U.S. Army Medical Department, Office of Medical History
Skip Navigation, go to content

HISTORY OF THE OFFICE OF MEDICAL HISTORY

AMEDD BIOGRAPHIES

AMEDD CORPS HISTORY

BOOKS AND DOCUMENTS

HISTORICAL ART WORK & IMAGES

MEDICAL MEMOIRS

AMEDD MEDAL OF HONOR RECIPIENTS External Link, Opens in New Window

ORGANIZATIONAL HISTORIES

THE SURGEONS GENERAL

ANNUAL REPORTS OF THE SURGEON GENERAL

AMEDD UNIT PATCHES AND LINEAGE

THE AMEDD HISTORIAN NEWSLETTER

Chapter 6, Part 1

Medical Science Publication No. 4, Volume II

THURSDAY MORNING SESSION
29 April 1954

MODERATOR
COLONEL ARTHUR P. LONG, MC


GENERAL ASPECTS OF PREVENTIVE MEDICINE IN THE FAR EAST COMMAND*

COLONEL ARTHUR P. LONG, MC

The General Background

For the purposes for this discussion the Far East Command is defined both as a military organization and as the delineation of a broad geographic area. Until fairly recently, this area included Japan, the Ryukus Islands (Okinawa), the Mariannas-Bonins Group of islands (Guam), the Philippines and Korea. A geographic and environmental description of these widely spaced areas might be of some interest. However, this is not a travelogue and it seems fair to assume that the audience here is acquainted, either directly or indirectly, with the general characteristics of these places. It is perhaps sufficient, then, to remark that almost all types of climatic conditions and features of terrain and general environment are encountered, from the tropical features of the Philippines and Guam to the semi-arctic characteristics of Northern Japan (Hokkaido) and Korea in the wintertime.

The level of sanitary practices in this broad area, though extremely variable, is in general consistently lower than that in most areas normally familiar to our forces. Added to the potential hazards posed by the physical environment are the presence of disease reservoirs found in the endemic and epidemic foci of a number of infectious diseases some of which are unique to this part of the world. Among these are malaria, the dysenteries, typhus fever, including those types transmitted by lice, fleas and mites, relapsing fever, smallpox, infectious encephalitis, schistosomiasis, filariasis and of course, the venereal infections, particularly chancroid.

Of all the areas in this broad Far East Command, none perhaps presents so many of these variables and offers such undesirable conditions as does the one with which we have been most concerned of late. This is, of course, Korea. Rarely have military forces in a single active campaign been called upon to take precautions against heat exhaustion, malaria and insect-borne encephalitis during one season of the operation, and at another time to carry out an intensive program for the prevention of cold injuries and louse-borne typhus fever.


*Presented 29 April 1954, to the Course on Recent Advances in Medicine and Surgery, Army Medical Service Graduate School, Walter Reed Army Medical Center, Washington, D. C.


248

Such, however, has been the experience in Korea. Because this symposium has to do almost entirely with the professional activities of the Medical Service during the Korean War and because the general interest relating to the Far East Command Medical Service has been largely centered in the Korean effort, this discussion will deal primarily with preventive medicine and its attendant problems in Korea with pertinent comparisons to the Far East Command as a whole and to the experience of the total Army.

Against the background thus hastily sketched, I shall attempt to review briefly some of the actual experiences encountered in the Far East Command and, particularly, in Korea, during the 6-year period, 1948 through 1953. In this connection, it is to be recalled that the Korean military campaign began in late June 1950 after the North Korean Communists crossed the 38th Parallel to invade South Korea on the 25th of that month, and that the active fighting continued for approximately 3 years from that time. In making such a review, it becomes at once apparent that it is quite possible for large numbers of men unused to many of the conditions present to live in these varied environments in the face of disease potentials not previously experienced, to carry on an effective and arduous military campaign, and to suffer only minimally from the special hazards presented. This is accomplished not by any sudden or radical development of new disease control measures and technics but rather by the vigorous application of procedures demonstrated to have been effective by long and careful trial and application in the laboratory and in the field.

In many instances, the procedures applicable for disease prevention here at home are also those applied in the Far Eastern areas; the principal differences in their application being quantitative in nature. Thus, it has been found that many of the basic problems arising in the Far East and the requirements for their solution were in many instances not significantly unlike those experienced in the various parts of the United States. In addition to these basic problems, however, there are, as has already been indicated, certain conditions and disease hazards which though not necessarily unique to the Far East, differ considerably from those seen in the United States and, hence, offer new experiences in prevention and management of disease to the American trained physician.

