Part 19

“_Retail Sales Outdoors_” includes sales agents, life insurance agents, traveling salesman, pedlers, newsboys, etc.

“_Office_,” officials, secretaries, stenographers, telephone operators, telegraph operators, etc.

We have observed that in 1918 infants presented the lowest incidence and school children the highest. Occupations designated Home and Office were surprisingly high. Children also showed a high incidence, one out of every five developing the disease. The records show that manual labor, both indoors and outdoors, was associated with a higher incidence than less strenuous work, as retail sales, indoors and outdoors (Chart XXIII).

The attack rates in most of the occupations are so nearly the same as to lead to no certain conclusions. It would appear from our records that individuals working out of doors were less frequently attacked than those whose occupation kept them in doors. The groups at the two extremes of incidence correspond to what we should expect when considering opportunities for contract. The infant has least direct contact. His contact is only with one or a few individuals, the mother or the nurse. This group developed the disease in 5.8 per cent. The school child not only has the same degree of contact as do adults, but also in the tussle and scramble of play the contact becomes much closer. The factor of age plays a large part in the occupational distribution and the apparent occupational susceptibility is influenced by the age susceptibility.

When we consider the occupational incidence in the various districts we find that the only constant feature in the relatively small groups is the low incidence among infants (Chart XXIV).

CHART XXIII.

CHART XXIV.

CHART XXV.

CHART XXVI.

The first fact gained from a study of the 1920 occupational case rate is that just as was the case in age incidence there is less variation between the highest and the lowest than in 1918–19. While in the first epidemic the highest occupational rate was five times the lowest, in the second it was only twice the lowest (Chart XXV). But at the extremes of the two charts we see some tendency to an inversion of the order. In 1918–19 those occupied in “retail sales” outdoors showed a low incidence, while in 1920 they were the highest. So also, the incidence in the school group changed from highest in 1918 to lowest in 1920. The incidence in infants increased; that in the office workers decreased. No general conclusions are warranted from these results.

In comparing the sex incidence by age groups we have found that females as a rule showed a slightly greater incidence than males. That this is not due fundamentally to occupational differences is suggested by a comparison of the sex incidence in the two epidemics studied. In 1918 the distribution is practically the same in the two sexes in all occupations except “Home,” “Manual Outdoors,” “Retail Sales Indoors,” “Retail Sales Outdoors” (Chart XXVI). In the first the number of males is so small and in the second and fourth the number of females is so small that these cannot justly be compared. The group, “Retail Sales,” consists in 1918–19 of 69 males and 27 females, out of a total distribution in the population of 426 males and 107 females. This is the only occupation that showed a definite higher incidence among the females, and even here the number is too small for accuracy. In 1920 this difference has practically disappeared.

_Effect of race stock._—Leichtenstern remarks in his monograph that the reported differences in influenza morbidity among different races, such for instance as European and other nationalities, doubtless are due to factors other than genetic racial differences, such as different modes of living, commerce, etc. The work of the last two years calls for a reconsideration of this idea.

Frost in his valuable work found that “in the seven localities with considerable colored population the incidence rates among the colored were uniformly lower than among the whites, the difference persisting after adjustment of the rate to a uniform basis of sex and age distribution. The extent of the difference varied, being relatively great in Baltimore, Augusta and Louisville, and very small in Little Rock. This relatively low incidence in the colored race is quite contrary to what would have been expected a priori, in view of the fact that the death rate from pneumonia and influenza is normally higher in the colored than in the white, and that the colored population lived generally under conditions presumably more favorable to the spread of contact infection.”

Brewer, in his study of influenza in September, 1918, at Camp Humphreys, finds that the colored troops showed a decidedly lower rate than the white troops throughout the epidemic. He finds that the incidence among colored troops was only 43 per cent. of that among whites. The difference between colored and white organizations was probably not due to difference in housing. Most of the colored troops were in tents and the white troops were all in barracks. But the 42d Company composed of negroes was housed in barracks under the same conditions as the white troops of other organizations and they had next to the lowest incidence of all organizations. Brewer concludes that the colored race when living under good hygienic conditions is not as susceptible to influenza as the white race under the same conditions. The age distribution was the same in both groups.

Armstrong concluded from figures based on reported cases of influenza that in the autumn of 1918 proportionately four times as much influenza and pneumonia was reported among the Italians as was reported for the rest of the Framingham community, made up largely of Irish or Irish-American stock. On the contrary, an examination of a large proportion of the population of that town showed a tuberculosis incidence among the Italian race stock of .48, in contrast to an incidence among the Irish of 4.85 per cent. and of 2.16 per cent. in the entire population. Armstrong contrasts the relative insusceptibility of Italian stock to tuberculosis, with the apparent marked susceptibility to acute disease of the respiratory tract, such as influenza and pneumonia; and the high susceptibility of the Irish to tuberculosis, with their low susceptibility to acute respiratory infection.

