The Histories of the Commissions - Contents
Commission on Enteric Infections
Foreword
The diarrheal diseases have accounted for rates of morbidity and mortality equal to those of enemy action. One has only to recall such disasters during the American Revolution, the Civil War, the western colonization of the United States, the Spanish American War, the war with Mexico, and World War Ito realize the impact of dysentery disorders and typhoid fever as two very disabling intestinal infections.
The Commission of Enteric Diseases was founded on rock and blessed during its history with such capable and enthusiastic directors as Drs. James Watt, Albert Hardy, Francis Cheever, Horace Gezon, and Tom Hendrix who guided the Commission`s activities from its inception in 1949 until its termination in 1973.
Mary Jane Wood and Dr. Richard B. Hornick, in their very informative and interesting history describe the events and contributions that led to understanding of pathogenesis and control of bacterial and amoebic dysentery better, including cholera and Escherichia coli infections, the salmonelloses, particularly typhoid fever, and the various forms of viral gastroenteritis, a new field to which much needed knowledge was added. Commission members were stars in their own right ,and their contributions helped clarify the roles of normal and pathogenic enteric agents. In addition, the importance of clean water and noncontaminated food, as well as the impact of control by newly developed vaccines, were recognized.
Many Commission members made personal sacrifices by traveling abroad during active medical military circumstances to observe and survey alongside their medical military counterparts. They not only helped to assess the magnitude of the problem, but also advised on the best practical way to reach a desirable solution.
To Dick Hornick, I am indebted for his part in preparation of this chapter. Not only does he have my grateful thanks, but also congratulations for his important contributions, along with his associates, to the development of knowledge in the important field of intestinal diseases. We regret, despite efforts to obtain them, that photographs of some of the key contributors are not available for inclusion in the section.
- Theodore E. Woodward, M.D.
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History of the Commission on Enteric Infections
Mary Jane Wood, B.S., R.N.
and
Richard B. Hornick, M.D.
THE COMMISSION ON ENTERIC INFECTIONS
Drs. Colin M. MacLeod and Thomas Francis, Jr., recognized the need to include diarrheal diseases, which are common military problems, in the spectrum of illnesses to be evaluated by the Armed Forces Epidemiological Board (AFEB). They developed plans for the Commission on Enteric Infections. Subsequently, they met with Dr. James Watt and decided on the formation of the Commission during the 1948 annual meeting of the American Public Health Association. The organizational meeting was held 29 January 1949,and was attended by Dr. MacLeod, as President of the AFEB, Dr. Watt, first Director of the Commission, and members William W. Frye, Albert V Hardy, and Myron E. Wegman. The meeting was held in New Orleans at Louisiana State University (LSU) as a convenience for Drs. Watt, Frye, and Wegman, who were faculty members at LSU or Tulane University. Dr. Hardy, a member of the Florida State Board of Health was associated with LSU faculty personnel on studies of diarrheal diseases as early as 1936.
At the initial meeting, the group decided that the Commission would comprise five members and direct its studies in five major categories: bacteriologic, parasitological, virological, epidemiological planning, and specific investigation. Drs. Hardy and Watt were asked to monitor parasitological work and clinical studies by Dr. Wegman. Virological activities were assigned at a later date. These five categories and responsibilities were consistently addressed during the 23 years of the Commission`s function.
Commission members decided to advance the knowledge on bacterial infections as the first priority. Salmonella and shigella also were selected as agents of the highest priority. Dr. Hardy proposed to survey and evaluate the pertinent problems and determine the relevance of current activities and suggest where additional support was needed to expand the knowledge base.
At the second meeting of the Commission, held in New Orleans on 3 April 1949,five areas of potential research on salmonellae were outlined and served as guidelines for studies in subsequent years. (1) Support was needed for a diagnostic center capable of obtaining accurate diagnoses of salmonella infections. It was noted that the Centers for Disease Control (CDC) could and would provide this service and provide necessary typing sera for specified laboratories. The Commission was expected to distribute the sera based on reliable clinical case reports. (2) Field studies were planned to obtain information on prevalence and incidence of human illness: These were expected to provide relevant data and to collect information on the relationship of human infections and those that occurred in animals. (3) The role of coproantibodies was to be evaluated as an investigative tool. (4) New methods of vaccination, especially those given by the oral route, were to be assessed. (5) New antibiotics were to be evaluated for use in the treatment of bacterial infections caused by salmonella arid shigella.
Two grants were approved that were related to the salmonella initiative. One supported analysis of data collected on the epidemiology of salmonella and shigella infections and their control. The second supported an animal model of salmonella infections designed to evaluate various antibiotics.
At the annual meeting of the Commission on 14 April 1950, progress on data analysis was reported with the use of standard key punch machines. The Commission believed that such data analysis would
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establish major points of difference in the epidemiological characteristics of shigella and salmonella infections.
Dr. Morris F. Shaffer of Tulane University reported his evaluation of various antibiotics for treatment of salmonellosis in baby chicks. He found that none of the available antibiotics, oxytetracycline (Terramycin), neomycin, polymyxin Band D, or chloramphenicol, were particularly effective in the treatment of salmonella infections. However, certain drug combinations and varying dosage schedules offered promising leads that prompted additional study.
At this meeting, it was recommended that Dr. Frye apply for funding to assess the need to find a single, simple, and reliable diagnostic tool, which was the most important issue in the field of amebiasis, and that Armed Forces representatives who work in the field of diarrheal disease be appointed as members of the Commission. It was conceived that individual research projects could be monitored and coordinated for the ultimate benefit of everyone.
The annual meeting of the Commission on Enteric Infections was held on 26 and 27 March 1951 at LSU. (From this meeting forward, the Enteric Disease Commission was called the Commission on Enteric Infections.) Those who worked in the field of enteric diseases accepted that progress on the fundamental biology of organisms that caused enteric infection had been conspicuously lacking for years. A consensus existed that those techniques that had been successfully applied to enhance knowledge of how bacteria and viral agents affect the respiratory tract had not been applied to the enteric group. Field investigations then used had not provided any completely effective methods of salmonella and shigella control. Commission members stressed that emphasis be placed on clarifying the fundamental biological characteristics of shigella and salmonella.
At this meeting, three groups were working on salmonellosis-Dr. Hardy in Florida, Dr. Watt in Georgia, and Dr. Shaffer in Louisiana. Jointly, they decided to coordinate their activity toward standardizing laboratory techniques and the use of culture medium.
The Committee reported on its consultative participation with the Department of the Army in preparation of a training film on the diagnosis, treatment, and prevention of shigellosis. Research on other films dealing with salmonellosis and typhoid fever was initiated.
The Commission, in association with the Public Health Service and the California Department of Health, conducted a 6-month study of a diarrheal outbreak that occurred in the central valley of California-Fresno and Hildago Counties. Studies were conducted in farm labor camps and fringe areas where housing and sanitary conditions were substandard. A control site consisted of a housing project where improved environmental conditions prevailed. Preliminary findings implicated bacteria of the Shigella group as causative agents in 70% of the cases studied.1
A severe outbreak of diarrheal disease among prisoners of war in Korea was reported to the Commission. A group was organized to travel to the Orient to perform field studies. Colonel Richard P. Mason, M.D., Department of the Army, and Dr. Hardy preceded the rest of the group to Korea to assess conditions fo rthe proposed investigation. It was planned to treat the infections with differing combinations of sulfadiazine and chloramphenicol, as well as chlortetracycline (Aureomycin), Terramycin, and streptomycin. Pharmaceutical firms contributed large quantities of drugs for some of these studies. To initiate studies and to ensure having these drugs immediately available, Dr. Hardy carried a 5-gallon container of medications on the airplane to Korea.
Work continued in the United States, with Drs. Watt, Quentin M. Geiman, R. S. Benham, and James N. DeLamater separately investigating the chemical composition and metabolism of Entamoeba histolytica. Progress was reported in design and the adaptation of equipment needed to provide large, pure quantities of E. histolytica for experimental purposes. Despite some progress, production of ameba in the absence of bacteria in culture media was unsuccessful.
By 1952 and 1953, clinical and laboratory data collected during the Korean study, conducted between April 1951 and January 1952, were interpreted, trended, and published. Five papers were published, two as lead articles in the Journal of the American Medical Association.2,3 Drs. Hardy and Colonel Mason (MC, Director, 406th Medical General Laboratory, Tokyo, Japan)published "The Dysenteries in the Armed Forces" in the American Journal of Tropical Medicine and Hygiene.4 The team of investigators in
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COLONEL RICHARD P. MASON, M.D.
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Korea accurately diagnosed the cause with the use of rectal cultures and proctoscopic evaluations in addition to clinical data.5 A total of 142 examinations was performed in 1 day by two physicians and their assistants! Between 300 and 400 rectal cultures were performed daily. The largest identifiable group of pathogens causing the diarrheal epidemic was shigella, although clinical and laboratory findings differed vastly from shigella infections in the United States. Clearly, the diarrheal infections manifested themselves differently from place to place and time to time. The fly was excluded as the prime disseminator of enteric disease because this particular epidemic occurred in the winter months and the military services had excellent insect control. Mass contamination of food was eliminated as a cause. It was apparent that multiple routes of transmission existed. Presumably, shigella survived in a symbiotic relationship until the environment was changed.4
Twenty-four different therapeutic or dosage schedules were studied in the treatment of amoebic dysentery; 18 different modalities were used for treatment of bacillary dysentery. In the case of amebiasis, the best therapy for patients with acute disease was a combination of drugs, e.g., oxytetracycline or Aureomycinplus emetine or chloroquine diphosphate or other less commonly used drugs such as carbarsone, chiniofon, and bismuth glycoloylarsanilate.2
In the 1940s and early 1950s, sulfonamide therapy was established as a highly effective treatment for shigellosis. Resistant strains became very common during the Korean conflict. The studies conducted on prisoners of war were designed, in part, to evaluate other antibiotics to replace sulfonamides. The tetracyclines and chloramphenicol were very effective in effecting a clinical and bacteriologic cure.
Dr. Shaffer, at Tulane, continued his work on the pathogenesis of salmonella infections. His studies with chicks showed a correlation between salmonellosisin animals and humans. The work of Drs. Shaffer and Hardy, who studied salmonella in greyhounds and hogs and at various abattoirs, clarified several points: (a) salmonellae are relatively hardy organisms capable of withstanding environmental stresses; (b) very large doses of salmonella are necessary to produce illness; and, (c) in epidemics, a propagation of salmonella in food is an almost universal finding.
The diagnostic value of the complement-fixation test in acute amoebic dysentery was studied by Dr. Marion Brooke, who concluded that the test was of little value. He also evaluated the Moan Precipitation Test. The latter was judged to be of no value.
The Commission on Enteric Infections decided to coordinate its activities with the Commission on Immunization with regard to possible field studies to evaluate the efficacy of typhoid vaccines.
Several changes in Commission membership occurred during this period: Dr. Watt resigned his position with the Commission to become Director of the National Heart Institute; Dr. Wegman resigned to devote more time to work with the World Health Organization (WHO); and Dr. Francis S. Cheever, Professor of Microbiology at the University of Pittsburgh, School of Public Health, became anew member.
The spring meeting of the Commission was held jointly with the Commission on Environmental Hygiene in Boston in April 1954. The subjects discussed included(a) amebiasis (Frye), (b) environmental factors related to the dissemination of enteric pathogens (Smith), (c) the control of diarrheal diseases in areas and in population groups with high prevalence (Hardy), and, (d) the pathogenesis of bacillary enteric infections (Dammin).
The Subcommittee on Amebiasis met before this meeting at the laboratory of Dr. DeLamater, School of Medicine, University of Southern California. Drs. Geiman, Frye, and William Balamuth attended. An outcome of their visit was the suggestion that the strains of E. histolytica (DK Band HK-9) be used for all studies to ensure consistency. Work on antibody production and the study of immunity was slow and somewhat discouraging.
The Commission on Enteric Infections continued to divide its work into two fields: studies of amebiasis, under the direction of Dr. Frye; and nonamebicenteric infections, under the auspices of Dr. Hardy. The possible role of viral agents as a cause of enteric diseases began and was reported in the annual report of the Commission in March of 1955. Dr. Cheever (University of Pittsburgh), Lieutenant Colonel R. Linberg, M.D. (Army Medical Service Graduate School), and Drs. Irving Gordon and Sonja
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Buckley (New York State Department of Health)conducted virological studies to explore the relationship between viruses and disease.
