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Two of the main features of human cholera-induction of diarrhoea and confinement of the infection to the lumen of the intestinal tract-may be reproduced in three experimental models: (a) the streptomycin-treated, starved guinea-pig; (b) the intestinal loop in the adult rabbit; and (c) the suckling rabbit. In this paper the author compares the two last-mentioned models with his earlier work in guinea-pigs.Intestinal antibody (coproantibody) was highly protective, while circulating antibody had little or no effect, in all three models. The protective coproantibody was specific for the heat-stable vibrio antigens. It did not affect the growth of vibrios in the intestine, and its function may possibly be regarded as antitoxic rather than antibacterial. Oral vaccination protected adult rabbits against challenge by the loop technique. Heat-killed vaccine was as effective in this respect as live vaccine.The author feels that the present uncertainty concerning the protective value of cholera vaccination may be due to the fact that conventional vaccine is designed to induce high serum titres only. He considers that since oral vaccine has been shown to induce and maintain the production of coproantibody in human volunteers, a field trial should be carried out to determine whether coproantibody is as protective in man as it has proved to be in the experimental models.

The treatment of cholera with bacteriophage has, in the past, been unsuccessful, owing to the fact that the phages prepared by the usual method (multiplication on cholera vibrios in broth) proved incapable of parasitizing cholera vibrios in vivo. In this paper, the author presents the results of therapeutic and prophylactic trials of a phage preparation prepared by a different method-namely, cultivation on cholera vibrios through alternate passages in the small intestine of guinea-pigs and in bile. This preparation was used effectively for the treatment of cholera patients and for the control of epidemic outbreaks in Afghanistan in 1958 and 1960. A single dose of the phage, administered with saline intravenously or intramuscularly, followed by an oral dose daily for three days, gave satisfactory results in the majority of cases, even if the patients were seriously ill and did not receive additional symptomatic treatment. As to the prophylactic value of the phage, when the preparation was administered simultaneously with a single dose of cholera vaccine to the entire population of an epidemic focus, no further cases of the disease occurred in that focus.

The identity of the El Tor vibrio is a controversial question that the usual methods of bacteriological investigation have as yet failed to settle. In this paper, the author presents the results of a study of the interrelationships between El Tor vibrios, true cholera vibrios and water vibrios, as revealed by the behaviour of the vibrios in the bile system and in the small intestine of experimental animals.The vibrios investigated included two strains isolated at the El Tor quarantine station on the Sinai Peninsula in 1934, two strains isolated at Makassar, Celebes, during a cholera epidemic in 1937 and identified as "El Tor" vibrios, four strains of true cholera vibrios and five strains of water vibrios. On the whole, the behaviour of the El Tor and Makassar vibrios was similar, closely resembling that of the cholera vibrios and differing markedly from that of the water vibrios. The author therefore considers that the strains of El Tor and Makassar vibrios examined are varieties of Vibrio cholerae and suggests that carriers of such strains should be subjected to the same measures as carriers of true cholera vibrios.

After freedom from cholera for over a quarter of a century, the Philippines in 1961 experienced an epidemic of cholera. The disease, shown to be caused by the El Tor strain of cholera vibrio, was clinically indistinguishable from classical Asian cholera. Studies were undertaken in Negros Occidental Province from August to October 1962 to characterize various aspects of the epidemics in this province. This paper describes the general characteristics of the epidemics in Negros Occidental from November 1961 through September 1962.Two types of epidemic occurred. The first, explosive in nature, suggested a common source of spread of infection; the second, with a more protracted course, seemed to be due to person-to-person spread of disease. In the second epidemic, a single hospitalized case in a household and a single hospitalized case in a community were the most common findings, suggesting that infection did not spread easily or, if easily spread, caused significant disease on rare occasions only.

Since 1961 cholera El Tor has been sweeping through the Far East, and this dissemination of the disease has stimulated research not only in the countries afflicted but also in Europe and the Americas. New laboratories and workers have entered the field and many fresh ideas and concepts have emerged. The time seemed ripe, therefore, to survey the most important papers published since 1959, when the literature on cholera was thoroughly reviewed by Pollitzer, for the benefit both of those engaged in research and of those concerned with public health practice.This review covers history and incidence, causative agents (including the "classical", "El Tor" and "incomplete" forms), pathophysiology, diagnosis, treatment, mode of spreading and control measures (with particular reference to public health education and the International Sanitary Regulations). An annex, intended for laboratory use, contains selected procedures for the isolation and identification of cholera vibrios.

This paper is a report on an attempt to study seasonal variations in endemic cholera in West Bengal by statistical analysis of monthly mortality records over a 21-year period. The annual death-rates have been calculated for each month in each district and the average of the seven lowest rates in each district is plotted diagrammatically to show the seasonal endemicity.BY THIS MEANS THREE GROUPS OF DISTRICTS ARE DISTINGUISHED: one of high, one of variable, and one of low or no endemicity. The statistical analysis suggests that cholera experience in West Bengal is not, as is sometimes contended, dependent on the intensity of infection in Calcutta.It is felt that the method described might to advantage be applied to other areas where cholera is endemic and would be helpful in selecting the most suitable times for carrying out control measures.

During the summer of 1962, cholera broke out in Taiwan after an absence of 16 years. This paper gives a full description of the prompt and energetic measures that were instituted to control the outbreak; these included the designation of emergency areas, the immediate detection and isolation of patients and probable carriers, and mass vaccination.In all, over 160 000 rectal swabs and stool specimens were examined for cholera organisms. The author's egg-starch medium, described in detail, proved very satisfactory for this purpose. During the main epidemic (July-September) 383 confirmed cases of cholera and 380 carriers were identified. While the over-all carrier: case ratio was thus approximately 1:1 the ratios in different age-groups varied considerably, being as high as 4:1 in children aged 0-4 years and as low as 0.3:1 in persons aged 55-59 years. The author suggests possible reasons for the older persons' tendency to develop clinical disease rather than become carriers.There were only 24 deaths in the outbreak (a fatality rate of 6%). The efficacy of vaccination was difficult to determine precisely, but in general more deaths and more cases occurred among the non-vaccinated than among the vaccinated.

A pandemic of El-Tor-type cholera began in south-east Asia during 1961. Many members of the medical profession, as well as government officials and the public, were confused by the relationship between the disease caused by the El Tor organism and classic Asiatic cholera. The authors observed large numbers of cholera patients admitted to San Lazaro Hospital, Manila, early in the Philippine epidemic, and in the present communication they draw attention to certain clinical and epidemiological features of so-called El Tor cholera. The paper not only describes the patients and the epidemic, but also suggests some of the treatment needs during such an epidemic. No indication was found that the disease caused by the classic cholera vibrio is different from that which is designated the El Tor variant.