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Chapter VIII

Communicable Diseases, Table of Contents

CHAPTER VIII

THE DIARRHEAL GROUP OF DISEASES

The diseases which may be grouped together as inflammations of the intestinal tract, and which possess in common the symptom diarrhea, were of much less importance during the World War than during any previous major conflict of which we have record. It will be the main attempt of this chapter, therefore, to show not only the fact of the greatly decreased incidence of these diseases as compared to that of earlier wars, but to study the causes of this decrease and to deduce, if possible, from this study the lines along which further progress in their prevention may be made.

In the comparison of the rates for the diarrheal diseases obtaining during the World War with those of earlier wars we are at once faced with a difficulty arising from differences in nomenclature. The last few decades have been so fruitful of discoveries in the pathology and etiology of disease and in advances in the exactness of clinical diagnosis that the significance of many a diagnostic term as understood to-day is widely different from that accepted only a short time ago. The modern conception of dysentery is that of a clinical entity or complex characterized by an increase in the number of stools, which contain pus, mucus, and blood, accompanied by abdominal pain and tenesmus. This symptom complex may be induced by several known specific agents, of which the most important are the dysentery bacilli and the Entamoba histolytica. Of the dysentery bacilli there are several well recognized, more or less nearly related strains, and possibly other bacteria such as the paratyphoid group organisms may at times cause the same group of symptoms. Conditions permitting accurate diagnostic work, the Surgeon General accepts the diagnosis "dysentery" only when supported by evidence as to the specific causative organism. Under war conditions it usually proved impossible to carry out the laboratory studies necessary to such proof and hence by far the greater number of cases of dysentery reported during the war period were unclassified etiologically. A minority, however, were reported as of bacillary or amebic origin. Headings are found in the war tabulations for balantidic dysentery and for dysentery due to other protozoal agents.

In addition to the dysenteries properly so called, there were reported during the war a large number of cases under the headings "diarrhea," "enteritis," and "colitis," the two latter combined in the tabulations. It is self-evident on account of the clinical character of these conditions that a certain number of cases recorded as diarrhea or as enterocolitis actually may well have been dysentery, and, conversely, that some of the cases recorded as "dysentery, unclassified" might better have been called diarrhea or enterocolitis had a strict etiological classification been possible. That in general, however, the

aUnless otherwise stated, all figures for the World War period are derived from sick and wounded reports sent to the Surgeon General.-Ed.


312

distinction between the dysenteries and the nonspecific diarrheal diseases is a valid one on clinical grounds there can be no doubt as will be shown later.

In the earlier records of the United States Army little attempt seems to have been made to distinguish accurately the different types of "intestinal flux." Diarrhea, dysentery, enteritis, and colitis, as well as other now archaic diagnostic terms, were used evidently more or less interchangeably. In the Medical and Surgical History of the War of the Rebellion,1 the "fluxes" are divided into four groups: Acute and chronic diarrhea and acute and chronic dysentery. Modern diagnostic criteria were not sufficiently in use during the period of the Spanish-American War and the Philippine insurrection to make the statistics of that period much more valuable in the differentiation of the various types of intestinal disease than were those of earlier years. Indeed, in spite of increased diffusion of knowledge and of greatly increased laboratory facilities, experience during the World War has shown that under field conditions-and the greater number of these cases must be expected to occur during active campaigning-accurate differentiation is impossible. For this reason comparisons between the incidence of diarrheal diseases in the World War, and that in earlier conflicts must necessarily be based on totals of the entire group. Nor is this necessarily an unscientific or illogical method of comparison for, so far as may be said at present, the methods of transmission of the diseases of this group, varying as they do clinically and etiologically, are essentially the same. We believe that they are all acquired by the ingestion of infected food or drinkb and that consequently the underlying predisposing causes and the necessary preventive measures must be considered to be the same for all these diseases however different the specific etiology of individual cases.

Returning to the question of the nomenclature of these diseases, it is evident that in spite of the probability of some confusion in recent statistics, and of the impossibility of separating from the statistics of the past any groups comparable to those of modern tables, there can be little doubt that in the statistics of the World War the diarrheal diseases can be divided into two clinically different groups, on the one hand those which were reported as dysentery on clinical grounds and on the other those cases which were perhaps more loosely classified as diarrhea, colitis, or enteritis. The distinction between these two groups originally made by the clinicians in the individual cases is emphasized and confirmed by the study of the incidence of the two groups month by month, and by a comparison of the severity of the cases as shown by the average number of days lost from duty per case. Table 47 shows the monthly incidence rates of these diseases for the white enlisted men on duty in the United States for the period of the war. Inasmuch as these figures are not influenced by sharp variations in sanitary conditions such as occurred during operations at the front in France, they furnish a better means of comparing the varying incidence of disease than would the figures for the entire Army. The rates under the heading "Dysentery (all)" include all specifically diagnosed cases of dysentery and all cases of "Dysentery, unclassified."

bWith the possible exception of diarrheas believed by some to be due to chilling of the abdomen.


313

TABLE 47.-Diarrheal diseases. Primary admissions, white enlisted men in the United States,April, 1917, to December, 1919. Annual rates per 1,000 by months

 


Dysentery
(all)

Diarrhea

Enteritis
and colitis

Total

 

Dysentery (all)

Diarrhea

Enteritis
and colitis

Total


1917

 

 

 

 

1919

 

 

 

 

April

1.76

2.09

17.63

21.48

January

.52

2.43

4.32

7.27

May

1.76

2.49

17.11

21.36

February

.38

1.17

4.10

5.65

June

2.41

4.70

23.75

30.86

March

.38

1.59

4.45

6.42

July

.63

5.44

26.88

32.95

April

.35

2.19

3.85

6.39

August

.87

6.21

43.36

50.44

May

.74

2.59

4.98

8.31

September

1.28

6.54

32.05

39.87

June

.49

3.06

8.85

12.40

October

.72

4.86

17.75

23.33

July

.28

4.07

10.88

15.23

November

.64

1.04

7.76

9.44

August

.23

5.43

14.85

20.51

December

.34

.69

6.72

7.75

September

.56

3.54

9.40

13.50

1918

 

 

 

 

October

.43

5.83

6.52

12.78

January

.36

1.20

6.75

8.31

November

.54

3.17

7.52

11.23

February

.14

.94

6.77

7.85

December

.27

2.04

8.95

11.26

March

.50

1.20

9.76

11.46

 

 

 

 

 

Average, 1917

1.16

3.78

21.45

26.39

April

.49

3.98

13.04

17.51

Average, 1918

.58

5.67

11.74

17.97

May

.79

5.28

15.62

21.69

Average, 1919

.46

3.09

7.39

10.94

June

1.17

9.78

18.70

29.65

Average for war

.64

4.89

12.92

18.45

July

.91

11.34

19.94

32.19

 

 

 

 

 

August

.69

13.66

21.69

36.04

September

.82

8.63

11.74

21.19

October

.29

4.48

6.21

10.98

November

.36

4.67

5.47

10.50

December

.38

2.83

4.31

7.52


CHART XXXVI.-The diarrheal group of diseases. Annual admission rates by months for dysentery (all), diarrhea, and enterocolitis, white enlisted men in the United States

Study of the figures given in Table 47, and the graphic comparison of the rates shown in Chart XXXVI, which is drawn from the same figures on a logarithmic scale of ordinates, leads to the conclusion that while the rates for cases classed as "diarrhea" and those for "enterocolitis" rose and fell together in almost perfect correlation, the cases classed as "dysentery" varied independently, showing not nearly so much seasonal variation, and the curve for dysen-


314

tery is quite independent of that for diarrhea or that for enterocolitis. We are thus justified on statistical grounds in assuming that the distinction made by the reporting officers is an entirely valid one. We are further supported in this conclusion by the analysis of the severity of the average case as shown by the number of days lost from duty per case under each heading. Three thousand five hundred and forty-seven cases of dysentery in white enlisted men accounted for the loss of 99,561 days, or 28.3 days per case. There were 19,125 cases classed as "diarrhea," with 215,420 days lost, or 11.2 days per case. Enterocolitis resulted in the loss of 605,811 days among 56,865 cases, the average case losing 11.4 days from duty. It is seen that the two latter conditions were of equal severity, while the dysentery cases averaged much greater severity. It seems amply justifiable, therefore, to divide the consideration of these diseases into two groups, the dysenteries, on the one hand, and the cases reported as "diarrhea" and as "enterocolitis," on the other. Both groups are doubtless of mixed etiology. In the dysentery group we shall find some data for conclusions as to the relative importance of the recognized inciting agents in the period of the war. In the second group no specific statements as to bacterial or protozoal etiology are possible.

Table 47 shows the further interesting fact that the rates for all classes of diarrheal diseases showed a marked tendency to decrease as time passed. The highest rates were shown during the first months of mobilization, during the period of voluntary recruiting, and before the completion of the great training camps and cantonments which housed the National Army during the period of preparation. During the following year, 1918, although the camps were constantly filled with recruits as the older troops were sent to the front, the rates for these diseases showed a definite decline. This may probably be best explained by the improved environmental conditions possible in the completed camps and by the results of training in sanitary matters. However, the rates for 1919 showed a still further improvement. During this year the camps were the scene of the rapid demobilization of the Army. Men returned from abroad and passed rapidly to the camp selected for discharge. Conditions were not as favorable for maintaining a high sanitary standard as was the case in the previous year, though every effort was made to do so. It may be permissible to argue that the low rates during demobilization indicate that in the intestinal infections as in those of the respiratory tract the seasoned soldier shows a greater resistance than does the recruit.


315

TABLE 48.-The diarrheal diseases (dysentery, acute and chronic, and diarrhea). Admissions and deaths, absolute numbers and ratios per 1,000 per annum, white enlisted men, United States Army, 1819 to 1919

aFor years 1819-1848, inclusive, statistics are for the year ending Sept. 30, for the years 1849-1882, inclusive, year ending June 30; for the years 1883-1919, inclusive, year ending Dec. 31.
bCholera epidemic, Black Hawk War.
cNo strength records available for these years.
dCovers period of Mexican War (1847-48).
eCivil War period: Ratios per 1,000 per annum for deaths, based on following strengths: 1862, 288,919; 1863, 659,955; 1864, 675,412; 1865, 645,506; 1866, 101,897; 1867, 40,183.
fYears 1898-1903, inclusive, covers period of Spanish-American War and Philippine insurrection; also covers period; of the China expedition. (1900-01).
gThese two years (1898-99) not tabulated separately; does not include enteritis.
hReported as "other diarrheal diseases," but does not include dysentery and enteritis.
iPrevious to this year, officers were included with white enlisted men; beginning 1904 they are excluded.
j1916 includes enteritis.
kCovers period of World War, through period of demobilization.


316

Table 48 and Chart XXXVII, drawn from the same figures on a logarithmic scale of ordinates, show the experience of the United States Army with diarrheal diseases for the 100-year period 1819-1919. Inasmuch as in the earlier years there were no colored enlisted men in the Army, the figures are for white enlisted men throughout. The rates are the total of dysentery, diarrhea, enteritis, and colitis, since for the reasons given no accurate differentiation of these diseases is possible during this period. While there are periods for which no figures are available it is evident that there has been a definite downward trend in the rates for admissions and deaths from these diseases broken only by wars and mobilizations. The figures for the Mexican War period are missing, but reports indicate that the rates for diarrhea and dysentery were excessively high at that time. The additional conclusion from these figures is that during the century each war showed a decreasingly great increase in the incidence of the diarrheas over the preceding peace-time figures. This tendency culminated in the World War, during which the rates for the combined diarrheal diseases were actually lower than at any previous time in the history of our Army.

CHART XXXVII.-The diarrheal group of diseases. Admissions and deaths in the United States Army, 1819 to 1919. Annual rates per 1,000 strength.

Some details of this record will be considered later and further comparisons made. Here it will suffice to point out that while in the record of the Civil War a large volume was required for the consideration of these diseases, here they occupy but insignificant space. In the Spanish-American War and Philippine insurrection, the dysenteries and diarrheas formed a formidable proportion of the total illnesses afflicting the troops. It should be remembered in this connection, however, that these campaigns were conducted in tropical countries and the special liability to intestinal disease of troops serving


317

in the Tropics has long been recognized. Doubtless some of the freedom from these diseases enjoyed by the Army in the World War was the result of the geographical location of the territory occupied, but making all allowance for this factor it becomes evident that the disparity in rates for diarrheal diseases between the World War and those preceding it must be mainly due to improved methods and practices of sanitation.


318-319

TABLE 49.-Dysentery (all), diarrhea, and enterocolitis. Officers and enlisted men, United States Army, by countries of occurrence. Primary admissions, deaths, discharges for disability, and noneffectiveness, absolute numbers and ratios per 1,000 per annum, April, 1917, to December, 1919


320-321

TABLE 49.-Dysentery (all), diarrhea, and enterocolitis. Officers and enlisted men, United States Army by countries of occurrence. Primary admissions, deaths, discharges for disability, and noneffectiveness, absolute numbers and ratios per 1,000 per annum, April, 1917, to December, 1919-Continued


322

OCCURRENCE IN THE WORLD WAR

A general view of the occurrence of the diarrheal group of diseases during the World War is given in Table 49. The figures are not only for the Army as a whole but also for those fractions stationed in the principal geographical locations occupied by our troops. The cases are grouped under four headings, "Dysentery (all)," which includes the unclassified cases as well as those etiologically diagnosed, "Diarrhea," and "Enterocolitis," the latter including cases reported as either enteritis or colitis. The fourth heading gives the total of the three named, thus representing for the World War period a close approximation to the totals given for the preceding century in Table 48. The absolute numbers under each heading are for the period of the war. The corresponding rates per thousand are based on a strength aggregate obtained by the summation of the mean strength for each year, the resulting rate being an annual rate per thousand strength. In the case of the noneffective rate the annual figure is further divided by 365 to give a rate directly comparable to the usual average noneffective rate of Army reports, which represents the number of men per thousand constantly excused from duty for any given cause.

