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 THEFAR EAST COMMAND*
COLONEL ARTHUR P.LONG, MC
The General Background
For the purposes for this discussion the Far East Command is definedboth as a military organization and as the delineation of a broad geographicarea. Until fairly recently, this area included Japan, the Ryukus Islands(Okinawa), the Mariannas-Bonins Group of islands (Guam), the Philippinesand Korea. A geographic and environmental description of these widely spacedareas might be of some interest. However, this is not a travelogue andit seems fair to assume that the audience here is acquainted, either directlyor indirectly, with the general characteristics of these places. It isperhaps sufficient, then, to remark that almost all types of climatic conditionsand features of terrain and general environment are encountered, from thetropical features of the Philippines and Guam to the semi-arctic characteristicsof Northern Japan (Hokkaido) and Korea in the wintertime.
The level of sanitary practices in this broad area, though extremelyvariable, is in general consistently lower than that in most areas normallyfamiliar to our forces. Added to the potential hazards posed by the physicalenvironment are the presence of disease reservoirs found in the endemicand epidemic foci of a number of infectious diseases some of which areunique 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, filariasisand of course, the venereal infections, particularly chancroid.
Of all the areas in this broad Far East Command, none perhaps presentsso many of these variables and offers such undesirable conditions as doesthe 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 calledupon to take precautions against heat exhaustion, malaria and insect-borneencephalitis during one season of the operation, and at another time tocarry out an intensive program for the prevention of cold injuries andlouse-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.
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Such, however, has been the experience in Korea. Because this symposiumhas to do almost entirely with the professional activities of the MedicalService during the Korean War and because the general interest relatingto the Far East Command Medical Service has been largely centered in theKorean effort, this discussion will deal primarily with preventive medicineand its attendant problems in Korea with pertinent comparisons to the FarEast Command as a whole and to the experience of the total Army.
Against the background thus hastily sketched, I shall attempt to reviewbriefly some of the actual experiences encountered in the Far East Commandand, particularly, in Korea, during the 6-year period, 1948 through 1953.In this connection, it is to be recalled that the Korean military campaignbegan in late June 1950 after the North Korean Communists crossed the 38thParallel to invade South Korea on the 25th of that month, and that theactive fighting continued for approximately 3 years from that time. Inmaking such a review, it becomes at once apparent that it is quite possiblefor large numbers of men unused to many of the conditions present to livein these varied environments in the face of disease potentials not previouslyexperienced, to carry on an effective and arduous military campaign, andto suffer only minimally from the special hazards presented. This is accomplishednot by any sudden or radical development of new disease control measuresand technics but rather by the vigorous application of procedures demonstratedto have been effective by long and careful trial and application in thelaboratory and in the field.
In many instances, the procedures applicable for disease preventionhere at home are also those applied in the Far Eastern areas; the principaldifferences in their application being quantitative in nature. Thus, ithas been found that many of the basic problems arising in the Far Eastand the requirements for their solution were in many instances not significantlyunlike those experienced in the various parts of the United States. Inaddition to these basic problems, however, there are, as has already beenindicated, certain conditions and disease hazards which though not necessarilyunique to the Far East, differ considerably from those seen in the UnitedStates and, hence, offer new experiences in prevention and management ofdisease to the American trained physician.
Disease Experiences
As a measure of the general experience with disease, it is appropriateto examine the over-all disease admissions. Figure 1 indicates such admissionsfor the 6-year period for the total Army, for the Far East Command andfor Korea only. It is noted that the admission rates for the Far East Commandare not excessively higher than those ex-
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perienced for the total Army except perhaps for the year 1950. The experiencein Korea that year, being of course for the latter 6 months only, accountingfor an admission rate of 824 per thousand per annum readily explains thishigh rate for the Far East Command as a whole. This was, of course, a directresult of those unhappy early months of the Korean operation when troopsessentially on garrison-type duty in Japan were suddenly thrown into combatin Korea under the most adverse conditions. As we shall see later, thediarrheal diseases and
FIGURE1.