In the continuing quest for a significant breakthrough, Dr. Gustave Dammin(Harvard Medical School) undertook a large-scale study on primates at the Okatie Farms (South Carolina). Broad-spectrum antibiotics, administered intramuscularly, yielded superior results to oral administration in altering the course of shigellosis.
The work of Dr. Shaffer continued at Tulane, using wet chicks as experimental hosts. Salmonella typhi were used as the major test organism; hyperimmune sera were prepared, and the effect of passive immunity in prevention of enteric infections was studied.
The annual meeting in 1955 comprised those well-qualified investigators who worked in this common field. This stimulating exchange of information, plans, and opinions represented one of the most important aspects of the Commission`s work. Because of limited opportunity to study amebic infections in the United States, it was recommended that members of the Commission participate, whenever possible, in studies underway in South and Central America. In addition, the Commission recommended that additional immunological and chemical research in the field of amebiasis be suspended until a sufficient quantity of amebic organisms was obtained in a purified state.
Dr. Cheever, University of Pittsburgh, School of Public Health, continued work on his grant, entitled "An Investigation of the Possible Role of Viruses in Enteric Infections with Particular Reference to Bacillary Dysentery." His studies characterized and identified those agents that might play a role in the pathogenesis of bacillary dysentery.
By 1956, Drs. Frye and Henry E. Meleney had made considerable progress toward discovering information about factors affecting the growth of E. histolytica. They produced an agar-free Shaffer-Frye medium in which all of their strains of E. histolytica multiplied satisfactorily. Attempts to eliminate the streptobacilli met with failure; the presence of small numbers of whole bacilli was required to permit multiplication of ameba. They concluded that multiplication of amoebae may occur in the absence of demonstrable bacterial growth, but not in the absence of the bacteria themselves.
Studies conducted at the Okatie Farms by Drs. Dammin and Cheever provided new and advanced knowledge in the field of enteric diseases. The epidemiological project of Dr. Hardy focused on determining whether there was a correlation between infection and mortality in monkeys. He found that no appreciable drop occurred in mortality rates after antibiotic therapy, even when the specific organism was largely eliminated. Overcrowding and excessive handling appeared to be the most important factors in increasing mortality rates.
Dr. Dammin`s research centered on the development of new media for the isolation and transportation of bacterial enteric pathogens. A new specimen preservative showed promise of being significantly superior to the standard buffered glycerol-saline broth. A new enrichment broth that contained sodium deoxycholate, sodium citrate, and mannitol was developed. In addition, work was carried out on development of a more effective tetrathionate broth and two new plating media.
Dr. Cheever continued his attempt to isolate, identify, and classify viral agents from cases of bacillary dysentery and other diarrheal diseases that occurred in humans and monkeys.6 The object was to determine what, if any, role these viruses played in the pathogenesis of enteric diseases. Possibly, they were a direct cause or a contributing factor in a synergistic type of relationship with a bacterial agent. The evidence reported indicated no advances despite exhaustive efforts by Drs. Hardy, Cheever, Shaffer, and Geiman to clarify the relationship of the viruses to clinical illness.
Slow but appreciable progress was made in providing a sufficiently large, pure source of E. histolytica for the purpose of studying immunological, chemical, and metabolic properties of this organism. In pursuit of this goal, considerable information was acquired relative to the fundamental biological activities of E. histolytica.
An article on the history of the Commission written in 1956 in the Medical Service Digest, observed that the chain of dysentery transmission was "still poorly understood, but progress has been made in treatment and prophylaxis using the newer antibiotics. Immunization does not seem, at this time, to aid in the control of diarrheal diseases."7
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The control of enteric diseases was aided by sanitary developments through water purification and sewage and waste disposal. In those areas of the world with poor sanitary standards, diarrheal diseases persisted as a major problem. In addition, many disorders were thought to be caused by viruses and not subject to control by vaccines or antibiotic drugs.
The Commission concentrated its efforts toward understanding the metabolic processes of organisms responsible for causing diarrheal infections-salmonella, shigella, ameba, and other bacterial and protozoan organisms. Efforts were intensified to isolate and categorize many viruses as they related to recognizable clinical syndromes. Of these, the enteric cytopathogenic human organ (ECHO) viruses were soon identified as etiologic agents.
In 1957, 1958, and 1959, the Commission on Enteric Infections met jointly with the Commission on Environmental Hygiene to discuss issues of mutual interest. In 1957, the annual meeting was devoted to reports on Arctic epidemiology, Arctic health problems, and field observations on Alaskan maneuvers. A discussion of Environmental Hygiene in the Arctic was conducted by personnel from the Arctic Health Research Center, Public Health Service. These reports indicated that a high incidence (72%) of intestinal parasites occurred among persons in Arctic Greenland. This percentage was higher than that found among Alaskan Eskimos and persons in Arctic Scandinavian countries. The incidence of diarrheal disease and parasites paralleled those of persons in the tropics.
Research grant applications submitted by members of the Commission included the following:
. The Chemical Composition and Metabolism of Entamoeba histolytica, Quentin M. Geiman, Ph.D., Stanford University;
. Effect of Antimetabolites on Growth of Entamoeba histolytica, Mitsuru Nakamura, Ph.D., Montana State University;
. An Investigation of the Possible Role of Viruses in Enteric Infections, with Particular Reference to Bacillary Dysentery, Francis S. Cheever, M.D., University of Pittsburgh;
. Host Tissue Reactions in Experimental and Naturally-Acquired Enteric Infections, Gustave J. Dammin, M.D., Harvard University;
. Growth Requirements of Entamoeba histolytica, William W. Frye, M.D., Louisiana State University; and
. Factors Controlling Encystation of Entamoeba histolytica In Vitro, William Balamuth, Ph.D., University of California, Berkeley.
Documentation contained in the 1959 Director`s Report written by Dr. Cheever revealed that there had been significant changes in the Commission`s program. One project that dealt with the serologic aspects of amebiasis was terminated because of difficulties in obtaining a relatively pure and effective antigen from the parasite. Two biochemical studies that dealt with the composition and metabolic activities of E. histolytica were phased out because of lack of significant progress in this difficult field. One project in this area, under the auspices of Drs. Frye and Richard E. Reeves, continued because of favorable progress. Their work showed that Bacteroides symbioses inactivated by exposure to cobalt 60 still retained the ability to support the multiplication of E. histolytica as well or better than penicillin-inhibited but viable cells. With the use of a three-amino acid medium, ferrous iron was an essential growth requirement for E. histolytica. The mechanism by which iron exerts its effect was not clear.
Dr. Balamuth transferred his sponsored studies on factors that controlled encystment of the parasite from the AFEB to the National Institutes of Health (NIH)as part of the NIH program in cellular biology. Dr. Balamuth continued as Deputy Director of the Commission on Enteric Infections, a post that permitted a continued close working liaison between interested members.
Dr. Geiman implemented a new approach on biological factors that governed occurrence of amoebic infections. The biochemical and biological aspects of E. histolytica in relation to amebiasis were concentrated in fewer projects. Dr. Horace Gezon continued his studies on the metabolism of shigella, with the goal to determine the mechanism of development of drug resistance.
Those projects dealing with the virological aspects of enteric infections yielded few positive results. No evidence was noted that viral agents played a significant role in the pathogenesis of "bacillary dysentery." The need to actively pursue this problem was stressed.
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The Commission increased its interest and work on cholera. It maintained a close liaison with the NIH Cholera Advisory Committee and the Southeast Asia Treaty Organization (SEATO) cholera research program.
Small working meetings became very productive, particularly among the amebiasis group. Joint meetings with the Commission on Environmental Hygiene lagged and ultimately ceased because of obvious divergent areas of mutual interest.
Unfortunately, in the United States in the late 1950s, little interest existed in diarrheal diseases, even though these infections were of great practical importance to the Armed Forces during war. One of the greatest challenges to the Commission was to maintain a vigorous, active, and critical program devoted to diarrheal diseases. It was obviously essential to acquire new knowledge and train competent professional personnel. Both components were necessary if progress was to be made toward control and eradication of diarrheal disease and other enteric infections: The Commission was concerned with a relative lack of achievement in this important field.
In 1961, Dr. Geiman continued his work on amebiasis but shifted emphasis from biochemical to basic biological aspects, which seemed to be the key to pathogenesis. In his report to the Commission, he decried the lack of meaningful results commensurate with the amount of effort expended. He expressed considerable difficulty in recruiting and holding qualified biochemists because of insufficient funds. Furthermore, he emphasized the need to consistently mass produce the quantities of amoebae needed to carry out the appropriate studies.
At the annual meeting of the Commission on Enteric Infections, held 6 and 7March 1961, it was recommended that the Commission meet with the Commission on Parasitic Diseases because of mutual interests in amebic diseases. Drs. Hoffert, Cheever, and Abraham reported their findings on establishing a possible link between viral agents and diarrheal disease. In their work, the viral isolation rate was low, with little evidence to suggest that these viral agents played a significant role in pathogenesis of diarrheal disease. Generally, all efforts to incriminate viral agents in the etiology of diarrheal disease of unknown origin were disappointing. The Commission recommended that such investigation be suspended until new techniques were established.
Drs. Gezon and Robert B. Yee described their continuing studies on protein and nucleic acid synthesis and the energy-producing pathways in shigella, including the effects of antibiotics on these mechanisms. Chloramphenicol was associated with an increase in soluble RNA but not ribosomal RNA. This increase in RNA was shown to be the result rather than the cause of the inhibition of protein synthesis. It was concluded that these biochemical studies on the nature of antibiotic activity against shigella, and especially the effect in resist an strains, were of potential importance and could lead to better antibacterialagents.9
Rudolph Hugh, PhD., George Washington University, Washington, D.C., reported his studies on the identification of the Vibrio group and related organisms. The significant revival of interest in cholera as a result of the outbreaks of the disease in Thailand, and the establishment of the SEATO laboratory in Dacca in East Pakistan (now Bangladesh), gave particular pertinence to these definitive taxonomic studies.
Drs. Reeves, Bragg, and Frye continued their investigations of factors of importance in the growth and multiplication of E. histolytica. It had been possible to propagate nine strains of E. histolytica in MSF medium containing bacterial cells inactivated by exposure to cobalt-60 irradiation. The bacterial cells, after such irradiation exposure, were able to metabolize carbohydrates, although they lost the ability to reproduce themselves by cell division.
Dr. Geiman initiated his work on the pathogenesis of E. histolytica at the Porterville State Hospital, California; because of illness, he was unable to submit a progress report.
Dr. Dammin continued his work at Harvard University on the pathogenesis of diarrheal disease. These important microbiological and pathological examinations of Guatemalan children, who died with or because of diarrheal disease, led to what are now basic concepts of the pathogenesis of these common infections. His work confirmed the importance of malnutrition as a predisposing cause of diarrhea. These children were shown to have large numbers of bacteria like E.coli in the jejunum. This
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led to the concept that bacteria in the upper small intestine in such children could act as the stimulus for fluid production. He clearly showed the pathological differences between illnesses caused by invasive versus noninvasive organisms. This work served as a stimulus for the ultimate identification of enterotoxins. In addition, Dr. Dammin continued to work on the production of diarrheal disease in experimental animals. The ultimate aim of these studies was to clarify those major factors responsible for the production of diarrheal disease.
Dr. Dammin, as President of the AFEB, informed Commission members that the entire budgetary allowance to the U.S. Army Medical Research and Development Command was $15 million, $2 million of which was allocated to the AFEB. The projected needs of the AFEB greatly exceeded this sum! Colonel John Rizzolo spoke of the public relations programs planned in recognition of the 20thanniversary of the founding of the AFEB. He stated the Journal of Military Medicine was now the outlet for AFEB publications. Editors of the Journal of Military Medicine had expressed their interest in publication of AFEB-sponsored scientific articles.