Of the total of 92,512 admissions only 4,738 were reported as dysentery cases, or 5.12 per cent of the group. It is probable, owing to the policy of the Surgeon General already referred to, of requiring an etiological diagnosis in reports of cases of dysentery whenever facilities for such work are available, that a certain proportion of cases of dysentery were reported under the other headings as diarrhea, or more probably as enteritis or colitis. However, a most liberal estimate of such cases could not more than double the probable number of dysentery cases and that would mean that but 10 per cent of the diarrheal group of diseases were dysentery. In the Philippines and in Panama that proportion was exceeded, but there is no reason for extending the effect of tropical environment to the mass of the Army. It would appear, then, that a striking fact in the figures before us is that the proportion of cases of the serious or fatal type, true dysentery, was small compared to the total of the group. That the total incidence, while impressive in absolute numbers of cases, was not of serious import in loss of man power, is shown by the annual admission rate of 22.41 per annum, which, distributed over a year, would mean a little less than two cases per month for each thousand men. As the greater number of these admissions were for the milder types of intestinal disturbance, the total number of days lost from duty on account of diseases of this group amounted to only 1,061,229, a figure that gives a noneffective rate for the period of 0.71, which means that on the average 1 man in a little over 1,400 was excused from duty on account of one of these conditions.

The loss to the Army by deaths due to this group totaled 267, with an annual rate per thousand of 0.07, or 1 death per year in each 14,282 men. An even smaller number of men were lost to the service by discharge for disability, namely, 243, which gives a rate of 0.05 per thousand per annum, or 1 each year to 20,000 men.

As a measure of the progress made in military sanitation in the last half century it is instructive to compare the record given above with that of the Civil War. There were during that conflict 1,585,196 cases of diarrhea and dysentery


323

in an average strength of 2,193,427 white troops.1 Had the same rate prevailed in the World War there would have been 2,601,915 cases among white troops. Had the incidence rate for colored troops in the Civil War obtained in the World War there would likewise have been 240,517 cases among our colored soldiers, a total of 2,842,432. As a matter of fact there were reported as diarrhea and dysentery during the World War but 27,171 cases, or less than 1 per cent of the number that would have obtained had Civil War conditions been repeated. If we include the enterocolitis cases reported during the World War the total, already given, is 92,512, or, roughly, 3 per cent of the cases to have been expected at Civil War rates.

In the Civil War there were 37,794 deaths among white troops and 6,764 among colored troops charged to dysentery and diarrhea. At these rates there would have been 62,021 deaths among white soldiers and 10,427 among the colored in the recent war, a total of 72,448. The total deaths ascribed to this group of diseases in 1917-1919 was only 267, a saving of 72,181 lives. It is perhaps claiming too much to attribute this impressive difference entirely to advances in sanitation and therapeutics, as other factors such as differences in the geographical location of the campaigns, questions of the nomenclature and classification of disease, may have entered into the comparison; but however explained, the impressive fact remains that this enormous saving of life and disability has been accomplished not only in this group of diseases but in the related typhoid-paratyphoid group as well. Instead of being the most important cause of illness and death in the Army, the diarrheal group ranked seventh among diseases for admissions, tenth for deaths, and twelfth for days lost from duty. That, nevertheless, these diseases are an ever-present menace to armies, and that military concentrations, especially under active service conditions, still present dangers from intestinal infections is shown by Table 50, which compares the death rates obtaining in the Army during the World War with those of the comparable age and sex groups in the United States registration area for the same period. It is seen that the Army rate for dysentery is ten times that of the civilians, for diarrhea and enteritis seven times, and for the group as a whole a little more than seven times as great.

TABLE 50.-Diarrheal group of diseases. Comparative mortality in the United States Army during the World War, and the United States registration area, males, age 20-34, 1917-1919. Annual death rates per 1,000

 


Registration area,a males, 20-34

U.S. Armyb

Dysentery

0.002

0.02

Diarrhea and enteritis

.007

.05

     


     Total

.009

.07

aCompiled from Mortality Statistics, Bureau of the Census, 1917-1919.
bReports of sick and wounded, S. G. O. 1917-1919.

Certain other facts are brought out by Table 49 which are worthy of more than passing notice. The admission rates for the group were approximately the same for officers and men whether stationed in the United States or in Europe. The same is true of the death rates for those stationed in the United States.


324

In Europe, however, the death rate for the group is much higher for enlisted men than for officers. This fact will be referred to again in the discussion of dysentery. In general, the rates for admissions and deaths in this group are much higher in Europe than is the case with troops in the training camps at home. That this was due to the stress of battle conditions is evident from the monthly rates for the diseases in question, which show that great military activity was always accompanied by an increase in the incidence of diarrhea.

The prevalence of diarrheal disease in our Army in Europe was undoubtedly greater than the figures of Table 49 would indicate. Many of the cases were of a mild type and as such were not made a matter of record. Moreover, early in the war only hospital admissions were recorded in Europe. The following quotation gives an idea of the general prevalence of the diarrheal diseases during the summer of 1918 in the American Expeditionary Forces.2

Epidemic diarrheas, with a considerable amount of dysentery and probably some unrecognized typhoid and paratyphoid fevers, developed in various parts of France late in June, appearing first in the more southern areas occupied by our troops, and wherever insanitary disposal of human wastes, fly breeding, and insufficient precautions in the preparation and serving of food prevailed. Immediately after the Chateau Thierry operation the troops suffered quite generally from diarrheal diseases, probably as many as 70 per cent having been so affected. This was inevitable under the conditions of a hard-fought and prolonged battle which made even the elementary principles of sanitation impracticable of application. Inadequate and ill-prepared food, chilling of the body at night, polluted water sources, and the plague of flies, which bred and fed upon human excreta everywhere exposed and upon the dead bodies of men and draft animals upon the battle fields, combined to produced a widespread epidemic of diarrhea among which was a certain proportion of true dysentery and typhoid-paratyphoid infections. Most of the cases never reached a hospital or obtained medical treatment. Spontaneous recovery in a few days was the rule. The enthusiasm of the victorious forward movement of the troops carried many men out of reach of hospitalization, and a true measure of noneffectiveness from that epidemic can only be guessed. A small number of serious and persistent infections found their way through the evacuation hospitals to the base hospitals, and of these the great majority examined early in the course of their disease were found to be suffering from true dysentery caused by well-known strains of bacilli. Fortunately the type of the infection was mild and very few deaths resulted from the entire epidemic. The disease prevailed during the warm weather while the fly-breeding season continued. In a few favored places, where medical care was combined with adequate physical equipment to avoid fecal exposure and pollution of food and water, only an occasional case of diarrhea developed and entire organizations escaped infection, but in the main the disease prevailed throughout the American Expeditionary Forces from July to the middle of September.

That these diseases continued through the fall of 1918, during the Meuse-Argonne operation and immediately thereafter, is shown in the following report of the surgeon of the Second Army.3

The movements of the 79th Division troops during October and November took them into the region formerly occupied by German troops around Etraye, Reville, Crepion, Gibercy, and Damvillers, where the Germans had a hospital with considerable intestinal disease, some of their latrines being reserved for "intestinal cases." Previous to this the troops, while in action in November, drank water from shell holes, springs, and wells. Diarrhea developed so that estimates of regimental medical officers ranged from 50 to 75 per cent of the command.


325

A mobile laboratory investigated the outbreak in the 79th Division and from the report it appears that there were cases reported as diarrhea which in reality were typhoid fever. The investigation also extended to the 7th Division, where a great many soldiers were examined for the typhoid carrier state. Of 100 kitchen personnel examined, 25 per cent gave a history of having had "bowel trouble."

A report from Base Hospital No. 89 shows the difficulty of classifying the diseases generally listed as "diarrhea."4

The cases of infectious diarrhea, which come to the hospital by the score, were nearly always in soldiers who had been ill for many days. The stools of practically every case were examined bacteriologically, but we were never able to find amebæ or the organisms of bacillary dysentery, although we all felt sure that the latter was the cause of the symptoms present. Numerous organisms resembling the bacillary types were isolated, but none of them agglutinated with known sera.

Of the relatively small bodies of our troops stationed in various parts of the world other than the United States and Europe, some were in tropical countries and such generally suffered more severely from the diarrheal diseases, especially from true dysentery. By far the highest admission and death rates for the diarrheal group in white enlisted men in the Army was shown by the force of about 17,000 men stationed in the Philippine Islands. The admission rates in Panama were not notably above the average for the group, though there was a disproportionately large incidence of a nonfatal form of dysentery. The incidence in Hawaii was about the same as that in the United States.

An interesting racial difference appears when the rates for white and colored troops are compared. Almost without exception admission rates in these diseases are definitely higher for the white soldier, sometimes several times as high. On the other hand, the greater fatality of the individual case in the negro brings his death rate up to or higher than that of the white. From the standpoint of noneffectiveness, the negro shows to excellent advantage, as his noneffective rate for the diarrheas is definitely less than that of the white.

The native Porto Rican and native Filipino soldiers, also of races indigenous to the Tropics, manifest no such advantage. After the whites in the Philippines, these groups showed the highest susceptibility to diarrheal diseases. It is perhaps possible that the colored American soldier benefited from the effects of discipline and sanitary training. The colored troops in the Tropics were in organizations of long service.

There were considerable differences in the rates of different training camps in the United States. In general the camps showing higher rates were more apt to be located in the Southern States than were camps showing low rates. The camps showing the highest annual admission rates were Camp Hancock, Ga. (27.21); Camp Beauregard, La. (26.91); Camp MacArthur, Tex. (26.51); and Camp Doniphan, Okla. (27.70). The lowest rates for admissions were Camp Forrest, Ga. (4.34); Camp Eustis, Va. (6.93); and Camp Fremont, Calif., (4.48).


326

THE DYSENTERIES

OCCURRENCE

In the discussion of the prevalence of true dysentery during the World War it is not permissible to rely exclusively on the records. Statistical tables are not always to be regarded as complete in themselves, nor are the various figures of which they are composed to be regarded as conveying always entirely truthful impressions, unless they are interpreted with some knowledge of the sources of the information which entered into their compilation, and of the difficulties which beset those making the original reports. Several of the difficulties which serve to render the recorded figures for the dysenteries an understatement of the actual facts have been brought out in the previous pages. The clinical characters of mild dysentery are so similar to those of a nonspecific enterocolitis that some confusion is to be expected in the reports of these conditions. It has already been pointed out that the number of days lost per case in dysentery as reported was much greater than was the cases in the nonspecific diarrheas. One is justified, therefore, in assuming that, as a class, the cases reported as diarrhea and as enteritis or colitis were different from and milder than the cases of dysentery. That some cases of dysentery were included in the epidemics of intestinal disease experienced by the troops at the front during periods of great military activity has been indicated by several reports quoted above. Also that an undetermined but probably large number of these cases escaped hospitalization entirely and were probably never reported at all. Of those which did reach hospitals and were reported as cases of diarrhea or enterocolitis, it is probable that many were true dysentery, although no specific diagnosis could be made. This was the opinion expressed in the report from Base Hospital No. 98 already quoted.

If a considerable proportion of the more severe dysentery cases were included under the headings "diarrhea" and "enterocolitis" it would serve to increase the average severity of the latter cases and increase the number of days lost per case, and also the case fatality. Of the 9,604 cases of diarrhea reported in white enlisted men in the United States (Table 49), only one proved fatal, a fatality of slightly over one one-hundredth of one per cent. The average duration of these cases was three and three-tenths days. Of the 8,921 cases reported from Europe, 16 were fatal, 0.18 per cent, and the average of the days lost was 20. The corresponding figures for enterocolitis in the United States were, case fatality 0.082 per cent with 5.5 days lost per case, and in Europe, fatality 0.43 per cent and 14.7 days lost per case. It is evident that some element was present in the European cases which greatly increased the severity of the average. That this was the inclusion under these headings of a certain number of cases of true dysentery is probable for all of the reasons given. An exact estimate of the number of cases so included is manifestly impossible, but judging from the excess number of deaths per thousand cases in Europe over the corresponding figures from the United States, and applying to these deaths the case fatality of the reported dysentery cases, it seems possible that the true incidence of dysentery was not far from


327

double that shown in the tables. This conclusion does not in any way vitiate the comparison already given between recent rates and those of the Civil War, as that comparison was based on totals of the entire group and not on dysenteries alone.