SOURCE: STATISTICAL HEALTH REPORT, WD AGO FORM8-122, 1948 THROUGH MAY 1951
MORBIDITY REPORT, DD FORM 422, RCS MED-78, JUNE 1951 THROUGH 1953 - OFFICEOF THE SURGEON GENERAL 15 APRIL 1954
malaria accounted for important parts of this high admission rate. Withimprovement in the military situation including stabilization and experiencein the field, plus improved sanitary discipline, specific and total diseaserates decreased, and 1952 and 1953 saw admissions not unlike those havingbeen experienced under peacetime conditions.
The ultimate indication, if not the measure, of success in disease controlis probably to be found in the number of deaths which occur from disease.Figure 2 indicates disease death rates for the same
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groups and for the same periods as shown in the previous figure fordisease admissions. It is noteworthy that in 1948 and 1949, disease deathsin the Far East were fewer proportionately than for the total Army. Theslight increases in 1950 and 1951 were the inevitable accompaniments ofthe situation previously indicated. Return to a level essentially thatof the pre-hostilities period is indicated for the years 1952 and 1953.The relatively low figures shown for Korea are, of course, in part functionsof the evacuation policy and system.
FIGURE2.
SOURCE: STATISTICAL HEALTH REPORT, WD AGO FORM8-122, JANUARY 1948 THROUGH MAY 1951:
SUBSEQUENT DATA FROM MORBIDITY REPORT, DD FORM 442. - OFFICE OF THE SURGEONGENERAL 15 APRIL 1954
Respiratory Diseases
Although the problems presented by them were by no means unique or unusualto the Far Eastern area, the respiratory group of diseases are of sufficientimportance and significance to deserve at least a passing comment. Figure3 depicts the admission rates per thousand per annum to medical treatmentfacilities for the combined conditions of common respiratory disease andinfluenza. It is apparent that the rate of admissions for this group ofdisorders has, in general, been about the same in the Far East as for theArmy as a whole. (It should
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be borne in mind when looking at these data that trends determined onan annual basis differ considerably from those which might have been calculatedon the basis of the respiratory disease season.)
During the period under consideration influenza A, A Prime and B weredemonstrated in Japan and isolated cases of influenza A Prime were recognizedin Korea during the 1950-51 season. During the early months of 1950 therewere two or three rather sharp but well circumscribed outbreaks of influenzaType B among our forces in
FIGURE3.
SOURCE: STATISTICAL HEALTH REPORT, WD AGO FORM8-122, 1948 THROUGH MAY 1951
MORBIDITY REPORT, DD FORM 442, RCS MED-78, JUNE 1951 THROUGH 1953 - OFFICEOF THE SURGEON GENERAL 15 APRIL 1954
Japan suggesting the possibility of the occurrence of this infectionon a larger scale during the coming season. This, however, failed to materialize.In fact the sporadic cases of influenza diagnosed in Japan the followingfall were found serologically to be principally due to the so-called typeA Prime or a closely related type.
There are, of course, no specific procedures and practices availableto use for the control of this general respiratory group of diseases. Reliancethen must still be placed on what benefits may be gained from the time-honoredmeans for the prevention of the dissemination of
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these infections. These benefits are in fact probably very few. Becauseof the demonstrated presence of influenza A Prime in Japan and Korea inthe fall of 1950 and the early months of 1951 and in view of the militarysituation, the polyvalent influenza vaccines then available (certain strainsof influenza virus A, A Prime and B) were administered to troops in thoseareas. No epidemic developed but the influence of the vaccine in avertingsuch remains unknown. The same type of vaccine was administered early in1953 after the demonstration of the presence of influenza A Prime in thearea. This procedure was applied too late to modify the course of a rathersharp outbreak among troops in Japan. A slight modification may have beenexperienced in Korea. This demonstrated once again that a vaccination programinitiated after an outbreak is recognized can be expected to have littleif any benefit. Vaccination utilizing the same type of vaccine was againaccomplished for the season 1953-54. It is evident now that there has beenessentially no influenza during this season.
Enteric Infections
It has become traditional to consider that enteric infections, includingthe common diarrheas, dysentery, both bacillary and amebic, Salmonellainfections and bacterial food poisoning, are major health problems in theOrient. A study of figure 4 suggests that this tradition may not be anentirely sound one. Certainly infections of this group were relativelyinfrequent 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 recalledthat these occupation forces remained in Korea until the end of June 1949and that except for a small number in Military Advisory Groups there wereno American troops in Korea after that until the outbreak of hostilitiesin the summer of 1950.)