Reports were presented by various members of the U.S. Army, Navy, and Air Force. The incidence of enteric disease had fallen among military personnel but risen among dependents who lived "on the economy." The incidence of infectious hepatitis increased significantly. Fluoridation of domestic water supplies was recommended and approved. Aerospray programs for mosquito control were being evaluated.
The amebiasis research program effort was critically reviewed-unpromising approaches were abandoned and those with potential were continued. Similarly, the virology program was assessed. Because the extensive virological studies had failed to reveal causal relationships in the pathogenesis of diarrheal disease, it was recommended that current studies be concluded and suspended until new techniques were developed or new leads discovered. It was further recommended that greater emphasis be made on investigation of possible host factors related to development of diarrheal disease.
The annual meeting of the Commission on Enteric Infections was held in conjunction with the Commission on Parasitic Diseases in 1962 and 1963. At the annual meeting in 1962, Drs. Hoffert, Cheever, and Abraham reported on their continuing virological and bacteriological studies. Although a variety of viral agents were isolated from cases of diarrheal disease, no clear-cut evidence was produced to link them to pathogenesis. These results represented the preliminary summary of the final report of this group.
Drs. Gezon and Yee reported on protein and nucleic acid synthesis and energy-yielding pathways in shigella, including the effects of antibiotics on these mechanisms. They developed an effective technique for the isolation of soluble and ribosomal ribonucleic acid for Shigella flexneri 3. Preliminary studies with chlortetracycline showed that low concentrations of this drug inhibit both protein and RNA synthesis.
Dr. R. Hugh continued his taxonomic studies on Vibrio comma (cholerae), chiefly including the El tor biotype. The clinical disease manifestations with the presence of the El for vibrio appeared to be classical cholera.
Drs. Reeves and Frye continued their biochemical investigation of E. histolytica.
Dr. Cheever presented Dr. Geiman`s report on studies conducted at the Porterville State Hospital. The population group studied was in an endemic areaof amebiasis. Clinical, parasitological, and chemotherapeutic studies were undertaken in an attempt to explain a morbidity rate of approximately 60% among infected individuals. Frequent recurrences were noted in a small group of amebiasis-prone individuals.
Dr. Dammin continued work on the pathological changes of host tissue reactions in experimental and naturally acquired enteric disease. Malnutrition did not produce intestinal lesions with any degree of consistency. In bacterial infections, V. comma (cholerae) produced no significant pathological changes. E. coli caused superficial lesions in most instances, whereas the various members of the shigella and salmonella groups produced gross ulcerative lesions. Dr. Dammin stated at the meeting that new research money was available and commented that fresh and more dynamic research approaches were needed.
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The incidence of amebic disease in the military appeared to be slowly declining, whereas the incidence of enteric disease remained constant. Nine outbreaks of bacillary dysentery among U.S. Navy personnel were reported. Diarrheal disease continued to be a problem to the Armed Forces overseas.
The emphasis of the Commission shifted from the study of individual infecting organisms to considerations of host and other environmental factors that might condition the ability of the potentially pathogenic organism to multiply and cause illness. The studies of Drs. Hoffert, Cheever, Hugh, and Gezon, as summarized above, were near completion. Dr. Gezon planned to outline a fresh approach for study of diarrheal disorders. Dr. Reeves planned to continue work on the metabolic requirements of E. histolytica. Dr. J. P. Ransom`s work would remain focused on the role of cellular interaction in open systems, mechanisms of resistance, or susceptibility to disease. The etiology and pathogenesis of diarrheal disease in several carefully selected population groups in Florida would be evaluated by Dr. Martin H. Kalser. It was hoped that Dr. Hoffert would initiate his investigations of the prophylactic and therapeutic use of Lactobacillus acidophilus in enteric disease, whereas Dr. Rolf Freter would focus on the protective role of coproantibody in humans and its induction by oral vaccination of volunteers.
Commission members concurred that the application of traditional study methods had not been productive and that new and bold measures were needed to provide answers to current problems. A noticeable lack of interest in such problems by the public sector simply emphasized the need for the Commission members working in collaboration with military scientists to take the lead. Highlights of the previous year`s research activities were reported at the annual meeting of the Commission on Enteric Infections, held at the Walter Reed Army Institute of Research (WRAIR) in Washington in March of 1963.10
Drs. Cheever and Abraham, working at the Detention Home of the Juvenile Court of Allegheny County, Pennsylvania, completed studies on the possible relationship of enteroviruses to outbreaks of diarrheal disease. Although no direct evidence was found to support the viral hypothesis, numerous enterovirus-like agents (apparently unrelated to any of the then recognized types) were isolatedf rom various population groups. Significant progress was made in the characterization and classification of these agents.
Dr. Hoffert gave a final report on studies of viral and bacteriological examinations involving control and autopsy specimens obtained during a Guatemalan outbreak. The viral isolation rate yielded no etiologic relationship to diarrheal disease observed during the outbreak; antibody studies led to the same conclusion. Concurrently, Dr. Hoffert began his investigation of the prophylactic and therapeutic use of L. acidophilus in enteric disease.
Dr. Dammin (who worked in conjunction with Dr. Hoffert) continued his evaluation of host tissue reactions in experimental and naturally acquired infections. Emphasis was placed on the correlation of the clinical, pathological, and microbiological data accumulated from severe and fatal diarrheal illnesses that occurred in Guatemalan children. He concluded the following:
. Viral agents do not play a significant role in the diarrheal disease observed.
. Malnutrition itself is not the basis for diarrheal disease.
. Fatal diarrheal disease occurs in the absence of recognized enteric pathogens. However, the presence of abnormally high numbers of "normal" bacteria in parts of the intestine usually characterized by scanty bacterial flora. Inflammatory lesions of the bowel are usually associated with the presence of recognized enteric pathogens such as members of the genus Shigella.
In presenting their data, Drs. Gezon and Yee reported that the action of chlortetracycline, as with chloramphenicol, resulted in the inhibition of protein synthesis when administered in low concentration.
Dr. Martin H. Kalser, who worked in collaboration with Dr. Hoffert, reported on their first 10 months of data on host factors in relation to the pathogenesis of diarrheal disease of infectious origins. Their subjects were migrant farm laborers, Cuban civilian refugees, and some Bay of Pigs prisoners. The Seminole Indian population was not available for study. The thorough evaluation of patients included bacteriological, viral, and parasitological study of the gastric, jejunal, ileal, and colonic contents. Bacterial counts were higher in the ileum than in the jejunum.
Dr. Ransom gave his annual report on the interaction of representatives of the normal intestinal flora with enteric pathogens in continuously fed cultures. Much of his work was on the design and
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construction of equipment necessary for the operation of continuous cultures. This preliminary work allowed him to explore the factors that govern interactions of organisms such as Salmonella typhimurium and Candidaalbicans and S. typhimurium and Saccharomyces cerevesiae.
Dr. Freter reported the results of human coproantibody studies with particular reference to its induction by oral immunization and its protective role in enteric disease. His study vaccine was a suspension of heat-killed Vibriocholerae ingested by medical student volunteers. The optimal schedule for the induction and maintenance of human coproantibody included a primary course of one dose daily for 4 weeks, followed by a weekly dose of this oral vaccine as long as a significant level of coproantibody should be maintained. The definitive test to evaluate vaccine efficacy for prevention of illness would obviously require a controlled field study. Available evidence suggested that coproantibody was not formed in the stomach but in the duodenum and probably in the jejunum, ileum, and large intestines. Dr. Freter believed that antibody response after oral vaccination was caused principally, if not entirely, by the formation of antibodies by the gut itself. In comparison, after parenteral immunization, antibodies were developed from many sites, probably including the gut. He felt that coproantibody was produced throughout the small and large intestines.
Dr. Hugh, The George Washington University Cancer Clinic, Washington, D.C., completed his work on identification of the Vibrio group and related organisms. He concluded that the El Tor vibrio represented a biotype (or physiological type) of V. cholerae. Dr. Reeves reported that cholesterol was an essential growth requirement for E. histolytica.
Dr. Geiman gave his final report on studies of the pathogenicity of E. histolytica. He described comparative studies of eight reputedly amebicidal drugs in a population group at the Porterville State Hospital in Porterville, California. None was found to be universally effective.
Colonel Robert W. Sherwood of the U.S. Army reported on three promising chemotherapeutic agents, Humatin (paromomycin), Entero-Vioform (iodocholorhydroxyquin),and Furoxone (furazolidone). Commander Jack W. Millar of the U.S. Navy described his experience as medical officer who made a 3-week global tour with a group of high-ranking medical officers. Each took prophylactic Furoxone twice daily, whereas the crew of the plane took no medication. The first group escape ddiarrheal disease until the closing days of the trip, when the drug was taken less regularly by some officers. The crew experienced numerous bouts of diarrheal disease during the first few days of the trip when they requested that chemoprophylaxis be made available to them. Commander Millar described an annoying side reaction of flushing. The promising results reported may possibly have been achieved by the prohibition of eating raw vegetables and fruits and drinking nonpotable water.
Dr. Geiman described his use of Entero-Vioform in the Sonoma State Hospital for retarded individuals. The drug successfully cleared the clinical manifestations and eradicated amoebae. The incidence of bacillary dysentery (Shigellasonnei) was markedly reduced. No effect on the course of salmonella infections was noted.
The Commission concluded that additional information was needed to define the properties of these drugs and to determine their toxicity for humans, before any recommendation could be made regarding their prophylactic use.
Dr. Dammin, as President of the AFEB, described a proposal to expand the scope of the Berry Plan to include the deferment of young investigators for conduct of research in the three military services and where facilities were available and where investigations conducted under the auspices of the AFEB. "There is a need for the Commission to stimulate interest on the part of young and talented investigators in the epidemiological problems of enteric disease...the need for new blood within the Commission is obvious."10
In 1964, The WHO published the Report of a WHO Expert Committee, Enteric Infections chaired by Dr. Dammin.11 Many findings and recommendations presented in the areas of pathology, prevalence, prevention, and, especially, control were based on work that had been performed by members of the Commission on Enteric Infections. Pertinent findings were:
. In the treatment of diarrheal diseases, the identification of the causative agent is important, but prompt assessment and treatment of fluid and electrolyte deficiency are essential for pa-
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CAPTAIN JACK W. MILLAR, MC, USN
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tient survival. Because of abuse of antibiotic treatment and progressive resistance of entero pathogens to antibiotics, it was strongly recommended that knowledge of susceptibility of entero pathogens to antibiotics was necessary for successful control of infection in individual patients. This knowledge would be particularly important for curtailing the duration of the convalescent carrier stage and for the control of infection within a group or community.
. Studies by Dr. Dammin et al on germ-free guinea pigs led to the finding that oral introduction of E. coli into germ-free guinea pigs caused no illness. Rather, it gave protection against a subsequent challenge of shigella, despite shigella and E. coli differing antigenically.
. Understanding of the significance of a pure water supply, effective excreta disposal, and methods of food handling is fundamental to the prevention of enteric infections.
. The effectiveness of enteric vaccines, at the time of this publication, had been substantiated only for typhoid vaccine.
By 1964, Drs. Cheever and Abraham had completed their studies on enteric viruses associated with diarrhea. In general, they reported little evidence, either serologic or epidemiological, to incriminate any virus as an agent in the etiology of diarrhea. Other investigators reported statistical and serologic evidence that diarrheal disease was frequently associated with specific viral agents, including adenoviruses. It was recommended that efforts to find virus agents in diarrheal illnesses be encouraged, especially as new viral techniques (interference phenomena) might reveal agents etiologically related to diarrhea.
Drs. Gezon and Yee concluded their studies on protein and nucleic acid synthesis and energy-yielding pathways in shigella and the effects of antibiotics upon these mechanisms. It was concluded that the stimulation of RNA synthesis by chloramphenicol was a result, rather than the cause of inhibition of protein synthesis by shigella; the mode of action of the drug may involve interference with peptide-bonding of amino acids.