ETIOLOGIC TYPES

Here again in order to properly evaluate the figures given it is necessary to appreciate certain facts in regard to the difficulties in the specific diagnosis of a given case of dysentery. The isolation of the specific dysentery bacilli from the stool of a patient depends for its success upon a combination of circumstances not easily attained under war conditions, indeed not always possible of attainment under most favorable surroundings. After the possession of adequate facilities the most important of these conditions are that the stool should have been recently passed, and that the patient should have been in the very early stages of his disease. The latter requirement is probably explained by the early development in the intestines of the bacteriophage of d'Hérelle, which inhibits growth of the specific organism. Under war conditions, therefore, when adequate laboratories were not always available, when stools were often necessarily delayed on the way to the laboratory, and when the majority of patients had been ill for several days before reaching a hospital at which bacteriological work could be initiated, it should be expected that many, probably a majority, of the cases of true bacillary dysentery should fail of bacteriological confirmation.

In a way the reverse is true of entamebic cases. It is coming to be more and more generally recognized that finding E. histolytica in the stool does not constitute valid grounds for the diagnosis of amebic dysentery. Of all individuals who harbor the entameba in their intestines, only a small proportion, probably not over 3 per cent, ever develop dysenteric symptoms. The others remain healthy carriers as evidenced by the more or less constant evacuation of the cysts of the organism. When such a carrier becomes affected with any diarrheal disease, the trophozoites or active vegetative forms of the organism are carried down and evacuated, and their discovery may lead to a diagnosis of amebic dysentery not justified by the facts. As will be shown later, a considerable proportion of our troops returned from France carrying this organism in their intestines. It seems probable that a certain percentage of cases on record as amebic dysentery were probably of bacillary origin in carriers of the entameba. Two circumstances fortify this conclusion. First, the entameba is readily identified under the microscope, especially as compared with the difficult and time-consuming process of isolation of the dysentery bacilli. Secondly, the cytologic methods by which it is now possible to distinguish with great accuracy between the two main types of dysentery had not at the time of the World War been perfected, but since, in the hands of Willmore and Shearman,5 Manson-Bahr,6 and Haughwout,7 have attained great reliability.

All these considerations lead to the conviction that the number of cases of bacillary dysentery were understated in the records, that that of the amebic cases was overstated, and that the majority of the cases reported as dysentery unclassified were probably in reality of the bacillary type. This was undoubtedly especially true in Europe where the dysentery cases occurred in


328

epidemic groups since, owing to the biological peculiarities of the organism, amebic dysentery is rarely known to occur in epidemic outbreaks.

Tables 51 and 52 show the incidence of the various types of dysentery in white enlisted men by months in the United States and in Europe. In Europe bacillary and amebic dysentery and the unclassified group as well, varied in a closely correlated manner. This would hardly be expected in two conditions epidemiologically so different as bacillary and amebic dysentery. In the United States, where there were no epidemic outbreaks of the disease, but only the slower seasonal variations, it is possible to compare the curve of the unclassified group with those of the bacillary and amebic cases in the attempt to see which pair are the more closely correlated. The curves are shown in Chart XXXVIII. That for bacillary dysentery ends with 1918, as but one case of this disease was reported during 1919. It is seen that the curve for bacillary dysentery more closely approximates that of the unclassified dysenteries than does the curve for amebic cases. The number of cases classified each month was so small that the comparison loses some of its value, but for as much as it is worth it bears out the conclusion already arrived at that the great majority of the cases reported in the tables as "dysentery unclassified" were in fact bacillary cases.

CHART XXXVIII.-Dysentery, incidence by etiologic types by months, annual rates per 1,000, white enlisted men, United States Army, in the United States.


329

TABLE 51.-Dysentery. Incidence by types, and annual ratios per 1,000 by months, white enlisted men, United States Army, in the United States, April, 1917, to December, 1919

 

Strength


Bacillary

Balantidic

Entamobic

Other protozoal

Unclassified

Total

Absolute numbers

Annual ratios per 1,000

Absolute numbers

Annual ratios per 1,000

Absolute numbers

Annual ratios per 1,000

Absolute numbers

Annual ratios per 1,000

Absolute numbers

Annual ratios per 1,000

Absolute numbers

Annual ratios per 1,000

1917

 

 

 

 

 

 

 

 

 

 

 

 

 

April

183,758

0

---

---

---

14

0.91

---

---

13

0.85

27

1.76

May

245,454

0

---

---

---

15

.73

---

---

21

1.03

36

1.76

June

309,205

3

0.12

---

---

28

1.09

---

---

31

1.20

62

2.41

July

458,817

1

.03

---

---

11

.29

---

---

12

.31

24

.63

August

562,714

5

.11

---

---

24

.51

---

---

12

.26

41

.87

September

776,466

12

.19

---

---

19

.29

---

---

52

.80

83

1.28

October

1,032,244

9

.10

---

---

19

.22

1

0.01

33

.38

62

.72

November

1,061,422

14

.16

---

---

28

.32

2

.02

13

.15

57

.64

December

1,129,065

1

.01

---

---

28

.30

---

---

3

.03

32

.34

1918

 

 

 

 

 

 

 

 

 

 

 

 

 

January

1,096,434

1

.01

1

0.01

16

.18

---

---

15

.16

33

.36

February

1,095,039

1

.01

---

---

3

.03

---

---

9

.10

13

.14

March

1,129,223

6

.06

---

---

11

.12

1

.01

29

.31

47

.50

April

1,168,558

5

.05

---

---

13

.13

---

---

30

.31

48

.49

May

1,197,757

10

.10

---

---

30

.30

---

---

39

.39

79

.79

June

1,303,746

12

.11

---

---

27

.25

2

.02

86

.79

127

1.17

July

1,328,513

6

.05

---

---

35

.32

4

.04

56

.51

101

.91

August

1,284,247

4

.04

---

---

15

.14

2

.02

53

.50

74

.69

September

1,321,440

5

.05

---

---

27

.25

1

.01

57

.52

90

.82

October

1,343,933

1

.01

---

---

12

.11

1

.01

19

.17

33

.29

November

1,255,195

1

.01

---

---

15

.14

1

.01

21

.20

38

.36

December

941,219

2

.03

---

---

15

.19

1

.01

12

.15

30

.38

1919

 

 

 

 

 

 

 

 

 

 

 

 

 

January

672,937

0

---

---

---

11

.20

---

---

18

.32

29

.52

February

471,815

0

---

---

---

5

.13

---

---

10

.25

15

.38

March

406,839

0

---

---

---

5

.15

---

---

8

.24

13

.38

April

339,836

0

---

---

---

2

.07

---

---

8

.28

10

.35

May

291,810

0

---

---

---

7

.29

---

---

11

.45

18

.74

June

246,903

0

---

---

---

7

.34

---

---

3

.15

10

.49

July

215,104

0

---

---

---

5

.28

---

---

0

---

5

.28

August

156,791

0

---

---

---

2

.15

---

---

1

.08

3

.23

September

149,360

0

---

---

---

3

.24

---

---

4

.32

7

.56

October

139,877

0

---

---

---

2

.17

---

---

3

.26

5

.43

November

132,403

0

---

---

---

3

.27

---

---

3

.27

6

.54

December

135,441

1

.09

---

---

1

.09

---

---

1

.09

3

.27

    

Total

1,965,297

100

.05

1

0

458

.23

16

.01

686

.35

1,261


.64


330

TABLE 52.- Dysentery. Incidence by types, and annual ratios per 1,000 by months, white enlisted men, United States Army, in Europe, April, 1917, to December, 1919

 

Strength


Bacillary

Balantidic

Entamobic

Other protozoal

Unclassified

Total

Absolute numbers


Annual ratios per 1,000

Absolute numbers

Annual ratios per 1,000

Absolute numbers

Annual ratios per 1,000

Absolute numbers

Annual ratios per 1,000

Absolute numbers

Annual ratios per 1,000

Absolute numbers

Annual ratios per 1,000


1917

 

 

 

 

 

 

 

 

 

 

 

 

 

April
May
June

13,420

1

0.89

---

---

---

---

---

---

1

0.89

2

1.79

July

28,821

2

.83

---

---

1

0.42

---

---

4

1.67

7

2.91

August

50,882

---

---

---

---

---

---

---

---

1

.24

1

.24

September

70,266

---

---

---

---

1

.17

---

---

2

.34

3

.51

October

92,139

---

---

---

---

3

.39

---

---

2

.26

5

.65

November

123,429

---

---

---

---

3

.20

---

---

7

.68

10

.97

December

160,178

---

---

---

---

2

.15

1

0.07

9

.67

12

.90


1918

 

 

 

 

 

 

 

 

 

 

 

 

 

January

193,264

3

.19

---

---

1

.06

---

---

5

.31

9

.56

February

223,130

1

.05

---

---

0

---

---

---

2

.11

3

.16

March

283,268

2

.08

---

---

3

.13

---

---

3

.13

8

.34

April

388,048

0

---

---

---

---

---

1

.03

5

.16

6

.19

May

587,240

1

.02

---

---

3

.06

0

---

5

.10

9

.18

June

796,427

1

.02

---

---

2

.02

0

---

7

.11

10

.15

July

1,063,192

55

.62

3

0.03

8

.09

2

.02

53

.60

121

1.37

August

1,266,592

67

.63

1

.01

21

.20

2

.02

275

2.61

336

3.47

September

1,527,793

34

.27

---

---

25

.20

2

.02

314

2.47

375

2.95

October

1,635,321

38

.28

---

---

11

.08

4

.03

493

3.64

546

4.01

November

1,682,836

9

.06

---

---

13

.09

0

---

239

1.70

261

1.86

December

1,591,962

5

.04

---

---

6

.05

1

.01

91

.69

103

.78


1919

 

 

 

 

 

 

 

 

 

 

 

 

 

January

1,488,683

3

.02

---

---

6

.05

---

---

26

.21

35

.38

February

1,310,083

1

.01

---

---

5

.05

---

---

22

.20

28

.26

March

1,115,693

0

---

---

---

1

.01

---

---

2

.02

3

.03

April

853,425

0

---

---

---

1

.07

---

---

3

.04

8

.11

May

569,842

0

---

---

---

0

---

---

---

0

---

0

---

June

271,633

0

---

---

---

0

---

---

---

5

.22

5

.22

July

111,634

4

.43

---

---

1

.11

---

---

4

.43

9

.97

August

48,006

15

3.75

---

---

1

.25

---

---

6

1.50

22

5.50

September

30,315

0

---

---

---

2

.79

---

---

1

.40

3

1.19

October

21,055

1

.57

---

---

1

.57

---

---

0

---

2

1.14

November

18,920

0

---

---

---

0

---

---

---

0

---

0

---

December

18,379

0

---

---

---

0

---

---

---

0

---

0

---

Not stated

18,379

0

---

---

---

0

---

---

---

3

---

3

---


     Total

1,469,656

243

.17

4

0

125

.09

---

---

1,590

1.08

1,975

1.34

Seventy per cent of the dysentery cases were reported without etiologic classification (Table 53), 47 per cent in 1917, 78 per cent in 1918, and 52 per cent in 1919. The proportion so reported varied greatly from month to month, usually highest when the absolute number of cases was greatest especially in the European cases. Of the classified cases, those reported as amebic consistently exceeded those called bacillary. During the World War (Table 53) there were reported 926 amebic cases to 460 demonstrated as bacillary, a proportion of nearly 2 to 1. Inasmuch as, combined, these two groups represented less than a third of the cases of dysentery, and as we have shown the probability that most of the other two-thirds were of bacillary origin as well as perhaps some that were reported as amebic, we shall not be greatly in error if we assume that the true proportion should be not far from five cases of bacillary dysentery to each amebic case.


331

TABLE 53.- Dysentery (all types). Primary admissions, United States Army, 1917 to 1919 shown by etiological types. Total cases in the United States and Europe. Absolute numbers

 


Cases

Bacillary

Balantidic

Amebic

Other protozoal

Unclassified

Total dysenteries in 1917

688

69

2

291

3

323

    

United States

484

50

0

195

2

237

    

Europe

41

3

0

10

1

27

Total dysenteries in 1918

3,573

325

6

428

30

2,784

    

United States

883

70

2

239

14

558

    

Europe

2,431

244

4

105

15

2,063

Total dysenteries in 1919

577

66

2

207

---

302

    

United States

151

3

0

62

---

86

    

Europe

188

31

0

43

---

114

        


           Total for the period

4,838

460

10

926

33

3,409

A few cases, as shown in the tables, were reported as of balantidic or other protozoal origin. The former organism is generally recognized as occasionally pathogenic with the production of chronic dysenteric symptoms. As for ciliates or other protozoa, however, the evidence of their pathogenicity is very doubtful, and the opinion is rather generally held among those qualified to judge that the finding of ciliates in a case of dysentery is an accidental occurrence without significance etiologically. In any case the number of cases so reported was so small as to merit no further consideration here.

PREVALENCE AND DISTRIBUTION

Bearing in mind the considerations just stated and the conclusions that in all probability the actual number of cases of true dysentery was twice that reported in the tables, and further that the reported proportion of amebic to bacillary cases can not be relied upon, but that we shall not greatly err if we assume that there were in fact about five bacillary cases to each of the amebic type, it is still possible to glean from the tables as reported information of great comparative value. It is possible to state from them the relative incidence in different countries and in different races.