With the onset of hostilities, however, and the commitment of combatforces in Korea, admissions for these infections increased sharply as indicatedby the admissions among troops in Korea of nearly 60 per thousand per annumfor the last 6 months of 1950. Although it appears unnecessary and is certainlyundesirable, increases of this kind have come almost to be expected uponthe first introduction of American troops into areas of generally insanitaryenvironment particularly under field conditions. During early phases ofactivities in such areas, there appear to be almost insurmountable problemssurrounding the establishment and enforcement of effective sanitary practices.This was so in Korea, and as a result the enteric infections were amongthe major health problems confronting our troops during the first tryingmonths in that area. The common diarrheas with unknown or undiagnosed etiologiesled the incidence with Shigella infections second in importance.
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FIGURE4.
SOURCE: STATISTICAL HEALTH REPORT, WD AGO FORM8-122, 1948 THROUGH MAY 1951
MORBIDITY REPORT, DD FORM 442, RCS MED-78, JUNE 1951 THROUGH 1953. - OFFICEOF THE SURGEON GENERAL 15 APRIL 1954
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It is important to note here that contrary to the general belief amebicdysentery is not necessarily a major problem in the Orient. This I believeto be true even after taking into consideration the fact that a certainnumber of these infections may well have been undiagnosed, particularlyduring the early phases of the Korean operation. On the other hand, bacillarydysentery, or to use a preferred terminology, shigellosis is somewhat morecommon than is indicated here, since specific reporting of these infectionsis known to have been incomplete. Infections of this type are unquestionablyof considerable importance but have not been a cause for major concernduring our time in the Far East. It is perhaps of more than passing interestto learn that during the last few years there has been a marked increasein the incidence of Shigella infections among the native population inJapan. These increases, however, were reflected almost not at all in theoccupation personnel stationed in Japan. (It should be appreciated thatthe rather sharp decreases in total diarrhea and dysentery rates presentedhere in 1951 are misleading. This is because the rates prior to June 1951included both diarrhea and dysentery but since that time dysentery only.)
With the enteric group of infections as well as with the common respiratorydiseases, there have been and continue to be essentially no specific controlmeasures available. The prevention and control must rest upon continuedemphasis and application of individual and group sanitary hygienic precautionsaimed at breaking the chain of transmission of the pathogenic microorganismsconcerned. Early recognition and treatment of the various specific infectionsin this group, however, are important measures not only for reducing morbiditybut also for shortening the acute and convalescent carrier periods anddecreasing the transmission potential. In this connection, it is to beborne in mind that person to person spread of these diseases is an extremelyimportant mode of continuation and build-up of their incidence.
Typhoid Fever
Typhoid fever, once a highly significant and important disease of armiesin the field, deserves mention here only because of its extremely infrequentoccurrence in the Far East among U. S. Forces. It has been almost unheardof among occupation personnel of Japan and other Far East Command areasand 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 90,000cases and 20,000 deaths reported among the native population of South Korea.There appears to be no single factor responsible for this relative freedomfrom typhoid fever of our forces. Certainly proper sanitation practices,
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the provision of safe water and enforcement of water discipline musthave played major roles. In view of the relatively high incidence of otherenteric infections, however, one cannot escape the definite impressionthat typhoid vaccination must have played an extremely significant partin 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 eitherin Korea or elsewhere in the Far East Command. None is known to have occurredamong enemy forces in Korea although rumors from time to time suggestedoutbreaks in those forces. Basic vaccination, plus the administration ofstimulating doses of vaccine at appropriate intervals, serves as an adjunctto general and individual sanitary and hygienic practices for the preventionof this disease. In this connection it should be pointed out that the truevalue of cholera vaccine has never been demonstrated or even tested inAmerican Forces.
Infectious Hepatitis
Infectious hepatitis represents not only one of the unsolved problemsin infectious disease prevention and control but also one of the most importantof 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 diseaseas on the length of its clinical course and period of convalescence.