Dr. Ransom reported his continued work on the role of cellular interaction in open systems in the mechanism of resistance or susceptibility to disease (Candida albicans.) Dr. Freter described the protective role of human coproantibody in enteric diseases and its induction by oral vaccination of volunteers. Sufficient evidence was now available to justify a field trial that compared oral and parenteral enteric vaccines; the objective was to determine whether coproantibodies were as effective in humans as in experimental animals. Field trials for cholera vaccine were initiated by military groups working with SEATO. WHO planned a study that used attenuate doral vaccine to be conducted in Calcutta, India, during the summer of 1965. At first a pilot evaluation would be conducted, then the study would be extended to involve between 100,000 and 200,000 individuals.
Dr. Kalser covered the first 2 years of his project on host factors in relation to the pathogenesis of diarrheal disease of infectious origin. He reported continuing difficulty in obtaining suitable subjects. Only 40 subjects had been studied thus far. All members agreed that basic studies on bowel physiology and changes of bacterial and viral flora in the normal and abnormal gut were essential to develop an understanding of the pathogenesis of diarrhea lillness.
Dr. Dammin updated the group on his continuing studies on the host tissue reactions in experimental and naturally acquired infections of military importance. The studies on fatal diarrheal cases in Guatemalan children were completed. Dr. Dammin shared his specimens and pathological data with several other investigators and commissions: Dr. Hoffert used the marmoset as an experimental animal for shigella infection in his exploratory studies. Drs. Goodwin and Wanner of the Phoenix branch of the CDC conducted similar studies.
Dr. Reeves reported his success in culturing E. histolytica in very large quantities by using a field sterilizing autoclave that he had converted into an anaerobic incubator. The amoebae were grown with Bacteroides symbiosus in a shallow broth layer in Petri dishes. Stock cultures were often contaminated with pleuropneumonia-like organisms (PPLO). Some of his biochemical studies had to be discontinued because of the contamination. Laterit was found that ameba culture could be grown free of PPLO if kanamycin and/orchlortetracycline (Aureomycin) were added to the culture medium.
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Dr. Geiman gave a sequel to his prior report on the pathogenicity of E. histolytica. He treated 2,200 patients at the Porterville State Hospital with 750 mg of iodochlorhydroxyquin (Entero-Vioform). Amebiasis and shigellosis were prevented in this hospital population over a period of 4 years.
In the discussion that followed Dr. Geiman`s presentation, Dr. Millar emphasized that a prophylactic drug for military use was urgently needed. Preferably, a drug for short-term, quick protection in individuals with unrestricted activity was desired. There was much discussion about a suitable test population and the need for proper control studies. Colonel Franklin L. Bowling of the U.S. Air Force stated that there was a need for the Commission to make specific recommendation regarding a useful prophylactic regimen. Diarrheal disease was so common at Reamy Air Force Base, Puerto Rico, that it was known as the "Reamy plague."
Samuel B. Formal, Ph.D., of WRAIR described his recent studies of an oral-attenuated shigella vaccine. A vaccine strain of Shigella flexneri 2that was streptomycin-dependent was given orally in doses of 109 to1011 cells to 20 volunteers. There were no untoward effects. Shigella was isolated from their stools up to 5 days after ingestion. Field trials in Yugoslavia were conducted involving 700 persons. They were given five doses of Shigellaflexneri 2 oral vaccine in doses of 3 x 1010 to 5 x 1011cells, spaced 3 days apart. There was a reaction rate involving mild diarrhea of4% compared with 3% in those who received the control. An epidemic of Shigellaflexneri 2 occurred later that year. No persons previously given the vaccine became symptomatic, but 21 persons who received the control developed diarrhea. More field trials were planned.
A new draft of TB MED 119 entitled, "Shigellosis (Bacillary Disease)" was prepared by Commission members to replace the outdatedbulletin.12 The problem of further chemoprophylactic field trials for prevention of Shigellosis was discussed under unfinished business. Selection of a suitable population for testing was discussed thoroughly.
The need for continued recruitment of competent investigators and new approaches was actively rediscussed. An important move was the appointment of Dr. Formal to the Commission; his appointment as a commission member was accepted with enthusiasm.
In 1965, there was noticeable improvement in the volume and caliber of activities of the Commission. Renewed interest and vigor during meetings led to productive discussions and active interplay with each of the military services. The Navy Department`s request for an effective serological test for the detection of amebiasis was fulfilled. To locate a suitable field site for achemoprophylaxis trial, Drs. Gezon and Hardy visited the LSU International Center for Medical Research and Training site in Costa Rica. Dr. Fred Payne, director of that facility, submitted an application to conduct trials using one or more chemosuppressive agents to prevent amebiasis. Dr. Dammin continued to render valuable assistance to numerous overseas military service laboratories.
The Commanding Officer of Naval Medical Research Unit (NAMRU) 3 requested several members visit for advice regarding additional studies on diarrheal diseases. There was considerable discussion regarding development of new knowledge aimed at determining the causes and indicating control of diarrheal diseases in Armed Forces personnel stationed in the Far East. The resources of the Commission were made available, provided its efforts were not in conflict with studies performed intramurally within the military services. Various Commission members offered to visit Korea or elsewhere on request.
The 1965 Annual Meeting of the Commission on Enteric Infections was held ointly with the Commission on Parasitic Diseases. Six authorities in immunological and serologic testing attended.
Drs. John Kessel (University of Southern California), Irving Kagan (CDC), and Iris Krupp (Tulane University) described their work on the use of hemagglutination test (HA) for diagnosis of amebiasis. Their findings are summarized:
. The HA test and the CF test (complement fixation) are quite specific in separating amebic from non amebic liver disease.
. There is good correlation between clinical intestinal varieties of amebiasis and a positive HA titer.
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. The exact diagnostic antibody titer is unclear. Moreover, the initial serum dilution, whether 1:50, 1:4, or 1:2 needed clarification.
. The HA test should be considered to be under development and unready for routine use. More work should be concentrated on making the test more specific and better able to maintain its current level of sensitivity.
Dr. Francesco Biagi (University of Mexico) described an immobilization test for amebiasis. Further experience was needed to clarify specificity of the test. Dr. Morris Goldman described the fluorescent antibody test (FA) for amebiasis. Despite his pessimism, his peers believed that the test had not been fully evaluated and deserved further investigation.
Dr. Shirley Maddison reported studies employing the gel-diffusion technique. She found a 97% correlation between a positive gel-diffusion test and the presence of amebic liver abscess. The test was negative in all cases of ulcerative colitis. The diagnostic fog seemed to be clearing, and two or three useful tests were now available for applied research and epidemiological investigators. For diagnosis of acute amebic liver involvement, the hemagglutination, complement-fixation, gel-diffusion, and immobilization tests all correlated well with clinical findings. For acute amebic dysentery, the complement fixation test appeared to be the best available procedure.
For more chronic amoebic infections and epidemiological surveillance, the hemagglutination and/or gel-diffusion tests were regarded as most likely to provide reliable information. Despite excellent progress, further standardization of the tests and evaluation of specificity were regarded as essential before their broad diagnostic application.
Representatives from the three Armed Forces presented data on the incidence of diarrheal diseases in the military services, particularly in Vietnam. Detailed reports were given. It was concluded that the precise magnitude and specific nature of the problem could not be determined because the majority of troops involved were self-treated. Patients were often not reported through any medical channels.
The first day of the spring meeting of the Commission on Enteric Infections,28 February 1966, was devoted entirely to discussion of the relationship of the gut flora to pathogenesis and therapy; military representatives made their reports on the second day.
Dr. Ren? Dubos (The Rockefeller Foundation, New York) discussed the ecology of the gut flora using pathogen-free NCS mice of the CFW strain; lactobacilli were established early in the gut and persisted at a high level throughout life. Anaerobic streptococci and bacteroides were established some what later and also persisted throughout life. Enterococci and coliforms normally reached a high level by the 10th day of life and then declined rapidly. Clostridia were the last to be established and persisted throughout life.
Dr. Dubos discussed the localization of flora in various regions of the gut. Streptococci and lactobacilli persisted principally in the stomach, small intestine, and caecum. They were adsorbed on to the surface mucosa and in the nonsecretory gastric mucosa. By contrast, bacteroides were localized only in the caecum; coliforms and enterococci were present principally in the caecum and large intestine.
The flora of the mouse gut could be altered by giving penicillin orally for 1week. Lactobacilli, bacteroides, and coliforms disappeared within 1 day and were replaced by Candida, enterococci, and especially clostridia. Mice treated with penicillin showed weight loss and poor food consumption. These findings persisted until the symbiotic flora returned.
Dr. Dubos demonstrated an example of bacteria interference by feeding mice an artificial diet of casein and such bacterial contaminants as slow-lactose-fermenting coliforms and E. coli. When each of the latter was fed simultaneously, they multiplied throughout the intestine. When the coliforms were given first and E. coli fed 2 days later, only the slow-lactose-fermenting organisms propagated.
Dr. Russell Schaedler (Jefferson Medical School, Thomas Jefferson University, Philadelphia, Pennsylvania) discussed his research on the reestablishment of gut flora in germ-free mice. When lactobacilli, streptococci, bacteroides, andc oliforms were fed separately or in combination, normal reestablishment of gut flora developed.
Dr. Edward Kass (Channing Laboratory, Harvard University, Cambridge, Massachusetts) discussed the importance of the bowel flora in various types of clinical infections. Specifically, colonic E. coli were
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The Agenda of the Spring Meeting of the Commission on Enteric Infections of the Armed Forces Epidemiological Board Symposium on the Relation of the Gut Flora to Disease and Therapy Conference Room 341 Moderator: Director of Commission 0900 Opening Remarks-Dr. Horace Gezon 0910 Ecology of the Gastrointestinal Tract-Dr. Ren? Dubos Discussant-Colonel Sprinz Reestablishment of the Gut Flora in Germ-Free Animals-Dr. Russell Schaedler Discussant-Dr. Rolf Freter Studies on Clinical Significance of Alteration in Bowel Flora-Dr. Edward Kass Discussant-Dr. Ingelfinger 1230 LUNCH 1345 Bacterial Overgrowth in the Blind Loop Syndrome-Dr. Robert Donaldson Discussant-Dr. Martin H. Kalser Therapy of Salmonellosis-Dr. Richard B. Hornick Discussant-Dr. Edward Kass Antibiotic Resistance and RTF in Enteric Organisms-Dr. Stanley Falkow 1730 Social Hour-Officers` Club |
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The Agenda of the Spring Meeting of the Commission on Enteric Infections of the Armed Forces Epidemiological Board Conference Room 341 Moderator: Director of Commission 0900 Opening Remarks By Commission Director-Dr. Horace Gezon 0915 Research and Development Command-General Vorder Bruegge 0930 Reports of Preventive Medicine Officers-Air Force, Army, Navy 1030 BREAK 1045 Coproantibody in Man-Dr. Rolf Freter 1120 Antitoxin Immunity in Cholera-Dr. William Burrows 1155 Host Studies of Heterogenous Infectious Diarrhea-Dr. Martin H. Kalser 1230 LUNCH 1330 Host Tissue Reactions-Dr. Gustave J. Dammin 1405 Comparative Biochemistry of E. histolytica-Dr. Richard Reeves 1440 Report on Visit to Cali, Columbia, and Guatemala-Dr. Horace Gezon 1515 ADJOURNMENT OF OPEN MEETING 1530 Executive Session (Full Members and Military Representatives) |
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etiologically implicated to urinary tract infections. These organisms contaminate the vagina and then ascend the urethrae to cause cystitis. Urinary tract infections could be controlled by feeding cranberry juice, which contains quinic acid. Intestinal bacteria convert this compound to hippuric acid, an antibacterial agent that is excreted in the urine. The hippuric acid involves altering the urinary pH. Dr. Kass demonstrated that a urine pH of 5 or less would inhibit bacterial growth. He also speculated that manipulation of the gut flora may have therapeutic possibilities. For example, the administration of lactose to a lactating mother replaced staphylococci in an infant`s stool with lactobacilli. However, manipulation of the gut flora can have deleterious effects; the implantation of E. coli into the intestine of rabbits caused endotoxin production.
Dr. Robert Donaldson, Boston University School of Medicine (Massachusetts),reported on bacterial overgrowth in the blind-loop syndrome. He made an analogy to tropical sprue. Both conditions may be associated with an increased level of fecal fat, a decrease in Vitamin B12 absorption, and bile salt abnormality. In each, the low concentration of normal bile salts causes steatorrhea in contrast to abnormal bile salt metabolites that are produced by the bacteria.