Of the 4,738 cases of dysentery reported, between April 1, 1917, and December 31, 1919, 254 were in officers and 3,547 in white enlisted men. The incidence of reported cases in officers was 1.23 per thousand per annum, while that for enlisted men was 0.99. One death only occurred among the officers and 54 among the white soldiers. The latter figure gives a death rate of 0.02 per thousand per annum, while the officers' rate is too small to be considered and is recorded as 0. In the troops in the United States there were 107 cases in officers (0.86 per 1,000 per annum) and 1,261 in white enlisted men (0.64). One officer and 14 enlisted men (white), died, a death rate in each case of 0.01 per thousand per annum. In Europe there were 133 cases in officers (1.80) and 1,975 among the white enlisted men (1.34), while there were no deaths from dysentery among officers and 35 among white soldiers (an annual rate of 0.02 per thousand).


332

These figures show that both in Europe and in America the incidence of dysentery was higher among officers than among enlisted men, but that, among officers, the type of the disease was less severe, the death rates, low as they were, were higher in the case of the enlisted men. The incidence among officers was a little more than twice as high in Europe as in the United States and the relative proportion among enlisted men comes to exactly the same figure, in Europe being two and nine hundredths times the incidence of those in the United States. Remembering the practical certainty that many other dysentery cases occurred in the troops in Europe, we must assume that the true ratio of incidence in Europe to that in the United States was probably nearer 4 than 2 to 1. The type of the disease was more severe in Europe, or perhaps treatment less prompt and efficacious on account of battle conditions. This is shown by the difference in the case fatality in the two places, 1.11 per cent in the United States and 1.77 per cent in Europe. This difference is less than could reasonably be expected considering the difference in conditions. Comparisons of the number of cases of discharge for disability between Europe and America are valueless, as large numbers of men were so discharged in America for disease originally contracted in France. There were 70 cases discharged for disability in the United States and only 8 in Europe. The greater severity of the European cases is  further shown by the average number of days lost per case, 24.6 in the United States and 31 in Europe. These figures are for all types of dysentery. A division into bacillary and amebic types would bring the figures down to such small size as to render averages valueless and conclusions unreliable.

In the Philippines, white troops encountered a more severe type of dysentery and conditions which rendered them more likely to contract the disease than was the case at home. Their rate of 8.94 per thousand per annum was more than four times the rate for the troops in Europe for the entire war period (1.34). In October, 1918, at the height of military activity in France there was a reported rate of 4.01. As this was the time when the greatest number of cases necessarily went unreported, and as by no means all of our troops in France were in the battle area, it is evident that the troops in the battle area must have been exposed to infection much more effectively than was the case in the Philippines for troops living under peace conditions. The Filipino strain of dysentery was more fatal, however, as is shown by the comparison of the case fatality rates, 1.77 per cent in Europe and 2.63 in the Philippines. The yearly death rate per thousand in the Philippines was 0.24, twelve times that of the Army as a whole.

In Hawaii, the case rate for white enlisted men was far below the average for the Army and there were no deaths. In Panama, 28 cases gave a rate of 1.42 per thousand per annum, but there were no deaths. This does not necessarily indicate a milder type of the disease, as the case fatality elsewhere was so low, from 1 to 2 per cent, that deaths would hardly be expected among 28 cases.

All the figures in the comparisons given above relate to white enlisted men or officers. Some interesting points are brought out by the study of the figures for the colored troops. (Chart XXXIX and Table 49.) In the first place, for the whole Army the incidence rates for the colored troops are 20 per cent lower than


333

CHART XXXIX


334

those for white troops, while their death rates are 50 per cent higher. The negro appears less likely to become infected with dysentery, but offers less resistance to the disease once acquired. The case fatality in the colored was 3.64 per cent for the whole Army; that in the white troops 1.52. The number of cases in the colored troops, 220 for the entire period, was so small, however, as to somewhat lessen the value of this comparison. The rates for colored troops were lower in Europe than in the United States. This striking difference must have been due to the large proportion of colored troops engaged in work under the better sanitary conditions of the Services of Supply. That the rate was actually lower than in the camps at home may be interpreted as supporting the idea already advanced that seasoned troops are less susceptible to intestinal infection than are recruits. In the Philippines the colored incidence rate of 2.92 was also strikingly lower than the rate for the whites, and there were no deaths among colored troops. Here again the small number of cases involved prevents drawing conclusions.

In Hawaii there were no cases of dysentery among 3,319 colored soldiers.

Of the native troops, serving in their home environment, the Filipinos and the Porto Ricans showed to poor advantage, having the highest incidence rates, 5.98 and 6.76, respectively, after the white troops in the Philippines. The number of deaths was so small as to render averages without value, but their rates as shown were far above those of the Army as a whole.

INCIDENCE BY MONTHS

Chart XL shows the varying monthly incidence of the total reported cases of dysentery in enlisted men in the United States and in Europe. It is seen that there is some tendency for the occurrence of higher rates during the summer months, with a distinct lessening of the incidence in cold weather. In the United States the rates were higher during the first three months of the war period than was the case at any time later. This fact already has been mentioned in the discussion of the incidence of the total diarrheal group. The reasons for the high rate at this time are not apparent. Of the 125 cases of dysentery reported from the white enlisted men in the United States for these three months, 57 were of the entamebic type, only 3 recognized as bacillary, and the balance, 65, were unclassified etiologically. These figures suggest that the accessions to the Army during that period of voluntary recruiting brought in an unusually large number of persons infected with the entameba. From this initial high point in June, 1917, there was a nearly uniform gradual fall in the rates until February, 1918, when they began to rise toward the second relatively high point in June of that year. From June, 1918, until May, 1919, the tendency was again downward, although the winter fall was not as low as in the previous year. From May, 1919, to the end of the year there were irregular rises and falls in the rates, but the absolute numbers of cases were so small at this time that the figures possess little value. It can be said, however, that there is little or no indication of a definite summer rise in 1919. Chart XXXVIII, which shows the monthly incidence rates for the bacillary and entamebic types of dysentery separately, together with the unclassified group, shows also


335

that in general the curves of the three classes of cases follow the same course with such minor divergencies as are to be expected from the small numbers of cases involved.

CHART XL

In Europe, too, a relatively high rate was observed in the summer of 1917. This is of little significance, however, as it was the result of seven cases in a strength of about 29,000. Two of the cases were reported as bacillary, one as entamebic, and four were unclassified. During the winter of 1917-18 the rates in Europe did not fall as low as those in the United States, but the summer rise was delayed until July, when decided military activity began, and a decidedly high rate prevailed until after the armistice began. From then until the follow-


336

ing summer the Army in Europe showed very low rates, much lower than was the case at home during the same period. In August and September, 1919, however, the rates again shot up to reach a point higher than was reported at any time during active operations. This outbreak, however, consisted of only 22 cases in a strength of about 48,000 men; 15 of the cases were recorded as bacillary, 1 as entamebic, and 6 were not classified. Perhaps the fact that at this time the army of occupation had received a large number of newly recruited replacements may account for this small outbreak. Leaving out of consideration this late peak and the one of July, 1917, on the grounds that the number of cases involved was too small to be significant, it is seen that the only high rates in the Army in Europe were those which occurred during periods of intense military activity. The conditions which of necessity prevailed during those months of battle will be described later. The death rates from the dysenteries, both in Europe and America, fluctuated so irregularly, due to the small number of cases involved, as to make their consideration useless. The same considerations prevent any conclusions from being drawn from the monthly incidence of cases among colored soldiers, or the troops in other countries than the United States and Europe.

ETIOLOGY

In spite of intensive study on the part of all the armies involved, the World War added very little of moment to our knowledge of the etiology of these conditions. Much work was done in the laboratories on the specific etiological agents, particularly of the bacillary types, and much experience accumulated confirming the knowledge previously attained as to the importance of food, feces, flies, and fingers in the mechanical transfer of the pathogenic agents. The influence of climate has long been known, and the higher rates to be expected in tropical and subtropical countries were experienced during the war as shown by the incidence in the Philippines and to some extent in Panama. The effect of race has already been discussed, and it has been shown that the colored soldier appeared to have less tendency to contract dysentery than the white soldier, but that once attacked his chances of death were greater.

More interesting and important is the consideration of the predisposing causes incidental to war conditions as shown by reports from the American Expeditionary Forces. In the camps at home conditions were well under control. In battle sanitary discipline usually was impossible of enforcement, and during the military operations at Chateau Thierry, St. Mihiel, the Argonne Forest, and elsewhere dysentery and other diarrheal conditions prevailed in epidemic form. Of the many descriptions of such outbreaks a few have been selected to give an idea of the conditions which prevailed.

August 6, 1918, a mild type of bacillary dysentery was reported in the First Army and a request made of the director of laboratories at Dijon to send an officer to investigate it.8 Accordingly a medical officer reported at First Army headquarters9 and began a study of the epidemic which had existed in that sector since early in July. It was difficult to determine the prevalence of the disease, as perhaps not more than 2 per cent of the cases were hospitalized and sick call was held very irregularly. At the time of the call for an investigation the 3d Division had 500 cases, with 60 in hospital, the 28th Division 300


337

cases, with 1 in hospital, and the 32d Division 1,200 cases, with 20 in hospital. In the 1st Battalion, 165th Infantry, it was estimated that 70 per cent of the command had diarrhea. The nature of the disease is shown by the following quotation from the report of the investigator.9

The large majority of the cases were clinically characterized by a simple though severe diarrhea, usually coming on suddenly and, in some cases, resembling the effects of a saline purge. Many cases subsided without treatment of any kind. Many yielded to simple treatment with saline cathartics, or castor oil, followed by bismuth. A great many cases persisted for three or four days and a percentage variously estimated at from 3 to 5 lasted longer and had blood and mucus in the stool. About the same percentage had a temperature of 100° or over, and a number of cases were seen by the undersigned in which the temperature was 102°, some even going up to 104°. In these cases also there was tenesmus. In many cases there were systemic symptoms consisting of pain in the muscles and back and feeling of great prostration. In the writer's own case, and in that of several nurses and doctors observed, systemic symptoms and prostration were noted. Then the condition was one of diarrhea which in perhaps 90 per cent of the cases was not accompanied by severe systemic symptoms, disabling the men merely for one, two, or three days. Among these cases, however, there were more severe ones, some of which took on the form of moderate true dysentery, a very few showing the picture of severe types of dysentery.

The report stated that diarrhea of a similar type was prevalent among neighboring French troops. Water in the entire area was bad; B. coli was present in all examinations, and it could not be regarded as safe without chlorination or boiling. Efforts at chlorination had been general, but it was frankly stated that during the time of battle it was quite impossible to chlorinate the water for the men in the more advanced posts and later it was found that water was not being chlorinated in many commands, owing in some cases to the difficulty in obtaining calcium hypochlorite. In this connection the investigator stated:9

It is our opinion that the disease may have been started by the drinking of unboiled water from contaminated sources and that some of it is being kept going in this way; nevertheless that this was not the only and main cause of the continuance of the disease was shown by such examples as the following: Mobile Hospital No. 2 had had nothing but chlorinated water since the beginning and have taken good care of their latrines, but have always been next to units with open latrines and many flies. At least 10 per cent of the command has had diarrhea. The 146th Field Artillery, as reported by Captain Stark, had only boiled water for a short period during which diarrhea appeared. Since this command, however, was subsequently scattered and detachments could not be controlled as far as drinking from unauthorized sources was concerned, water could not entirely be excluded as being in part at least responsible, and 8 out of every 10 men have had the disease.

Sanitary conditions throughout this entire area were atrocious. At first, of course, there were many unburied bodies of men and horses throughout the area; at the time of the arrival of the undersigned, human bodies had been buried, but there were still many unburied horses. The writer no longer saw any unburied human bodies, but was told that until a few days before August 10 there had still been unburied bodies and many had not been buried very deeply. Major McKoy told the writer of some German bodies that he had seen several days after the writer arrived, buried with the hands sticking out of the ground, and there were areas of the country in which on riding through in an automobile one passed through a strongly noticeable stench.

Feces disposal except in a few instances was in a condition of utter neglect. To describe well-cared-for latrines would consist merely in picking out a few exceptions. The wretched conditions of the latrines applied not only to the front and forwarded areas, but also to areas as far back as Ussy. Many latrines were seen, some at Ussy, some in the town


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of Chateau Thierry, and many in other places, consisting of shallow ditches, half or more filled with feces, with no attempt whatever to even cover them with dirt. Flies swarmed in and about them, and in some cases such as the latrine in the Chateau de la Foret near Ville Moyenne, and one in the medical supply depot of the 32d Division in Chateau Thierry, they were within short distances of messes. In addition to this, feces were deposited without any regard to latrines. In many of the woods occupied by troops there were piles of feces here and there throughout the area, on the ground, uncovered, with the paper used for cleansing purposes scattered irregularly about them. This was true not only of woods in the forward areas, but in such places as gardens at the backs of houses, such as, for instance, the one mentioned above in Chateau Thierry at the medical supply depot of the 32d Division. Again the men in the forward areas had made use, for defecating, of the shallow trenches dug for the immediate protection of a few men at a time, and no attempt had been made to cover them. This condition was true of places like the woods occupied by the 304th Field Artillery, and at Moreuil where the 77th Division units entered places previously occupied by units of the 4th Division and found them in the condition described above.