Disease Experiences

As a measure of the general experience with disease, it is appropriate to examine the over-all disease admissions. Figure 1 indicates such admissions for the 6-year period for the total Army, for the Far East Command and for Korea only. It is noted that the admission rates for the Far East Command are not excessively higher than those ex-


249

perienced for the total Army except perhaps for the year 1950. The experience in Korea that year, being of course for the latter 6 months only, accounting for an admission rate of 824 per thousand per annum readily explains this high rate for the Far East Command as a whole. This was, of course, a direct result of those unhappy early months of the Korean operation when troops essentially on garrison-type duty in Japan were suddenly thrown into combat in Korea under the most adverse conditions. As we shall see later, the diarrheal diseases and

FIGURE 1.
SOURCE: STATISTICAL HEALTH REPORT, WD AGO FORM 8-122, 1948 THROUGH MAY 1951
MORBIDITY REPORT, DD FORM 422, RCS MED-78, JUNE 1951 THROUGH 1953 - OFFICE OF THE SURGEON GENERAL 15 APRIL 1954

malaria accounted for important parts of this high admission rate. With improvement in the military situation including stabilization and experience in the field, plus improved sanitary discipline, specific and total disease rates decreased, and 1952 and 1953 saw admissions not unlike those having been experienced under peacetime conditions.

The ultimate indication, if not the measure, of success in disease control is probably to be found in the number of deaths which occur from disease. Figure 2 indicates disease death rates for the same


250

groups and for the same periods as shown in the previous figure for disease admissions. It is noteworthy that in 1948 and 1949, disease deaths in the Far East were fewer proportionately than for the total Army. The slight increases in 1950 and 1951 were the inevitable accompaniments of the situation previously indicated. Return to a level essentially that of the pre-hostilities period is indicated for the years 1952 and 1953. The relatively low figures shown for Korea are, of course, in part functions of the evacuation policy and system.

FIGURE 2.
SOURCE: STATISTICAL HEALTH REPORT, WD AGO FORM 8-122, JANUARY 1948 THROUGH MAY 1951:
SUBSEQUENT DATA FROM MORBIDITY REPORT, DD FORM 442. - OFFICE OF THE SURGEON GENERAL 15 APRIL 1954

Respiratory Diseases

Although the problems presented by them were by no means unique or unusual to the Far Eastern area, the respiratory group of diseases are of sufficient importance and significance to deserve at least a passing comment. Figure 3 depicts the admission rates per thousand per annum to medical treatment facilities for the combined conditions of common respiratory disease and influenza. It is apparent that the rate of admissions for this group of disorders has, in general, been about the same in the Far East as for the Army as a whole. (It should


251

be borne in mind when looking at these data that trends determined on an annual basis differ considerably from those which might have been calculated on the basis of the respiratory disease season.)

During the period under consideration influenza A, A Prime and B were demonstrated in Japan and isolated cases of influenza A Prime were recognized in Korea during the 1950-51 season. During the early months of 1950 there were two or three rather sharp but well circumscribed outbreaks of influenza Type B among our forces in

FIGURE 3.
SOURCE: STATISTICAL HEALTH REPORT, WD AGO FORM 8-122, 1948 THROUGH MAY 1951
MORBIDITY REPORT, DD FORM 442, RCS MED-78, JUNE 1951 THROUGH 1953 - OFFICE OF THE SURGEON GENERAL 15 APRIL 1954

Japan suggesting the possibility of the occurrence of this infection on a larger scale during the coming season. This, however, failed to materialize. In fact the sporadic cases of influenza diagnosed in Japan the following fall were found serologically to be principally due to the so-called type A Prime or a closely related type.

There are, of course, no specific procedures and practices available to use for the control of this general respiratory group of diseases. Reliance then must still be placed on what benefits may be gained from the time-honored means for the prevention of the dissemination of


252

these infections. These benefits are in fact probably very few. Because of the demonstrated presence of influenza A Prime in Japan and Korea in the fall of 1950 and the early months of 1951 and in view of the military situation, the polyvalent influenza vaccines then available (certain strains of influenza virus A, A Prime and B) were administered to troops in those areas. No epidemic developed but the influence of the vaccine in averting such remains unknown. The same type of vaccine was administered early in 1953 after the demonstration of the presence of influenza A Prime in the area. This procedure was applied too late to modify the course of a rather sharp outbreak among troops in Japan. A slight modification may have been experienced in Korea. This demonstrated once again that a vaccination program initiated after an outbreak is recognized can be expected to have little if any benefit. Vaccination utilizing the same type of vaccine was again accomplished for the season 1953-54. It is evident now that there has been essentially no influenza during this season.