Figure 5 indicates the experience with hepatitis for the total Armyin the Far East, among our forces in Korea and those in Europe for the6-year period under consideration. That part of the period of particularinterest, of course, is from 1950 on when it will be seen that attack ratesincreased sharply in 1950, remained high in 1951 and receded to the usuallevels by 1953. (Because of difficulties in differential diagnosis, thedata 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 theincidence of hepatitis among American Forces in the Far East was not unlikethat experienced in the United States and was in fact lower than in Europe.The exception to this, of course, was experienced among the garrison forceswho had remained in Korea following World War II. Admissions for this disease,however, increased sharply in the fall of 1950; the first significant increaseoccurring in November just 2 months after the peak of the diarrhea anddysentery incidence which was in September. This fact provides some groundfor speculation and may have considerable significance. The peak of
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FIGURE5.
SOURCE: STATISTICAL HEALTH REPORT, WD AGO FORM8-122, 1948 THROUGH MAY 1951.
MORBIDITY REPORT, DD FORM 442, RCS MED-78, JUNE 1951 THROUGH 1953 - OFFICEOF THE SURGEON GENERAL 15 APRIL 1954
the admissions for infectious hepatitis was reached in February andMarch of 1951 with monthly rates for troops in Korea being in the neighborhoodof 35 per thousand per annum. It is believed that this is the highest reportof incidence of this disease among a military organization of this size.Following this peak, admissions decreased gradually and by October 1951rates of between seven and eight were experienced in Korea with subsequentdeclines as indicated here. There have been no subsequent seasonal risesof significant magnitude.
The reasons for this high incidence of infectious hepatitis occurringas it did in the early phases of the Korean campaign are not clear.
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Speculation perhaps is allowable. In the late summer and early fallof 1950, the dark days of the Korean operation, U. S. Forces were packedinto 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, asyou will recall, that there were experienced the highest reported incidencesof the enteric disturbances. Opportunities for transmission and interchangeof 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 virusof infectious hepatitis. (It is generally felt that the great majorityof the hepatitis experienced was in fact due to infection with the IH virusrather than that of the SH variety.) Following this seeding, it seems likelythat the disease progressed in a normal epidemiological manner probablyspreading largely by person to person contact.
The general situation has been quite different in Korea since thosedays in the late summer of 1950. Our troops have been much more widelydispersed; there have been relatively fewer natives in the forward areasand our sanitary practices have undoubtedly been markedly improved. Thismay furnish at least part of the answer. Group immunity has played no significantrole since troops have been rotated to an extent to nullify such an effect.Early in 1951 the practice of chlorination of water to a concentrationof 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 thedisease remains unknown.
Malaria
Malaria has been one of the most important of the infectious diseasesin the Far East, particularly in Korea. Certainly our experience with malariain that area has been most interesting and instructive. Figure 6 showsthat again with the exception of those troops in Korea the problem of malariawas being handled quite well prior to the onset of the Korean campaign.After the onset of hostilities in Korea, the situation appears to havereversed itself. In other words, it is noted that for the year 1950 therate for malaria admissions in Korea was only about 11 per thousand witha drop to approximately 10 in 1951 whereas in 1951 the rate for the totalArmy was nearly 12 and for the Far East Command itself, approximately thesame. This means, of course, that malaria among troops in Korea, whilenot controlled, was being adequately suppressed and that relapses wereoccurring at a relatively high rate both in the Far East Command outsideof Korea, and in the United States among Korean returnees. This is, ofcourse, exactly what happened.
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Since malaria is to be discussed later in this symposium, no detailedreview of the malaria situation will be presented here. It is enough tosay that the occurrence of malaria among our forces in Korea was inevitablebecause of the environmental situation, the outstanding features of whichwere the general presence of the malaria vector, the Anopheles hyrcanussinensis, a rice field breeder, and the relative frequency and densityof reservoir hosts among the South Korean
FIGURE6.