The abundance of flies was greater than the writer has ever seen anywhere before. This was probably due to the fact that the areas had been so thickly covered by breeding places, dead bodies of animals and men, and manure, and because of the coincident hot weather. During the early part of the writer's stay it was impossible to sit at a mess and eat any of the food placed on the table before myriad flies had settled upon it, and the tables in the kitchen and the food in the kitchen were at all times covered with flies.

The investigator concluded his report by saying that it was believed the epidemic of diarrhea which had been prevalent in the Paris group of the First Army was not due to any single cause. It was believed to have been started by the drinking of unchlorinated water and the contamination of food by feces; and kept alive chiefly by flies in this latter manner.

Medical officers were advised by the chief surgeon, A. E. F., of the insanitary conditions as follows:10

Intestinal flux has been quite prevalent recently in the American Expeditionary Forces. Whether we call it cholera morbus, dysentery, diarrhea, enterocolitis, or acute intestinal indigestion, we can not blink the fact that the causes of practically every case have been preventable and well within the control of the officers and men of the American Expeditionary Forces. The ingestion of dirty food and water is the simple and the correct explanation of the extensive epidemics which have caused a large burden of unnecessary suffering and inconvenience to our men in every part of France. The dirt has in 99 per cent of the cases been our own dirt and the food and water have been of our own providing. Feces have got into the food. All varieties of infecting organisms familiar to dwellers in temperate zones and plenty of tropical organisms have been identified. Among them the commonest have been Shiga, Flexner, Hiss-Y, Wheeler, paratyphoid, and the Entameba histolytica.

Do not unload the responsibility for summer diarrhea upon the filthy fly; carriers-i. e., men sick with diarrhea, typhoids, dysenterics, etc-have served food in many kitchens. Officers and men, even in parts of France far from the turmoil and disorganization of the recently captured areas south of the Vesle, constantly drink water from unapproved sources in utter disregard of orders issued for their protection. A diarrhea of only one day, followed by three days of constipation, in a negro private of Engineers was found to be due to the Flexner bacillus. Most of those clinically recovered from what seems a simple dietetic diarrhea continue, as do typhoid convalescents, to spread their infection by hand contact with their fecal discharges. That France has been well seeded must be acknowledged if one will but count the harvest. It is verily in our own hands to prevent a continuance or a recurrence.

This graphic picture of the conditions allowed to persist after a great battle, as well as the opinion expressed from headquarters, shows what may be expected when the lessons of sanitary discipline have not been sufficiently


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well ingrained upon new troops. Had the germs of cholera or even of typhoid fever been present instead of the comparatively mild strain of dysentery bacilli, the results would have been calamitous. That the American Expeditionary Forces learned its lesson and perfected its sanitary discipline is shown by the remarkably low rates for intestinal diseases which followed the signing of the armistice and to which attention has already been called.

The conditions just described served as a causative factor in the occurrence of both major types of dysentery as well as of other intestinal infections grouped in the reports as diarrhea and as enteritis and colitis. The results of such conditions have long been known and they are repeated here only to emphasize the lesson they teach.

In the matter of specific etiology of the dysenteries little of importance was added to the sum of our knowledge by the extensive research conducted not only in the laboratories of the American forces but also by all the other armies engaged. It would appear from the reports that the outbreaks of dysentery during the period of active military operations differed from those usually occurring in civil life in being of mixed etiology. In civil life an outbreak of dysentery is usually the result of one type of organism and all cases show the same type and all are directly or indirectly due to the same source of infection. In such conditions as those just portrayed, where perhaps hundreds of thousands of men are involved, the chances for the spread of infection are so favorable that several different strains or varieties of organisms find it easy to get a foothold and so not all the cases of the same outbreak are due to the same bacterial agent. In the outbreak described, the investigator9 reported that:

In several instances, dysentery bacilli were isolated which agglutinated in Shiga serum, but showed some slight irregularity on the Russell double sugar medium. But since the stock Shiga bacilli brought from Dijon showed the same irregularity on this medium, one felt justified in regarding these organisms as of true dysentery. In one case bacilli of the Flexner type were isolated. Dysenterylike organisms, but unidentified, were isolated from other cases. In two cases paratyphoid bacilli, probably B. paratyphosus were isolated from the blood.

The difficulties of isolation of this group of bacteria even under favorable circumstances have been described. It is therefore to be expected that no large proportion of successful isolations will result from any given outbreak. A few typical instances of investigations in the field follow.

In July, 1918, an epidemic of diarrhea was reported among the personnel of the 355th Infantry at Grand.11 During the 17 days covered by the report there were about 170 cases. Examination of the stools was negative for organisms of the typhoid-dysentery group and for amebæ. The blood was also negative. The outbreak was attributed to the use of polluted water.

An outbreak of diarrhea in August, 1918, in A. R. C. Base Hospital No. 111 and in Evacuation Hospital No. 5, at Chateau Thierry, was investigated.12 Eighty cases were examined bacteriologically. B. dysenteriæ Shiga was found in 4, the Flexner variety in 1, the "Y" type in 2, and the B. paratyphosus B in 2.

An investigation of an epidemic among troops in Camp No. 1 and troops in the vicinity of St. Nazaire, in August, 1918, failed to reveal any organisms of the dysentery group.13 The outbreak was thought to be due to bacterial infection of a mild type and spread most probably by water and flies.


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An officer of the base laboratory, intermediate section, reported cases of diarrheal disease at Romorantin and Gievres.14 No cases of dysentery were diagnosed at the former place, but diarrhea had been common. At Gievres one case each yielded B. dysenteriæ (Morgan 1) and B. dysenteriæ (Shiga). The cases were not of a severe type.

An epidemic in the 37th Division was investigated and in October, 1918, it was reported that the Shiga bacillus had been isolated from soldiers and from civilians living in the vicinity.15 The cases were attributed to water and to contact infection through flies.

The nature of an atypical dysentery-like bacillus found at the embarkation hospital, Newport News, Va., was investigated in September, 1918.16 The theory was advanced that the change in environment resulting from any intestinal disturbance, constipation, diarrhea, etc., invariably changed the normal flora and resulted in an increase of atypical, nonlactose, fermenting bacilli which often outgrow the causative agent. The conclusions drawn from this investigation were as follows:17 (a) The investigation failed to establish any causal relationship between atypical bacilli and dysenteric infection. (b) Repeated bacteriological tests are of value in making a diagnosis. (c) Where bacteriological results are negative or doubtful, serological tests may prove of value in establishing the cause of infection.

The importance of early examination of stools was shown by the experience with 1,050 cases from which 158 successful isolations were made. Sixty-eight per cent of the successful isolations were made in the first five days of the disease, after which the percentage of positive results rapidly diminished whether the dejecta remained characteristically dysenteric or not.

During the World War there was a tendency on the part of some workers further to subdivide the already complicated group of dysentery bacilli. Thus several varieties of para-Shiga and of para-Flexner bacilli made their appearance. The truth will probably prove to be that there are two species of dysentery bacilli represented by the Shiga and Flexner types, and that other slightly different organisms are varieties of the two main species which will prove to be more or less interchangeable. The British investigators, Willmore and Shearman,5 made the statement that almost weekly a new type of bacillus, nonmotile Gram-negative anaerogenic, nonlactose fermenting, turned up on their plates. Each new type showed infinite gradation affinities with, and divergence from, the classical in its bearing toward recognized agglutinating sera and fermentation of sugars.

From the consideration of all the reports it is apparent that we emerged from the war with the original Shiga type as the most important etiological factor in the bacillary dysenteries; the Flexner comes second. There are several allied organisms beside the paratyphoid B which seem to have entered into the production not only of true clinical dysentery but of the milder diarrheas as well.

Little has been added to our knowledge of the etiology of entamebic dysentery as the result of the war. Two new species of apparently nonpathogenic amebæ were discovered in British laboratories. The E. nana of Wenyon and O'Connor,18 and the Dientameba fragilis of Jepps and Dobell.19 The former is important in the diagnosis of entameba carriers, as the cysts at times


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resemble those of E. histolytica. Kofoid, Kornhauser and Plate20 found E. nana to be the commonest ameba found in returned American troops in the large series of examinations which they conducted.c

CARRIERS

Opinions have been divided as to the importance of carriers in the epidemiology of bacillary dysentery. The importance of the carrier in entamebic dysentery is unquestioned. Russell21 regarded acute and chronic carriers of dysentery bacilli as equally as important in the propagation of dysentery as are typhoid carriers in the spread of typhoid fever. He arbitrarily considered a patient a carrier if bacilli persisted in his discharges more than three months from the date of first symptoms. There is usually a clear history of dysentery. Carriers of the Flexner bacillus may remain free from symptoms and show no abnormalities in the stools. Shiga carriers, on the other hand, are more apt to present the picture of chronic cases, seldom recovering, even for a short time, sufficiently to be considered healthy. He called attention to the intermittent character of the discharge of bacilli in known carriers.

The carrier of dysentery bacilli, according to Nichols,22 is apparently of less importance in the spread of bacillary dysentery than are carriers in the spread of typhoid fever and cholera. There are fewer true carriers in bacillary dysentery; the individual carrier is less chronically ill and excretes fewer bacteria. The spread of infection is usually due to acute and chronic cases. Incubationary carriers are known; however, in view of the absence of a test for susceptibility, and in view of the relapsing character of the attack, it is difficult to diagnose them. In temporary convalescent carriers, the excretion of bacilli diminishes after clinical recovery. According to Nichols, the number does not become low for about two months, and it requires repeated examinations to exclude the carrier state. Chronic convalescent carriers on the other hand, running up to 1 year, occur in from 1 to 5 per cent in different series. It is difficult to draw the line between relapsing carriers and chronic cases. Nichols and Russell agree on the difference between Flexner and Shiga cases from the carrier standpoint. The Flexner cases are more apt to result in the carrier state while the Shiga cases tend to become chronic. Nichols concluded that contact carriers have usually been considered rare, but with improvement in the technique of examination they have been found more frequently.

The percentage of cases that became carriers and the proportion of examinations that resulted in positive findings of dysentery bacilli were variously reported by different workers. Arkwright, Yorke, Priestley, and Gilmore23 examined 50 dysentery convalescents for the carrier state. The cases varied from three to six months after the onset of symptoms. The Shiga bacillus was found in two and E. histolytica in nine. Kennedy and Rosewarne24 examined several hundred typhoid and dysentery convalescents for the detection of carriers. More than 5,000 examinations were made. The results showed 6 dysentery carriers, of which 3 were of the "Y" type and 3 Shiga. Fletcher and Mackinnon25 examined 935 dysentery convalescents and 847

cFor further details in this connection, consult Chapter XIX of this volume.


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convalescents from other diseases, such as enteric and trench fevers. Among the dysentery convalescents, 6.95 per cent were found to be dysentery carriers; 2.78 per cent persisted in the carrier state. There were 58 carriers of the Flexner organism and 13 of the Shiga. Of the nondysenteric cases, 1.06 per cent were carriers of dysentery bacilli. Two-thirds of these patients gave a history of dysentery; all were of the Flexner type. All the Shiga carriers were persistent and suffered from chronic dysentery and mental depression. The Flexner carriers were usually in good condition and fit for work under favorable conditions. The carrier of Flexner bacilli does not excrete the organism continuously but intermittently, with periods of perhaps five or six weeks during which it can not be found. This renders the diagnosis of the carrier state extremely difficult and indicates the necessity of frequent examinations over a considerable period before a given patient may safely be considered free from bacilli.

According to Dopter,26 the main source of entamebic infection during the war was the presence of carriers of the organism among the French colonial troops from North Africa. These men infected the soil of the trenches they occupied, and healthy troops relieving them became infected in their turn. Thus with the general interchange of troops the infection became widely scattered. The number of cases was never large enough to menace military effectiveness, but sanitarians were preoccupied with the thought that the creation of an army of entameba carriers might present a serious problem to the countries concerned on the return of their soldiers to civil life.

Sporadic cases of entamebic dysentery have been known for years in all parts of the United States, but the condition has remained somewhat of a pathological curiosity. However, during the Mexican border mobilization in 1916, Craig27 identified the organism in 158 cases of dysentery among some 110,000 men. The cases were milder than those usually seen in the Philippine Islands, possibly because treatment was instituted earlier. True and convalescent carriers were demonstrated and were regarded as the source of the disease. There was no evidence of contact infection.

Dobell28 examined 200 soldiers for E. histolytica as a routine measure and found 22, or 11 per cent, infected. Half of these denied any history of diarrhea or dysentery. Among these men, 4 were undoubted contact carriers. Matthews and Smith,29 at the Liverpool School of Tropical Medicine, examined the stools of 4,062 dysentery patients from the Western Front and found 12.1 per cent infected with the ameba.

The degree of infection in American troops both at home and abroad is indicated by the results of examination of returned soldiers at Debarkation Hospital No. 3 at New York City and of home-service men at the port of embarkation; 230 overseas men and 576 home-service men were thus examined.20 Of the former, 12.8 per cent and of the latter 4.3 per cent were found to harbor E. histolytica. Very few of the men had dysenteric symptoms at the time of examination. Later, an examination was conducted at the University of California on students who had served as soldiers overseas. On this occasion repeated examinations were possible and each of 154 men received an average of 3.8 examinations. Of these men, 67 per cent were found positive for E. his-


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tolytica. The authors of the investigation conclude that the number of ameba carriers in the country must have been substantially increased by the return of infected soldiers from overseas. These figures confirm the statement earlier made that the proportion of carriers of E. histolytica who manifest no clinical evidence of their condition is very large.