Enteric Infections

It has become traditional to consider that enteric infections, including the common diarrheas, dysentery, both bacillary and amebic, Salmonella infections and bacterial food poisoning, are major health problems in the Orient. A study of figure 4 suggests that this tradition may not be an entirely sound one. Certainly infections of this group were relatively infrequent causes for disability in the Far East prior to the Korean operation, except among our forces on occupation duty in Korea. (It is to be recalled that these occupation forces remained in Korea until the end of June 1949 and that except for a small number in Military Advisory Groups there were no American troops in Korea after that until the outbreak of hostilities in the summer of 1950.)

With the onset of hostilities, however, and the commitment of combat forces in Korea, admissions for these infections increased sharply as indicated by the admissions among troops in Korea of nearly 60 per thousand per annum for the last 6 months of 1950. Although it appears unnecessary and is certainly undesirable, increases of this kind have come almost to be expected upon the first introduction of American troops into areas of generally insanitary environment particularly under field conditions. During early phases of activities in such areas, there appear to be almost insurmountable problems surrounding the establishment and enforcement of effective sanitary practices. This was so in Korea, and as a result the enteric infections were among the major health problems confronting our troops during the first trying months in that area. The common diarrheas with unknown or undiagnosed etiologies led the incidence with Shigella infections second in importance.


253

FIGURE 4.
SOURCE: STATISTICAL HEALTH REPORT, WD AGO FORM 8-122, 1948 THROUGH MAY 1951
MORBIDITY REPORT, DD FORM 442, RCS MED-78, JUNE 1951 THROUGH 1953. - OFFICE OF THE SURGEON GENERAL 15 APRIL 1954


254

It is important to note here that contrary to the general belief amebic dysentery is not necessarily a major problem in the Orient. This I believe to be true even after taking into consideration the fact that a certain number of these infections may well have been undiagnosed, particularly during the early phases of the Korean operation. On the other hand, bacillary dysentery, or to use a preferred terminology, shigellosis is somewhat more common than is indicated here, since specific reporting of these infections is known to have been incomplete. Infections of this type are unquestionably of considerable importance but have not been a cause for major concern during our time in the Far East. It is perhaps of more than passing interest to learn that during the last few years there has been a marked increase in the incidence of Shigella infections among the native population in Japan. These increases, however, were reflected almost not at all in the occupation personnel stationed in Japan. (It should be appreciated that the rather sharp decreases in total diarrhea and dysentery rates presented here in 1951 are misleading. This is because the rates prior to June 1951 included both diarrhea and dysentery but since that time dysentery only.)

With the enteric group of infections as well as with the common respiratory diseases, there have been and continue to be essentially no specific control measures available. The prevention and control must rest upon continued emphasis and application of individual and group sanitary hygienic precautions aimed at breaking the chain of transmission of the pathogenic microorganisms concerned. Early recognition and treatment of the various specific infections in this group, however, are important measures not only for reducing morbidity but also for shortening the acute and convalescent carrier periods and decreasing the transmission potential. In this connection, it is to be borne in mind that person to person spread of these diseases is an extremely important mode of continuation and build-up of their incidence.

Typhoid Fever

Typhoid fever, once a highly significant and important disease of armies in the field, deserves mention here only because of its extremely infrequent occurrence in the Far East among U. S. Forces. It has been almost unheard of among occupation personnel of Japan and other Far East Command areas and only about two dozen cases have occurred among our forces in Korea. This is despite the fact that in the year 1951 alone there were some 90,000 cases and 20,000 deaths reported among the native population of South Korea. There appears to be no single factor responsible for this relative freedom from typhoid fever of our forces. Certainly proper sanitation practices,


255

the provision of safe water and enforcement of water discipline must have played major roles. In view of the relatively high incidence of other enteric infections, however, one cannot escape the definite impression that typhoid vaccination must have played an extremely significant part in the prevention of typhoid fever in Korea.

Cholera

Cholera must always be considered as a potential hazard in the Orient. Thus far, however, no cases have occurred among American troops either in Korea or elsewhere in the Far East Command. None is known to have occurred among enemy forces in Korea although rumors from time to time suggested outbreaks in those forces. Basic vaccination, plus the administration of stimulating doses of vaccine at appropriate intervals, serves as an adjunct to general and individual sanitary and hygienic practices for the prevention of this disease. In this connection it should be pointed out that the true value of cholera vaccine has never been demonstrated or even tested in American Forces.