Dr. Richard B. Hornick, University of Maryland School of Medicine, Baltimore, Maryland, presented work on experimental typhoid infection in volunteers and its prevention with vaccines and chemotherapeutic agents. The Quailes strain of Salmonellatyphi was used for producing experimental human infections. Varying numbers of organisms were placed in milk and ingested by healthy fasting volunteers. The infectious doses and attack rages were 109 organisms, 98%; 108, 94%; 107, 68%; and 105, 24%. None were infected with 103organisms. The aerosol method of inoculation was attempted unsuccessfully, which suggests that the respiratory tract is not a normal portal of entry. Localization of the typhoid bacillus in the gut was studied at various time intervals after ingestion. Jejunal biopsies were performed after infection of 109Salmonella typhi. There was marked evidence of inflammatory responses in the mucosa as early as 2 to 3 days prior to clinical illness.
Chloramphenicol, streptomycin, and neomycin were used as chemoprophylactic agents before and after ingestion of Salmonella typhi. None prevented infection. Those who received long-term chloramphenicol therapy remained afebrile, but demonstrated evidence of bacteremia and a rise in antibody titers.
Evaluation of three typhoid vaccines (acetone-extracted K, phenol-extracted L, and purified Vi antigen) were made on volunteers using the Quailes strain of Salmonellatyphi. When challenged with 109 cells, no volunteers were protected; practically all became ill. Lower challenge doses were used subsequently, and protection was demonstrated against a challenge of 105organisms. It was concluded by Dr. Hornick that large numbers of Salmonella werer equired to produce typhoid fever in healthy adults who resided in a nonendemic area. He commented that heavy bacterial contamination and/or the opportunity for Salmonella typhi to multiply would create the proper environment for causing illness.11
The final presentation of the day was by Dr. Stanley Falkow, who discussed multiple drug resistance of enteric bacteria. Enteric bacteria with multiple drug resistance are prevalent worldwide. The Japanese investigators showed that this resistance was carried by a composite nonchromosomal resistance transfer factor, the "R factor." The R factor is present in Shigella, E. coli, Salmonella, Klebsiella, Serratia, Arizona, Vibrios, Pasteurella pestis, Pasteurella pseudotuberculosis, Pseudomonas aeruginosa, Proteus, and Citrobacter.
Dr. William Burrows and his coworkers at the University of Chicago, continued to investigate the role of antitoxic immunity as a prophylaxis against cholera. Their experimental model was the ileal loop of the adult rabbit.14
Dr. Freter, of the University of Michigan, described two hypotheses that could explain the paradoxical situation by which coproantibodies protect animals from illness without reducing the total number of vibrios in the gut. He found that antibody does not inhibit the production of toxin, but it does interfere with the adherence of vibrios to epithelial cells. With the use of the fluorescent antibody technique, he showed that cholera vibrios were absent on the mucosal surface in the presence of antibodies.
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The Agenda for the Symposium on Shigella Vaccines, Killed and Living- Conference Room 341 Moderator: Director of Commission 0900 Introduction of Topic-Dr. Horace Gezon, Dr. Gustave J. Dammin 0915 Killed Shigella Vaccines-Dr. Albert V. Hardy, Captain Thomas Floyd Discussant-Dr. William Ewing Gut Immunity and Antibody Formation-Dr. Rolf Freter Discussant-Dr. William Burrows 1330 Living Attentuated Shigella Vaccines-Dr. Samuel Formal Testing in Primates-Dr. Robert C. Good Discussion of Role of Commission in Further Developmental Studies and Military Application 1700 ADJOURNMENT 1730 Social hour at Georgian Motel, Silver Spring, MD All members, Military Representatives, and guests are invited. 2000 Executive Meeting-Commission Members and Executive Secretary |
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At the University of Miami, Dr. Kalser completed his investigations on the bacterial flora of the small intestine in normal subjects and in those with diarrheal diseases. He described the effects of antibiotic therapy on the intestinal flora, particularly in patients with malabsorption syndrome. Clinical improvement in these patients, after antibiotic therapy, generally preceded the restoration of a normal intestinal bacterial pattern. He studied electrolyte changes and water loss associated with diarrhea. In patients with steatorrhea or diabetic diarrhea, there was usually little loss of sodium and potassium ions in the stool. In patients with diarrhea associated with a hypermotility, there was a marked loss of these two ions.
Dr. Carlos Ramirez of the New England Institute for Medical Research, completed work initiated by Dr. Ransom on interactions in gut. Inhibition of Salmonella typhimurium by Candida albicans appeared not to be a result of a metabolic product of the yeast but probably of a competition between the organisms for nutrients.
Drs. Reeves and Lionel G. Warren from Louisiana State University described their biochemical characterization of strains of Entamoebahistolytica. An attempt is being made to distinguish those with differing pathogenic properties.
In 1966, the Commission proposed that an investigation be conducted under its auspices to evaluate the etiology, physiological alterations, and control of diarrhea in newly arrived troops in Vietnam. The proposal was not approved by the Research and Development Command; malaria and problems of trauma were higher priority issues. General Vorder Bruegge, of the Research and Development Command, described the fiscal problems faced by the Command that significantly reduced the availability of funds for extramural-sponsored research.
Colonel Adam Rapalski, Chief of Army Preventive Medicine Division, reported that enteric diseases were second only to venereal diseases in prevalence in Vietnam. Captain Townsend of the Air Force described the annual spring diarrhea epidemic at Clark Air Force Base. The Air Force expressed interest in the development of an effective shigella vaccine. Captain Millar of the Navy described nine outbreaks of enteric disease involving over 800 personnel, mostly in Vietnam. Three outbreaks were caused by shigella, with the largest number caused by Shigella flexneri 2a. In each of these three outbreaks, sulfa and tetracycline-sensitive strains were the cause. Patients responded well to tetracycline therapy. Nonpotable water and defects in sewage disposal were the apparent sources.
Dr. Gezon, Director of the Commission, opened the Annual Meeting on 27 February 1967. The entire day was spent discussing shigella vaccine developments. Dr. Hardy and Captain Thomas Floyd described the effects of the killed shigella vaccine on humans. Data were obtained from vaccine trials in retarded children and prisoner volunteers. Parenteral inactivated shigella vaccines did not provide protection against illness and infection. Apparently, there is strict specificity to an immune response (an attack of one serotype of shigella confers a degree of immunity to that serotype for a certain period of time but not to others). Hence, information is needed regarding the number and various serotypes prevalent in a geographic area where a vaccine is to be used.
The work helped clarify the pathogenesis of shigella infection. It was found that pathogens penetrate the intestinal epithelial cells and invade the laminapropria. It was suggested that intestinal antibodies (coproantibodies), which are short-lived, probably prevented adherence to the epithelial cells. Conceivably, oral vaccination could help prevent bacterial penetration if shigella contained an antigen responsible for invasion. There was little evidence to support this concept. Cellular immunity could possibly help by enabling phagocytic cells to inactivate pathogens intracellularly. If immune mechanisms proved effective against shigella, the mechanism was thought to be specific in action rather than nonspecific. Researchers concluded that live attenuated suspensions of bacteria would be needed to induce immunity.
Dr. Formal presented his group`s data on living attenuated shigella vaccines. Virulent strains of shigella were shown to penetrate intestinal epithelial cells, enter the lamina propria, and multiply. Avirulent mutants did not penetrate, whereas attenuated shigella-escherichia hybrids did penetrate but were unable to survive in the lamina propria. Dr. Robert Good, from the Primate Center in Davis, California, confirmed Dr. Formal`s findings on the effectiveness of the living oral vaccines in monkeys.
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Dr. Hornick reported on the safety testing of lyophilized mutant Shigella flexneri at the Maryland House of Corrections. No significant adverse problems were reported. Shigella sonnei and a few Shigella flexneri serotypes (Shigella flexneri 2a) account for essentially all the shigella infections that occur in low socioeconomic and confined populations. Another study site, the Wisconsin Southern Colony for mentally defective children, has been selected for field testing. Recurring problems with shigella infections have been reported there. Before the testing could begin, safety had to be ensured and the study required approval by authorities at the CDC. Dr. Hornick was assigned responsibility for conducting these safetystudies.15
Research applications submitted by members of the Commission in 1967 included
. DA-49-193-MD-2492 W. Burrows. "Antitoxic Immunity to Cholera. " University of Chicago.
. DA-49-193-MD-2530 G. J. Dammin. "Host Tissue Reactions in Experimental and Naturally Acquired Infections of Military Importance." Harvard University.
. DA-49-193-MD-2840 R. Freter, Ph.D. "Coproantibody in Man: Its Protective Role in Enteric Diseases and its Induction by Oral Vaccination of Volunteers." University of Michigan, Ann Arbor. Postulation: The principal effect of coproantibody maybe in preventing absorption of the intestinal pathogens to the epithelial surfaces and, therefore, interfering with their entrance into the cell.
. DA-49-193-MD-2254 (APR 62-DEC 66) M. H. Kalser, M.D., Ph.D. "Systemic Reaction to Heterogeneous Diarrhea and Evaluation of Therapy." University of Miami.
Dr. Kalser performed one of the largest studies of microflora of the human gut. The intestinal microbiological environment was determined in about 200 adult individuals. Gastric, jejunal, ileal, and/or fecal specimens were cultured for evidence of viral, bacterial, or microflora growth. A striking finding was the absence of any viral isolates in 450 specimens from normal persons and patients with acute or chronic diarrheal disease. He evaluated several patients with tropical sprue and malabsorption syndrome before, during, and after completion of a several-month course of therapy with tetracycline. There was clinical and functional improvement and a modest decrease in intestinal bacteria. After the antibiotic was discontinued, the bacteria count rose but the clinical improvement persisted.16
. DA-49-193-MD-2620 R. E. Reeves, Ph.D. "Comparative Biochemistry of Strains of Entamoeba histolytica." Louisiana State University.
With the use of enzymatic techniques, Dr. Reeves attempted to identify the difference between strains of Entamoeba histolytica derived from various global areas and of varying degrees of pathogenicity. The specified goal was to identify those strains that are human pathogens through their chemical properties.
At the 1967 fall meeting, Commission members discussed in depth those areas where the military continued to have problems, especially problems with enteric diseases. Acute amebiasis remained a significant problem among Marines in Vietnam. Specific measures were taken to ensure potable water and adequate sewage disposal in an attempt to prevent illness.
Commander Millar, the newly appointed Director of the Preventive Medicine Division of the Navy Department, reported 53 diarrheal outbreaks in Southeast Asia involving 5,800 persons. The pathogen was only identified in 16 of the outbreaks: 4, Shigella flexneri; 2, Shigella sonnei; 6,staphylococcal food poisoning; and 4, Salmonella. A Preventive Medicine Unit was established in Da Nang to help deal with diarrheal problems.
Representing the U.S. Army, Colonel Irvin C. Plough reported that to derive funds for research from the Medical Research and Development Command, the Commission must clearly verify that programmed investigative studies directly supported the military services, and most particularly, those personnel stationed in the field. Presumably, studies of enteric disease in the field received a relatively small percentage of the total research money available.
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The Agenda for the Spring Meeting of the Commission on Enteric Infections Conference Room 341 0900 Introductory Remarks-Dr. Horace Gezon, Dr. Gustave Dammin 0915 Reports of Preventive Medicine Officers-Air Force, Army, Navy 1030 COFFEE BREAK 1045 Normal Gut Architecture and Changes Associated with Celiac Syndrome-Dr. J. Trier Diarrhea and Malabsorption in Vietnam-Major L. Legters 1245 LUNCH 1400 Clinical Aspects of Tropical Sprue in Puerto Rico-Dr. T. Bayless Flora Changes Associated with Malabsorption-Dr. F. Goldstein 1700 ADJOURN |
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The Commission on Enteric Infections held its spring symposium on 18 March1968. The topic of discussion was "Malabsorption and Its Relation to Non-Specific Diarrhea." An impressive cadre of knowledgeable clinical investigators attended. (See the 1968 agenda.) Little additional information was presented on pathogenesis of bacterial diarrhea in military personnel in Vietnam. New knowledge of the etiologic role of Cholera vibrio toxin in production of watery diarrhea in infected persons was discussed. It became apparent that studies of enteric toxins would provide new knowledge on the cause of nonspecific diarrhea and the role played by enterotoxin produced by Escherichiacoli and other species. During the executive session, the Commission learn edit would now receive grant proposals and contracts for review. Formerly, such reviews were conducted by the Research and Development Command and its Committee on Enteric Infections. That committee was disbanded; hence, the transfer of the review system to the Commission.
