This consolidated area presented throughout the disease all the signs of lobar pneumonia in its various stages, excepting that it was apt to give more marked bronchial breathing and increased vocal resonance than the dullness would account for. Broncho-pneumonia might present these symptoms, but this disease can be excluded because of the total absence of a primary bronchitis, and the fact that though it was secondary to a disease similar to influenza, there were none of the usual precursors of pneumonia. The rusty sputum is very rare in broncho-pneumonia, and the postmortem examination of the fatal case showed typical lobar pneumonia of the whole of the right lung and a middle portion of the left lung; the left lung presented, ante mortem, all the signs found in the other cases.
For the year 1892 it is reported that "Of influenza there were 1,793 cases reported. Many posts reported no such cases, but these had usually an increased rate for catarrh and bronchitis."
In the year 1893 it is reported that "the outbreaks of influenza occurred in November and December." The admission rate declined in 1894, but it was reported at Jefferson Barracks that "many cases were complicated with catarrhal pneumonia." At West Point "the characteristic features of the epidemic were severe spasmodic cough, tracheal or bronchial, and the frequent occurrence of otitis media." After 1894 the epidemic, as such, apparently disappeared from the Army.
It can be said, then, that after the close of the Civil War and certainly after the early seventies, no marked epidemic of influenza or pneumonia occurred in the Army until the epidemic of 1889 and 1890. This epidemic apparently began in 1887 and continued during 1888, showed a decline in death rate in 1889, with an increase in 1890, when it was first recognized and rose to the high point of the epidemic in 1891.
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During the Spanish-American War there was some increase in the death rate for respiratory diseases. In 1898 it was 0.98, as compared with0.31 in the preceding year. In 1899 it was 1.02 and in 1900 it showed a rather marked decline to 0.48. After this time the rate for deaths, as well as for admissions for pneumonias and "other respiratory diseases," showed a general tendency to decline, with some fluctuations from year to year. In 1917the death rate for total respiratory diseases increased to 1.71. The admission rate for this class of disease for this year also increased, being 253.46 and127.12 in 1916.
UNITED STATES, BY MONTHS.
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TABLE 308.- Influenza with lobar pneumonia-Admissions, 1918-Absolute numbers and ratios per 1,000-United States total.
TABLE 309.- Influenza with others-Admissions, 1918- Absolute numbers and ratios per 1,000- United States total.
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TABLE 310.- Broncho-pneumonia and pneumonia unclassified-Admissions, 1918- Absolute numbers and ratios per 1,000- United States total.
TABLE 311.- Lobar pneumonia -Admissions, 1918- Absolute numbers and ratios per 1,000- United States total.
TABLE 312.- Broncho-pneumonia and lobar pneumonia-Admissions, 1918- Absolute numbers and ratios per 1,000- United States total.
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TABLE 314.-Influenza (all), pneumonia(all), other respiratory diseases-Admissions, 1918-Total cases United States-Absolute numbers and ratios per 1,000.
During the fall of 1917, after the camps were filled with drafted men, acute epidemic diseases swept through a number of them. Measles was one of the most prevalent and one of the most fatal of the infectious diseases that occurred. It was noted during the fall and early winter that there were a number of cases of pneumonia which were unlike the pneumonia that ordinarily occurred. This was apparent both to the physicians in civil life and in the Army camp. It was reported by all classes of practitioners that numerous cases of pneumonia were occurring which resembled the pneumonia following measles but occurring among men who had not had measles recently. In a number of the camps, both in the North and in the South, rather extensive epidemics of pneumonia occurred and a number of deaths resulted. The same variety of pneumonia occurred in the late winter and spring of 1918. In many of the camps pneumonia was practically epidemic during March and April. In many camps a number of cases occurred later in the spring and summer. It was again reported by a number of medical men that these cases of
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pneumonia that were occurring were different from the types of pneumonia ordinarily encountered and very similar to pneumonia following measles but again that the cases occurred among men who had not had measles recently. The pneumonias were very difficult to type and classify both in the fall and winter of 1917 and in the early part of 1918. A number of reports were received indicating that many cases would be reported to the Surgeon General`s Office as unclassified pneumonias. This report was so frequent that it was decided that it would be advisable to include the term of" unclassified pneumonias" in the list of tabulation terms. Later when the reports were received, it was found that most of the pneumonias had been classified either as broncho or lobar pneumonia. However, the figures for the various camps show the classification varied for the different camps.
