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ARMYEXPERIENCE WITH DIARRHEAL DISORDERS DURING WORLD WAR II
Incidence
The average strength of the Army for the years 1942-45 was approximately 6,076,135 men. Within this population and time, 523,331 cases of diarrhea and dysentery were reported (table 54), a crude rate of 21 per annum per 1,000 average strength. Cases among troops in continental United States numbered 133,620, or 25 percent of the total, but 60 percent of the average strength of the Army during the war years was stationed in the Zone of Interior. The rate of
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9 per 1,000 average strength was low;that for troops overseas was more than 4 times as great.
When the United States entered the war, combat troops were sent overseas in progressively increasing numbers and into numerous poorly sanitated areas with highly endemic diarrheal disease. However, the 1942 rate for the total Army, 11 cases per 1,000, was somewhat less than the 1941 rate of 15. Scarcely 17 percent of the average strength was overseas in 1942, and one-half the troops were favorably located in the British Isles, Hawaii, the Panama Canal Zone, and North American bases, areas that never contributed heavily to diarrheal disease during these military operations. Rates were less satisfactory in the Southwest Pacific, in the Antilles Department, and especially in Asia. The rate for all overseas troops in 1942 was 30 cases per 1,000. The continental United States rate of 8 was acceptable for an Army in training under wartime conditions.
In late 1942 and in 1943, increasing numbers of troops entered North Africa and the Mediterranean, the Middle East, and the China-Burma-India theaters, all north of the Equator. Rates for the total Army rose to 25 per 1,000 and for troops overseas to 66 per 1,000, the 1943 annual rate for all overseas troops being the highest of the war. June 1943 marked the high point in monthly rates for troops overseas, the figure being 164 (chart 28). Large numbers of unseasoned young men made a first entry into poorly sanitated areas of highly endemic diarrheal disease. Conditions were different in subsequent years for smaller numbers of men were rotated into already established bases where preventive medicine practices were established and the bulk of troops had become accustomed to conditions. For overseas troops in 1943, 7.4 percent of all disease and 3.5 percent of all noneffectiveness was due to the diarrheas and dysenteries (table 67).
Rates for the total Army were better in 1944 and 1945, 22 and 22, respectively. Rates overseas fell from 66 in 1943, to 38 in 1944, and to 33 in 1945 (table 54). All overseas theaters participated, except the Southwest Pacific area where return to the Philippines, combat conditions, and other circumstances of environmental sanitation resulted in higher morbidity. Beginning with 1943, sharp seasonal peaks characterized June and July of each war year (chart 28).
The rate of cases per 1,000 strength per annum for troops within continental United States during the 4 war years (table 54) compares favorably with the 13 cases per 1,000 strength per annum of the 1940-41 period of preparation (chart 27). Reception and training of recruits was accelerated, but large-scale maneuvers were not conducted. A rate of 26 per 1,000 in July 1943 represents the highest seasonal peak (chart 28).Gordon 8 points out that these high rates for troops in continental United States "suggests a relation to the unprecedent concentration in August and September of that year of a number of major outbreaks of common diarrhea on board transports bringing troops to Europe," the inference being that cases in these outbreaks may have been allotted to the
8 See footnote 3, p. 326.
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Zone of Interior. Carriers in thecrowded populations aboard troop transports doubtless providedthe necessary etiologic agents, and breaks in sanitation resulted inepidemics which furtherreflected in the experience in the European theater.
Annual rates for continental United States troops for 1942-45 were respectively 8, 12, 9, and 6 (table 54). The highest rate of 12 was at that time when great numbers of troops were in training and when transport of personnel to overseas theaters was frequent. In connection with previous discussion of the total problem, 1943 also was the peak year for bacillary dysentery, for the Army as a whole and for troops in the continental United States (table 59).
The principal difficulty was in the Fourth, Fifth, and Eighth Service Commands, especially in the Tennessee and Louisiana maneuver areas (chart 29). "Rates of the order of those shown for June and July [1943] * * * are compatible only with interpretation that sanitary discipline among troops is deficient. This deficiency is the more serious because of the increased hazards to which these men are likely to be exposed if they are sent overseas." 9 The validity of this opinion finds support in the subsequent records of dysentery and diarrheal disease in the several overseas theaters.