Infectious Hepatitis

Infectious hepatitis represents not only one of the unsolved problems in infectious disease prevention and control but also one of the most important of the infectious diseases from a military point of view. This importance, of course, is based not so much on the high attack rates from the disease as on the length of its clinical course and period of convalescence.

Figure 5 indicates the experience with hepatitis for the total Army in the Far East, among our forces in Korea and those in Europe for the 6-year period under consideration. That part of the period of particular interest, of course, is from 1950 on when it will be seen that attack rates increased sharply in 1950, remained high in 1951 and receded to the usual levels by 1953. (Because of difficulties in differential diagnosis, the data presented here represent admission rates for total hepatitis, i. e., the sum of those for infectious hepatitis and for homologous serum hepatitis.)

It is of interest to note that prior to taking the field in Korea the incidence of hepatitis among American Forces in the Far East was not unlike that experienced in the United States and was in fact lower than in Europe. The exception to this, of course, was experienced among the garrison forces who had remained in Korea following World War II. Admissions for this disease, however, increased sharply in the fall of 1950; the first significant increase occurring in November just 2 months after the peak of the diarrhea and dysentery incidence which was in September. This fact provides some ground for speculation and may have considerable significance. The peak of


256

FIGURE 5.
SOURCE: STATISTICAL HEALTH REPORT, WD AGO FORM 8-122, 1948 THROUGH MAY 1951.
MORBIDITY REPORT, DD FORM 442, RCS MED-78, JUNE 1951 THROUGH 1953 - OFFICE OF THE SURGEON GENERAL 15 APRIL 1954

the admissions for infectious hepatitis was reached in February and March of 1951 with monthly rates for troops in Korea being in the neighborhood of 35 per thousand per annum. It is believed that this is the highest report of incidence of this disease among a military organization of this size. Following this peak, admissions decreased gradually and by October 1951 rates of between seven and eight were experienced in Korea with subsequent declines as indicated here. There have been no subsequent seasonal rises of significant magnitude.

The reasons for this high incidence of infectious hepatitis occurring as it did in the early phases of the Korean campaign are not clear.


257

Speculation perhaps is allowable. In the late summer and early fall of 1950, the dark days of the Korean operation, U. S. Forces were packed into the boundaries of that area which became known as the Pusan Bridgehead. Here there were also at least three million Koreans and here it was, as you will recall, that there were experienced the highest reported incidences of the enteric disturbances. Opportunities for transmission and interchange of enteric pathogens were legion and such obviously did occur. It is possible, then, that it was here that our troops became well seeded with the virus of infectious hepatitis. (It is generally felt that the great majority of the hepatitis experienced was in fact due to infection with the IH virus rather than that of the SH variety.) Following this seeding, it seems likely that the disease progressed in a normal epidemiological manner probably spreading largely by person to person contact.

The general situation has been quite different in Korea since those days in the late summer of 1950. Our troops have been much more widely dispersed; there have been relatively fewer natives in the forward areas and our sanitary practices have undoubtedly been markedly improved. This may furnish at least part of the answer. Group immunity has played no significant role since troops have been rotated to an extent to nullify such an effect. Early in 1951 the practice of chlorination of water to a concentration of five parts per million at all water-processing points in Korea was established. Whether or not this was a factor in the decline in the occurrence of the disease remains unknown.

Malaria

Malaria has been one of the most important of the infectious diseases in the Far East, particularly in Korea. Certainly our experience with malaria in that area has been most interesting and instructive. Figure 6 shows that again with the exception of those troops in Korea the problem of malaria was being handled quite well prior to the onset of the Korean campaign. After the onset of hostilities in Korea, the situation appears to have reversed itself. In other words, it is noted that for the year 1950 the rate for malaria admissions in Korea was only about 11 per thousand with a drop to approximately 10 in 1951 whereas in 1951 the rate for the total Army was nearly 12 and for the Far East Command itself, approximately the same. This means, of course, that malaria among troops in Korea, while not controlled, was being adequately suppressed and that relapses were occurring at a relatively high rate both in the Far East Command outside of Korea, and in the United States among Korean returnees. This is, of course, exactly what happened.