During 1917 a large number of cases of influenza had been reported in the United States Army, approximately 40,512. However, it was not apparent at that time that influenza might be present in a fatal epidemic form. Consequently no separate tabulations by camps by months were made for the annual report. It was again observed in the reports received from the camps during the early part of 1918 and especially for the months of January, March, and April that there were many cases of influenza being reported as well as many fatal cases of pneumonia. Few of the influenza cases during the early part of 1918 and practically none during the latter part of 1917 were reported as associated with pneumonia. It was not until later in the year when it was recognized that the fatal epidemic form of influenza was present, that pneumonia was reported as a frequent and fatal complication.
In the preparation of the statistics for this report the statistics were prepared for influenza showing the occurrence by camps for each month for white and colored for influenza with its various complications, for broncho and lobar pneumonia, and for the common respiratory diseases combined in one. Tabulations are included for all of these diseases except "other respiratory" for 1917. Unfortunately time did not permit of the preparation of the statistics for the common respiratory diseases for the latter part of 1917. It will be observed from study of the tables showing for the various camps the occurrence of influenza, pneumonias, and other respiratory diseases that in a large number of such camps as existed during 1917, there was an epidemic of influenza began in October, extended through November, usually decreasing in December with some further decrease in January with a decided decrease in February, and a marked increase either in March or April. It will also be observed that the pneumonias ran a very similar admission course and that the number of cases increased from October through November and December with some decrease in January and February and with a considerable increase in March or April. Furthermore, that a number of cases of influenza were reported during the summer months as well as cases of pneumonia. It will also be noted that during the early part of 1918 there were some cases of pneumonia reported as associated with influenza. From the beginning of 1918it will also be noted that the common respiratory diseases had a rate above the normal, Table 367 shows from 1906 to 1915 the monthly rates for the ordinary respiratory diseases.
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It is apparent that there was a marked difference in the classification of pneumonias at the various camps and that some classified the majority of pneumonias as lobar and some as broncho. Furthermore, that at different periods in the year there was a more pronounced increase in the rate for the common respiratory disease at some camps, while at others there was a more pronounced increase in the rate for influenza.
It was during the early autumn of 1918that the overwhelming epidemic of influenza with the fatal form of pneumonia occurred. The maximum height of the epidemic occurred in September and early October, In many of the camps it began in the latter part of September and ran well into the month of October. In some camps it apparently began in August, though it was not recognized as such at that time. During August a great many of the cases were reported as pneumonia or as "other respiratory." Even during the height of the epidemic the diagnosis returned from the various camps varied materially. Some of them reported very few primary pneumonias, others reported a large number of the pneumonias as primary. For example, in the month of September Devens had an admission rate for lobar pneumonia of 268.24 and broncho-pneumonia 53.43, while Custer in the same month had a rate of 0.65 for primary lobar pneumonia and 51.95 for primary broncho-pneumonia. In October Custer had a rate of 1.90 for primary lobar pneumonia and 192.08 for primary broncho-pneumonia. All of the pneumonias complicating the influenza in September were reported at Custer as bronchopneumonia and practically so all in October, the rate being 344.53 for influenza with broncho-pneumonia in October and 0.95for it with lobar pneumonia. At Devens in September the rate for secondary lobar pneumonia was 236.51 and for secondary broncho-pneumonia 53.70, and in October for secondary lobar pneumonia 19.85 and for secondary broncho-pneumonia 5.11. It is apparent, then, without further illustrations, which could be multiplied many times over, that there was a great lack of uniformity in the classifying of pneumonias, both the primary or secondary forms, even during the height of the epidemic.
There was also great confusion even during the height of the influenza epidemic in the confusion of the diagnosis of influenza with "the common types of respiratory diseases." A few examples will be sufficient. In October Camp Cody reported a rate of 3,833.33for uncomplicated influenza and a rate of 72.78 for the common types of respiratory diseases; Camp Gordon during the month of September reported a rate for uncomplicated influenza of 205.19 and for the common respiratory diseases of933.08.
The only way to obtain a correct picture of the epidemic during the autumn is to combine both the admission and death rates of influenza, of both pneumonias, and of the common types of respiratory diseases. The excess then of the combined rates over the ordinary rates for this class of diseases for the same period of the year will probably give approximately the correct figure for influenza with its complications. From the figures and charts it appears probable that an epidemic of influenza of a fatal type was present in the camps during the latter part of 1917, decreased during December with still further decrease in January and February, with a marked increase in March and April, and that the influenza with pneumonia was present through-
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out the summer months. With the advent of the chilly damp weather of the autumn, the overwhelming epidemic occurred. Incomparing the figures of the various camps many factors must be considered-the population of the camp, the housing, the degree of crowding, the weather conditions, and many other factors, the value of which it is difficult or impossible to estimate.