SYMPTOMATOLOGY AND PATHOLOGY

The clinical course of the average case of dysentery observed during the World War naturally presented nothing different from the cases seen elsewhere; however, certain additions to our knowledge were made, either by American workers or by those of other armies, which deserve passing mention.

There is no discoverable record of anything to show the incubation period of bacillary dysentery. The onset was usually described as sudden, with frequent bloody stools, prostration, tormina, and rectal tenesmus. Generally, the cases were mild or moderately severe in type. No cases were described of the type resembling cholera-acutely toxic with death occurring without change in the number and character of the stools. Russell,21 in his description of bacillary dysentery, states that the stool itself is quite characteristic and at the height of the disease is quite unlike the stool in any other disease, not excluding amebic dysentery. It is small and consists exclusively of blood and mucus, without a trace of fecal matter. Under the microscope one sees red blood cells in enormous numbers, and epithelial cells in masses; they are thrown off by the mucous membrane. These are often to be recognized as columnar epithelial cells, arranged like closely aligned pickets on a fence, like a typical textbook picture. In addition, single epithelial cells in all stages of swelling, degeneration, and necrosis are seen. The single swollen cells are often roundish and suggest at first quiescent amebæ, but they do not possess the power of motion or the ability to send out pseudopodia. They may also be readily distinguished from amebic cysts by the large size and different character of their nuclei. These various elements are embedded in masses of glairy and stringy mucus. As the disease progresses and increases in severity the character of the stool changes from that described above, the epithelial masses increase in size until one sees sloughs of large ulcers, or even a pseudomembranous cast of the entire circumference of the gut. Under the microscope it is no longer possible to make out the structure of the epithelial cells, since the entire mass is coagulated and necrotic. The fluid part of the stool is no longer watery, but serous, and dark from altered hemoglobin. Such stools are extremely offensive.

Bacillary dysentery usually runs an acute course, terminating with recovery in the course of a few days or weeks. A small percentage become chronic or terminate fatally. Although not always true, this was the experience of the Army during the World War. The case fatality was 2.17 and but 1 case was discharged for disability.

The chronic cases suffer from depression, emaciation, and relapses. Jacob30 described a series of cases in which relapse occurred between the nineteenth and twenty-first day. Normal temperature preceded the relapse by one to three weeks. Intestinal symptoms were absent or stools were much like those of diarrhea; however, he isolated the Shiga and Flexner strains from the stools


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during the relapse. Headache and joint pains were frequently present. Pain along the colon is not an uncommon complaint. The proctoscope often reveals ulceration in the lower bowel.

PROGNOSIS

The prognosis of dysentery as observed during the World War is very favorable. Of the 4,738 cases of all types of dysentery reported, but 73 terminated fatally. This gives a case fatality of 1.54 per cent. Taking into consideration the admittedly large number of cases never reaching the hospital, or being entered upon the records, it is evident that even this low fatality is stated much too high. The prognosis appears to be decidedly less favorable in the colored race than in the white. The case fatality in 220 cases in negroes was 4.55 per cent, while of 3,547 cases in white enlisted men, but 1.48 per cent died. Again, the small number of cases in the colored, 220, with 8 deaths, introduces a large probable error and lessens the value of the comparison. The same considerations render the figures for case fatality of the various types of dysentery of less value than would be the case had a larger proportion been classified etiologically in the reports. The case fatality for bacillary cases was 2.17 per cent, while that of the entamebic cases was 1.29 per cent.

The entamebic cases were responsible for 85 of the 86 dysenteric cases discharged for disability during the war. This is to be expected on account of the chronic and relapsing character of this disease. Indeed, Craig27 recommended that the carriers of the entameba who are not readily cleared up after a reasonable period of treatment should be discharged from the service as a measure of protection to uninfected troops. Experience has shown that such men can not stand the strain of active campaigning and soon suffer relapses and become a burden rather than an asset to the service. The average case of bacillary dysentery lost 19.6 days from duty; the amebic, 34.6. The unclassified dysenteries averaged 21.6 days lost, a figure much nearer that of the bacillary group than that of the amebic cases. This confirms the deduction previously made that the vast majority of the unclassified cases were of the bacillary type. Prognosis is of course modified by the promptness and efficacy of treatment and hence proved more favorable in the training camps in the United States than was the case under battle conditions in France.

AUTOPSY FINDINGS

There are on file in the Surgeon General's Office the protocols of 35 autopsies performed on dysentery cases. These are classified as follows: Bacillary dysentery, 7 cases; amebic dysentery, 8 cases; mixed infection, bacillary and amebic, 3 cases; dysentery with negative laboratory findings, 9 cases; complicated dysentery, 8 cases (pneumonia, 4; ulcerative endocarditis, 2; influenza, 1; and tuberculosis, 1).

The autopsy findings in the bacillary cases were those commonly seen in this type of dysentery. In 6 of the 7 cases the heart showed acute myocarditis. In 5 cases occurring in the American Expeditionary Forces the diagnosis of bacillary dysentery was made by laboratory examination of the stools. Two cases were diagnosed a few days before death, the patients having been admitted


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in extremis; one case dying from Flexner infection showed slight degenerative changes in the liver.

All of the amebic cases coming to autopsy showed abscess of the liver. The entameba was found in the pus of the abscess, in the intestinal ulcers, or both. The lesions differed only in extent, and consisted of ulceration of the large bowel and in some cases the lower 2 feet of the ileum. The ulcers were generally very numerous and at times confluent, so as practically to destroy the mucosa. No perforations were reported. The other changes found in these cases were secondary to perforation of abscesses into the pleural or peritoneal cavities. The liver abscesses were located in the convex portion of the right lobe of the liver in all cases but one, which involved the left lobe only. The diagnosis had been made clinically in but one case; in 2 others it was suspected while of the remaining 5, tuberculous peritonitis was diagnosed twice and appendicitis, lobar pneumonia, and bronchopneumonia once each.

From the necropsy standpoint, 8 of the 9 cases of dysentery coming to examination without laboratory diagnosis were most probably bacillary dysentery. The location of the lesions, edema of the intestinal wall, areas of ulceration, pseudomembrane, and necrotic mucosa indicate the grounds on which this conclusion is based. In one case without laboratory findings, the conditions resembled those of the amebic type. Symptoms had persisted for four months before death.

DIAGNOSIS

Under war conditions the diagnosis of a case of dysentery must necessarily be made usually upon clinical grounds exclusively. The differentiation of type in bacillary dysentery and even the distinction between bacillary and amebic cases require the use of laboratory equipment and trained personnel. Therefore, under field conditions, the majority of cases were reported as "dysentery, unclassified." The occurrence of a considerable proportion of unclassifiable cases of clinical dysentery among the troops in the camps in the United States shows that even under favorable conditions a specific diagnosis can not be arrived at in every case. The difficulties and uncertainties of diagnosis, and the resultant effects upon the statistics have been touched upon incidentally in previous paragraphs.

The importance of early diagnosis has been indicated in relation to the early institution of serum treatment. In the prompt identification of the bacillary forms all authorities agree that it is of first importance to secure a properly selected, fresh stool for bacteriological examination. Kligler and Olitsky31 reported failures to isolate B. dysenteriæ from cases of clinical bacillary dysentery and attribute the failure to (1) improper selection of stool specimens for culture and (2) the use of unfavorable culture media. The stool selected should be one containing blood and mucus, with little or no fecal matter. It is essential to plate the stool directly, or at least very shortly after it is evacuated. Experiments with artificial mixtures of Shiga bacilli and feces showed a 50 per cent reduction in 4 hours, and from 85 to 90 per cent reduction in 24 hours when kept at room temperature. They recommended the use of a modified Endo-medium or the eosin-methylene blue medium.


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A simple and satisfactory medium was devised in the central medical department laboratory, A. E. F., for the isolation of B. dysenteriæ from stools.32 It consists of:

Distilled water

100 c.c.

Agar

15 gm.

Peptone (difco)

10 gm.

Dipotassium phosphate

4 gm.

To each 100 c. c. is added:

Lactose, 20 per cent solution

5 c.c.

Glucose, 5 per cent solution

1 c.c.

Rosolic acid, 1 per cent in 90 per cent alcohol

1 c.c.

China blue, 0.5 per cent in water

1 c.c.

The hydrogen ion concentration of this medium is 7.4 to 7.5 and it needs no adjustment. If the sugars are clean and white it needs no filtration. The dysentery bacilli grow as luxuriantly on this as on any other medium, and the lactose nonfermenters are readily recognized.

In addition to the precautions suggested by Kligler and Olitsky, the importance of securing, if possible, a stool for diagnosis early in the course of the disease should not be overlooked. Recent work suggests that the bacteriophage developed in the intestine after the first few days of the disease may be the inhibiting agent which causes failure to grow on the part of the infecting organism even when doubtless present in large numbers. With the disappearance of the lytic agent during convalescence it is frequently again possible to isolate the bacillus in large numbers.

The application of the agglutination test to the patient's serum as a means of diagnosis has not resulted in great success. Specific agglutinins would not be expected to develop in much concentration until the disease had progressed several days. This would militate against the use of this test in early cases when diagnosis is most important. The American opinion is voiced by Kligler,16 who remarks that it is a well-known fact that agglutinins for the Flexner bacillus are present in fairly high concentration (1:50 or 1:75) in normal individuals. This is not true for Shiga agglutinins, which are rarely demonstrable in dilutions over 1:10. It would thus appear that the diagnosis of Shiga infection might be predicated upon a positive agglutination in specific serum at a dilution of 1:20 or over, but that Flexner infection could only be diagnosed were the test positive at a dilution of at least 1:100.

War experience has shown the fallacy of ascribing pathogenic properties to bacteria isolated from the stools of dysentery patients merely because they conform in cultural characters to dysentery bacilli. An accurate diagnosis must be based both on cultural and specific serological criteria and sometimes even upon animal experimentation. Examination of fresh stools early in the course of the attack, the use of suitable media, and skill in their use are essential for satisfactory results. A single negative examination is of little or no value.

To our knowledge of the diagnosis of amebic dysentery little was added as the result of war experience. The importance of the differentiation between E. histolytica and E. nana, especially in the diagnosis of cyst carriers, has been brought out earlier.


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The differential diagnosis between the bacillary and amebic types of dysentery must be ultimately based upon laboratory findings. However, differences in the clinical appearance of the patient and in the general as well as microscopic appearance of the stool may be valuable in making this differentiation. The amebic patient, generally speaking, is less toxic, the temperature is little if at all elevated, the number of stools, although increased, is small as compared with the bacillary type, rarely exceeding 10 to 14 per day, and the course of the disease is more prolonged. In bacillary cases of moderate to severe grade there is usually a sudden onset, the patient is toxic, temperature high, stools numerous-30 to 40, or more, in 24 hours. He presents the appearance of a very sick man and the disease is usually of short duration. Descriptions of the microscopic characters of the stools in these two conditions published during the war period have been superseded by the exact cytological diagnostic work of Willmore and Shearman,5 Manson-Bahr,6 and others, which appear to have made the distinction easily possible on microscopic grounds.

TREATMENT

This is a subject necessarily treated differently for the different types of the disease. So, too, the treatment of the acute, initial attack must differ from that of the chronic forms in cases in which the disease obtains a prolonged hold. This latter unfortunate happening is usually the result of delay in starting treatment and is characterized pathologically by an ulcerated condition of the intestine even in the bacillary cases, and symptomatically by intermittent diarrhea, usually without much blood or mucous, but showing pus, anemia, and varying degrees of prostration. There is no record of this type of disease having attracted attention in the American forces during the World War although presenting a serious problem to some of our Allies, especially in the East. Consequently only the treatment of the acute attack will be considered here.

The most important thing in the treatment of acute bacillary dysentery is the establishment of at least a probable diagnosis. In epidemic times this is usually evident, although when both bacillary and amebic dysentery are prevalent the differentiation is important. The treatment should be along lines both specific and symptomatic. The specific treatment of bacillary dysentery consists of the administration of a reliable polyvalent antidysenteric serum in a sufficient dosage and as early as possible. This treatment has not been used extensively in the United States, possibly because severe clinical forms of dysentery are not common here and possibly because the treatment has not habitually been administered early enough on account of delay for the purpose of obtaining a bacteriological confirmation of the diagnosis before the administration of serum.

According to Russell21 the serum is best given in large doses following Shiga's rule, 1 dose of 10 c. c. in mild cases, 2 such doses at intervals of 6 hours, in cases of moderate severity, and in severe cases 10 c. c. twice a day for 2 or 3 days. The tendency seems to be to increase the dosage, and even a dose of 100 c. c. daily has been given to severe cases with apparent benefit.