SOURCE: STATISTICAL HEALTH REPORT, WD AGO FORM8-122, 1948 THROUGH MAY 1951
MORBIDITY REPORT, DD FORM 442, RCS MED-78, JUNE 1951 THROUGH 1953 - OFFICEOF THE SURGEON GENERAL 15 APRIL 1954
population. Even with these factors the reported incidence of clinicalmalaria among troops in Korea was relatively low, as already indicated.This was accomplished through the application of all the known means ofmalaria control, including drug suppression, personal protection againstbites of mosquitoes and unit and area adult and larval mosquito control.
It is now readily apparent that of these drug suppression was by farthe most effective procedure. As is now well known, the drug used was chloroquinediphosphate, chloroquine being one of the four ami-
259
noquinoline compounds. At the beginning of the Korean campaign, therewere large supplies of atabrine readily available in the Far East but inview of the studies and field trials with chloroquine, the latter drugappeared to have a marked advantage over the older preparations. Consequently,suppressive medication in Korea was delayed for a time until an adequatesupply of chloroquine could be obtained. Fortunately, this was accomplishedvery quickly and the chloroquine suppressive program was initiated in July.By mid-August the program was well established and its effectiveness isbeyond question.
The only delay in this program was due to the necessity for learningonce again that a procedure of this type to be effective must be directedand administered through and by the appropriate command. As soon as thiswas learned, the program became quite effective. Thereafter, during thespring, summer and early months of the campaign, chloroquine diphosphatewas administered in weekly doses of 0.5 gram each. For the sake of uniformityand complete coverage, it was decided that in Korea this administrationwould be accomplished on a specific day of the week. Hence, in that areaduring the malaria season Sunday was malaria pill or chloroquine day.
It is now apparent that the low incidence of clinical malaria reportedfrom Korea itself did not mirror the extent of acquired malaria parasitism.This was brought to light by the high incidence of clinical malaria occurringamong Army returnees to the United States and among those returning toJapan for further duty. Estimated incidence among such personnel approximated15 percent. It appears that this problem has now been met quite adequatelythrough the administration of primaquine, 15 mg. per day for 14 days, forthose departing the Korean area. This drug appears to have been extraordinarilyeffective in eradicating the malaria parasite from its exerythrocytic ortissue phases and hence the actual eradication of the parasitism. The adoptionand use of this drug in the control of the Temperate Zone (long latentperiod) type of malaria encountered in Korea marks one of the great advancesin the medical conquest of the disease, malaria.
Japanese B Encephalitis
An insect-borne disease, probably unique to the Far East, is JapaneseB encephalitis. This infection is a member of the large mosaic of virusencephalitides and for practical purposes it is clinically indistinguishablefrom the others. It is to be found in Korea, Okinawa and Japan and probablyin the Philippines. (In addition, a limited outbreak was experienced inGuam in December of 1947 and January of 1948.) A more detailed discussionof this disease will be presented
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at another time in this symposium. Consequently, only the briefest ofreviews will be given here.
The disease is believed to be transmitted by Culex mosquitoes, Culextritaeniorhymchus being the vector most commonly blamed although othershave been incriminated. The reservoir host is probably in the native populationof the areas concerned and in domestic animals and birds. The season ofhighest incidence appears to be in the late summer in Okinawa and Japanand possibly extending into the early fall in Korea.
Prior to the Korean hostilities, the disease had been experienced inrelatively minor fashion by occupation personnel both in Japan and Okinawa.For example, in 1948 there were 29 cases among occupation personnel and2 in Okinawa. Again in 1949, there were 13 clinical cases of Japanese Bencephalitis among personnel in the Far East. Ten of these were in Japanand three in Okinawa. In 1950, from among some 350 cases of infectiousencephalitis reported among Americans in the Far East, approximately 300from Korea were considered to have been due to the virus of Japanese Bencephalitis. The case fatality in this group was approximately 10 percentand severe central nervous system residuals were relatively uncommon. Sincethat time the disease has been reported with considerably less frequency.Just under 40 cases of infectious encephalitis were reported in each ofthe years 1951 and 1952 from Korea and in 1953 less than 25 such caseswere reported. Only a small proportion of these were specifically demonstratedto have been due to the virus of Japanese B encephalitis.
