Part 23
The housing methods in the cantonments and even in the tent camps resulted in a degree of congestion and close physical contact among individuals that was attained in no civil communities with the possible exception of some institutions. In cantonments the number of men in individual rooms ranged from 30 to 100 and even under the best circumstances there was very evident close crowding. An individual in any of these large rooms contracting a contagious disease had opportunities to spread it by contact and by droplet infection not only to one or two others, as in the case of the average family, but to a large group of the men in the same room. A vicious circle was thus formed which tended to propagate the disease throughout any camp with utmost rapidity. Brewer has compared the influenza incidence rate in the principal white organizations at Camp Humphreys with the floor space allowed each man in the respective organizations, and concludes that, “It is not proper or just to attribute the differences shown, alone to the amount of floor space allowed each organization, but it certainly points very strongly to the fact that the incidence of the disease varied with the density of the population, although not with mathematical regularity.” Brewer cites regiments which although housed alike showed definite variation in the influenza incidence. This merely shows that other factors also play a part. Thus, in one instance, the difference in the two regiments was in length of service. Brewer also found that among the white troops the incidence of pneumonia appears to vary with the density of the population.
V. C. Vaughan has reported on the relationship between incidence in tents and in barracks at Camp Custer. From this one observation it would appear that the incidence is little changed under the two conditions.
“During September and October, 1918, a study was made on the relationship, if any, of influenza to methods of living. Of the command, 3,633 were in tents. The morbidity per thousand in these was 129. There were in barracks 36,055. The morbidity per thousand among those was 275. At first glance the lower morbidity of those in tents is striking, but going further into the matter it was found that the entire morbidity of the Quartermaster Corps was very low. Of the Depot Brigade 2,881 were in tents, with a morbidity of 128 per thousand, while 3,824 were in barracks, with a morbidity of 134 per thousand.”
Howard and Love offer three reasons why during the last four months of 1918 the deaths from influenza and pneumonia in the Army in the United States ran at a rate nearly three times as high as that among our troops in France: First, that the troops in the United States were recent recruits and therefore more susceptible to disease; second, that probably many of the troops in France who had seen much longer service had had the disease in mild form in the early spring; and, third, that the method of housing was entirely different in France. There the men were spread over a wide territory and whenever in rest area they were billeted in houses rather than crowded into barracks. Furthermore, they were living much more in the open. It was found that in commands of the Service of Supply, where troops were housed in barracks with a large number of men to a single room, the epidemic ran much the same course with high mortality, as it did in the cantonments in the United States. The percentage of infection and the fatalities from influenza and pneumonia in France were much greater among troops of the S. O. S. than among troops at the front.
_Domestic cleanliness._—We have studied the relationship between influenza incidence and the cleanliness of the household by the same method used in studying overcrowding. In Table VIII we have classified according to cleanliness and according to the number of cases developing in each family. We have had four subdivisions, “very clean,” “clean,” “dirty,” and “very dirty.” There is greater opportunity for erroneous results in this table than in the one preceding because the standards of cleanliness are difficult to define. As a matter of fact we are guided entirely by the inspector’s own impression of each household, as she examined it during her visits. The following is an excerpt from the instructions given each inspector on this subject:
“A few words on this subject may describe much. State of cleanliness of the individual, slovenly condition, dust and dirt, foulness of air noticed on first entering, condition of children, of kitchen sink, etc., should be noticed, and good or bad features recorded. In the poorer districts not a few families will be found in which the cleanliness, considering the surroundings, is quite laudable. Of particular importance are amount of daylight, ventilation, care of bathroom and toilet, garbage, whether windows are kept open at night.”
On the basis of these returns we have classified the families as indicated, but each inspector was governed to a certain extent by the average cleanliness of her district, and it is difficult to compare the cleanest tenement with any of the districts of well-to-do individuals. We will therefore probably find it more profitable and more nearly accurate to combine the groups and classify them only as “clean” and “dirty.”