Ten Broeck, Kuhns, and others, studying the incidence of clinical dysentery in several commands within the continental United States, observed that "the problem of dysentery was in direct relation to the presence or absence of waterborne sewage facilities." 10
Deathsand Noneffectiveness Resulting From Diarrheal Disorders
Deaths.-Diarrheal disorder in military populations has become established in recent years as a notorious cause of morbidity and noneffectiveness and of relatively little significance in respect to mortality. These conditions held for United States troops in World War II. Only 64 deaths were ascribed to the dysenteries, all forms, including bacillary, unclassified, and protozoal (table 56), as follows: 16 to bacillary dysentery, 16 to unclassified dysentery, and 32 to amebic dysentery. Estimated case fatality rates for bacillary dysentery were in the order of 0.06 percent. Case fatality for unclassified dysentery was approximately 0.05 percent, and for amebic dysentery, 0.09 percent. Case fatality for dysentery, all forms, was 0.07 percent. The common diarrheas to include all of ulcerative colitis, ileitis, and gastroenteritis along with enterocolitis, colitis, enteritis, and diarrhea, cause not specified-were responsible for only 52 deaths, a case fatality less than 0.01 percent. Total deaths ascribed to combined diarrheas and dysenteries were 116. As more than 500,000 cases were recorded on the morbidity reports and additional cases were recognized after admission to hospital for other causes, this group of diseases produced approximately 1 death for each 4,500. If gastroenteritis is included, as in former wars, 1 death occurred among each 7,400 cases. An
9 MonthlyProgressReport, Army Service Forces, War Department, 31 Aug. 1943, Section 7:Health.
10 Personalcommunicationto author.
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estimated case fatality for totaldiarrheas and dysenteries plus gastroenteritis is approximately0.014 percent.
Deaths due to dysenteries and diarrheas in the total Army during the war years are presented in table 56, on the basis of data derived from complete files of individual medical records, a most reliable source. The condition specified as the cause of death is not necessarily that for which the patient was admitted. Table 56 probably includes deaths other than the total among
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patients admitted as having dysentery or diarrhea; and likewise some deaths in the group, due to such causes as amebiasis, amebic abscess, liver abscess, or drug reactions may be included under other titles. In addition to deaths from the diseases included in the data for table 54 (as defined in AR 40-1080, p. 324), deaths due to gastroenteritis, ileitis, and ulcerative colitis, which were not separately coded during 1942 and 1943, are also included. The infectious agents of ulcerative colitis and ileitis may or may not be related to conditions under consideration in this section, but nonetheless deaths from these causes are included despite the fact that the diseases themselves are not here included in the category of common diarrheas.
The crude annual death rate of 0.46 per 100,000 average strength of the Army during World War II for diarrhea and dysentery, gastroenteritis, ileitis, and ulcerative colitis combined is remarkable when compared with rates in former wars.The lesson to be learned from this trend is that deaths from these causes are indeed preventable.
Noneffectiveness.-Information on the average time spent in medical treatment facilities by patients with several types of diarrhea and dysentery are available for 1942, 1943, and 1945 (table 57).
TABLE57.-Time lost intreatmentof various types ofdiarrhea and dysentery inselected years
Based on weighted averages of the 1942, 1943, and 1945 durations, and total admissions for 1942-45, except where indicated otherwise below, the following estimated average daily noneffectiveness (per 1,000 average strength) due to the listed diseases during 1942-45 are presented for the total Army:
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Diagnosis | Rate |
Dysentery: | |
| Amebic | 0.14 |
| Bacillary | .04 |
| Unclassified | .03 |
| Total | 0.21 |
Dysentary carriers: | |
| Amebic1 | .01 |
| Bacillary1 | .00 |
| Total | .01 |
Diarrhea: | |
| Enteritis2 | .10 |
| Enterocolitis1 | .05 |
| Colitis1 3 | .06 |
| Diarrhea, cause undetermined | .08 |
| Total | .29 |
1 Based on 1942 and 1945 average durations, andadmissions for 1942-45.
2 Based on 1945 average durations, andadmissions for 1944-45.
3 Includes ulcerative colitis.
CommonDiarrheas
Preliminary admission data based on sample tabulations of individual medical records for the war years 1942-45 are presented in table 58. All separate diagnostic titles of the common diarrhea group of diseases from morbidity report data of table 54 are not included, but admissions data (number of cases and rates for instances in which these conditions were primary causes of admission for medical treatment) are presented for the numerically more important titles of enteritis, enterocolitis, colitis, and diarrhea of undetermined cause. The inclusion of gastroenteritis, ileitis, and ulcerative colitis in table 58 is to be noted, since these diseases were not specifically included in the morbidity report data.
