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Medical Science Publication No. 4, Volume II



Enteric infections, particularly bacillary dysentery, historically arediseases of major importance to confined population groups. Epidemics repeatedlyoccur aboard ships, in institutions for mentally defective and mentallyill, jails, orphanages, and prison camps. Experience with dysentery inthe United Nations prisoner-of-war camp in Korea followed this historicalpattern. After the landings at Inchon and the breakout of United NationsForces from the Pusan perimeter had occurred, a large number of prisonersof war were gathered. During the winter of 1950-51 these people were concentratedunder the care of the South Korean Army near Pusan, while a semi-permanentcamp was being constructed on the island of Koje, 20 miles south of Pusan.During that winter epidemic disease was a major problem, and enteric infectionsincluding bacillary dysentery, amebic dysentery, and Salmonella infectionswere responsible for a high rate of morbidity and mortality

After the prisoners were transferred to the improved facilities of theprison camp at Koje, diarrheal disease continued to be one of the majorproblems confronting the medical authorities responsible for the care ofthe prisoner group. The ultimate care of the patients with diarrheal disease,particularly due to Shigella organisms, was complicated by the fact thatthe majority of the cases were caused by organisms which were sulfonamide-resistant.At that time salfonamides were the only specific anti-bacterial agentsavailable to the clinical personnel. As a result, these diseases createda problem which required that an effort be made to determine the ways inwhich enteric diseases were transmitted through this specific camp, andto evaluate other antibiotic drugs so that the infections could be broughtunder control. The severity of the epidemic encountered presented an unusualopportunity to conduct these investigations.

The studies on the character of the acute enteric infections in theprison camps as well as those on diagnosis and treatment of bacillary andamebic dysentery were carried out by a unit known as the Joint

*Presented 27 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.


Dysentery Unit and were under the sponsorship of the Commission on EntericInfections of the Armed Forces Epidemiological Board. The persons participatingin this study came from the United States Army, the United States Navy,the United States Public Health Service and civilian laboratories. Thisunit operated in the facilities of the Sixty-fourth Field Hospital whichwas responsible for the care of the prisoners in the Koje Island Camp.

To understand why enteric disease was such a problem in the camp andto establish the pattern of its epidemiology several factors must be evaluated:(1) the physical characteristics of the camp itself; (2) patterns of routineliving within the camp; (3) the prevalence of individuals who carried pathologicorganisms in their stools.

The prisoner-of-war camp at Koje was composed of a number of enclosureswithin which was a series of compounds. Each compound was an autonomousunit unto itself, and was divided as a military unit into battalions andcompanies. The compounds varied in size; there were 1,000 to 10,000 menper unit. The men were housed in tents or adobe mud huts, and because oflimited space crowding was a major problem. As many as 90 men were housedin a single squad tent and often 350 men lived in one adobe hut. They slepton straw mats. Each man was issued three or four woolen blankets whichhe alone used. These blankets were aired every day. Toilet facilities werecrude. The usual method of disposing of excreta involved the use of largeportable buckets which were emptied several times a day into the sea. Washingfacilities also were inadequate, although the men attempted to improvisemethods for bathing and hand washing. Some of these devices were both ingeniousand workable. The majority of the prisoners in the compound, however, didnot have the advantages of such improvements and hand washing followingdefecation was rare.

Food for the entire compound was prepared by a group of food handlersin a large central kitchen. The primary items of diet were boiled rice,a soup made of vegetables, meats and spices, and a fish sauce which wasadded to the rice. After being prepared in the central kitchen the foodwas taken in large 10-gallon cans to the various feeding lines. There itwas ladled into each man's bowl or dish, which had previously been dippedinto boiling water. Individual battalions had their own feeding lines.Therefore, there were as many as five or six different areas of food dispersalin each compound. The foodstuffs were supplied by the U. S. Army QuartermasterDepartment, except for some vegetables which were purchased from the localmarket. Water, brought to the compound in large cans and tanks, was obtaineddirectly from the reservoirs, and was well chlorinated and filtered. Thesame reservoirs supplied the mili-


tary staff of the camp and little or no dysentery was seen in this group,although mild diarrhea was common.

An important contributing factor to the presence of enteric diseasewas the high endemic level of infection among the prisoners at the timeof their capture. Routine studies of random groups of prisoners in thecompound revealed that from 3 to 6 percent of them, most of whom were clinicallywell, harbored Shigellae in their stools. About 3 percent of them harboredthe cysts of E. histolytica. One group of 1,000 Chinese prisonerswas cultured immediately upon arrival at the prison camp. Eight percentwere found to be infected with pathogenic Shigellae. Examinations of stoolsof men who were involved in the handling of food were also done. The incidenceof E. histolytica cysts or pathogenic Shigellae in this group wascomparable to that in the general population of the compound.

No one factor could be incriminated as the primary cause for the spreadof enteric infections in this camp. The lack of proper toilet and bathingfacilities was, of course, considered to be of importance. The open toiletcans were easily accessible to flies. However, the incidence of entericdisease was lowest during the summer when flies were most numerous andhighest during the winter when they were most scarce. Accordingly, crowdingwas considered to play a more important role. It appeared likely that infectedmucus from the hands, clothing or skin of infected persons could be easilypassed to the hands of neighbors in the crowded bathing areas, tents andhuts.

Numerous attempts were made to incriminate food as the source of infection,but no evidence could be obtained to substantiate this possibility. Studiesmade of the temperatures of the food at the various feeding lines, 3 to4 hours after cooking, revealed that most of the food was maintained attemperatures well above those needed for pasteurization. Bacteriologicalexaminations of food and of water were also consistently negative for pathogenicorganisms. Epidemiological observations likewise seemed to eliminate foodas the source of infection. Outbreaks within a compound tended to be localizedto battalions or even to tents, suggesting local transmission rather thanorigin from a central source.

The clinical characteristics of the enteric diseases encountered werevaried. The incidence of diarrhea was extraordinarily high. Dispensarystatistics indicated as many as 5,000 to 10,000 cases per 1,000 individualsper year, and many men never reported to sick call. The majority seekingtreatment complained of simple watery diarrhea associated with few abdominalcramps, mild tenesmus and the passage of small amounts of mucus in thestools. These patients were seen by the Korean physicians in the compounddispensaries, were treated with supportive measures, and were usually asymptomaticin 2 or 3


adays. Some, however, did not respond to this treatment. Their diarrheatended to increase, as did the severity and frequency of their abdominalcramps. Fever appeared and was usually followed by the onset of bloody,purulent dysentery. Individuals with such symptoms were transferred tothe Sixty-fourth Field Hospital for further diagnosis and specific therapy.The majority were found to have Shigella infections. About 10 percent haddysentery due to E. histolytica, and a smaller group were infectedwith Salmonella organisms.

Many of the patients with the milder form of diarrhea were also foundto be suffering from bacillary dysentery. Cultures were taken from randompatients who reported to the daily sick call in the compound complainingof diarrhea; 25 to 60 percent were positive for pathogenic Shigellae.Theresponse of this group of patients, however, clearly indicated that mildbacillary dysentery is a self-limited disease. Only those patients withthe more severe form of the disease required specific therapy. Becausesulfonamides failed to control many of the most fulminating infections,a clinical study was undertaken to evaluate the effectiveness of the newerbroad-spectrum antibiotics.