Influenza, together with its complications, is charged with 688,869 admissions for the Army, including officers and enlisted men, American and native troops, for the year. The total rate was 273.52. Probably many of the ordinary acute respiratory diseases, as well as many cases diagnosed as pneumonia, should have been charged to influenza. This disease, with its complications, also caused 23,007 deaths for the entire Army, officers and enlisted men, American and native troops, which gave a rate of 9.14. In addition to this number of deaths there were 431 charged to bronchitis, 6,814 to bronchopneumonia, 8,407 to lobar pneumonia and 450 to pneumonia unclassified, a great many of which no doubt should have been charged to influenza. In addition to this number there were 262 charged to pleurisy. If these deaths were added to the deaths from influenza the total would be 39,371.If the number of deaths which were charged to the ordinary respiratory diseases, which as a rule were complicated by pneumonia and amounted to 330, be added to the figure above for the other respiratory diseases, it would give a grand total of 39,701 in one year out of a strength of 2,518,499 men charged to acute respiratory diseases, a rate of approximately 15.75 per 1,000. The total deaths for diseases for the Army for the year amounted to 47,384. Approximately 82 percent of all the deaths were then attributed to the acute respiratory diseases. If this death rate of 15.75 per 1,000 should be deducted from the total death rate for disease, 18.82 for the Army for the year, it would leave the exceedingly low rate of 3.07 for the year.
EUROPE, BY MONTHS,
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[TABLE] 316.-Influenza uncomplicated-Admissions,1918-Absolute numbers and ratio per 1,000-Europe.
TABLE 317.-Influenza andbroncho-pneumonia-Admissions,1918-Absolute numbers and ratio per 1,000-Europe.
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TABLE 319.-Influenza with others-Admissions,1918-Absolute numbers and ratio per 1.000-Europe.
TABLE 321.-Lobar pneumonia-Admissions,1918-Absolute numbers and ratio per 1,000-Europe.
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TABLE 322.-Pneumonia (all)-Admissions,1918-Total cases Europe-Absolute numbers and ratios per 1,000.
TABLE 323.-Other respiratory diseases-Admissions,1918-Absolute numbers and ratio per 1,000-Europe.
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Considering influenza alone, this disease was reported to have caused for enlisted men, American troops 657,405 admissions, a rate of 276.27, or 28.26 percent of the total. In the United States the number of cases was 473,279, rate of 361.21, or 27.9 percent of the total; in Europe 167,141 admissions, a rate of 167.19 or 28.99 percent of the total; in Philippine Islands, 1,402 admissions, a rate of 189.95 or 18.45 percent of the total; in Hawaii, 862 admissions, a rate of 118.81 and 19.63 percent of the total and in Panama, 2,792 admissions, a rate of 336.95 or 35.61 percent of the total. The order of admission rate would then stand: United States, Panama, Philippine Islands, Europe and Hawaii. For officers the number of admissions were 23,813, a rate of 196.35 or 31.82 percent of the total; for officers in the United States, 15,872, a rate of 222.96 or 31.92 percent and for officers in Europe, 7,272 a rate of 155.21 or 31.02 percent of the total. For native troops the admission rate was higher than the admission rate for American troops. There were 7,651 admissions, a rate of 433.07 or 36.61 percent of the total. For native troops the Porto Ricans had the highest admission rate,527.30, Philippine troops stood second with 395.19, and Hawaiians third with 275.94.
This epidemic was in truth a world-wide pandemic affecting heavily the American and native troops wherever they were serving.
For deaths for influenza alone, 22,402 occurred among enlisted men, American troops, a rate of 9.41 or 48.61 percent of the total deaths. For enlisted men in the United States there were 15,749 deaths, a rate of 12.02 or 54.82 percent of the total. In Europe 6,072 deaths, a rate of 6.07 or 37.93 percent of the total. In Philippine Islands only one death occurred, a rate of 0.14, or 3.13 percent of the total. Hawaii had four deaths, a rate of 0.55, or 44.44 percent of the total. Panama had 9 deaths, a rate of 1.09 or 36 percent of the total. The rates then for deaths for American troops by countries would be United States, 12.02; Europe, 6.07; Panama, 1.09; Hawaii, 0.55; and Philippine Islands, 0.14. For officers the total deaths were 518, a rate of 4.27 or 47.31 percent of the total. For those in United States there were 363 deaths, a rate of 5.10 or 54.83 percent of the total and for those in Europe 138 deaths, a rate of 2.95 or 35.48 percent of the total. The death rate for native troops was lower than that for American troops, it being 4.92, and as stated above, 9.41 for American troops. The highest death rate was for the Porto Ricans, 7.80, second for the Philippine troops, 2.84, and third for the Hawaiians, 1.72. The death rates for the native troops were slightly higher than the rates for American troops serving in the same countries.