258

Since malaria is to be discussed later in this symposium, no detailed review of the malaria situation will be presented here. It is enough to say that the occurrence of malaria among our forces in Korea was inevitable because of the environmental situation, the outstanding features of which were the general presence of the malaria vector, the Anopheles hyrcanus sinensis, a rice field breeder, and the relative frequency and density of reservoir hosts among the South Korean

FIGURE 6.
SOURCE: STATISTICAL HEALTH REPORT, WD AGO FORM 8-122, 1948 THROUGH MAY 1951
MORBIDITY REPORT, DD FORM 442, RCS MED-78, JUNE 1951 THROUGH 1953 - OFFICE OF THE SURGEON GENERAL 15 APRIL 1954

population. Even with these factors the reported incidence of clinical malaria among troops in Korea was relatively low, as already indicated. This was accomplished through the application of all the known means of malaria control, including drug suppression, personal protection against bites of mosquitoes and unit and area adult and larval mosquito control.

It is now readily apparent that of these drug suppression was by far the most effective procedure. As is now well known, the drug used was chloroquine diphosphate, chloroquine being one of the four ami-


259

noquinoline compounds. At the beginning of the Korean campaign, there were large supplies of atabrine readily available in the Far East but in view of the studies and field trials with chloroquine, the latter drug appeared to have a marked advantage over the older preparations. Consequently, suppressive medication in Korea was delayed for a time until an adequate supply of chloroquine could be obtained. Fortunately, this was accomplished very quickly and the chloroquine suppressive program was initiated in July. By mid-August the program was well established and its effectiveness is beyond question.

The only delay in this program was due to the necessity for learning once again that a procedure of this type to be effective must be directed and administered through and by the appropriate command. As soon as this was learned, the program became quite effective. Thereafter, during the spring, summer and early months of the campaign, chloroquine diphosphate was administered in weekly doses of 0.5 gram each. For the sake of uniformity and complete coverage, it was decided that in Korea this administration would be accomplished on a specific day of the week. Hence, in that area during the malaria season Sunday was malaria pill or chloroquine day.

It is now apparent that the low incidence of clinical malaria reported from Korea itself did not mirror the extent of acquired malaria parasitism. This was brought to light by the high incidence of clinical malaria occurring among Army returnees to the United States and among those returning to Japan for further duty. Estimated incidence among such personnel approximated 15 percent. It appears that this problem has now been met quite adequately through the administration of primaquine, 15 mg. per day for 14 days, for those departing the Korean area. This drug appears to have been extraordinarily effective in eradicating the malaria parasite from its exerythrocytic or tissue phases and hence the actual eradication of the parasitism. The adoption and use of this drug in the control of the Temperate Zone (long latent period) type of malaria encountered in Korea marks one of the great advances in the medical conquest of the disease, malaria.

Japanese B Encephalitis

An insect-borne disease, probably unique to the Far East, is Japanese B encephalitis. This infection is a member of the large mosaic of virus encephalitides and for practical purposes it is clinically indistinguishable from the others. It is to be found in Korea, Okinawa and Japan and probably in the Philippines. (In addition, a limited outbreak was experienced in Guam in December of 1947 and January of 1948.) A more detailed discussion of this disease will be presented


260

at another time in this symposium. Consequently, only the briefest of reviews will be given here.

The disease is believed to be transmitted by Culex mosquitoes, Culex tritaeniorhymchus being the vector most commonly blamed although others have been incriminated. The reservoir host is probably in the native population of the areas concerned and in domestic animals and birds. The season of highest incidence appears to be in the late summer in Okinawa and Japan and possibly extending into the early fall in Korea.

Prior to the Korean hostilities, the disease had been experienced in relatively minor fashion by occupation personnel both in Japan and Okinawa. For example, in 1948 there were 29 cases among occupation personnel and 2 in Okinawa. Again in 1949, there were 13 clinical cases of Japanese B encephalitis among personnel in the Far East. Ten of these were in Japan and three in Okinawa. In 1950, from among some 350 cases of infectious encephalitis reported among Americans in the Far East, approximately 300 from Korea were considered to have been due to the virus of Japanese B encephalitis. The case fatality in this group was approximately 10 percent and severe central nervous system residuals were relatively uncommon. Since that time the disease has been reported with considerably less frequency. Just under 40 cases of infectious encephalitis were reported in each of the years 1951 and 1952 from Korea and in 1953 less than 25 such cases were reported. Only a small proportion of these were specifically demonstrated to have been due to the virus of Japanese B encephalitis.

Since 1946, troops in Japan, Okinawa and Korea were given Japanese B encephalitis vaccine as an adjunct to mosquito control for the prevention of this disease. The first real opportunity for the evaluation of this procedure presented itself in 1950 with the occurrence of the approximately 300 cases of the disease in Korea as indicated previously. After careful study of the admittedly incomplete data available at this time, it was concluded that there was no conclusive evidence either for or against the efficacy of the vaccination for the prevention of Japanese B encephalitis. As a result, the vaccine has not been administered since the 1951 season.