The Commission made the following recommendation to the AFEB concerning boiling water to make it potable: "Any method of boiling water that would make it potable in terms of inactivating infectious hepatitis, would make it free from other infectious agents as well. Boiling water for one minute followed by gradual cooling to ambient temperatures would yield potable drinking water.(At altitudes where water boils at 98?C, boiling is required for five to ten minutes)."17 By 1969, the Commission became increasingly interested in clarifying the problem of nonspecific types of diarrhea. It was clear that many intestinal infections involving military personnel result from agents currently unknown and that a specific microbe might be the cause.
The 1-day spring meeting was devoted to the subject, "Symposium on Gut Physiology," presented by the gastroenterology group from Walter Reed (seethe 1969 Agenda).
The overall objective for the Symposium on Gut Physiology was to elucidate those physiologic abnormalities associated with diarrheal disorders, including the various chemical or physiologic stimuli responsible for such changes. With that basic concept in mind, Commission members enhanced their knowledge of gastrointestinal physiology.
The Commission activities were directed to the problem of experimental infections in an attempt to establish appropriate model systems aimed at clarifying relevant human problems. The need to reexamine the issues of viraletiology and conduct of field trials with chemotherapeutic agents, vaccines, and environmental control measures was reaffirmed.
Dr. Victor M. Villarejos, Louisiana State University ICMRT, San Jos?, Costa Rica, submitted a long and interesting addendum to his project request for virologic studies of stools of patients in Honduras then being evaluated in chemoprophylactic studies. It was his view that in spite of previous negative findings, sophisticated virological studies needed to be repeated in a tropical or semitropical area with poor health standards.
In his earlier work, Dr. Villarejos obtained fecal specimens from patients with acute diarrhea (less than 24 hours between time of onset and that of specimen collection). His collection included fecal specimens from patients whose illness had occurred 48, 72 and 96 hours earlier. Virological studies were conducted on the two groups. He observed an inverse relationship between the rates of isolation of Enterovirus coxsackie B types as compared with the noncoxsackie B types in each diarrhea group. The maximum isolation rates of coxsackie B types were derived from patients with acute diarrhea (less than 24hours between onset and that of specimen collection). This indicated to him the need for the collection of fecal specimens for virologic study as early after the onset of the disease as possible.
The agents belonging to this virus group were ubiquitous. There was abundant clinical evidence describing the diarrhea-producing potential as a result of infection by numbers of this virus group. There were reports of limited epidemics of diarrhea in which members of the virus group were the only pathogenic agents isolated.
Dr. Villarejos concluded that the etiologic role of coxsackie B type toxins should be confirmed as a common cause of enteritis, the possibility of developing a suitable vaccine for prevention was obvious. A vaccine of this type would be useful for new, unexposed persons who travel into a known endemic area.
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The Agenda of the Spring Meeting of the Commission on Enteric Infections Conference Room 341 Monday,17 March 1969 0900 Introductory Remarks-Dr. Horace Gezon, Dr. Gustave Dammin Neuromuscular Physiology and Gut Motility COFFEE BREAK Interactions between Blood Flow and Motility-Dr. E.D. Jacobson 1245 LUNCH 1345 Transport Mechanisms Biochemical Approaches to Diarrheal Diseases-Dr. P. Curran ADJOURNMENT Tuesday, 18 March 1969 0900 Executive Session-Full members only 1200 ADJOURNMENT
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The annual spring meeting of the Commission on Enteric Infections was held on 20 March 1970 at the WRAIR, Washington, D.C. Cholera and cholera-like diseases were discussed.
Several publications by Dr. Burrows, Department of Microbiology, University of Chicago, on cholera enterotoxin were completed under Commission sponsorship. In one article entitled, "The Extractable Lipid of the Cholera Enterotoxin,"Dr. Burrows examined extracted lipid from Vibrio cholerae by thin layer chromatography and gas liquid chromatography. Previously observed inactivation of the toxic activity by chloroform-methanol extraction but not by ethanol-ether precipitation was not associated with demonstrable differences in the nature of extractable lipid. He concluded that extractable lipid was not associated withtoxicity.18
In another article published later the same year, "Towards an Effective Prophylactic Immunity to Cholera," Dr. Burrows reported that potent antigens capable of eliciting antibacterial and antitoxin immune responses were now available. It remained unclear whether such agents provided an effective level of vibriocidal antibody.19 In July, 1970, President Richard M. Nixon appointed a panel to investigate the research programs of the Department of Defense to determine whether a possible conflict of interest existed between the AFEB and its Commissions (vide infra). This review and its subsequent effect on the AFEB Commission system is well-covered on pages 119 through 133 in The Armed Forces Epidemiological Board-Its First Fifty Years: 1940-1990.20
On 5 March 1971, the Commission convened its annual meeting. The principal topic of discussion was "Local Immunity: Is it a Factor in Determining the Response to Enteric Infections." There is no report available for this meeting (see the 1971 agenda).
The spring meeting of the Commission on Enteric Disease was convened by its new Director, Dr. Thomas R. Hendrix, of The Johns Hopkins University on 3 March1972. The meeting was devoted to the subject of shigellosis. A summary of the research accomplishments of the year follows:
. In his final report, Local Immunity to Infectious Diarrheal Disease, Dr. Burrows reported that immunization of rabbits by parenteral and intraluminal routes was followed by the appearance of antibody in serum and intestinal contents. Resistance to toxin challenge more closely paralleled serum titers than coproantibody titers. The toxin-neutralizing antibody identified was IgA.21
. Lawrence M. Corwin, Ph.D., Associate Professor of Microbiology, Boston University School of Medicine, spoke on Factors Affecting Virulence of Shigella flexneri 2a. He found that immunologically identical strains of Shigella flexneri 2a have differences in their cell envelopes. The altered configuration of the cell wall, rather than its chemical composition, accounted for its lack of penetration of the intestinal epithelial cell and the resulting loss of virulence.22
. Dr. Dammin, et al, reported on "Host Tissue Reaction in Experimental and Naturally acquired Infections of Military Importance." These studies revealed that only invasive Salmonella typhimurium caused rabbit ileal loop to secrete fluid. Fluid accumulation that occurred before invasion was demonstrable, accompanied by discharge of the goblet cells of the villi. Unlike the response associated by the toxigenic bacteria, Vibrio cholerae and Escherichia coli, no exotoxin had been identified.
. Dr. Falkow, Georgetown University, presented his work, "Infectious Multiple Drug Resistance in the Enterobacteriaceae." He also described the genetic and molecular nature of enterotoxic plasmids.
. Dr. Freter reported on his research, "Coproantibody: Its Protective Role in Enteric Diseases and Its Induction by Oral Vaccination of Volunteers." In conventional mice, germ-free mice, and rabbits, such antibodies appeared as a result of local synthesis or possibly derived from serum antibody. Serum antibody was degraded in the intestine in both types of mice. In germfree mice, the degradation was so rapid that no serum antibody was detectable in the intestine. Therefore, the presence and probably the quality of intestinal flora was shown to affect host resistance by a new mechanism: the sparing of intestinal antibody.
. Dr. Sherwood L. Gorbach reported his studies," The Role of Intestinal Bacteria in Acute Diarrheal Disease." He indicated that there was a need for a rapid and simple method for identifying toxin-producing Escherichia coli.
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The Agenda for the Spring Meeting of the Commission on Enteric Infections Conference Room 341 0900 Introduction-Dr. T. R. Hendrix, Dr. G. J. Dammin Mechanism of Local Immunity-Dr. Arthur M. Silverstein, Johns Hopkins University 1045 COFFEE BREAK 1100 Studies on Protective Function of Secretory Antibodies; Developmental and Functional Aspects of Local Immunity to Viral Infections-Dr. Pearay L. Ogra, 1245 LUNCH 1345 The Role of Antigens in the Development of Immunologic Defense; Lessons from Antigen-Free Cellular Immunity in Determining Defense Against Enteric Infections-Dr. Frank M. Collins, 1530 COFFEE BREAK 1545 Symposium on Management of Diarrhea-Dr. Herbert L. DuPont, University of Maryland Management of Fluid and Electrolyte Problems in Diarrhea-Dr. Charles C. J. Carpenter, Johns Hopkins University 1700 ADJOURNMENT
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. Drs. Hornick and Herbert Dupont reported on their work on Shigella vaccines in humans. Although some protection was achieved with oral shigella vaccines, it was not at a level they desired. They initiated a new series of human studies with Escherichia coli, combined with shigella group and type antigens. All vaccines were produced in Dr. Formal`s laboratory at WRAIR. They evaluated filterable agents that caused "viral gastroenteritis" and, at the time of their presentation, had identified three separate viruses involved in recent outbreaks. The researchers performed their work at the University of Maryland School of Medicine and Hospital. They planned to determine the duration of homologous immunity and degree of heterologous immunity.
. Drs. Kurt J. Isselbacher, W. Allan Walker, David A. Shafritz, and Joseph L. Perrotto reported on the "Pathophysiology of Acute Non-Specific Diarrhea: Uptake of Exotoxins and other Macromolecules and Their Effect on the Intestines." They extended their observations that immunization interferes with antigen uptake by the intestine. They speculated that this effect may be produced by oral or parenteral immunization and is dependent on local (intestinal) antibody. Because cholera toxin must first bind to the mucosa to exert an effect on secretion, comparisons were conducted of the binding of cholera toxin and bovine serum albumin (BSA) in vitro, using sections of rat intestine brush borders. It was found that binding of BSA was enhanced by specific antibody at physiological, but not higher, concentrations. The in vitro model demonstrated that cholera toxin and bovine serum albumin exhibited greater binding in the ileum than in the jejunum. Cholera toxin was able to bind by a factor of 10 compared with BSA. Their studies were developed to provide a rational basis for immunization against enterotoxins.
. Dr. Yee presented a final report, "Laboratory Studies on Shigella Pathogenesis and Immunity." Oral immunization of guinea pigs with an attenuated hybrid Escherichia coli and Shigella flexneri 2a elicited both cellular and humoral immune response. Peritoneal macrophages from immunized animals were resistant to the lethal action of virulent Shigella flexneri 2a.
SUMMARY
In mid-1970, in response to charges of flagrant conflict of interest practices in the government and to a general atmosphere of suspicion and unrest, President Nixon embarked on a thorough governmental housecleaning. He created a panel to investigate the Department of Defense. An ad hoc committee was established to perform a management survey of the AFEB. This panel completed its management survey and presented it to the AFEB in May 1971. The management report cast suspicion that the Board had shown a conflict of interest in the practice of awarding research grants and in its failure to be "responsive to the changes in missions and priorities of the military medicaldepartments."20 The panel`s report continued, questioning whether the function of the AFEB was a duplicate of, and in conflict with, the research activities of the NIH.
A response to the findings of this panel may be found in an impassioned speech to the AFEB on the occasion of its 30th anniversary, given by Dr. Colin MacLeod, Director of the AFEB from 1947 to 1955.20 He answered the charges point by point, emphasizing that the AFEB provided the "real continuity in military preventive medicine" and that "excellent science ... has always been the hallmark of ... the AFEB."23Anger and bruised feelings were prevalent among the AFEB members; the AFEB, as it had been known, could easily have been dissolved save the efforts of Dr. Dammin. Through his leadership and mediation skills, the AFEB was reorganized; the Commission system was abolished and a new committee structure was adopted.
A new mission was established for the AFEB and its designated committees. They were chartered to function solely as advisors to the Armed Forces when specific problems arose. (A complete account
427
COMMISSION ON ENTERIC INFECTIONS
Fall Meeting, 18-20 October 1972
Walter Reed Army Institute of Research
Washington, D.C.