Since 1946, troops in Japan, Okinawa and Korea were given Japanese Bencephalitis vaccine as an adjunct to mosquito control for the preventionof this disease. The first real opportunity for the evaluation of thisprocedure presented itself in 1950 with the occurrence of the approximately300 cases of the disease in Korea as indicated previously. After carefulstudy of the admittedly incomplete data available at this time, it wasconcluded that there was no conclusive evidence either for or against theefficacy 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 potentialimportance in the Far East. Classical or epidemic louse-borne typhus feverhas for many years been endemic and at times epidemic in parts of thisarea, including Japan and Korea. In Japan, there has been no serious outbreaksince 1945 and 1946, while in Korea significant epidemics continued tooccur among the native population. It is
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definitely possible, though not conclusively proven, that this diseasewas of considerable importance among enemy forces during the 1950-51 winterseason. 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, some38,000 cases with over 5,000 deaths reported among the civil populationin South Korea. It is of some interest to note that typhus fever in SouthKorea tends to occur with the highest incidence in the late winter andearly spring months, frequently reaching its peak as late as May.
The prevention and control of louse-borne typhus fever of necessitywas based on the prevention and control of lousiness, a problem frequentlypresenting some difficulty in the winter months. Strict attention to hygienicmatters, insistence on bathing as frequently as possible with the provisionof changes of clothing and the application of insecticides prophylacticallywere the mainstays of the typhus control program among our forces in Korea.In this connection, more than a casual interest has developed in the developmentof the relative noneffectiveness of DDT as a lousicide in Korea. The observationsof a number of qualified workers indicate that Korean lice apparently becameextremely resistant to this material.
Another insecticide has been supplied to our troops in the Far Eastand has since then been in use. This is benzene hexachloride, perhaps morecommonly known as lindane. It has been shown to be extremely effectiveagainst the Korean lice. Thus another stumbling block has been effectivelyremoved from the path of effective prevention and control of louse-bornetyphus.
During the Korean campaign, the anti-louse program has been highly effective.That it has not been completely effective, however, has been evidencedby the occurrence of a few cases of louse-borne relapsing fever. This suggeststhat typhus vaccine administered as an added safeguard in the control andprevention of typhus has in fact been important in the preventive program.More and more evidence is thus accruing to indicate that this vaccine ishighly effective in the prevention of epidemic or louse-borne typhus fever.It would be unthinkable for American Forces to attempt to operate in areaswhere this disease is known to exist without the benefit of the protectionafforded by this vaccine.
Scrub typhus or tsutsugamushi disease has its home in Japan and untilvery recently had not been demonstrated elsewhere in the Far East. Theseveral cases reported by British troops in Korea, however, together withthe evidence brought to light by the hemorrhagic fever study group, stronglysuggest that this disease is present in Korea. Up to now, however, it haspresented essentially no problem.
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Smallpox
Smallpox, a disease now almost unknown in the United States, but oneof extreme importance in certain areas of the world including the Far EastCommand areas, is to be considered in more detail at another time in thissymposium. Only a brief review will be attempted here. The experiencesof 1945 and 1946 in Korea and Japan sensitized all concerned to the possibleand even probable difficulties from this disease which could be encounteredin the Far East. It was known, for example, that highly virulent formsof this infection continued to occur among native Koreans and that epidemicproportions were frequently reached.
With the advent of hostilities in Korea, and the resultant confusionand disruption in the native population, the disease there became a definitethreat to our forces. In 1951 alone, for example, nearly 50,000 cases withover 12,000 deaths were reported among South Koreans. Stemming from thisinfectious potential, some 40 cases of smallpox occurred among United Nationspersonnel between July 1950 and June 1951. Of these, approximately 30 wereamong Americans including Army, Navy, Air Force and Merchant Seamen. Theremainder were among personnel of the various other United Nations. SinceMay 1951, only scattered cases of the disease have occurred.
Smallpox experienced among United Nations personnel has varied in characterfrom cases which were so mild as to be distinguishable only with greatdifficulty from chickenpox, to the rapidly fulminating type of hemorrhagicsmallpox known as purpura variolosa. Fortunately, there were very few ofthe latter type which is essentially 100 percent fatal.