The Typhus Fevers

Typhus fever is another insect-borne disease of considerable potential importance in the Far East. Classical or epidemic louse-borne typhus fever has for many years been endemic and at times epidemic in parts of this area, including Japan and Korea. In Japan, there has been no serious outbreak since 1945 and 1946, while in Korea significant epidemics continued to occur among the native population. It is


261

definitely possible, though not conclusively proven, that this disease was of considerable importance among enemy forces during the 1950-51 winter season. No cases have occurred among American Forces in Korea to date. This is despite the fact that there were in a single year, 1950-51, some 38,000 cases with over 5,000 deaths reported among the civil population in South Korea. It is of some interest to note that typhus fever in South Korea tends to occur with the highest incidence in the late winter and early spring months, frequently reaching its peak as late as May.

The prevention and control of louse-borne typhus fever of necessity was based on the prevention and control of lousiness, a problem frequently presenting some difficulty in the winter months. Strict attention to hygienic matters, insistence on bathing as frequently as possible with the provision of changes of clothing and the application of insecticides prophylactically were the mainstays of the typhus control program among our forces in Korea. In this connection, more than a casual interest has developed in the development of the relative noneffectiveness of DDT as a lousicide in Korea. The observations of a number of qualified workers indicate that Korean lice apparently became extremely resistant to this material.

Another insecticide has been supplied to our troops in the Far East and has since then been in use. This is benzene hexachloride, perhaps more commonly known as lindane. It has been shown to be extremely effective against the Korean lice. Thus another stumbling block has been effectively removed from the path of effective prevention and control of louse-borne typhus.

During the Korean campaign, the anti-louse program has been highly effective. That it has not been completely effective, however, has been evidenced by the occurrence of a few cases of louse-borne relapsing fever. This suggests that typhus vaccine administered as an added safeguard in the control and prevention of typhus has in fact been important in the preventive program. More and more evidence is thus accruing to indicate that this vaccine is highly effective in the prevention of epidemic or louse-borne typhus fever. It would be unthinkable for American Forces to attempt to operate in areas where this disease is known to exist without the benefit of the protection afforded by this vaccine.

Scrub typhus or tsutsugamushi disease has its home in Japan and until very recently had not been demonstrated elsewhere in the Far East. The several cases reported by British troops in Korea, however, together with the evidence brought to light by the hemorrhagic fever study group, strongly suggest that this disease is present in Korea. Up to now, however, it has presented essentially no problem.


262

Smallpox

Smallpox, a disease now almost unknown in the United States, but one of extreme importance in certain areas of the world including the Far East Command areas, is to be considered in more detail at another time in this symposium. Only a brief review will be attempted here. The experiences of 1945 and 1946 in Korea and Japan sensitized all concerned to the possible and even probable difficulties from this disease which could be encountered in the Far East. It was known, for example, that highly virulent forms of this infection continued to occur among native Koreans and that epidemic proportions were frequently reached.

With the advent of hostilities in Korea, and the resultant confusion and disruption in the native population, the disease there became a definite threat to our forces. In 1951 alone, for example, nearly 50,000 cases with over 12,000 deaths were reported among South Koreans. Stemming from this infectious potential, some 40 cases of smallpox occurred among United Nations personnel between July 1950 and June 1951. Of these, approximately 30 were among Americans including Army, Navy, Air Force and Merchant Seamen. The remainder were among personnel of the various other United Nations. Since May 1951, only scattered cases of the disease have occurred.

Smallpox experienced among United Nations personnel has varied in character from cases which were so mild as to be distinguishable only with great difficulty from chickenpox, to the rapidly fulminating type of hemorrhagic smallpox known as purpura variolosa. Fortunately, there were very few of the latter type which is essentially 100 percent fatal.

It is to be emphasized that the occurrence of smallpox among American personnel does not suggest in any way failure of American vaccines to protect. Rather, it indicates clearly that such vaccines are highly effective within the limits well recognized for them. Were this not true, instead of having had some 40 cases, we might well have had 4,000 cases or more. It is difficult to overemphasize the obvious facts that smallpox, even the virulent severe type seen in the Orient, can be prevented and that cases represent technical failure on the part of the vaccination. Prevention can be accomplished by the use of potent vaccine within its expiration date applied with the proper procedure and technic, the reaction therefrom adequately interpreted and the vaccination results recorded with repetition of all unsuccessful attempts until a successful vaccination has been accomplished. With strict application of these procedures and technics, there can be every assurance that smallpox, if it does occur at all among our forces, will be so rare that there will be no epidemics of this highly fatal disease.