TABLE VIII. _Relationship between cleanliness and number of cases in family._ (Clean families were invaded less frequently and had solitary cases more often than did dirty households.) ══════════════════════════════════════════════════════════════════════════ Very clean. (47.62 per cent. had none.) ─────────┬─────────┬────┬─────┬────┬─────┬─────┬─────┬──────┬───────────── Cases in │ Total │’18.│ Per │’20.│ Per │Both.│ Per │Total.│ Per cent. families.│families.│ │cent.│ │cent.│ │cent.│ │ ─────────┼─────────┼────┼─────┼────┼─────┼─────┼─────┼──────┼─────┬─────── 1│ 124│ 72│15.65│ 50│10.87│ 8│ 1.74│ 460│26.96│ 2│ 53│ 41│ 8.91│ 27│ 5.87│ 15│ 3.25│ │11.52│} 25.42 3│ 37│ 33│ 7.17│ 13│ 2.82│ 9│ 1.95│ │ 8.04│ „ 4│ 18│ 16│ 3.48│ 8│ 1.74│ 6│ 1.30│ │ 3.91│ „ 5│ 4│ 3│ 0.65│ 2│ 0.43│ 1│ 0.21│ │ 0.87│ „ 6│ 3│ 3│ 0.65│ 0│ 0.0│ 0│ 0.0│ │ 0.65│ „ 7│ 2│ 2│ 0.43│ 1│ 0.21│ 1│ 0.21│ │ 0.43│ „ 8│ 0│ 0│ │ 0│ │ 0│ │ │ │ ─────────┴─────────┴────┴─────┴────┴─────┴─────┴─────┴──────┴─────┴─────── Clean. (41.52 per cent. had none.) ─────────┬─────────┬────┬─────┬────┬─────┬─────┬─────┬──────┬───────────── Cases. │Families.│’18.│ Per │’20.│ Per │Both.│ Per │Total.│ Per cent. │ │ │cent.│ │cent.│ │cent.│ │ ─────────┼─────────┼────┼─────┼────┼─────┼─────┼─────┼──────┼─────┬─────── 1│ 301│ 212│18.45│ 120│10.44│ 31│ 2.70│ 1149│26.19│ 2│ 177│ 143│12.45│ 91│ 7.92│ 57│ 4.96│ │15.40│} 32.29 3│ 101│ 83│ 7.22│ 52│ 4.53│ 34│ 2.96│ │ 8.79│ „ 4│ 52│ 47│ 4.09│ 20│ 1.74│ 15│ 1.26│ │ 4.53│ „ 5│ 30│ 29│ 2.52│ 17│ 1.48│ 16│ 1.22│ │ 2.61│ „ 6│ 8│ 7│ 0.61│ 3│ 0.26│ 2│ 0.17│ │ 0.70│ „ 7│ 3│ 3│ 0.26│ 0│ 0.0│ 0│ 0.0│ │ 0.26│ „ 8│ 0│ 0│ │ 0│ │ 0│ │ │ │ ─────────┴─────────┴────┴─────┴────┴─────┴─────┴─────┴──────┴─────┴─────── Dirty. (36.89 per cent. had none.) ─────────┬─────────┬────┬─────┬────┬─────┬─────┬─────┬──────┬───────────── Cases in │ Total │’18.│ Per │’20.│ Per │Both.│ Per │Total.│ Per cent. families.│families.│ │cent.│ │cent.│ │cent.│ │ ─────────┼─────────┼────┼─────┼────┼─────┼─────┼─────┼──────┼─────┬─────── 1│ 79│ 59│17.40│ 36│10.62│ 16│ 4.72│ 339│23.30│ 2│ 58│ 48│14.16│ 29│ 8.55│ 19│ 5.61│ │17.11│} 39.81 3│ 37│ 31│ 9.14│ 22│ 6.49│ 17│ 5.01│ │10.91│ „ 4│ 26│ 22│ 6.49│ 12│ 3.54│ 8│ 2.36│ │ 7.67│ „ 5│ 6│ 5│ 1.79│ 4│ 1.18│ 3│ 0.94│ │ 1.77│ „ 6│ 7│ 7│ 2.06│ 4│ 1.18│ 4│ 1.18│ │ 2.06│ „ 7│ 0│ 0│ │ 0│ │ 0│ │ │ │ „ 8│ 1│ 0│ 0.0│ 1│ 0.29│ 0│ 0.0│ │ 0.29│ „ ─────────┴─────────┴────┴─────┴────┴─────┴─────┴─────┴──────┴─────┴─────── Very dirty. (39.26 per cent. had none.) ─────────┬─────────┬────┬─────┬────┬─────┬─────┬─────┬──────┬─────┬─────── 1│ 22│ 16│14.95│ 8│ 7.47│ 2│ 1.85│ 107│20.56│ 2│ 11│ 8│ 7.47│ 6│ 5.10│ 3│ 2.80│ │10.28│} 40.18 3│ 14│ 12│11.21│ 10│ 9.35│ 7│ 6.54│ │13.08│ „ 4│ 7│ 5│ 4.67│ 4│ 3.73│ 2│ 1.85│ │ 6.54│ „ 5│ 6│ 6│ 5.10│ 1│ 0.93│ 0│ 0.0│ │ 5.61│ „ 6│ 3│ 3│ 2.80│ 2│ 1.85│ 2│ 1.85│ │ 2.80│ „ 7│ 2│ 2│ 1.85│ 0│ 0.0│ 0│ 0.0│ │ 1.87│ „ 8│ 0│ 0│ │ 0│ │ 0│ │ │ │ ─────────┴─────────┴────┴─────┴────┴─────┴─────┴─────┴──────┴─────┴───────
But even without combining in this way, the table shows us that for both years 27 per cent. of the very clean families, 26 per cent. of the clean, 23 per cent. of the dirty and 21 per cent. of the very dirty, had but one case, while 25 per cent. of the very clean, 32 per cent. of the clean, 40 per cent. of the dirty, and 40 per cent. of the very dirty, had multiple cases.