Coding procedures were such that enteritis, gastroenteritis, and ileitis during 1942 and 1943 comprised a single category; individual data for enteritis are available for 1944 and 1945 only.Similarly, for 1942 and 1943 ulcerative colitis was included with colitis, not elsewhere classified.With these reservations, the data are suited to the immediate purpose of determining occurrence of certain of the common diarrheas in the several theaters of operations.
Of the group, gastroenteritis had numerically the greatest incidence. Diarrhea of undetermined cause (table 58) was next, with approximately 153,000 admissions tabulated during the war years, representing an admission rate of 6 per annum per 1,000 average strength. Approximately 80 percent of patients were overseas. The year of greatest frequency was 1943, with troops outside the continental United States having a rate of 24.3, with appreciable improvement in the two succeeding war years.For individual theaters
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TABLE 58.-Admissions for certain diseases of the gastrointestinal tract, included in the category of common diarrhea, plus gastroenteritis, ileitis, and ulcerative colitis in the U.S. Army, byt area and year, 1942-45 -Continued
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of operations, however, the general pattern was a decline in rates each successive year, starting with highest rates in 1942.
Inspection of data not here presented revealed similar trends but fewer cases and lower rates for the other common diarrheal diseases. The Mediterranean theater was an outstanding exception. The rate during 1942 of 11 for diarrhea of undetermined cause was followed by an epidemic rate of 49 during 1943 and a decline to rates of 17 and 7 for the 2 subsequent years. During 1943, an outbreak of bacillary dysentery also occurred among Allied troops, spreading across all of North Africa. The association of the two epidemics is subject to differing interpretation, one of which is that the diagnosis of common diarrhea was made extensively for cases of unrecognized bacillary dysentery or for those cases from which Shigella was not recovered. Another interpretation is that the same faulty sanitation which contributed to bacillary dysentery also was responsible for epidemics of diarrhea of unknown etiology. In the Middle East where the incidence of bacillary dysentery was higher than for any other theater, rates for diarrhea of undetermined cause also exceeded those of any other theater or area.The converse is also true; in theaters or areas, such as the Canal Zone, North American area, and Alaska, where rates for dysentery were extremely low, so also were rates for the common diarrheas.
Dysentery, All Forms
The cases of dysentery, all forms, in tables 59, 60, and 61 include admissions and also instances in which dysentery existed concurrently with some other disease or occurred after admission to hospital for other reasons. Outpatient cases are excluded. The data derived from sample tabulations of individual medical records therefore include both primary and secondary diagnoses among excused-from-duty patients and are not strictly comparable to the combined data for diarrheas and dysenteries accumulated from current morbidity reports. Some 91,626 patients, about 1.5 percent of the average strength for the Army as a whole, had one or another of the three forms of dysentery-amebic, bacillary, or unclassified-during the war years.The group includes most of the more seriously ill of the individuals with diarrheas and dysenteries of World War II and therefore warrants separate consideration.
The crude rate for dysentery of all forms for the war years was 3.59 cases per 1,000 average strength per annum. Troops stationed overseas (40 percent of the total Army average strength) accounted for 81,462 cases or 88.9 percent of the total number of cases. Morbidity reports reveal that of the total number of cases of diarrheas and dysenteries as a group that occurred in the Army during the war years 75 percent occurred in troops located overseas. In other words, among troops overseas, there was more diarrheal disease and also a relatively higher proportion of the more serious forms than among troops stationed in the United States. This relation is reflected also by deaths, for 52 (81 percent) of the 64 deaths ascribed to dysentery (bacillary, amebic, and unclassified) occurred among admissions in overseas theaters (table 56).
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Presumably, some deaths from amebic dysentery in continental United States would be allocated properly to an overseas theater on the basis of place of exposure rather than place of admission.
Four men in every 1,000 were afflicted with recognized bacillary dysentery some time during the 4 war years, for incidence was 1 per 1,000 average strength per year. Similarly, 5 men per 1,000 had unclassified dysentery and 5 per 1,000, amebic dysentery. Incidence for unclassified dysentery was 1.25 per 1,000 average strength per annum (table 61) and for amebic dysentery 1.33 (table 60). The frequency of amebic dysentery increased each successive war year in every theater population except the Middle East. On the other hand, the incidence of bacillary dysentery reached a peak early in the history of each theater, commonly 1943, in general coinciding with maximum numbers of unacclimated troops (table 59). Thereafter, rates were regularly less except in theaters with annual rates less than 1 per 1,000 per annum, where a slight increase was the rule.Unclassified dysentery tended to follow the same pattern except that highest rates were at te inception of the theater for the Pacific and Middle East, with a lesser frequency each succeeding year. Troops when first introduced into hyperendemic environments tended to contract bacillary dysentery or unclassified dysentery promptly, a feature also true of the common diarrheas.Amebic dysentery differed in that increasing incidence was associated with prolonged exposure.