263

Cold Injuries

Cold injuries had presented no problem in the Far East prior to the onset of the Korean conflict. During this conflict, however, great and serious problems with these injuries were experienced. Since this subject has been discussed previously, only brief mention of it will be made here.

FIGURE 7.
SOURCE: STATISTICAL HEALTH REPORT, WD AGO FORM 8-122, 1948 THROUGH MAY 1951.
MORBIDITY REPORT, DD FORM 442, RCS MED-78, JUNE 1951 THROUGH 1953. - OFFICE OF THE SURGEON GENERAL 15 APRIL 1954

Figure 7 shows the rate per thousand per annum for our troops in Korea for the winter seasons 1950-51, 1951-52, and 1952-53. It is immediately apparent that it was during the first winter that the greatest losses from injury due to colds were experienced. It is to be recalled that these months were the ones during which the Chinese


264

Communist forces entered the conflict and when our troops deployed far to the North were engaged in the bitterest of battles, many of them in positions which could not be adequately supported from the rear. The great majority of the injuries experienced during that time and subsequently have been the result of true frostbite following exposure for variable periods of time to severe cold. Wetness, per se, has not been a significant part of the problem.

The occurrence of cold injuries among our troops in Korea including those of the first winter season occurred despite an intensive preventive program effected by the Medical Services, Quartermaster Services and the various echelons of command. Without this program, it is felt that many more cases would have been encountered. Based upon the experiences learned in Europe, this preventive program was built around the triad of adequate cold weather clothing and equipment, proper indoctrination and training in the use of this equipment, and individual preventive measures and unceasing command supervision and enforcement of cold weather discipline. The experience of the 1951-52 and 1952-53 seasons indicates that even in severe climates if there is adequate cold weather clothing and equipment, proper indoctrination and training and continued emphasis on cold prevention and discipline, the cold injury problem can be met in reasonable fashion; all of this, of course, provided that the tactical situation is such that these various factors can be adequately applied and maintained.

Hemorrhagic Fever

First making its appearance in June of 1951, a disease hitherto not experienced by United States medical personnel occurred among United Nations forces in Korea. The clinical syndrome observed was one suggestive of an acute infectious process coupled with a hemorrhagic diathesis. The first diagnoses submitted were those of leptospirosis. It was soon determined, however, that the condition being encountered was not due to leptospiral infection, but rather was a disease previously described by the Japanese and others and called epidemic hemorrhagic fever. This, too, has been discussed in considerably more detail at another time during this symposium and hence will be given but a brief résumé here.

Figure 8 indicates the important incidence of this disease per thousand per annum for the years 1951, 1952 and 1953. It is noted that the reported occurrences differed practically not at all in the first 2 years but that during the calendar year 1953 a rather marked decline in reported cases has occurred.

Extensive and comprehensive investigation has been conducted in the field, in the laboratories of the Far East Command, in the labora-


265

tories here at the Army Medical Service Graduate School and elsewhere in the United States. Up to this time, a specific etiological definition of this disease has not been made. However, much of value has been learned about the condition. Epidemiologically, epidemic hemorrhagic fever resembles scrub typhus in many of its aspects, most particularly in the fact that it appears to be a place disease and that it presents characteristics entirely compatible with an arthropod-borne disease, the reservoir host of which could be in field rodents. Perhaps of all the conditions encountered in the Far East to date, hemorrhagic fever has posed the greatest single challenge of any problem in the field of epidemiology, microbiology and preventive medicine.

U. S. ARMY PERSONNEL
EPIDEMIC HEMORRHAGIC FEVER RATES IN KOREA ONLY
RATES PER 1000 AVERAGE STRENGTH PER YEAR

YEAR

RATE

19511/

3.85

1952

3.72

1953

1.76

FIGURE 8.
SOURCE: MORBIDITY REPORT, DD FORM 442, RCS MED-78
OFFICE OF THE SURGEON GENERAL
15 APRIL 1954

Venereal Disease

Presumably no discussion of preventive medicine in its general aspects can be complete without at least a reference to the venereal infections. Certainly, these have not been uncommon in the Far East Command in general nor in Korea in particular. In these areas, the most commonly experienced infections of this category have been gonorrhea and chancroid. Syphilis has occurred with considerably less frequency. This is seen from figure 9, which depicts the reported incidence of these infections over a 6-year period of time. The unusually low reported incidence of this group of infections in Korea for 1950 is possibly explainable by the fact that the troops in that area at that time were extremely preoccupied in the fighting business of the defense of the Pusan perimeter.