Seated, left to right: Dr. Francis S. Cheever, Dr. Horace M. Gezon, Dr. Thomas R. Hendrix (Com. Dir.), Dr. Albert V Hardy
Standing, left to right: Dr. Eugene J. Gangarosa Dr. Rolf Freter, Dr. Samuel B. Formal, Dr. Gustave J. Dammin (Pres. AFEB), Dr. Charles C., J. Carpenter, Dr. Marion M. Brooke, Dr. Richard B. Hornick, Dr. Russell W. Schaedler
of the restructuring of the AFEB is contained in The Armed Forces Epidemiological Board-Its First Fifty Years:1940-1990 by T. E. Woodward).20
This action formally ended the Commission on Enteric Infections, established in 1948. In the 23 years since the inception of the Commission, it had provided the means of controlling and preventing the ravages of many of the acute diarrheal diseases and their subsequent deleterious impact on military effectiveness through its research stimulus and recommendations. The work was not only germane to the Armed Forces but to the general public throughout the world.
The Commission on Enteric Infections served an important leadership role during a period when great advances were made in the understanding of the pathogenesis of diarrheal diseases. The original group wisely chose and clearly defined its objectives. These initiatives kept the Commission focused
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on those areas critical to expansion of knowledge on pathogenesis, the use of this information to support measures to develop diagnostic tests to obtain epidemiological data, and to implement preventive measures. Such control measures included the use of, and enlightened methods of, treatment. This critical period featured the new discoveries of enterotoxins and the methods by which they invoke secretory activity of the epithelial cells of the small bowel. No longer was it necessary to implicate differences in water or jet lag or even unculturable viruses as the cause of nonspecific diarrhea, often called travelers` diarrhea. Escherichia coli, and other common entero pathogens were found to be clear offenders, responsible for the ubiquitous watery diarrhea that had plagued military personnel for years. Oral replacement fluids were shown to greatly simplify treatment. Oral attenuated typhoid vaccine was shown to be effective in prevention and gave credence to the potential for development of similar vaccines for shigella, salmonella, and Escherichiacoli. As the knowledge of R-factor plasmids unfolded, antibiotic treatment was found to have significant limitations. Difficulties in the use of antibiotics for established enteric infections remain.
Previously, little was known regarding the control, treatment, and diagnosis of amebiasis. The Commission on Enteric Infections was instrumental in sponsoring key studies that resulted in the successful growth of such organisms on new synthetic media. The availability of pure strains led to sensitive and specific diagnostic tests; this was a major advance in the field of parasitology.
These milestone advances fully justify the time, effort, and financial expenditures of the Commission on Enteric Disease. The financial support and inspired direction of the Commission was critical to the success that the investigators so fully provided. The mission of fulfilling combat readiness and better health was realized in full measure. These military achievements were of equal benefit to the general public.
REFERENCES
1. Watt, J., Hollister, A. C. Jr., Beck, M. D., and Hemphill, E. C. Diarrheal diseases in Fresno County California. Am. J. Public Health.1953, 43(6, part 1), 728-741.
2. Martin, G. A., Garfinkel, B.T., Brooke, M. M., Weinstein, P. P., and Frye, W. W. Comparative efficacy of amebacides and antibiotics in acute amebic dysentery. J. Am. Med. Assoc. 1953, 151, 1055-1059.
3. Garfinkel, B. T., Martin, G. M., Watt, J., Payne, F.J., Mason, R. P., and Hardy, A. V. Antibiotics in acute bacillary dysentery. J.Am. Med. Assoc. 1953, 151, 1157-1159.
4. Hardy, A. V., Mason, R. P., and Martin, G. A. The dysenteries in the Armed Forces. Am. J. Trop. Med. Hyg. 1952, 1, 393-394.
5. Brooke, M. M., Swarzwelder, C., Payne, F. J., Weinstein, P., and Frye, W. W. Intestinal parasite survey of Korean prisoner-of-war camp. U.S. Armed Forces Med. J. 1956, 7: 798-814.
6. Hoffert, W. R., Bates, M. E., and Cheever, F. S. Study of enteric viruses of simian origin. Am. J. Hyg. 1955,68, 15-30.
7. Armed Forces Commission on Enteric Disease. History of the Commission on Enteric Disease. Med. Serv. Dig. 1956,7(6).
8. Gordon, J. E., Freundt, E. A., Brown, E. W., and Babbott, F. L. Endemic and epidemic diarrheal disease in arctic Greenland. Am. J. Med. Sci. 1961, 242,374-390.
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9. Yee, R. B., and Gezon, H. M. Ribonucleic acid of chloramphenicol-treated Shigella flexneri. J. Gen. Microbiol. 1963, 32,299-306.
10. Dammin, G. J. Report of the Commission on Enteric Infections. Annual Meeting, 4-6 March 1963.
11. Dammin, G. J. Report of a WHO Expert Committee, Enteric Infections. Geneva: WHO, 1964
12. TB MED 119 AFP 160-5-12: Shigellosis (Bacillary Dysentery). Office of the Surgeon General, 1963.
13. Hornick, R. B., Greisman, S. E., Woodward, T. E., DuPont, H. L., Dawkins, A. T., and Synder, M. J. Typhoid fever: pathogenesis and immunologic control. N. Engl. J. Med. 1970, 283,686-691, 739-746.
14. Leitch, G. H., and Burrows, W. Experimental cholera in the rabbit ligated intestine: Ion and water accumulation in the duodenum, ileum and colon. J. Infect. Dis. 1968, 118, 349-359.
15. DuPont, H. L., Hornick, R. B., Dawkins, A. T., Snyder, M.J., and Formal, S. J. The response of man to virulent Shigella flexneri 2a.J. Infect. Dis. 1969, 119, 296-299.
16. Kalser, M. H., Cohen, R., Arteaga, I., Yawn, E., Mayoral, L., Hoffert, W. R., and Frazier, D. Normal viral and bacterial flora of the small and large intestines. N. Engl. J. Med. 1966,274, 500-505, 558-563.
17. Memorandum to the Surgeon General, Department of the Army. Subject: Recommended Length of Boiling Time. 24 May 1968.
18. Kaur, J., K?nig, H. C., Martin, W. R., and Burrows, W. The extractable lipid of the cholera enterotoxin. J. Infect. Dis. 1970,121, 78-80.
19. Burrows, W. Towards an effective prophylactic immunity to cholera. J. Infect. Dis. 1970, 121(suppl.), S58-S61.
20. Woodward, T. The Armed Forces Epidemiological Board-Its First Fifty Years: 1940-1990. Washington, D.C.: U.S. Army Office of The Surgeon General and the Center of Excellence in Military Medical Research and Education, 1990.
21. Burrows, W., Kaur, J., and Cercavski, L. Discussion: The cholera enterotoxin and local immunity. Ann. N.Y. Acad. Sci. 1971, 176,323-329.
22. Rothman, S. W., and Corwin, L. M. Factors affecting virulence of Shigella flexneri: Defective methionine syntheses in an Escherichiacoli shigella hybrid. J. Bacteriol. 1972, 1, 103-106.
23. MacLeod, C. Address to the Armed Forces Epidemiological Board and its military members. 18 February 1971.
ADDITIONAL ARTICLES PUBLISHED BY MEMBERS OF THE COMMISSION
Hallman, F.A., and DeLamater, J. N. Demonstration of amylolytic activity in cultures of Entamoeba histolytica. J. Exp. Parasitol. 1953, 2, 170-173.
Babbott, F. L. Jr., Frye, W. W., and Gordon, J. E. Intestinal parasites of man in Arctic Greenland. Am. J. Trop. Med. Hyg. 1961,10, 185-190.
Dammin, G. J. The pathogenesis of acute diarrhoeal disease in early life. Bull. World Health Organ. 1964, 31, 29-34.
Dammin, G. J. Pathogenesis of acute clinical diarrheal disease. Fed. Proc. 1965, 24, 35-38.
Yee, R. B., and Gezon, H. M. Effect of chloramphenicol on protein and nucleic acid synthesis by Shigella flexneri. J. Gen. Microbiol. 1961, 27, 521-527.
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DIRECTORS` REPORTS, ANNUAL MEETINGS, AND NOTES
First Annual Report: Enteric Disease Commission, Army Epidemiological Board, War Department, Office of the Surgeon General, 1950.
Minutes of meeting of the Commission on Enteric Infections, 6-27 March 1951.Louisiana State University School of Medicine. James Watt, Chairman.
Commission on Enteric Infections. Annual Report to the Armed Forces Epidemiological Board, May 1951-April 1952. James Watt, Chairman.
Commission on Enteric Infections Annual Report to the Armed Forces Epidemiological Board, April 1952-March 1953. Albert V. Hardy, Director.
Frye, William W. Report of the Committee on Ambiasis. Commission on Enteric Infections; 1954.
Annual Report of the Commission on Enteric Infections to the Armed Forces Epidemiological Board, April 1954-February 1955. Albert V. Hardy, Director.
Report of the Director of the Commission on Enteric Infections of the Armed Forces Epidemiological Board, 1956. Albert V. Hardy, Director.
Commission on Enteric Infections: Recommendations to the Armed Forces Epidemiological Board; 1957. Francis S. Cheever, Director.
Notes from the Joint Meeting of the Commissions on Enteric Infections and Environmental Hygiene, 18-20 March 1957. Armed Forces Epidemiological Board;1957.
Applications for Research Contracts to the Commission on Enteric Infections,1958.
Notes from the Annual Meeting of the Commission on Enteric Infections, 2-3March 1959.
Report of the Director, Commission on Enteric Infections, to the Armed Forces Epidemiological Board, 1960. Francis S. Cheever, Director.
Armed Forces Epidemiological Board. Annual Report of the Commission on Enteric Infections of the Armed Forces Epidemiological Board. Armed Forces Epidemiological Board, 1961. Francis S. Cheever, Director.
Report to the Director of the Commission on Enteric Infections of the Armed Forces Epidemiological Board, 1962. Francis S. Cheever, Director.
Director`s Summary. Commission on Enteric Infections, 1963.Francis S. Cheever, Director.
Annual Report of the Commission on Enteric Infections, 1964.Horace M. Gezon, Director.
Annual Report of the Commission on Enteric Infections, 1965.
Director`s Summary Report. Commission on Enteric Infections, 1966. Horace M.Gezon, Director.
Mission Statement and Director`s Report. Commission on Enteric Infections,1967. Horace M. Gezon, Director.
Mission Statement and Annual Reports of Responsible Investigators. Commission on Enteric Infections, 1969. Horace M. Gezon, Director.
Annual Report to the Armed Forces Epidemiological Board from the Director of the Commission on Enteric Infections. Commission on Enteric Infections, 1972.Thomas R. Hendrix, Director.
431
CONTRACTS UNDER THE AUSPICES OF THE COMMISSION ON ENTERICINFECTIONS
Contract No. W-49-007-MD-480 Shigellosis Studies (1951-1956),
Contract No. W-49-007-MD-481 and DA-49-007-MD-22 Salmonellosis Studies(1955-1956). Dr. Albert V. Hardy, Bureau of Laboratories, Florida State Board of Health.
Contract No. W-49-007-MD-112 Enzyme Systems of Entamoeba histolytica (1951-1955).Dr. James N. DeLamater, University of Southern California.
Contract No. DA-49-007-MD-113 & 639 Chemical Composition and Metabolism of Entamoeba histolytica (1951-1956 and 1958-1959). Dr. Quentin M. Geiman, Harvard School of Public Health.
Contract No. DA-49-007-MD-158 Antigen Analysis of Entamoeba histolytica (1951-1952).Dr. Richard J. Porter, University of Michigan, School of Public Health.
Contract No. DA-49-007-MD-202 Study of Immunological Relationships of Entamoeba histolytica (1951-1956). Studies on the Entozoic Amoebae (1954-1956). Dr. Ross S. Benham and Dr. Joseph G. Otero, University of Chicago.
Contract No. W-49-007-MD-480 Epidemiology of Shigella and Salmonella Infection and Their Control (1949). Dr. William W. Frye, Louisiana State University, School of Medicine.