It is to be emphasized that the occurrence of smallpox among Americanpersonnel does not suggest in any way failure of American vaccines to protect.Rather, it indicates clearly that such vaccines are highly effective withinthe limits well recognized for them. Were this not true, instead of havinghad some 40 cases, we might well have had 4,000 cases or more. It is difficultto overemphasize the obvious facts that smallpox, even the virulent severetype seen in the Orient, can be prevented and that cases represent technicalfailure on the part of the vaccination. Prevention can be accomplishedby the use of potent vaccine within its expiration date applied with theproper procedure and technic, the reaction therefrom adequately interpretedand the vaccination results recorded with repetition of all unsuccessfulattempts until a successful vaccination has been accomplished. With strictapplication of these procedures and technics, there can be every assurancethat smallpox, if it does occur at all among our forces, will be so rarethat there will be no epidemics of this highly fatal disease.
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Cold Injuries
Cold injuries had presented no problem in the Far East prior to theonset of the Korean conflict. During this conflict, however, great andserious problems with these injuries were experienced. Since this subjecthas been discussed previously, only brief mention of it will be made here.
FIGURE7.
SOURCE: STATISTICAL HEALTH REPORT, WD AGO FORM8-122, 1948 THROUGH MAY 1951.
MORBIDITY REPORT, DD FORM 442, RCS MED-78, JUNE 1951 THROUGH 1953. - OFFICEOF THE SURGEON GENERAL 15 APRIL 1954
Figure 7 shows the rate per thousand per annum for our troops in Koreafor the winter seasons 1950-51, 1951-52, and 1952-53. It is immediatelyapparent that it was during the first winter that the greatest losses frominjury due to colds were experienced. It is to be recalled that these monthswere the ones during which the Chinese
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Communist forces entered the conflict and when our troops deployed farto the North were engaged in the bitterest of battles, many of them inpositions which could not be adequately supported from the rear. The greatmajority of the injuries experienced during that time and subsequentlyhave been the result of true frostbite following exposure for variableperiods of time to severe cold. Wetness, per se, has not been a significantpart of the problem.
The occurrence of cold injuries among our troops in Korea includingthose of the first winter season occurred despite an intensive preventiveprogram effected by the Medical Services, Quartermaster Services and thevarious echelons of command. Without this program, it is felt that manymore cases would have been encountered. Based upon the experiences learnedin Europe, this preventive program was built around the triad of adequatecold weather clothing and equipment, proper indoctrination and trainingin the use of this equipment, and individual preventive measures and unceasingcommand supervision and enforcement of cold weather discipline. The experienceof the 1951-52 and 1952-53 seasons indicates that even in severe climatesif there is adequate cold weather clothing and equipment, proper indoctrinationand 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 variousfactors can be adequately applied and maintained.
Hemorrhagic Fever
First making its appearance in June of 1951, a disease hitherto notexperienced by United States medical personnel occurred among United Nationsforces in Korea. The clinical syndrome observed was one suggestive of anacute infectious process coupled with a hemorrhagic diathesis. The firstdiagnoses submitted were those of leptospirosis. It was soon determined,however, that the condition being encountered was not due to leptospiralinfection, but rather was a disease previously described by the Japaneseand others and called epidemic hemorrhagic fever. This, too, has been discussedin considerably more detail at another time during this symposium and hencewill be given but a brief résumé here.
Figure 8 indicates the important incidence of this disease per thousandper annum for the years 1951, 1952 and 1953. It is noted that the reportedoccurrences differed practically not at all in the first 2 years but thatduring the calendar year 1953 a rather marked decline in reported caseshas occurred.
Extensive and comprehensive investigation has been conducted in thefield, in the laboratories of the Far East Command, in the labora-
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tories here at the Army Medical Service Graduate School and elsewherein the United States. Up to this time, a specific etiological definitionof this disease has not been made. However, much of value has been learnedabout the condition. Epidemiologically, epidemic hemorrhagic fever resemblesscrub typhus in many of its aspects, most particularly in the fact thatit appears to be a place disease and that it presents characteristics entirelycompatible with an arthropod-borne disease, the reservoir host of whichcould be in field rodents. Perhaps of all the conditions encountered inthe Far East to date, hemorrhagic fever has posed the greatest single challengeof any problem in the field of epidemiology, microbiology and preventivemedicine.