In addition to the deaths caused by influenza and its complication there were a large number, as stated above, caused by pneumonia, many cases of which were no doubt secondary to influenza. The total deaths attributed to lobar pneumonia for American troops was 8,227,for broncho-pneumonia 6,637, a respective rate of 3.46 and 2.79 and 17,85 percent and 14.40 percent of the total deaths. Of these deaths 4,793 for lobar pneumonia occurred among enlisted men in the United States, and 3,436 of broncho-pneumonia. The rate for lobar pneumonia was 3.66 and for broncho-pneumonia 2.62, with a respective percentage of 6.68 and 11.96 of the total deaths. In Europe for enlisted men for broncho-pneumonia there were 3,068 deaths and for lobar pneumonia 3,007, the rates being 3.07 and 3.01,
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percentage of the total deaths 19.16 and 18.78. In the Philippine Islands for American troops there were 5 deaths for lobar pneumonia and 4 for broncho-pneumonia. In Hawaii one death for broncho-pneumonia, and in Panama 2 deaths for lobar pneumonia. For officers there were 148 deaths for broncho-pneumonia, and 144 for lobar pneumonia, with rates of 1.22 and 1.19and percentages of 13.52 and 13.15, respectively. For officers in United States there were 75 deaths for lobar pneumonia and 66 for broncho-pneumonia, and for officers in Europe 62 deaths for lobar pneumonia and 76 for broncho-pneumonia. The total death rate for the two pneumonia in the United States for enlisted men was 6.28 and for Europe 6.08; for officers in the United States 1.98, and in Europe 2.94, and for the native troops 3.68, and for American troops 6.25.
For loss of time respiratory diseases were also a matter of great importance. From a military point of view the efficiency of the fighting forces depend upon the number of men who were present for duty. The total time lost for influenza amounted to 9,055,659 days for officers and enlisted men, American and native troops. There were constantly absent from duty 9.85 men out of each 1,000 on account of this disease. In addition to this time there were 1,996,118 days charged to bronchitis, 1,347,368days to lobar pneumonia, 745,009 days to broncho-pneumonia, and 54,874 to pneumonia unclassified. About 1,500,000 days were charged to "other acute respiratory diseases," The total time lost for acute respiratory diseases amounted to 14,994,812 days. The average number of men absent each day during the year for this class of diseases amounted to 41,082, almost two divisions of troops.
Of the time lost for influenza, there were 250,174 days for officers, 8,743,102 days for enlisted men, American troops; 62,383 days for native troops. For officers there were146,364 days lost in the United States, 99,231 in Europe, and of American troops 5,469,858 days were in United States and 3,152,990 in Europe. Among the native troops the greatest loss of time, proportionately speaking, was for the Porto Ricans, the noneffective rate being 13.68, and a loss of 40,988 days. Philippine troops stood second, with a rate of 7, a total of 15,275 days, and Hawaiians troops third, with a rate of 4.82, and 6,120 days. For lobar pneumonia, there were 22,498 days lost for officers, and for broncho-pneumonia 19,432 days. In he United States the loss of time for lobar pneumonia for officers was 12,237days, and for broncho-pneumonia 7,617 days, and in Europe for lobar pneumonia9,819 days, and for broncho-pneumonia 11,487 days. For enlisted men, American troops, for lobar pneumonia the loss of time amounted to 1,320,505 days, and for broncho-pneumonia 723,206. In the United States for these troops there were898,340 days lost for lobar pneumonia, and 374,651 days for broncho-pneumonia. In Europe, for lobar pneumonia, 396,699 days were lost, and for broncho-pneumonia 343,621 days.
Combining the figures for influenza, pneumonia, and common respiratory diseases for the year, Camp Eustis, a rather small camp, and one which came into existence late in the year, had the highest rate, 1,314.33; Travis was second, with a rate of 928.16;Funston third, with a rate of 805.32; Dodge fourth, with a rate of 783.70; Pike fifth, with a rate of 746.72; Beauregard sixth, with a rate of 698.78; Taylor had a rate of 68175; Sherman a rate of 677.82; Meade a rate of 647.28, and Syracuse a rate of 636.88. Doniphan, which had a
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rather small strength at this time, had a rate of 497.70. Forrest, Johnston, and Greene, all small camps, had rates of 302.57, 535.55, and 325.19.