The cleaner the family the less is the likelihood of multiple cases.
It is rather difficult to find concrete examples of the influence of domestic habits and environment in the 1918 pandemic. The remarkably high incidence among the natives of India and among the American Indians might by some be attributed to unfavorable environment. Lynch and Cumming obtained records from a large number of institutions and from business concerns having their own records, and discovered that the influenza incidence was higher in those institutions where dish washing was done manually than in those in which mechanical washing was performed. They appear to conclude that the difference in the two methods of washing dishes was the cause for the greater incidence in influenza, thus bearing out their theory of the propagation of influenza chiefly through eating utensils. On the contrary it is possible that the presence of the mechanical washer is an indication of advanced methods, greater care in the kitchen, and better hygiene probably not only in the kitchen and dining room, but throughout the institution.
_Economic status._—Although in our survey information has been obtained regarding the economic status of the various families we would not stress this phase of our subject. Obviously the amount of money an individual has in his bank will not directly influence the amount of influenza he will have in his home. As nearly an accurate classification by wealth is by the separation into the districts, Districts I and III being very poor, District II poor, Districts IV and V moderate, and VI well-to-do. From Chart XXVI we see no definite relationship between influenza incidence and economic status.
Dr. Niven has had similar experiences. He remarks that the disease does not appear to have affected especially any class or section of the community. Rich and poor suffered alike. Inquiry in some towns shows that the epidemic not infrequently started in the well-to-do districts and only later involved the poorer and less prosperous areas.
We cannot state with any degree of accuracy in what section of Boston the 1920 recurrence first began. The sections studied are for relatively small portions of the city, and it is possible or probable that the original increase was in some area outside of our districts. In the districts studied the earliest increase in reported cases was from the section of the city known as Dorchester (Districts IV and V), where there was some increase in December, 1919. The latest definite increase was in the Irish district of South Boston. Geographically these two areas are quite near. The relative insusceptibility of the Irish population is probably a much more important factor in the difference.
Frost found after classifying the white population canvassed in Little Rock and San Antonio according to economic status, and adjusting the incidence rate in each group to a uniform sex and age distribution, that the ratios of incidence in each economic group to incidence in total white population did show an increase with increasing poverty. “Notwithstanding that the classification according to economic status is a very loose one, based solely on the judgment of inspectors with widely different standards, a considerably higher incidence is shown in the lower as compared to the higher economic group.”