Cases of dysentery, all forms, approximated 92,000 for the total Army in World War II (tables 59, 60, and 61). In continental United States, bacillary dysentery had the highest incidence of the three dysentery groups followed in order by amebic dysentery and unclassified dysentery, the latter two showing little difference. By contrast, cases overseas and for the total Army were in reversed order with respect to bacillary dysentery, so that amebic, unclassified, and bacillary dysentery represented, in that order, 37, 35, and 28 percent of dysentery cases in the total Army and 38, 36, and 26 percent of the dysentery cases overseas.
Because recognition of amebic and bacillary dysentery required identification of the specific agents, the percentage of unclassified dysenteries would be expected to exceed the other two except in areas where dysentery was infrequent or where good laboratory facilities were available. These conditions were met in the continental United States with the result that 43 percent of the dysenteries were diagnosed as bacillary and only 24 percent as unclassified. Conversely, where incidence was high and laboratory facilities deficient, the proportion of unclassified dysentery exceeded the other two, as in several overseas theaters; 36 percent of dysenteries occurring overseas were unclassified, and only 26 percent were determined as bacillary despite the presence of several large epidemics.
The greater simplicity of stool examinations for ameba, in contrast to determinative bacteriologic techniques, would suggest that more amebic dysenterv would be recognized than bacillary under conditions of less than average laboratory service. However, this did not hold true. The first 2 war years saw
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TABLE 59.- Incidenceofbacillary dysentery in the U. S. Army, by area and year,1942-45
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TABLE 60.-Incidence of amebic dysentery in the U. S. Army, by area and year, 1942-45
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TABLE 61.-Incidenceof unclassified dysentery inthe U.S. Army,by area and year, 1942-45
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widespread epidemics of bacillary dysentery overseas, years in which 33 and 39 percent, respectively, of dysenteries were diagnosed as bacillary and only 6 and 12 percent as amebic. With acclimatization or seasoning, rates and percentage distribution of bacillary dysentery decreased progressively. The proportion of amebic dysentery among total dysenteries increased in each successive war year, both overseas and in the United States (because most military personnel were overseas at one time or another). In 1945, 72 percent of dysenteries among troops in the United States and 55 percent in troops overseas were noted as amebic dysentery. There is reason to believe that these relations are to an extent artificial because of increased emphasis upon laboratory diagnosis of amebic dysentery. A preventive medicine officer in the Philippines stated 11 that laboratories were giving undue emphasis to recovery of helminths and ameba and insufficient attention to the bacterial causes of diarrheal disease then epidemic among troops. Stool surveys 12 were made among troops returning to the United States from overseas. Many essentially symptom-free individuals, with organisms resembling E. histolytica, were considered cases of amebic dysentery.
As measured by incidence rates for amebic, bacillary, and unclassified dysentery, officers fared worse than enlisted personnel, and female personnel fared worse than male. (Information of this sort is available for 1942 and 1943.) The reasons for these differences doubtless relate to many factors, but the most probable explanation is that more mild cases among officers and women were admitted to hospitals. It is probable also that more effort was expended in establishing an etiologic diagnosis in officers and women.
Race.-In the continental United States, higher rates for amebic dysentery obtained among Negro troops than among white troops. The reverse was true overseas. On the other hand, both in the Zone of Interior and overseas, Negro troops had lower rates than white troops for both bacillary dysentery and unclassified dysentery. Foodhandler examinations, which included stool examination for amebas and helminths but not for bacilli, perhaps account in some degree for this finding. Throughout the war, Negro troops had lower rates for dysenteries and diarrheas than white troops in both the European and Mediterranean theaters. Explanation of these differences is probably to be sought not in any genetic difference in racial susceptibility but rather in differences in the social environment. During the Civil War, Negro troops were more seriously affected with diarrheal diseases than were white troops. Greater exposure of Negro troops to enteric pathogens before World War II Army service and a consequently higher level of immunity in Negro troops than in white troops has been suggested in explanation of these observations. Another possibility is that many Negro troops served within relatively well-sanitated environments.
11 Memorandum,Preventive Medicine, Southwest Pacific Area, for Deputy Chief Surgeon,25 Feb. 1945, subject:Diarrheal Diseases of the Southwest Pacific Area.
12 Survey of IntestinalParasites in Soldiers Being Separated from Service. Bull. U. S. Army M.Dept. 6: 259-262,Sept. 1946.