The total admission rate for military posts and commands stationed outside of the large camps was 585.87. The total for the United States enlisted men was 572.81. It is apparent, then, that there was very little difference in the rates of occurrence of this disease in the small posts and commands, as compared with the large camps. While it appears that the camps which had the highest admission rates were, as a rule, barrack camps, it is also true that a number of the tent camps had rather small strengths during the period of the fall epidemic, as the divisions organized at the tent camps had gone overseas, and a number of them had not been filled again to their maximum capacity.
Taking the deaths for total respiratory diseases, Eustis stands at the head of the list, with a rate of 43.41; Camp Sherman second, with a rate of 41.63; Humphreys third, a rate of 40.38; Syracuse fourth, a rate of 35.92; Grant fifth, a rate of 34.12; Dodge next, with a rate of 33.07, and then Custer, with a rate of 29.28; Funston, a rate of 28.48, and Beauregard a rate of 28.15. The low death rate was at Camp Shelby, with a rate of 3.43; next at Camp Forrest, a rate of 3.73; then Lewis, a rate of 6.42;Logan, a rate of 7.05; Johnston, a rate of 8.11, and Gordon with a rate of 8.57.
Examining a few of the camps with low rates, we find that Camp Shelby, where the greatest number of deaths for the camp occurred in October, had during this month a very small strength, the mean average strength being 7,502 for enlisted men, when the camp at its maximum strength in August had a strength of 35,110. Camp Lewis, where the height of the epidemic was also in October, had an average strength for the month of 33,750. Logan, which had its highest death rate in September, had a mean monthly strength of 9,353 men, as compared with a maximum of 31,596 in April. At Johnston the strength was about the average of the preceding month, Gordon, where the height of the epidemic was in September and October, had a decline in the strength during this time, although not a very large one, in September the strength being 40,703 and in October 31,928. In August it had been 46,112.
Of the larger camps having a high death rate, all of them, with the exception of Beauregard, were barrack camps and all had large garrisons, with the overcrowding of the barracks during the height of the epidemic. Beauregard was a tent camp and had a smaller garrison during the epidemic than it had during some of the preceding months.
For the troops stationed at posts and commands outside of the large camps the death rate for influenza, pneumonia, and "Other respiratory diseases" was 16.28. The total rate for enlisted men stationed in the United States was 18.53. It is apparent that the death rate for troops stationed in the large camps was a little higher than that for the troops stationed in the small posts and commands. The death rate was also higher in the more crowded camps than in the smaller and less crowded camps, usually the tent camps.
For the troops stationed in Europe the admission and death rates for this class of disease was not as high as for those stationed in. the United States. For the total of this class of diseases in Europe the admission rate was 253.09 and for the troops in the United States577.51. Reports received from Europe indicate that the occurrence
650
rate for this class of disease was higher for troops arriving on transports and for troops in services of supply living in barracks and billets than for the troops in the front-line trenches and advanced areas. As has been pointed out, influenza was probably epidemic in the United States during the latter part of 1917 and early part of 1918. It is also probable that a certain number of the troops in Europe had acquired an immunity to this disease when serving in the camps in the United States before they were sent to Europe. No doubt the troops in the fighting area were less exposed to close personal contact with their comrades than the troops stationed in the rear in the services of supply in billets, or those traveling on transports or living in barracks in the United States. The total death rate for troops serving in Europe for this class of disease was 12.96, as compared with18.53 in the United States, The troops in Europe were men of longer service and more thoroughly seasoned.
UNITED STATES, BYMONTHS,
TABLE 325.-Influenza (all)-Deaths, 1918-Absolute numbers and ratios per 1,000-United States total.
651
652
TABLE 330.-Broncho-pneumonia-Deaths, 1918-Absolute numbers and ratios per 1,000-United States total.
TABLE 331.-Lobar pneumonia-Deaths, 1918-Absolute numbers and ratios per 1,000- United States total.
653
The admission rate in the United States for influenza in January was 145.19. It declined in February to 100.65, increased in March to 226.75, and still further in April, to 362.91. In May it declined to 103.84, in June to 41.72, and in July to 34.11. It began to increase again in August, when it was 38.95, and increased still further in September to 646 and in October to reach its maximum of 1,774.50. There was a decided decline in November to 191.16 and in December to 147.46.