With regard to our work it is sufficient to state that the lowest incidence in both epidemics, as well as in recurrent cases, was in the Irish tenement districts. Both the Jewish and the Italian tenement districts were slightly higher in both epidemics (Charts XIX and XXI). The age distribution of the entire population of each of these three districts was about the same, so it does not appear that the slightly lower incidence among the Irish is due to a variation in the age distribution of the population.

The subject of race in relation to influenza will be discussed further under mortality.

MORTALITY.

According to Marchese, in 1387 at Forli in Italy, not a person escaped the disease, but only a few died. Gassar says that during the same epidemic in Germany the patients suffered four, or at most five, days with the most disagreeable catarrhal symptoms and delirium, but recovered, and only very few were removed by death.

Pasquier remarks concerning an epidemic in 1411 that an infinitude of individuals were attacked but that none died.

Concerning the epidemic of 1414 in France, Lobineau relates that the disease was fatal only for the aged. Mezeray also speaks of the high mortality of the old in this epidemic.

Regarding the pandemic of 1510, Thomas Short remarks that none died except some children. Mezeray, on the other hand, says that the disease had claimed many victims.

Pasquier and Valleriola both write of the epidemic of 1557, in France, as being distinctly mild in character. Children only who could not freely cough out the phlegm died. Coyttar speaks of the absence of death except in tuberculous patients.

In the pandemic of 1580 individual observers report enormous death rates. Thus, according to Schenkius, the disease killed 9,000 persons in Rome, while Madrid, Barcelona and other Spanish cities were said to have been nearly depopulated by the disease. This high mortality was, however, even at that time attributed by some physicians to the injudicious employment of venesection. Throughout the more recent history of pandemic influenza opinion seems to have been nearly unanimous that blood letting has had very bad results in the outcome of influenza cases. Remarks to this effect have been made by the contemporaries of nearly every epidemic since 1580.

According to Rayger and others during the epidemic of 1675, nobody died of the disease itself with the exception of debilitated persons, although it spared neither the weak nor the strong.

Concerning the epidemic of 1688, Thomas Short writes for England that though not one of fifteen escaped it, yet not one of a thousand that had it died.

In 1712, Slevogt writes that in Germany “Fear soon vanished when it was seen that although it had spread all over the city, it left the sick with equal rapidity.”

Finkler remarks, concerning 1729–30, that, “The great mortality which attended the epidemic in England and Italy seems somewhat remarkable. Thus Hahn states that in London in the month of September one thousand persons died each week, and in Mayence forty persons daily. Most likely, however, other diseases which were present at the same time added their quota to the mortality, especially as the disease in other places, for example in Germany, ran a benign course.”

Perkins, Huxham, Pelargus, Carl and others, concerning the epidemic of 1732–33, all testify that the disease was of very low fatality.

In 1742 the epidemic was evidenced by an enormous morbidity but the disease was not dangerous as a general rule although Huxham occasionally speaks of the virulent character of the disease in England, and Cohansen says that in January, 1743, over 8,000 persons died from influenza in Rome and 5,000 in Mayence.

We have the testimony of Robert Whytt, for 1758, and that of Razoux and Saillant and Ehrman for 1762, as to the low mortality of the epidemic for those years.

According to Heberden the same was true for 1775, while Webster tells us for 1780 that the disease was not dangerous but its effects were seen the following year in the increased number of cases of phthisis.

Finkler remarks concerning the epidemic of 1802, “The mortality in this epidemic was small, only the abuse of venesection brought many to the grave. Thus, so many farmers are said to have died in Russia from it that venesection was forbidden by an imperial ukase. Jonas says that many patients were bled either on the advice of a simple village barber or by their own wish, and most of them died. In Prussia also bleeding was declared detrimental by the Government.”

He continues regarding 1836–37, that, “In London there died, during the week ending January 24, 1837, a total of 871 persons, and among these deaths there were 295 from disease of the respiratory organs; during the week ending January 31st, out of a total of 860 deaths there were 309 from diseases of the respiratory organs.”