266

FIGURE 9.
SOURCE: STATISTICAL HEALTH REPORT, WD AGO FORM 8-122, 1948 THROUGH MAY 1951
MORBIDITY REPORT, DD FORM 442, RCS MED-78, JUNE 1951 THROUGH 1953
OFFICE OF THE SURGEON GENERAL 15 APRIL 1954


267

There is nothing unusual or unexpected about the occurrence of these infections in Korea or other areas of the Far East. (In this connection, it is noted that these reported cases are CRO, which means carded for record only. In other words, the venereal diseases today are treated on an outpatient status causing only that loss of time, incident to the report to the dispensary and the diagnosis and appropriate treatment of the condition. Only those with complicated cases are admitted to the hospital.) The relatively high incidence of the venereal infections reported from troops in Korea, and elsewhere in the Far East for that matter, may be attributed largely to the following factors:

    1. High proportion of very young men in new and unusual environments.

    2. Legality and acceptance of prostitution in the areas.

    3. The extremely high infectious rates among available consorts with whom troops can easily establish contact.

    4. Little effective reduction of the civilian infectious reservoir.

    5. The extreme difficulty in identification of contacts.

    6. Complete faith on the part of troops in modern therapy.

    7. Relatively high degree of reporting as compared to areas where civil medical attention is more readily obtainable.

Summary and Conclusions

Reviewing the experiences with disease and its prevention among United States Forces in the Far East and particularly in Korea, it becomes apparent that many of the basic problems of disease prevention and control in that area are not significantly unlike those experienced in the United States and elsewhere. The differences frequently are found to be quantitative rather than qualitative. The preventive procedures that are applicable in the Far Eastern Area are in the main those which must be applied even under more favorable conditions. It is necessary, however, in many instances that they be applied with increased vigor and thoroughness. In this connection, it is of interest to compare the proportionate admissions for disease, non-battle injury and battle injury and wounds for the active phase of the European theater campaigns of World War II and Korea, July 1950 through June 1951. This is shown in table 1. It is noted that in the European theater for the period noted, 63 percent of admissions were for disease, 14 for non-battle injury and 23 percent for battle injury and wounds. For Korea, during the period July 1950 through June 1951, the phase of most active combat, these proportions were 60, 17 and 23 respectively.

It has been learned, however, that in addition to the basic health problems common to most areas of the world, there have been actual


268

Table 1. Admissions for Battle and Non-battle Causes, U. S. Army European Theater in World War II and Korea

 

Percentage of admissions

 

Disease

NBI

BI and W

European theatera

63

14

23

Koreab

60

17

23

 

Admissions per 1,000 men per year

European theatera

484

111

176

Koreab

749

217

293

a June 1944 through May 1945.
b July 1950 through June 1951.

and potential health hazards arising from environmental and disease sources not usually encountered by our troops in the field. Under this situation, it has been necessary to apply a preventive medicine program comprehensive in nature and broad in scope. This program was neither conceived nor applied by any single individual or small groups of individuals in the area. Rather, it was based upon developments and achievements in the field of preventive medicine throughout the years. What success has been achieved in its application has been made possible by the cooperation and united efforts of many and the utilization of great resources of talents, skills and knowledge available, not only in the military organization but also from a multiplicity of civilian sources.

The practice of military preventive medicine in the Far East has been an exemplification of the fact that to be effective preventive medicine must use all of these skills and all of these resources in the aid and assistance of personnel trained in almost every field of modern medicine. These, of course, include the internist, the entomologist, the sanitary engineers, the laboratory workers and others as well as preventive medicine officers. All of these must be welded into an effective team whose goal is the prevention and control of disease and other conditions which could reduce the effectiveness of military forces. There is such a team today in the Far East and the effectiveness of our military preventive medicine program there is at a high level. There remains little room for complacency, however. Without question, the success of military preventive medicine in the Far East and elsewhere will depend upon the success of the constant efforts of all in the various branches of the medical sciences.


269

An outstanding need, at least paralleling the requirement for continued acquisition of new information and knowledge, is the need for the practical application of this information and knowledge. It is important that the ever present gaps between expectation and accomplishment be bridged and that basic knowledge be converted into successfully applied technic. It is also important that disease prevention and control be given at least equal emphasis and support in all respects as that afforded medical care and hospitalization. More man-days can be saved outside the hospital than in it.