Of the two pneumonias, the primary type of lobar pneumonia had an admission rate in January of 33.38, declined to 20.18 in February, increased to 23.04 in March, decreased to 22.00 in April, to 11.62 in May, to 5.95 in June, to 6.35 in July. It increased to 8.94 in August, to 22.02 in September, to 30.20 in October, and again decreased in November to 5.70 and in December to 6.90. Primary
654
broncho-pneumonia followed exactly the same course. It was 4.60 in January, 2.40 in February, 3.35 in March, 3.81 in April, declined to 2.59 in May, to 1.46 in June, to 1.25. in July, increased to 2.17 in August, to 15.28 in September, to 50.62 in October, when it declined to14.03 in November and 11.11 in December. Of other respiratory diseases the rates ran somewhat a similar course, though with a. decided decline, proportionately speaking, during the autumn epidemic. The rates were as follows: In January, 388.71; February, 252; March, 279.71; April, 235.90; May, 141.37; June, 88.16; July,
Fig. 103 RESPIRATORY DISEASES-ADMISSIONS ANDDEATHS, ENLISTED MEN, U.S. RATIO PER 1000
88.05; August, 98.10; September,180.64; October, 176.64; November, 189.10; and in December, 247.45.
As a matter of historical comparison, it will be noted from Tables 364 and 369 that taking the years 1906 to 1915, inclusive, that the highest rates for influenza, pneumonia, and "other respiratory diseases" found during any of these years for the various months are as follows: January, 351; February, 291.18; March, 322.44; April, 213.66; May, 140.22; June, 91.05; July, 79.93; August, 90.47; September, 97.79; October, 110.43; November, 120.39; and December, 285.81.
655
The rates for each month in 1918 were higher than the highest rate for the corresponding month for any of the years 1906-1915.
In the same way, taking for the two pneumonias the years 1906-1915, giving the highest rate for each month for any of the years in question, we have: In January, 6.05; February, 5.09; March,
Fig. 104. RESPIRATORY DISEASES-ADMISSIONS ANDDEATHS, ENL. MEN, EUROPE, RATIO PER 1000
6.83; April, 5.13; May, .56; June,2.57; July, 3.02; August, 2.53; September, 5.06; October, 2.66; November, 3.38; and December, 5.03. The rates for each month of 1918 are higher.
For Europe the admission rates by months for the year for influenza were in January 160.50, with a decline in February to 84.13,
656
an increase in March to 95.29, a practically stationary rate in April with an increase in May to 128.96, in June to 134.37, a decline in July and August, with a decided increase in September to234.26 in October to 344.85, with a decrease in November to 164.26 and in December to 146.45, For total pneumonias the rate was, in January, 33.46;February, 15.20; March, 25.32; April, 15.60; May 11.56; June, 7.92; July, 6.39; August, 6.37; September, 27.33; October, 50.45; November, 16.29; and December,16.31.
The admission rate for the pneumonias was higher in. the United States than in Europe every month of the year, with the exception of the month of June, when in the United States it was 7.41 and in Europe 7.92.
For the common respiratory diseases the rates in Europe could hardly be compared with the rates in the United States, particularly after the month of June, for after this time only hospital cases were reported. The rate in January for this class of disease was 268.50 in February, 141.61; March, 142.06; April, 106.43; May, 74.10; June, 44.46; July,2 9.55; August, 27.14; September, 44.22; October, 61.87; November, 65.52; and December, 92.04.
For deaths in the United States the rate for influenza in January was 0.20; February, 0.07; March, 0.37; April,0.48; May, 0.21; June, 0.14; July, 0.32; August, 0.45; September, 39.55;October, 70.03; November, 6.34; and December, 4.08. For combined pneumonias the death rate in January was 6.09; February, 2.76; March, 5.88; April, 5.54; May, 2.35; June, 0.90; July, 0.97; August, 1.79; September, 12.86; October, 25.15;November, 2.90; and December, 2.38, The only high rates for the other respiratory diseases were in September, when it was 1.26. In October it was0.22; November, 0.21; and December, 0.31. For Europe the death rate for total influenza in January was 0.30; in February, 0; March, 0.12; April, 0.21; May,0.28; June, 0.30; July, 0.28; August, 0.93; September, 13.57; October, 20.87; November, 3.97; and December, 2.53.
For total pneumonia the rate was 5.53in January, 2.01 in February, 3.26 in March, 1.41 in April, 1.23 in May, 1.23 in June, 0.95 in July, 1.57 in August, 11.21 in September, 22.57 in October, 3.56in November, and 2.65 in December.