Parsons, in 1891, discussed the influence of poverty, but believed that it is the concomitants of poverty which were the cause of the higher incidence among the poor.
“Sanitary conditions do not seem to have had any influence in determining the occurrence of influenza, and what share they have had in determining its extent or fatality cannot yet be decided. On the occasion of the last great epidemic, Dr. Peacock concluded, ‘The more common predisponents to disease, _e.g._, defective drainage, want of cleanliness, overcrowding, impure air, deficient clothing, innutritious or too scanty food, powerfully conduce to the prevalence and fatality of influenza.’ And Dr. Farr showed that in the last six weeks of 1847, while in the least unhealthy districts of London the annual rate of mortality was raised from a mean rate of twenty per 1,000 to thirty-eight, in the unhealthiest districts it was raised from a mean rate of twenty-seven to sixty-one.
“That overcrowding and impure air must have a powerful influence in aiding the development of the epidemic follows from what we have seen of its greater prevalence among persons associated together in a confined space; and though rich and poor have alike been sufferers from the epidemic, and even royal personages have been fatally attacked by it, it cannot be doubted that poverty must have in many cases conduced to a fatal issue in persons, who, if placed under more favorable circumstances, might have recovered, seeing that it often involves not only inferior conditions of lodgment, but also want of appropriate food, of sufficient warmth and clothing, and of ability to take the needed rest.”
_Distribution of the disease through the household._—During the autumn and winter epidemic of 1918 there was considerable discussion, and particularly were there popular newspaper reports of entire families being taken ill with influenza, sometimes all on the same day. This was less true of 1920. But few of us are personally acquainted with such instances and at best they must have been relatively rare.
Among 1,236 families with influenza in either epidemic we found only 94 or 7.6 per cent. in which the entire family contracted the disease. No family consisting of over seven individuals was reported as having all the members of the family sick in either epidemic. Over two-thirds of the families with even numbers of individuals (464 out of 605) suffered the illness of less than half of the household. One quarter of all families of more than one (539 out of 2,107) had but one case per family. Over a third of all families of over two individuals (745 out of 2,006) had two or less cases per household. _As a rule there were at least one and usually several individuals in each household who did not contract influenza._
That as a rule the disease did not appear explosively in a family; but that cases developed successively, is indicated by the fact that out of 577 families contracting influenza in the epidemic of 1920 the cases were all of simultaneous development in but fifteen. In thirteen of these, two individuals fell ill on the same day and no subsequent cases developed. In the other two families three individuals came down on the first day and no other cases developed. In addition there were, out of the 577 families, fourteen in which there were two or more cases developing on the first day of the invasion, but which were followed on subsequent days by later cases in the same family. Again, there were eleven families in which two or more cases occurred simultaneously at an interval of one or more days after the development of a single prior case.
We may say that _as a rule in the 1920 epidemic, cases of influenza developed in families successively and not simultaneously_. In only 29, or 5 per cent. of the families contracting the disease in 1920, did more than one case develop on the first day of the appearance of the disease in the family.
A certain difficulty in determining the date of onset is that we must rely upon the patient’s statement. One individual may have been sick for hours or days before a second member coming down with the disease called forth recognition of the fact that they both had it.
Unfortunately we are not able to give similar statistics for the 1918–19 epidemic. Our investigation occurred so long after the epidemic that specific dates of onset of the disease would have been entirely unreliable. The nearest date we have attempted to obtain was the month of the attack.
Dr. A. L. Mason states that 63 cases came under his observation in the epidemic of 1889 as occurring in groups in families. In but six instances were two persons attacked on the same day. The average interval between cases in the same household was four days. Sometimes a week or more elapsed. Whole families were never stricken at once.
Parsons in 1891 concluded from the results of questionaires sent to physicians that in the first spread, 1889–90, there was an interval between cases in individual households just as we have described. Among the replies to his questionaires nine described intervals of one day and under, six described intervals of two days, three of three days, three of four days, and four replies described intervals of more than four days.