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The British believe33 that the value of the specific serum has been established and that the sooner it is administered the better. They recommend an initial dose of from 20 c. c. to 60 c. c. Bahr and Young34 recommend administration of the serum in all doubtful cases while awaiting the results of laboratory examination. They believe that the benefits obtained by prompt administration outweigh any objections to the treatment of an occasional nonbacillary case and state that it does not act deleteriously in any case, irrespective of the nature of the disease. In a memorandum on medical diseases in the tropical and subtropical war areas, the British state that the action of antidysenteric serum is often remarkable, as much as 400 c. c. having been given in severe cases, and (apparently) it has been the means of saving the patients.35 The French used serotherapy extensively but with varying results.26 Among the Germans, Schittenhelm36 remarks that, as in the case of diphtheria, it should be given as soon as possible. He recommends the intramuscular route as more rapidly effective. The dose used by the Germans was larger than that used by the Americans.

The patient should be confined to his bed, and the use of the bedpan enforced. The diet should be nonirritating and at first liquid, using the strained types of diet which leave little residue. An important point in the nonspecific treatment is the clearing of the bowel by means of salines. A method for accomplishing this is as follows: A dose of 20 c. c. of saturated solution of magnesium sulphate is given every four hours, each dose followed an hour later by 10 drops of aromatic sulphuric acid in water. This results at first in an increase in the number of stools, but within two days they are greatly reduced in number, pain becomes less, and general improvement is noted.

The following saline treatment was recommended by Balfour:33

Rx

Sodium sulphate

gr. lx.

Acid. sulph. aromat

m. xv.

Tr. zingiberi

m. v.

Aq. menth. pip

oz. ss.

M.

This mixture above should be administered every 2, 3, or 4 hours until the stools become watery. It is claimed to be better than magnesium sulphate. Bismuth subnitrate, 60 grains, and salol, 3 grains, every 6 hours are useful in the later stages. In very severe cases, drained by the constant evacuations, Balfour recommends the Rogers cholera treatment,33 the intravenous administration of hypertonic salt solution to restore blood volume and prevent acidosis. Ipecac and its alkaloid are without value in bacillary dysentery and opium and its derivatives are probably harmful by forcibly checking the number of evacuations and retaining within the intestine the toxin of the invading organisms.d

dWith the postwar development of the cytological method of diagnosis in the dysenteries, it has become possible in the great majority of cases to render an opinion as to the type of dysentery, bacillary or amebic, within a few minutes after a stool specimen has been received in the laboratory. The use of this aid places the early administration of the serum upon a sound scientific basis; and judging from our experience in the Philippine Islands, a majority of cases could be diagnosed and treated with success in a medical echelon very close to the front, and need never reach the larger hospitals.


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Little new developed from war experience in the treatment of acute amebic dysentery, although much work was done along this line. It resolves itself into the effective administration of emetine. First suggested as a remedy for dysentery in 1829 by Bardsley37 of Manchester, it was found to be amebacidal by Vedder38 of the United States Army (1910-11), and its use in amebic dysentery was established in 1912 by Sir Leonard Rogers.39 The routine treatment consists in the daily administration of 1 grain of the alkaloid subcutaneously for a period of 12 days. Such a course usually causes a rapid improvement with cessation of dysenteric symptoms, but it can not be relied upon to cure the disease in the sense of completely removing the infecting amebæ. It is necessary to keep the patient in bed during such a course of emetine, not only for the purpose of controlling the diet, but also as a protection to the heart. Dale40 showed that emetine in large doses is cumulative in its action, and that neuritis has followed its use. Two fatal cases of emetine poisoning were reported in 1916 from Base Hospital No. 2, at Fort Bliss, Tex.41 The possible deleterious effect on the heart is pointed out by Wenyon and O'Conner, whose report describes two cases.

Attempts to develop a form of emetine administration more effective in clearing up the infection than the alkaloid alone led to introduction by Du Mez42 of the double iodide of emetine and bismuth which contains 58 per cent of iodine, 12 per cent bismuth, and 29 per cent emetine. The alkaloid is gradually liberated under the action of the alkaline secretions of the intestine. It is less emetic in its action than is emetine alone, but may cause nausea in some instances. This may be mitigated by the previous administration of 10 to 12 drops of the tincture of opium, preferably after the patient has retired for the night and after a light meal. Under this treatment it does not appear to be necessary to confine the patient to his bed. The dose is 3 grains daily, preferably in a single dose rather than in divided doses. The treatment is continued for 12 days. This treatment is usually regarded as less effective in the removal of the symptoms of the acute state than is the subcutaneous emetine treatment, but is more effective in clearing up the carriers. 

The use of emetine bismuth iodide in conjunction with the hypodermic injections of emetine would seem to be beneficial in that convalescence is established earlier and patients are less apt to become carriers.43 But it can not be considered as a substitute for emetine, as attempts to treat acute cases with it alone ended in failure until emetine was used in addition.

Patients may be completely cured by the emetine treatment, but probably two-thirds of the cases, though completely relieved from their symptoms, still harbor the organism, as shown by the excretion of cysts. Such patients are almost sure to suffer relapse at some later date and of course are the main source of infection of others. The clearing up of carriers has thus become a major problem of the treatment. Wenyon and O'Conner18 advised the combined oral and hypodermic use of emetine hydrochloride in the treatment of carriers. One grain of the drug is given hypodermically in the morning daily for 12 days, and one-half grain in a keratin-coated tabloid is given by mouth each evening. They reported 30 carrier cases treated by this method with no relapses. In 37 carriers treated by the hypodermic method alone, there were 10 relapses, and in 5


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the drug failed to act. Of six cases treated orally, half showed either no reaction to the drug or suffered relapse. Jepps and Meakins44 concluded that emetine bismuth iodide cured 95 per cent of E. histolytica carriers, and that the best method of administration is in the form of a loose powder contained in a cachet, in daily doses of 3 grains. At least 36 grains should be given in all. The Medical Research Council45 reports on the results of treatment of 155 E. histolytica carriers with emetine bismuth iodide in various forms, and in doses of 3 grains daily for 12 or more consecutive days. A single first course of treatment cured 90 per cent of their cases. When they remain uncured after such treatment, the best method of retreatment is to give them a double course of the drug; that is, 3 grains daily for 24 days. Such treatment has not cured every case, but there is no evidence that those who are not curable by such means constitute more than 5 per cent of all carriers of E. histolytica.

In conclusion, it may be said that emetine hydrochloride, alone or in conjunction with emetine bismuth iodide, was the preferred form of specific therapy for amebic dysentery during the World War, while the use of the double salt gave the best results in the treatment of carriers.

PREVENTIVE MEASURES

The preventive measures used during the World War fall into two classes, the general and the specific measures. The former comprise nothing that was not previously known, but instructions issued by the War Department on the subject and examples of conditions under which the troops had to operate are of value. Some such examples have been given already.

Of the general preventive measures the early diagnosis and isolation of the sick, discovery, isolation and treatment of carriers, destruction of flies and prevention of fly breeding, safe-guarding of water supplies, precautions to prevent contamination of food, and the proper disposal of feces were the methods on which we depended for the limitation of the dysenteries as well as of the typhoid group and other intestinal infections. In 1917 the Surgeon General issued the following instructions relative to the causation and prevention of the dysenteries:46

Dysentery-Causes and natur -Dysentery, or inflammation of the large intestine, is caused by two classes of microorganisms, an ameba and certain bacteria. The former gives rise to amebic, the latter to bacillary dysentery. The bacterial or bacillary form of dysentery is more widely distributed over the world than the amebic. While the former is found in all climates, the latter is chiefly restricted to warm countries. But persons suffering from amebic dysentery may carry the disease from a warm to a cold climate.

Sources of infection - The amebæ and bacilli which cause dysentery are contained in the intestinal contents and are discharged with them. They are, therefore, subject to the same manner of distribution as are the typhoid bacilli, and the preventive measures to be employed are identical with those employed in typhoid fever. It may be well, however, to emphasize the common occurrence of carriers of dysentery bacilli and amebæ among exposed and recovered cases and the necessity of enforcing habits of personal cleanliness and other related measures to control the disease.

Diarrhea, etc. -In addition to dysentery, slighter and nondysenteric forms of intestinal trouble are more or less common. As the results of chill or indiscretion in diet, diarrhea, griping, and even bloody stools may arise. But any case of persistent diarrhea in which blood and mucus are being discharged should be regarded as suspicious and submitted to a


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laboratory examination in order to determine whether it may be dysentery. The amebæ are searched for by direct microscopic examination; the bacilli may be obtained in culture, or an agglutination test made with the patient's blood to determine their presence.

The intestinal group of diseases -(a) Typhoid and paratyphoid fever, cholera, with amebic and bacillary dysentery form a group of intestinal infections in which the causative microorganisms are discharged with the excreta and gain access to healthy persons through the mouth. The general principles of their prevention are practically identical. The first effort should be made to destroy the infectious agents at their source, namely, in the discharges from the intestine. The next effort should be to control the water and food supply and the personal habits of the men, so that any of the microorganisms which escape destruction may not find their way into the digestive tract in a living condition.

(b) No man should be employed as cook or handler of food or water who is a carrier of B. typhosus, B. paratyphosus, A or B, or cysts of Entameba histolytica.

(c) Stools of all cooks and food handlers (including handlers of water and drivers of water and ice wagons) will be examined for typhoid, paratyphoid A and B, and dysentery bacilli, and for cysts of Entameba histolytica. In the case of enlisted men, notation of positive findings should be made upon the service record.

As missed and mild cases are undoubtedly responsible for much spread of infection, it is advisable, when military considerations permit, to hospitalize, at least for a brief period, as large a proportion of these cases as possible to permit the disinfection of dejecta, clothing, linen, etc. Such a measure is particularly practicable in the case of troops not actively engaged with the enemy.

Specific vaccination against the dysenteries, using a polyvalent vaccine prepared along the same general lines as is that against the typhoid group, had been practiced to some extent before the war. According to Russell,21 such measures are theoretically correct and under suitable conditions should give good results. Antidysenteric vaccination was not used as a routine measure in the Army during the World War and practical experience confirmed the judgment that it is rarely necessary. Dysentery was not, except for very brief periods, an important cause of disability in the areas occupied by our troops. The main objection to its routine use, unless special conditions demand it, has been the severe character of the reaction induced by effective doses of the vaccine. To overcome this difficulty several expedients were tried. One was the introduction of sensitized vaccines by Boehnke and Elkeles47 in 1915 and by Gibson48 in 1917. The Boehnke prophylactic was prepared for the German Army by adding the B. dysenteriæ toxin and antitoxin in varying proportions to an emulsion of dysentery bacilli of various types. This was termed "dysbakta." It is doubtful according to Russell,21 whether the advantages of such a mixture are marked enough to justify the use of repeated small doses of the contained horse serum. Dopter49 and Besredka50 attempted to produce vaccines which could be administered orally. Under experimental conditions they attained some degree of success and the application of their methods to the human is still under trial. So far, the degree of success attained has not been such as to make oral vaccination the method of choice.

The application of the lipovaccine to the prevention of dysentery was attempted. Officers at the Army Medical School51 produced such a vaccine. It contained 2,000,000,000 Shiga bacilli, with the same number of the Flexner and of the "Y" types, per cubic centimeter. The local and general reaction


352

to a dose of 1 c.c. of this vaccine was said to be no greater than that induced by the regular saline triple typhoid vaccine. Olitsky52 confirmed the safety and practicability of producing a vaccine by the emulsion of various types of dysentery bacilli in oil. The method is still in its experimental stage. A main difficulty appears to be the attainment of effective sterilization of the vaccine.

Against amebic dysentery the same general hygienic measures as have proven of value against the bacillary form should be effective. The prophylactic use of emetine might be of value in situations where a high incidence of the disease was to be expected. The French under these conditions used 4 or 5 grains of emetine hydrochloride dissolved in tincture of opium in the proportion of 1 to 15. Of this mixture, 8 to 10 drops were added to a cup of strong tea and taken each night. The method is comparable to the prophylactic administration of quinine in malaria and might serve an equally useful purpose.

NONSPECIFIC DIARRHEA, ENTERITIS, AND COLITIS

The affections included in this heterogeneous group of generally mild diarrheal affections were classified under one heading or the other, according to the individual preference of the reporting officer. If his preference was for a symptomatic diagnosis, the case was called diarrhea; if for a pathologic or anatomic designation, it became enteritis or colitis on the records.

The occurrence of these diseases is shown in the basic table from which most of our figures have been drawn-Table 49. The totals shown in Table 49 for the group as a whole include the dysentery cases as well, but the percentage of the total cases represented by the dysenteries as reported is so small, about five, that their inclusion is without effect upon the relative position of the different personnel groups when the latter are compared. Therefore it would be a work of supererogation to go again into the effect of geographical location of troops, race, etc., in regard to the incidence of these diseases. What has already been said with regard to the group as a whole is equally true of the nonspecific diarrheas and enterocolitis.

In the discussion of the true dysenteries it was brought out that many such cases were undoubtedly reported under the nonspecific headings for various reasons which were there discussed. It seems probable that most of the fatality associated with the conditions now under discussion was the result of this inclusion among them of cases of true dysentery. Another possibility is that a certain number of chronic cases were also included among them. Most of such cases were probably classified in the tables under the heading "Miscellaneous diseases of the intestinal tract," but others could easily have been reported as "chronic diarrhea" or "chronic colitis" and so have become included in our figures. Such chronic cases would have tended to increase the fatality of the group, its proportion of discharges for disability, and the number of days lost from duty over what would have been the case had only acute cases been reported.