Contract No. DA-49-007-MD-756 Identification of Intestinal Parasites Found in Korean and Chinese Prisoners of War and Their Relationship to Diarrheal Diseases (1951-1952). Studies of the Growth Requirements and MassC ultivation of Entamoeba histolytica (1958-1961). Dr. William W. Frye, Louisiana State University, School of Medicine.
Contract No. W-49-007-MD-481 Evaluation of Various Antibiotics in the Treatment of Salmonellosis in Animals (1950-1952 and 1954-1956). Dr. Morris Shaffer, Tulane University.
Contract No. DA-49-007-MD-547 An Investigation of the Possible Role of Viruses in Enteric Infections with particular Reference to Bacillary Dysentery (1954-1956 and 1958-1961). Dr. Francis S. Cheever, University of Pittsburgh.
Contract No. DA-49-007-MD-498 Studies of Non-Bacterial Gastroenteritis(1954-1956). Dr. Irving Gordon, New York State Department of Health.
Contract No. DA-49-007-MD-603 Pathogenesis of Bacterial Protozoan and Metazoan Infections of the Intestinal Tract in the Experimental Animal (1954-1956 and 1958-1959), Contract No. Da-49-007-MD-2530 Host Tissue Reactions in Experimental and Naturally Acquired Enteric Infections of Man and Laboratory Animals (1959-1961,1966-1967 and 1969-1970). Dr. Gustave J. Dammin, Harvard Medical School.
Contract No. DA-49-007-MD-515 Factors Controlling Encystation of Entamoebahistolytica in vitro (1954-1956,1958-1959). William Balamuth, Ph.D., University of California.
Contact No. AF 18(600)-1251 The Development of New Transportation, Enrichment and Plating Media for the More Rapid Recovery of Enteric Pathogens by Conventional Methods and by Use of the
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Membrane Filter (1955-1956). Samuel R. Damon, Ph.D., Bureau of Laboratories, Indiana State Board of Health.
Contract No. DA-49-007-586 Transmission of Intestinal Pathogens in Polar Climates (1954-1956). Dr. John E. Gordon, Howard University.
Contract No. DA-49-007-MD-202 Immunological Relationships of Entamoebahistolytica (1951-1955) Studies on the Entozoic Amoebae Entamoebahistolytica (1954-1956). Dr. Isabelle Havens, University of Chicago.
Contract No. DA-49-007-MD-965 Protein and Nucleic Acid Synthesis and Energy-Yielding Pathways in Shigella and the Effects of Antibiotics on These Mechanisms (1958-1961). Dr. Horace M. Gezon, University of Pittsburgh.
Contract No. DA-49-007-MD-1003 Investigation of the Possible Link Between Viral Agents and Diarrheal Disease (1958-1961).
Contract No. DA-49-193-MD-2353 An Investigation of the Prophylactic and Therapeutic Use of Lactobacillus acidophilus in Enteric Disease (1962-1964). Dr. Warren R. Hoffert, Florida State Board of Health.
Contract No. DA-49-007-MD-2044 (1959-1961) Studies on the Identification of the Vibrio Group and Related Organisms. Dr. Rudolf Hugh, George Washington University.
Contract No. DA-49-007-MD-891 Effects of Antimetabolites on the Growth of Entamoebahistolytica (1958-1960) Dr. Mitsuru Nakamura, Montana State University.
Contract No. DA-49-193-MD-2254 Systemic Reaction to Heterogeneous Infectious Diarrhea and Evaluation of Therapy (1964). Dr. Martin H. Kalser, University of Miami School of Medicine.
Contract No. DA-49-007-MD-771 Inter cerebral Salmonellatyphosa Infection in Chicks: Passive Protection by Chicken Antisera of Differing Specificities (1964). Dr. Inn Soo Suh, So Do Medical School, Seoul, Korea and Dr. Morris F. Shaffer, Tulane University School of Medicine.
Contract No. DA-49-193-MD-64-G112 The Role of Cellular Interaction in Open Systems in Mechanisms of Resistance or Susceptibility to Disease (1965). Dr. Carlos Ramirez and Dr. J. P. Ransom, New England Institute for Medical Research.
Contract No. DA-49-007-MD-2620 Comparative Biochemistry of Strains of Entamoebahistolytica (1966-1967). Dr. Richard E. Reeves, Louisiana State University.
Contract No. DA-49-193-MD-2492 Antitoxin Immunity to Cholera (1966-1967). Dr. William Burrows, University of Chicago.
Contract No. DA-49-193-MD-2307 Coproantibody in Man: Its Protective Role in Enteric Diseases and Its Induction by Oral Vaccination of Volunteers (1966-1967, 1970). Dr. Rolf Freter, University of Michigan.
Contract No. DA-17-67-C-7057 Study of Shigella Vaccines in Man (1972). Dr. Richard B. Hornick and Dr. Herbert L. DuPont, University of Maryland School of Medicine.
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Contract No. DADA 17-67-C-7061 Infectious Multiple Drug Resistance in the Enterobacteriaceae (1972). Dr. Stanley Falkow, University of Washington.
Contract No. DADA 17-68-C-8146 Factors Affecting Virulence of Shigella flexneri (1972). Dr. Lawrence M. Corwin, Boston University School of Medicine.
Contract No. DADA 17-70-C-0110 The Role of Intestinal Bacteria in Acute Diarrheal Disease (1972). Dr. Sherwood L. Gorbach, The Hektoen Institute of Medical Research, Chicago, Illinois.
Contract No. DA-49-139-MD-2707 Diarrhea from Bacterial Enterotoxins (1972).Dr. George F. Grady, Tufts University School of Medicine.
Contract No. DADA 17-68-C-8162 The Role of the Normal Intestinal Flora in Shigella Infections (1972). Dr. David J. Hentges, University of Missouri School of Medicine.
Contract No. DADA 17-70-C-0113 Pathophysiology of Acute Non-Specific Diarrhea: Uptake of Exotoxins and other Macromolecules and Their Effect on the Intestine (1972). Dr. Kurt J. Isselbacher, et al, Harvard Medical School.
Contract No. DADA 71-C-1042 The Role of Shigella Enterotoxin in Shigellosis(1972). Dr. Gerald T. Keusch, Mount Sinai School of Medicine.
Contract No. DADA 17-70-C-0111 Intestinal Enzyme Adaptation in Health and Disease (1972). Dr. Norton S. Rosenweig, St. Luke`s Hospital Center.
Contract No. DADA 17-69-C-9071 Gut Mucosal Effect of Bacterial Exotoxins(1972). Dr. Craig K. Wallace, The Johns Hopkins University.
Contract No. DADA 17-69-C-9157 Laboratory Studies on Shigella Pathogenesis and Immunity: Final Report (1972). Dr. Robert B. Yee, University of Pittsburgh School of Public Health.
Contract No. DADA 17-72-C-2071 The Etiology of Acute Infectious Non-Bacterial Gastroenteritis (1972). Dr. Neil R. Blacklow, University Hospital, Boston, Massachusetts.
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SECTION 5-APPENDIX
COMMISSION ON ENTERIC INFECTIONS
1949
Director
James Watt, M.D. (1949-1954)
Members
William W. Frye
Albert V. Hardy
Myron E. Wegman
Associates:
NO INFORMATION AVAILABLE
1950
Members
William W. Frye
Albert V. Hardy
Myron E. Wegman
Associates:
NO INFORMATION AVAILABLE
1951-1952
Members
Gustave J. Dammin
William W. Frye
Albert V. Hardy
Myron E. Wegman
Associates:
James N. DeLamater
Quentin M. Geiman
Richard J. Porter
Morris F. Shaffer
1953
Members:
Justin M. Andrews
Francis S. Cheever
Gustave J. Dammin
William W. Frye
Albert V. Hardy
James Watt
Associates:
Ross S. Benham
James N. DeLamater
Quentin M. Geiman
Henry E. Meleney
Richard J. Porter
Morris F. Shaffer
1954
Director:
Albert V Hardy (1954-1956)
Members:
Justin M. Andrews
Francis S. Cheever
Gustave J. Dammin
William W. Ferguson
William W. Frye
Quentin M. Geiman
Morris F. Shaffer
James Watt
Associates:
William B. Balamuth
Theodore Bauer
Ross S. Benham
Marion M. Brooke
Irving Gordon
Henry E. Meleney
Richard J. Porter
1955
Members:
Justin M. Andrews
Francis S. Cheever
Gustave J. Dammin
William W. Ferguson
William W. Frye
Quentin M. Geiman
Morris F. Shaffer
James Watt
435
Associates:
William B. Balamuth
Theodore Bauer
Ross S. Benham
Marion M. Brooke
Irving Gordon
Henry E. Meleney
Richard J. Porter
1956
Director:
Francis S. Cheever (1956-1963)
1956-1958
Members:
Justin M. Andrews
Gustave J. Dammin
William W. Ferguson
William W. Frye
Quentin Geiman
Albert V. Hardy
Morris F. Shaffer
Associates:
William B. Balamuth
Theodore Bauer
Ross S. Benham
Marion M. Brooke
Horace M. Gezon
Irving Gordon
Richard J. Porter
William H. Stewart
James Watt
1959-1961
Members:
Justin M. Andrews
William B. Balamuth
Gustave J. Dammin
William W. Ferguson
William W. Frye
Quentin Geiman
Horace M. Gezon
Albert V. Hardy
Morris F. Shaffer
Associates:
Theodore Bauer
Marion M. Brooke
Harry Eagle
Irving Gordon
Franz J. Ingelfinger
George W. Kidder
Henry E. Meleney
William H. Stewart
Jerome T. Syverton
William Trager
James Watt
1962
Members:
Justin M. Andrews
William B. Balamuth
Gustave J. Dammin
William W. Ferguson
William W. Frye
Quentin M. Geiman
Horace M. Gezon
Associates:
Marion M. Brooke
Harry Eagle
Albert V. Hardy
Franz J. Ingelfinger
George Kidder
1963
Director:
Horace M. Gezon (1963-1970)
Members:
William B. Balamuth
Francis S. Cheever
Gustave J. Dammin
William W. Ferguson
William W. Frye
Quentin M. Geiman
Associates:
Marion M. Brooke
Harry Eagle
Samuel B. Formal
Albert V Hardy
Franz J. Ingelfinger
436
1964
Members:
William B. Balamuth
Francis S. Cheever
Gustave J. Dammin
William W. Ferguson
William W. Frye
Quentin M. Geiman
Associates:
Marion M. Brooke
Harry Eagle
Samuel B. Formal
Rolf Freter
Albert V. Hardy
Franz J. Ingelfiner
1965
Members:
William B. Balamuth
Francis S. Cheever
Gustave J. Dammin
William W. Ferguson
Samuel B. Formal
William W. Frye
Quentin M. Geiman
Albert V. Hardy
Franz J. Ingelfinger
Associates:
Marion M. Brooke
Harry Eagle
Rolf Freter
1966-1967
Members:
William B. Balamuth
Francis S. Cheever
Gustave J. Dammin
William W. Ferguson
Samuel B. Formal
William W. Frye
Quentin M. Geiman
Horace M. Gezon
Albert V. Hardy
Franz J. Ingelfinger
Associates:
Marion M. Brooke
Rolf Freter
Russell W. Schaedler
1968-1969
Members:
William B. Balamuth
Francis S. Cheever
Gustave J. Dammin
Samuel B. Formal
Rolf Freter
William W. Frye
Albert B. Hardy
Thomas R. Hendrix
Franz J. Ingelfinger
Associates:
Marion M. Brooke
Eugene J. Gangarosa
Richard B. Hornick
Russell W. Schaedler
1970
Director:
Thomas R. Hendrix (1970-1973)
Members:
Francis S. Cheever
Gustave J. Dammin
Samuel B. Formal
Rolf Freter
Albert V. Hardy
Franz J. Ingelfinger
Associates:
Marion M. Brooke
Robert M. Donaldson, Jr.
Eugene J. Gangarosa
Richard B. Hornick
Russell W. Schaedler
1971-1973
Members:
Charles C. J. Carpenter
Francis S. Cheever
Gustave J. Dammin
Samuel B. Formal
Rolf Freter
Horace M. Gezon
Albert V. Hardy
Associates:
Marion M. Brooke
Eugene J. Gangarosa
Richard B. Hornick
Russell W. Schaedler