Leichtenstern observed likewise: “In large families the contagious character of influenza is evidenced by the fact that the other members of the family become sick one after the other following the first case. This rule of succession is most easily seen in the early or late period of an epidemic and is less noticeable at the height, where the opportunity for all the members of the family to acquire the influenza outside the home is enormous. This latter fact explains why, when all sicken at once, the disease appears to be miasmatic in origin. There are many examples where other members of a family living with a sick individual remained unaffected. Parsons reports such cases, and this was so frequently the case that some British physicians state that it is the rule that there is but one case in a family or that the cases are widely separated in time. This was only partly true during the period of the pandemic and was very frequent in the epidemic following it. In this respect influenza acts like the common contagious diseases, diphtheria, scarlet fever, measles, etc., while the difference lies in the short incubation period and the very high contagiousness of the disease.”
That West, in England, had observed the same phenomenon is indicated by the following quotation: “How is it, for instance, that one member of a household may be picked out and the others escape, though they are susceptible, as is shown by their acquiring the disease shortly after in some other way?”
Again Leichtenstern wrote: “It is noteworthy that influenza on ships usually did not occur explosively, but spread gradually, and on ships usually lasted several weeks, as on the Bellerophon, from the 27th of March to the 30th of April; on the Canada from the 11th of April to the 24th of May; on the Comus from the 10th of April to the 3d of May.
“The German Marine Report states, ‘Everywhere on the ships the disease began not suddenly but gradually.’ The frigate Schwalbe first had a large number of cases only on the 6th day after the beginning of the epidemic. There are, however, some exceptions, where the disease has begun suddenly with the greatest violence on ships as on land. Such was true of the frigate Stag which on the 3d of April, 1833, neared the influenza infected coast of Devonshire, and as it came under the land wind the epidemic suddenly broke out with great violence. Within two hours forty men took sick. Within six hours the number had increased to sixty. Within twenty-four hours 160 men were sick. As Parkes has remarked the evidence is insufficient that there had been no communication with the coast. There have been other examples of sudden outbreaks on ships, as on a Dutch frigate in the harbor of Mangkassar, where 144 men out of 340 took sick in a few days (1856); on the Canopus (1837) in the harbor of Plymouth, where on the 15th of February three-fourths of the men took sick with influenza.”
Garvie, in reporting his personal experiences with influenza in 1918 in an industrial area in England, experiences not based on statistical study, concludes that there are two types of cases, the sporadic case which occurs mainly among the wage-earning members of the family and has little tendency to affect other members of the household, and second, the type of case where a large number of individuals in the household are affected. He called this the “household wave.” If we interpret him aright he really means that there are either single or multiple cases, and that the single cases are more apt to occur in the wage-earner, the individual who is more exposed on the outside of the household. He also believes that the household wave is more severe in character than the so-called sporadic case, and is accompanied by a greater number of complications.
Armstrong, in his survey in Framingham, examined influenza convalescents. He found that of these 10 per cent. were in families in which no other cases had developed, and 87 per cent. were in families where one or more additional cases had occurred. In three per cent. information was lacking.
It is important in studying the literature on this subject to distinguish between definitely established fact and less definite description. Thus one is still left in some doubt when one reads in a London letter in the Journal of the American Medical Association for 1915 concerning the epidemic in London at that time that, “whenever it has seized an individual it has usually run through the entire household. Whole offices have succumbed.”
_The first case in the family._—Chart XXVII shows clearly that in both epidemics in our experience the wage-earner was much more frequently the first case in a family than was any other occupation. The individuals whose occupations kept them at home were second. Infants, as was to be expected, were recorded as being “first case” in the smallest number of instances.
In 1889 the distribution was practically the same. Parsons found that out of 125 households the first case was a bread-winner in 96; a housekeeper in nine; a child at school in thirteen; a child not at school in two families. In the last five families the first case was in adults, occupation not given. This order is identical with our own. Neither our own observations nor those of Parsons consider the relative proportions of wage earners in the population as a whole. The results are nevertheless suggestive.