In spite of such probable inclusions, the type of disease represented was evidently mild, as shown by the average duration of the cases. The figures show that these cases in the United States occasioned only from three to five days' loss of time per case. In Europe, owing to the inclusion of a considerable


353

proportion of the more severe dysenteries, and to the loss of time occasioned by the delays in reaching hospitals, the average time lost was longer. It is evident, however, from the descriptions of epidemics in the battle zones that the great majority of the diarrhea cases were not severe enough to go regularly on sick report.

No specific statement of the etiology of these milder diarrheas as distinct from the dysenteries is possible. Dietary indiscretions, or more frequently the character and condition of the only food available, have been blamed in some instances. However, in the latter case the actual cause of the trouble may with more probability be considered to have been bacterial infective agents contained in the food. The same may be said of the drinking of polluted water. Such water probably always contains the germs of dysentery or typhoid or paratyphoid fevers, and the result of its use would naturally be the mixed type of epidemic seen in France. 

The monthly incidence of these conditions as shown in Chart XXXVI indicates that in the United States, where the curves were not broken by periods of military activity, there is a definite seasonal increase of incidence, culminating in July or August. At this season air temperature renders almost any food exposed to infection a suitable culture medium for bacteria of the types under consideration, and the large number of flies usually to be seen about food in connection with the filthy feeding and breeding habits of this insect provides an easy explanation of the method in which infection reaches the food.

By no means the last word has been said on the subject of the etiology of diarrheal infections. It is entirely possible that many mild attacks which occur more or less typically in epidemic form in the civilian population have a specific etiology at present entirely unknown. That most cases, however mild, owe their inception to some infective agent, whatever it be, may be considered to be proven by the close correlation between the incidence of these milder diseases with those of known bacterial etiology. Those measures of sanitation which suffice to limit typhoid, cholera, and dysentery, serve also to reduce the incidence of the milder diarrheas. When conditions permit effective sanitary discipline all these conditions are reduced almost to the vanishing point.

REFERENCES

(1) Medical and Surgical History of the War of the Rebellion, Part Second, Medical Volume, Government Printing Office, Washington, D. C., 1879, 1.

(2) Report of the division of sanitation and inspection, Chief Surgeon's Office, A. E. F., by Col. Haven Emerson, M. C., May 31, 1919, to the Surgeon General, U. S. Army. On file, Historical Division, S. G. O.

(3) Annual Report of the Surgeon General, U. S. Army, 1919, Vol. 1541.

(4) Report on diarrheal diseases, Base Hospital No. 89, A. E. F., made by the commanding officer. On file, S. G. O., 710-1 (old), Dysentery.

(5) Willmore, J. G., and Shearman, C. H.: On the Differential Diagnosis of the Dysenteries. The Lancet, London, August 17, 1918, ii, 200.

(6) Manson-Bahr, P.: The Commoner Complications of Bacillary Dysentery in Military Practice. The British Medical Journal, London, June 12, 1920, i, 791.

(7) Hanghwout, F. G.: Protozoologic and Clinical Studies on the Treatment of Protozoal Dysentery with Benzoate. Archives of Internal Medicine, Chicago, 1919, xxiv, No. 4, 383.


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(8) Telegram, August 6-7, 1918, from "Wright" to Director of Laboratories at Dijon. On file, Historical Division, S. G. O.

(9) Letter from Major Hans Zinsser, M. R. C., to the Director of Laboratories and Infectious Diseases, A. E. F., August 19, 1918. Subject: Epidemic of diarrhea in the area occupied by the Paris group of the First Army, A. E. F. On file, Historical Division, S. G. O.

(10) Weekly Bulletin of Diseases, No. 20, Chief Surgeon's Office, August 26, 1918, A. E. F. On file, Historical Division, S. G. O.

(11) Spencer, H. R.: Report on an investigation of an epidemic of diarrhea, among the personnel of the 355th Infantry at Grand, July 27, 1918. On file, Historical Division, S. G. O.

(12) Letter from Harry C. Travelbee, 1st Lieut., and Lawrence A. Kohn, 1st. Lieut., to the Chief Surgeon, Paris group, A. E. F., August 28, 1918. Subject: Report of bacteriological findings in so-called dysentery cases investigated August 12, 1918, to August 26, 1918. On file, Historical Division, S. G. O.

(13) Letter from R. M. Taylor, Capt., M. C., to the Director of Laboratories, Base Section No. 1, A. E. F., Subdivision, Department of Infectious Diseases, August 26, 1918. Subject: Diarrhea and dysentery. On file, Historical Division, S. G. O.

(14) Letter from J. E. Walker, M. C., to Chief Surgeon, A. E. F., August 31, 1918. Subject: Report on an investigation of a dysentery outbreak at Romorantin and Gievres. On file, Historical Division, S. G. O.

(15) Letter from Lawrence A. Kohn, 1st. Lieut., Sanitary Corps, to the commanding officer, Central Medical Department Laboratory, October 9, 1918. Subject: Final report of investigation of epidemic of dysentery in the 37th Division, A. E. F., August 28, 1918, to September 4, 1918. On file, Historical Division, S. G. O.

(16) Kligler, I. J.: Report on the nature of a supposedly atypical dysentery bacillus, embarkation hospital, Newport News, Va., September, 1918. On file, Historical Division, S. G. O.

(17) Martin, C. J., and Williams, F. E.: The Chance of Recovering Dysentery Bacilli from the Stools According to the Time Elapsing Since the Onset of the Disease. British Medical Journal, London, 1918, i, 447.

(18) Wenyon, C. M., and O'Connor, F. W.: An Inquiry into Some Problems Affecting the Spread and Incidence of Intestinal Protozoal Infections of British Troops and Natives in Egypt, with Special Reference to the Carrier Question, Diagnosis and Treatment of Amoebic Dysentery, and an Account of Three new Human Intestinal Protozoa. Journal of the Royal Army Medical Corps, London, 1917, xxviii, No. 2, 151, No. 3, 346, No. 4, 461.

(19) Jepps, M. W., and Dobell, C.: Dientamoeba fragilis, n. g., n. sp., a new Intestinal Amoeba from Man. Parasitology, Cambridge, England, 1918, x, No. 3, 352.

(20) Kofoid, C. A.; Kornhauser, S. I.; and Plate, J. F.: Intestinal Parasites in Overseas and Home Service Troops of the U. S. Army. The Journal of the American Medical Association, Chicago, 1919, lxxii, No. 24, 1721.
Kofoid, C. A., and Swezy, O.: On the Prevalence of Carriers of Endamoba dysenteriæ among Soldiers Returned from Overseas Service. New Orleans Medical and Surgical Journal, New Orleans, 1920-21, lxxiii, No. 1, 4.
Kofoid, C. A.; Kornhauser, S. I.; and Swezy, O.: Criterions for Distinguishing the Endamoba of Amobiasis from Other Organisms. Archives of Internal Medicine, Chicago, 1919, xxiv, No. 1, 35.

(21) Russell, F. F.: Bacillary Dysentery. Tice's Practice of Medicine. W. F. Prior Co., Hagerstown, Md., 1924, iv, 375.

(22) Nichols, Henry J.: Carriers in Infectious Diseases. Williams & Wilkins Co., Baltimore, 1922, 64.

(23) Arkwright, J. A.; Yorke, W.; Priestley, O. H.; and Gilmore, W.: Examination of Fifty Dysentery Convalescents for Carriers. Journal of the Royal Army Medical Corps, London, 1916, xxvii, No. 6, 755.

(24) Kennedy, A. M., and Rosewarne, D. D.: Observations upon Dysentery Carriers. The British Medical Journal, London, 1916, ii, 863.


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(25) Fletcher, Wm., and Mackinnon, D. L.: A Contribution to the Study of Chronicity in Dysentery Carriers. National Health Insurance, Special Report Series, No. 29, Medical Research Committee, London, 1919, 5.

(26) Dopter, M.: Les Maladies Infectieuses pendant la Guerre. Librairie Félix Alcan, Paris, 1921, 119.

(27) Craig, C. F.: The Occurrence of Endamoebic Dysentery its the Troops Serving in the El Paso District from July, 1916, to December, 1916. The Military Surgeon, Washington, 1917, xl, No. 3, 286 and 432.

(28) Dobell, C.: Incidence and Treatment of Entamoba histolytica Infection at Walton Hospital. The British Medical Journal, London, 1916, ii, 612.

(29) Matthews, J. R., and Smith, A M.: The Intestinal Protozoal Infections Among Convalescent Dysenteries examined at the Liverpool School of Tropical Medicine. Annals of Tropical Medicine and Parasitology. London, 1919, xiii, No. 1, 83.

(30) Jacob, L.: Klinischie Beobachtungen bei Bazillenruhr. Zeitschrift fuer Hygiene und Infectionskrankheiten, Leipzig, 1917, lxxxiii, 467.

(31) Kligler, I. J., and Olitsky, P. K.: Method for the Isolation and Rapid Identification of Dysenteric Bacilli. The Journal of the American Medical Association, Chicago, 1918, lxxi, No. 26, 2126.

(32) Levine, Max: Dysentery and Allied Bacilli. Journal of Infectious Diseases, Chicago, 1920, xxvii, 31.

(33) Balfour, A.: Notes on the Treatment of Diarrhea and Dysentery Issued by the Advisory Committee for the Prevention of Epidemic Diseases in the Mediterranean Expeditionary Force. Journal of the Royal Army Medical Corps, London, 1915, xxv, No. 5, 473.

(34) Bahr, P. H., and Young, J.: War Experiences in Dysentery, 1915-1918. Journal of the Royal Army Medical Corps, London, 1919, xxxii, No. 4, 268.

(35) Memoranda on Medical Diseases in the Tropical and Subtropical War Areas, 1919. His Majesty's Stationery Office, London, 67.

(36) Schittenhelm: Handbuch der Aerztlichen Erfahrungen im Weltkriege, 1914-1918. Innere Medizin. Ambrosius Barth, Leizig, 1921, Band iii, 136.

(37) Bardsley, J. L.: Hospital Facts and Observations. Burgess and Hill, London, 1830, 148.

(38) Vedder, E. B.: A Preliminary Account of some Experiments Undertaken to test the Efficacy of the Ipecac Treatment of Dysentery. Bulletin of Manila Medical Society, Manila, March, 1911.

(39) Rogers, L.: The Rapid Cure of Amoebic Dysentery and Hepatitis by Hyperdermic Injections of Soluble Salts of Emetine. The British Medical Journal, London, June 22, 1912, i, 1424.

(40) Dale, H. H.: A Preliminary Note on Chronic Poisoning by Emetine. The British Medical Journal, London 1915, ii, 895.

(41) Johnson, H. H., and Murphy, J. A.: The Toxic Effect of Emetine Hydrochloride. The Military Surgeon, Washington, 1917, xl, 58.

(42) Du Mez, A. G.: Two Compounds of Emetin which may be of service in the treatment of Entamoebiasis. The Philippine Journal of Science, Manila, 1915, x, No. 1, 72.

(43) Lambert, A. C.: The Treatment of Amoebic Dysentery with Emetine and Bismuth Iodide. British Medical Journal, London, 1918, i, 116.

(44) Jepps, M. W., and Meakins, J. C.: Detection and Treatment with Emetine Bismuth Iodide of Amoebic Dysentery Carriers among Cases of Irritable Heart. The British Medical Journal, London 1917, ii, 645.

(45) Great Britain, National Health Insurance Joint Committee. Medical Research Committee. A Contribution to the Study of Chronicity in Dysentery Carriers. His Majesty's Stationery Office, London, 1919, No. 29.

(46) Special Regulations No. 28, August 10, 1917, War Department.
Annual Report of the Surgeon General, U. S. Army, 1919, Vol. II, 1585.
Report of the sanitary inspector, 35th Division, October 11, 1918. On file, Record Room, S. G. O.,720-1, A. E. F.


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(47) Boehnke and Elkeles: Ruhr schuetzimpfungen mit Dysbakta. Muenchener Medizinische Wochenschrift, Muenchen, 1918, lxv, Part 2, No. 29, 784.

(48) Gibson, H. G.: A New Method of Preparation of a Vaccine against Bacillary Dysentery which abolishes severe local Reaction. Also Experiments with this Vaccine on Animals and Man. Journal of the Royal Army Medical Corps, London, 1917, xxviii, No. 6, 615.

(49) Dopter, Ch.: Vaccination antidysentérique experimentale par les voies digestives. Comptes Rendus Hebdomadaires des Séances et Mémoires de la Société de Biologie, Paris, 1908, i, 868.

(50) Besredka, A.: Du mécanisme de l'infection dysentérique de la vaccination contre la dysentérie par la voie buccale et de la nature de l'immunité antidysentérique. Annales de l'Institut Pasteur, Paris, 1919, xxxiii, No. 5, 301.
-- Reproduction des infections paratyphique et typhique. Sensibilisation au moyen de la bile. Ibid. No. 8, 557.

(51) Whitmore, E. R.; Fennel, E. A.; and Petersen, W. F.: An Experimental Investigation of Lipovaccines. The Journal of the American Medical Association, Chicago, 1918, lxx, No. 7, 427.

(52) Olitsky, P. K.: An Experimental Study of Vaccination against Bacilli Dysenteriae. The Journal of Experimental Medicine, New York, 1918, xxviii, 69.