The highest death rate for "other respiratory diseases" was in October, when it was 0.88. Comparing the death rate for total respiratory diseases for United States and Europe and for the decade 1905-1916, we have the following:
|
Month |
United States |
Europe |
Decade 1905-1916, highest rate |
|
January |
6.35 |
6.31 |
1.53 |
|
February |
2.84 |
2.27 |
.97 |
|
March |
6.30 |
3.58 |
1.02 |
|
April |
6.05 |
1.74 |
1.33 |
|
May |
2.62 |
1.71 |
1.13 |
|
June |
1.07 |
1.65 |
.67 |
|
July |
1.32 |
1.29 |
.60 |
|
August |
2.26 |
2.60 |
.69 |
|
September |
53.67 |
25.55 |
.92 |
|
October |
95.40 |
44.32 |
.46 |
|
November |
9.45 |
8.06 |
.51 |
|
December |
6.77 |
5.58 |
1.16 |
|
Total |
18.53 |
12.96 |
|
657
Taking the highest rate for each month for the decade, the excess over this rate should probably be attributed to the influenza and pneumonia epidemic.
EUROPE, BY MONTHS,
TABLE 335.-Influenza (all)-Deaths,1918-Absolute Numbers and ratios per 1,000- Europe.
TABLE 336.-Influenza uncomplicated-Deaths,1918-Absolute numbers and ratio per 1,000-Europe.
658
TABLE 337.-Influenza andbroncho-pneumonia-Deaths,1918-Absolute numbers and ratio per 1,000-Europe.
TABLE 338.-Influenza with lobar pneumonia-Deaths, 1918-Absolute numbers and ratio per 1,000-Europe.
TABLE 339.-Influenza with others-Deaths,1918-Absolute numbers and ratio per 1,000- Europe.
659
TABLE 341.-Lobar pneumonia-Deaths,1918-Absolute numbers and ratio per 1,000-Europe.
660
TABLE 342.-Pneumonia (all)-Deaths,1918.-Absolute numbers and ratio per 1,000-Europe.
TABLE 343.-Other respiratory diseases-Deaths,1918-Absolute numbers and ratio per 1,000-Europe.
661
The nativity rates for influenza (all)show that it is the rural States, especially of the South, with some few scattering ones from New England and occasional ones from the Middle West, that stand at the head of the list, and that the States of the West and Northwest, the soldiers from which seem to be less susceptible to this disease as shown, stand at the bottom of the list. The States standing at the head of the list are: Vermont, Kansas, South Carolina, Kentucky, North Carolina, Mississippi, Nebraska, Texas, Arkansas, Louisiana, Iowa, Alabama, Missouri, Georgia, and Virginia. Practically the same States stand at the head of the list for uncomplicated influenza, but for influenza with broncho-pneumonia we find that South Carolina, Texas, Maryland, Kentucky, Iowa, Louisiana, Vermont, West Virginia, Virginia, Kansas, Nebraska, and North Carolina head the list, Practically the same States stand at the head of the list for influenza with lobar pneumonia: Louisiana, Vermont, Mississippi, Maine, Kansas, New Hampshire, Kentucky, Nebraska, Alabama, Iowa, Wisconsin, Florida, and North Carolina. In all these cases it is the States of the Northwest which stand at the bottom of the list, with the densely populated eastern urban States just above. Excluding Alaska, for influenza we have Montana, Wyoming, Arizona, Idaho, Nevada, California, District of Columbia, Washington, New Jersey, Connecticut, and New York. These same States, with some slight variation, stand at the bottom of the list for uncomplicated influenza and influenza with the two pneumonias. As shown, the Eastern States stand next above the States of the West and the Northwest, which are at the bottom of the list, with the States of the Middle West in middle position. For lobar pneumonia we have at the top of the list Florida, Georgia, Mississippi, Alabama, South Carolina, Louisiana, Texas, Arkansas, Vermont, Kansas, Tennessee, Nebraska, Kentucky, and North Carolina.
For broncho-pneumonia and pneumonia unclassified we have South Carolina, Tennessee, Louisiana, Mississippi, Georgia ,Alabama, Florida, Arkansas, North Carolina, Virginia, and Kentucky. It is
662
again the States of the West and Northwest that stand at the bottom of the list, with the States of the East, which are urban and densely populated districts, just above.