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 |
FIGURE8.
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 aspectscan be complete without at least a reference to the venereal infections.Certainly, these have not been uncommon in the Far East Command in generalnor in Korea in particular. In these areas, the most commonly experiencedinfections of this category have been gonorrhea and chancroid. Syphilishas occurred with considerably less frequency. This is seen from figure9, which depicts the reported incidence of these infections over a 6-yearperiod of time. The unusually low reported incidence of this group of infectionsin Korea for 1950 is possibly explainable by the fact that the troops inthat area at that time were extremely preoccupied in the fighting businessof the defense of the Pusan perimeter.
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FIGURE9.
SOURCE: STATISTICAL HEALTH REPORT, WD AGO FORM8-122, 1948 THROUGH MAY 1951
MORBIDITY REPORT, DD FORM 442, RCS MED-78, JUNE 1951 THROUGH 1953
OFFICE OF THE SURGEON GENERAL 15 APRIL 1954
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There is nothing unusual or unexpected about the occurrence of theseinfections 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 recordonly. In other words, the venereal diseases today are treated on an outpatientstatus causing only that loss of time, incident to the report to the dispensaryand the diagnosis and appropriate treatment of the condition. Only thosewith complicated cases are admitted to the hospital.) The relatively highincidence of the venereal infections reported from troops in Korea, andelsewhere in the Far East for that matter, may be attributed largely tothe 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 withwhom 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 civilmedical attention is more readily obtainable.
Summary and Conclusions
Reviewing the experiences with disease and its prevention among UnitedStates Forces in the Far East and particularly in Korea, it becomes apparentthat many of the basic problems of disease prevention and control in thatarea are not significantly unlike those experienced in the United Statesand elsewhere. The differences frequently are found to be quantitativerather than qualitative. The preventive procedures that are applicablein the Far Eastern Area are in the main those which must be applied evenunder more favorable conditions. It is necessary, however, in many instancesthat 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 ofthe European theater campaigns of World War II and Korea, July 1950 throughJune 1951. This is shown in table 1. It is noted that in the European theaterfor the period noted, 63 percent of admissions were for disease, 14 fornon-battle injury and 23 percent for battle injury and wounds. For Korea,during the period July 1950 through June 1951, the phase of most activecombat, these proportions were 60, 17 and 23 respectively.
It has been learned, however, that in addition to the basic health problemscommon to most areas of the world, there have been actual
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Table 1. Admissions for Battle and Non-battleCauses, 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 diseasesources not usually encountered by our troops in the field. Under thissituation, it has been necessary to apply a preventive medicine programcomprehensive in nature and broad in scope. This program was neither conceivednor applied by any single individual or small groups of individuals inthe area. Rather, it was based upon developments and achievements in thefield of preventive medicine throughout the years. What success has beenachieved in its application has been made possible by the cooperation andunited efforts of many and the utilization of great resources of talents,skills and knowledge available, not only in the military organization butalso from a multiplicity of civilian sources.
The practice of military preventive medicine in the Far East has beenan exemplification of the fact that to be effective preventive medicinemust use all of these skills and all of these resources in the aid andassistance of personnel trained in almost every field of modern medicine.These, of course, include the internist, the entomologist, the sanitaryengineers, the laboratory workers and others as well as preventive medicineofficers. All of these must be welded into an effective team whose goalis the prevention and control of disease and other conditions which couldreduce the effectiveness of military forces. There is such a team todayin the Far East and the effectiveness of our military preventive medicineprogram there is at a high level. There remains little room for complacency,however. Without question, the success of military preventive medicinein the Far East and elsewhere will depend upon the success of the constantefforts of all in the various branches of the medical sciences.
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An outstanding need, at least paralleling the requirement for continuedacquisition of new information and knowledge, is the need for the practicalapplication of this information and knowledge. It is important that theever present gaps between expectation and accomplishment be bridged andthat basic knowledge be converted into successfully applied technic. Itis also important that disease prevention and control be given at leastequal emphasis and support in all respects as that afforded medical careand hospitalization. More man-days can be saved outside the hospital thanin it.