Watson, in describing the epidemic of 1847, discusses the mortality:

“The absolute mortality has been enormous; yet the relative mortality has been small. You will hear people comparing the ravages of the influenza with those of the cholera, and inferring that the latter is the less dangerous complaint of the two; but this is plainly a great misapprehension. Less dangerous to the community at large (in this country at least) it certainly has been; but infinitely more dangerous to the individuals attacked by it. More persons have died of the influenza in the present year than died of the cholera when it raged in 1832; but then a vastly greater number have been affected with the one disease than with the other. I suppose that nearly one-half of those who were seized with the cholera perished; while but a very small fraction, indeed, not more probably than two per cent. of those who suffered influenza have sunk under it.”

Leichtenstern remarks on the very low mortality of 1889–90. In Munich 0.6 per cent. died; in Rostock 0.8 per cent.; in Leipzig 0.5 per cent.; in fifteen Swiss cities 0.1 per cent.; in Karlsruhe 0.075 per cent.; in Mecklenburg-Schwerin 1.2 per cent. This does not, however, include the numerous deaths from complications, as from pneumonia, and does not express the true mortality.

Newsholme gives the following table for mortality from influenza, bronchitis and pneumonia, in England and Wales during the epidemic years and the years immediately preceding them. The figures express annual death rate per million of population. The highest rate was reached in 1891. The table does not include deaths registered as from other diseases, but due directly or indirectly to influenza. Respiratory diseases in general show a greatly increased death rate in years in which influenza is epidemic. Such is also true to some extent with diseases of the nervous and the circulatory systems.

═══════════╤═════════════════════════════╤═════════════════════════════ Death rate │ │ per million│ │ of │ Non-epidemic years. │ Epidemic years. population │ │ from │ │ ───────────┼─────────┬─────────┬─────────┼─────────┬─────────┬───────── „ │ 1887│ 1888│ 1889│ 1890│ 1891│ 1892 ───────────┼─────────┼─────────┼─────────┼─────────┼─────────┼───────── Influenza │ 3│ 3│ 2│ 157│ 574│ 533 Bronchitis │ 2,117│ 2,041│ 1,957│ 2,333│ 2,593│ 2,266 Pneumonia │ 1,113│ 1,093│ 1,022│ 1,404│ 1,471│ 1,250 ───────────┴─────────┴─────────┴─────────┴─────────┴─────────┴─────────

In a report by the United States Public Health Service early in 1919 the death rates from all causes in twelve large cities of this country were compared for 1889–90 and for 1918–19. It was found that while considerable irregularity in the curves was evident, the curves of the two epidemics manifested on the whole quite a striking similarity for the same cities considered individually and for the group as a whole. The death rate rose to a much higher point during the autumn wave of the 1918 epidemic than in the epidemic of 1889–90 in nine out of the twelve cities. During both epidemics the rate was relatively low in St. Louis, Milwaukee and Minneapolis. The mortality in all of these cities was 26.7 in 1889, as against 35.2 for 1918. In the peak week the rate rose to 55.6 in 1918 as against 35.4 in 1889.

The influenza deaths in Massachusetts in the year 1890 during a period of fifty days were estimated by Abbott to have been 2,500. In 1918 Jordan estimates the mortality for the same state to have been six times as great. The population of the state had not doubled in the interval. The highest mortality from influenza in Massachusetts during the 1889–93 epidemic occurred in January, 1892, during which month the total deaths amounted to 6,309 which was greater by 2,246 than the mean monthly mortality of the year, and greater by more than 1,000 than the mortality of any month in the ten year period 1883–92.

A comprehensive comparison of the damage done by influenza in 1918 with the deaths from other plagues has been made by Vaughan and Palmer.

“The pandemic of 1918, when compared with that of 1889–90 is estimated to have caused _six times as many deaths_.

“During the four autumn months of 1918, 338,343 cases of influenza were reported to the Surgeon General. This means that in the camps of this country _one out of every four men had influenza_.

“The combination between influenza and pneumonia during the fall of 1918 seems to have been closer and more destructive than in any previous pandemic. During the autumn season there were reported to the Surgeon General 61,691 cases of pneumonia. This means that _one out of every twenty-four men encamped in this country had pneumonia_.

“During the same period 22,186 men were reported to have died from the combined effects of influenza and pneumonia. This means that among the troops in this country _one out of every sixty-seven died_.

“This fatality has been unparallelled in recent times. The influenza epidemic of 1918 ranks well up with the epidemics famous in history. Epidemiologists have regarded the dissemination of cholera from the Broad Street Well in London as a catastrophe. The typhoid epidemic of Plymouth, Pa., of 1885, is another illustration of the damage that can be done by epidemic disease once let loose. Yet the accompanying table shows that the fatality from influenza and pneumonia at Camp Sherman was greater than either of these. Compared with epidemics for which we have fairly accurate statistics the death rate at Camp Sherman in the fall of 1918 is surpassed only by that of plague in London in 1665 and that of yellow fever in Philadelphia in 1793.