Fig. 105. NATIVITY, INFLUENZA (ALL),U.S. AND EUROPE
Reading from the bottom of the list up for broncho and unclassified pneumonia, there is (excluding Alaska) Montana, Arizona, Wyoming, Nevada, Idaho, Connecticut, New Jersey, New York, California,
Fig. 106. NATIVITY, INFLUENZA WITH BRONCHO-PNEUMONIA, U.S. AND EUROPE
District of Columbia, Washington, and Massachusetts; and for lobar pneumonia, Montana, Wyoming, Idaho, Washington, Nevada,, District of Columbia, California, New Jersey, Arizona, Utah, New York, and Rhode Island.
663
The relative immunity to this disease and to the pneumonia of the soldiers from the Eastern States with their urban and densely populated districts might be attributed to previous attacks of influenza
Fig. 107. NATIVITY. INFLUENZA WITH LOBAR PNEUMONIA, UNITED STATES AND EUROPE
or possibly to pneumonia infection, which had assumed the form of an ordinary respiratory disease, or to a general hyperleucocytosis, with temporary relative immunity to infectious disease in general.
FIG. 108. NATIVITY.BRONCHO-PNEUMONIA AND PNEUMONIA UNCLASSIFIED, US, AND EUROPE
The immunity of the soldiers from the Northwest can not, however, be explained in this way. The men from certain of these States are apparently very robust and have a relative lack of susceptibility to various respiratory infections.
664
Due to the frequent immigration to the new States of the West and Northwest from the Southern and Eastern States, there were a number of drafted men who had immigrated to these States either in adult life or childhood. Many possibly who were inducted from these States and who were included in the figures of the Provost Marshal General`s Office for these States may have given as their nativity their own native State rather than their adopted State. The number of inductions would thus be increased without a proportionate increase in the number of cases and the ratios lowered.
Fig. 109. NATIVITY. LOBAR PNEUMONIA, U.S. AND EUROPE
For the colored and white troops the various types of infectious diseases are total admission rates for the as follows:
665
Considering only the Southern States, the nativity rate for influenza for the white was 247.11 and for the colored 154.58. For lobar pneumonia it was 10.77 for the white and 28.31 for the colored. For broncho-pneumonia it was 7.26 for the white and 11.43 for the colored. It seems probable that the Negro is less susceptible to influenza than the southern whites, but that he is much more susceptible to pneumonic infections, either primary or secondary. The case mortality for influenza for the colored was 4.2, for the white 3.3. The case mortality for total pneumonia for the colored was 21.7, for the white 26.7. It appears that the Negro while more susceptible to pneumonia infections than the whites has a lower, case mortality. The apparent reason for the higher case mortality for influenza for the colored as compared with the whites is probably to be attributed to the fact that secondary pneumonia developed in a much larger percentage of the cases for the colored.
The total number of cases of pneumonia occurring among the white troops, enlisted men, serving in the United States and in Europe, together with the cases of pneumonia complicating measles and influenza, for the year was 94,505, with 28,969 deaths. The cases among the colored troops, enlisted men, serving in the United States and Europe, including also the cases with measles and influenza, was 19,319, with 4,720 deaths. The incidence rate for the whites was 44.11 and for the colored 115.28. The death rate for the whites was 13.52 and for the colored 28.17. The case mortality for the white troops was 30.6 percent and for the colored 24.4 percent, It is apparent that the colored troops had an incidence rate for pneumonia of nearly three times as high as that for the whites and a death rate more than twice as high, but that the whites have a case mortality rate of 20 percent higher than the colored.
666
667
668
669
TABLE 355.-Pneumonia (all), United States-Admissions and deaths-Absolute numbers and ratios per 1,000.
670
TABLE 356.-Pneumonia (all), Europe-Admissions and deaths-Absolute numbers and ratios per 1,000.
671
TABLE 357.-Influenza (all)-United States and Europe, 1918.
672
TABLE 358.-Influenza uncomplicated-United States and Europe, 1918.
673
674
675
676
677
TABLE 363.-Lobar pneumonia-Ratio per 1,000 nativity strength-Total cases United States and Europe.
678
679
680
681
682
683
684
685
TABLE 370-1.-Influenza,pneumonia, and common respiratory diseases, 1862-1918, inclusive-Admissions-Enlisted men, American troops (all) [1902-1918].
686
TABLE 371.-Influenza,pneumonia, and common respiratory diseases, 1862-1918, inclusive-Deaths-Enlisted men, American troops (all)[1862-1901].
687
TABLE 371-1.-Influenza,pneumonia, and common respiratory diseases, 1862-1918, inclusive-Deaths-Enlisted men, American troops (all)[1902-1918].
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