“The plague killed 14 per cent. of London’s population in seven months’ time. Yellow fever destroyed 10 per cent. of the population of Philadelphia in four months. In seven weeks influenza and pneumonia killed 3.1 per cent. of the strength at Camp Sherman. If we consider the time factor, these three instances are not unlike in their lethality. The plague killed 2 per cent. of the population in a month, yellow fever 2.5 per cent. and influenza and pneumonia 1.9 per cent.

“In four months typhoid fever killed 1.5 per cent. of the soldiers encamped in this country during the war with Spain. Influenza and pneumonia killed 1.4 per cent. of the soldiers in our camps in 1918 and it also covered a period of four months.”

The Bureau of the Census has made the following report concerning influenza deaths in the United States:

“In forty-six American cities, having a combined population of only a little more than one-fifth the total for the country, the mortality resulting from the influenza epidemic during the nine weeks period ended November 9th was nearly double that in the A. E. F. from the time the first contingent landed in France until the cessation of hostilities.”

The mortality, even as the morbidity, has varied in different localities and at different periods. The low morbidity and mortality in the spring of 1918 has been frequently mentioned. Among the Esquimaux in Alaska the death toll was terrific. Whole villages of Esquimaux lost their entire adult population. It has been estimated that in British India the death roll totalled 5,000,000. “The central, northern and western portions of India were the worst sufferers. The hospitals in the Punjab were choked so that it was impossible to move the dead quickly enough to make room for the dying. The streets and lanes of the cities were littered with dead and dying people. The postal and telegraph services were completely disorganized; the train service continued, but at all principal stations dead and dying people were being removed from the trains. The burning ghats and burial grounds were literally swamped with corpses, while an even greater number awaited removal. The depleted medical service, itself sorely stricken by the epidemic, was incapable of dealing with more than a minute fraction of the sickness requiring attention. Nearly every household was lamenting death, and everywhere terror and confusion reigned. No part of the Punjab escaped.”

The Bureau of the Census estimates that 445,000 deaths from the epidemic of influenza occurred in the United States in the period between September 1st and December 31st, 1918. There is no doubt but that the total death toll for that epidemic exceeded 500,000 individuals.

According to Winslow and Rogers, the two highest annual death rates on record in Connecticut are both rates of 19.4 per 1,000 and these two rates are for the influenza epidemic years of 1892 and 1918. In the earlier of these two the normal general death rate was several points higher than it is today, so that the effect of the recent epidemic was much more serious than was that of its predecessor. For a single month the death toll of October, 1918, was absolutely unprecedented in Connecticut. They estimate that the epidemic between September, 1918, and January, 1919, cost the State 5.5 lives per 1,000 population, or, in all, 7,700 lives.

In the United States Army there was a total of 688,869 admissions for influenza. The total deaths ascribed to the disease are 39,731, which gives a rate of 15.64 per 1,000 for the acute respiratory diseases out of the total disease death rate of 18.81 for the year. In 1915 the per cent. of deaths from this group of infections was under 18 per cent. of the total from all diseases. During the last four months of 1918, 11,670 deaths from influenza and pneumonia occurred in the American Expeditionary Forces in France. There were approximately 1,600,000 officers and men in the United States and an equal number in France.

Carnwath gives the following comparison of the number of deaths in London and in certain American cities from influenza and all forms of pneumonia during the eight weeks of the 1918–19 epidemic.

_Deaths in London and in American cities._ Number of deaths. Rate eight weeks per 100,000 of population.

London 13,744 341

New York 20,681 360

Chicago 8,785 343

Philadelphia 12,806 749

Boston 4,211 548

The cause of death in the vast majority of cases is some form of pneumonia. In fact it has been questioned whether influenza uncomplicated can cause a fatal issue. Postinfluenzal meningitis has been the cause of death in an appreciable number of cases. More remotely the disease has caused many deaths by hastening the fatal outcome of what were otherwise subacute or chronic conditions of the respiratory, cardiovascular, or renal systems.

Vaughan and Palmer record that, “The pandemic of influenza in 1918 seems to have been more closely associated with the pneumonias than appears in any previous pandemic. From the reports as sent to the Surgeon General’s Office, it appears that uncomplicated influenza was not by any means a fatal disease and that the high death rate was due to the pneumonias which followed. Pneumonia is a serious disease at all times. Recent records for the United States Army show that the case mortality rate for this disease has been as follows during the different periods of the last two years: