Effect of a live enteral dysentery vaccine from spontaneous Flexner mutant 2a 516m on the immunoglobulin-producing cell count in the large intestine mucosa in dysentery

The influence of vaccinal therapy with live oral dysentery vaccine prepared from S. flexneri 2a 516M on the content of immunoglobulin-producing cells in the mucous membrane of the large intestine was studied. A considerable increase in the number of IgA- and IgM-synthetizing cells was shown to occur in the course of the infectious process in acute dysentery. In chronic dysentery the content of IgA- and IgM-synthetizing cells in patients was considerably lower than in a smooth course of acute dysentery. The use of the vaccine for the therapy of patients with chronic and especially acute dysentery resulted in a considerable rise in the number of plasma cells synthetizing IgA, IgM and IgG.     

Isolation and characteristics of Shigella antigens during the course of dysentery

In 2,436 fecal samples and 1,272 urinary samples taken from 633 patients with dysentery caused by S. flexneri, S. newcastle and S. sonnei, Shigella antigens were detected by means of the passive hemagglutination test with antibody diagnostic agents and the antibody neutralization test. The antigen-binding activity of shigellae in urine dynamically increased in the course of dysentery. The comparison of the parallel results of both serological tests made it possible to evaluate the dispersion of the released antigen: it dynamically increased in the course of the disease, this increase being particularly high in feces. The dispersion of Shigella antigens in urine was greater than in feces over the entire course of the disease. These regularities in the release of the antigens and especially the specific features of the serological tests determined the scheme of the serological diagnosis of dysentery by the indication of Shigella antigens.     

Patterns determining the dynamics of the epidemic process in Sonne dysentery and its relation to the type of causative agent]

The results of studying the dynamics of the epidemic process of dysentery, based on the data from 3 districts of Moscow, are presented. The study revealed the periodicity of 3 years in the course of the epidemic process of dysentery, occurring against the background of a considerable predominance of Sh. sonnei, biochemical type 2. The use of the cohort method for analyzing the age structure of dysentery cases showed the possibility of using this method to find out to what extent the epidemic process repeatedly affected the same groups of population.     

Epidemiology of dysentery in Dagestan]

Analysis of material on bacterial dysentery and other acute intestinal infections morbidity in the Dagestan ASSR for a period of 15 years showed high morbidity level and its variations, with reduction and elevation in individual years, and the leading role played by Shigella flexneri among the causative agents of dysentery. The greatest incidence of dysentery was revealed among children aged under one year and between 1 and 2 years. A high bacterial dysentery incidence was recorded in Dagestan throughout the whole year. However analysis of the seasonal dysentery curve showed the beginning of elevation in July, reaching the maximum in August, and lasting four months with a decline beginning in October. The persisting activity of the water route of dysentery transmission in the Dagestan ASSR requires particular attention to the organization of good-quality water-supply to the population of the republic.     

Epidemiology of bacillary dysentery in Algeria. II. The seasonality of dysentery

Morbidity rises during the period of summer and autumn are characteristic of bacterial dysentery in Algeria. During the last 18 years no essential changes in the seasonal character of bacterial dysentery were observed in the country taken as a whole. However, in different climatic and geographical zones of the country the seasonal character of dysentery greatly varies from one zone to another and essentially differs from the seasonal character of dysentery morbidity, typical of the country as a whole for many years. The most pronounced manifestations of seasonal rises are observed in the Sahara zone. The seasonal character of dysentery is formed mainly by morbidity among patients belonging to 3 age groups. The seasonal rises of dysentery can be probably explained by the complex of social and climatic factors, as well as by the biological features of the causative agents of this disease.     

An analysis of the dysentery epidemic process in Blagoveshchensk

The retrospective analysis of dysentery morbidity in Blagoveshchensk for the period of 1960-1987 was made. The regularities linking general natural and biological factors triggering the epidemic process with dysentery morbidity among the population are emphasized. The study revealed that under the conditions of Blagoveshchensk dairy products were of major epidemic importance among factors contributing to the transmission of dysentery. Such a factor as flies also had a definite influence on the epidemic process of dysentery. Another risk factor was drinking water which influenced the epidemic process both directly and indirectly through dairy products and, probably, other foodstuffs. Reliable correlation between dysentery morbidity among the population and the quality of dairy products, tap water and the number of flies was established.     

Dynamics of bacterial polysensitization in acute dysentery in children depending on the species of the causative agent

Studies on polysensitization, evaluated by the neutrophil damage index, have been made with the use of dysenterin and the allergens of hemolytic staphylococci, enterococci and Escherichia coli. The studies have revealed that both specific and nonspecific sensitization to hemolytic staphylococci and enterococci is higher in dysentery caused by Shigella flexneri than in dysentery caused by S. sonnei and has the tendency to increase in the course of the disease.     

Analysis of the seasonality of acute intestinal diseases with regard to the detection of dysentery by antigen indication

Coincidence in the seasonal changes of the registered morbidity in dysentery and in other acute intestinal diseases is observed. The occurrence of Shigella antigens, detected with the use of erythrocyte diagnostic reagents, in the excreta of patients with the clinical diagnosis of dysentery and patients with other acute intestinal disease has a seasonal character, its peak coinciding with the period of increased morbidity in bacteriologically confirmed dysentery. The correction of monthly morbidity levels in dysentery and in other acute intestinal diseases with due regard for the proportion of Shigella antigens in the findings, made in the groups of patients with the clinical diagnosis of dysentery and with the diagnosis of other acute intestinal diseases for the corresponding month, has revealed that the actual morbidity in other acute intestinal diseases has a less pronounced seasonal character in comparison with the registered morbidity. This fact substantiates the statement that in the group of patients with other acute intestinal diseases a large proportion of such diseases is, actually, of a noninfectious nature.     

Population migrations and the epidemic process of Flexner and Sonne dysentery

Analysis of the materials from the Khabarovsk Territory for the representative period of 25 years (1956-1980) revealed the influence of the migration of the population on the level and dynamics of morbidity in different kinds of dysentery, Flexner's dysentery shown to occur more frequently than Sonne dysentery. Intensive migrations increase the proportion of susceptible persons among the population, thus facilitating the formation and circulation of Shigella strains with pronounced virulence.     

The mechanism of the development of the epidemic process in Sonne dysentery

An epidemic outbreak of Sonne dysentery has been studied. The data of epidemiological monitoring before and after the epidemic have been analyzed. The real prognostication value of controlling the biological properties of Shigella sonnei and the increase of their intrapopulation heterogeneity at the period of the activation of the epidemic process of Sonne dysentery has been established.     

Indicators of spontaneous and stimulated nitroblue tetrazole test of polymorphous-nuclear leucocytes in acute dysentery patients

140 healthy individuals and 93 sick with acute dysentery were subjected to an examination by spontaneous and by bacterial preparations stimulated reaction with nitroblue tetrazole (NBT test). Indicators in healthy persons were normal in the spontaneous, and increased in the NBT test, stimulated by bacterial preparations. Indicators of the spontaneous NBT test in patients with acute dysentery were raised with a maximum in the period of early convalescence. Stimulation by a live shigella culture--the dysentery vaccine--revealed by means of Sonne diagnostic high, and when endotoxin from Serratia marcescens and dysenterin was used as an inductor, mild indicators of NBT test activity. When a polyvalent agglutinating dysentery serum was used as a stimulator, the activity increased considerably, and a simultaneous use of serum and vaccine had an inhibiting effect on the indicators of the stimulated NBT test. The obtained results testify the sufficient high reserve possibilities of leucocytes towards complete phagocytosis and the efficiency of the NBT test, stimulated by bacterial preparations for the study of functional and metabolic activity of leucocytes in the process of acute bacterial dysentery.     

The excretion of Shigella antigens in persons recovering from dysentery]

Shigella antigens can be detected in the excreta of convalescents after dysentery for a long time. Most frequently these antigens occur in feces, less frequently in urine and rarely in saliva. According to indirect data, S. flexneri 1-6 antigens can be detected in excreta for a longer period after convalescence than S. sonnei antigens. When antigen indication is used for the diagnosis of dysentery and epidemiological analysis is carried out, one should bear in mind the length of the agent persistence in the body, related to Shigella type.     

Field trials with an oral cell-free vaccine made from Shigella flexneri

The data on the study of the reactogenicity, safety and prophylactic potency of a new acellular vaccine prepared from S. flexneri 2a antigenic complexes are presented. According to the results of two epidemic experiments, the vaccine, introduced by oral administration, showed low reactogenicity, safety and sufficient prophylactic potency. The vaccine decreased morbidity rate in dysentery caused by S. flexneri 2a and ensured the protection of 74% (72-80%) of the vaccinees. The complete course of immunization consisting of three administrations followed by the booster administration induces the formation of specific immunity whose duration is sufficient for ensuring the protection of immunized persons during the epidemiologically unfavorable period (for at least 3 months).     

Ways of determination of the intensity of the epidemic process in Shigella sonnei dysentery]

Proper view on the true prevalence of Sonne dysentery characterised by polymorphous clinical picture in which many cases coursed in subclinical form could be reached only by using additional active methods for detecting the infection rate of the population. For this purpose the authors applied passive hemagglutination test which permitted to reveal the response of the organism to the antigenic stimulation in the course of two months after the sustained sickness. Over 12 000 persons were examined. According to the results of passive hemagglutination test seasonal activization of the epidemic process occurred one month earlier than it was revealed by recording of the incidence of the disease. The results of the mentioned test also showed infection rate of the population with Sonne dysentery to be as a rule greater than established by the official statistics.     

A comparison of the dynamics of changes in large intestinal mucosa of acute dysentery patients with detection of a specific antigen in urine

The relationship between the elimination of shigellae from the body with urine and the dynamics of morphological changes in the mucous membrane of the large intestine of acute dysentery patients at the early convalescence period has been studied. The persistence of Shigella antigen in acute dysentery patients and its elimination with urine is, as a rule, accompanied by local immune cell reaction in the mucous membrane of the large intestine. The antigen circulating in the body is a factor contributing to the inflammatory process in the intestine, the amount of the eliminated antigen being higher in pronounced inflammations of the intestinal mucosa than in residual inflammatory phenomena. A group of patients (3 persons) releasing Shigella O-antigen with urine and having the inflammatory process in the large intestine, but showing no signs of local immune reaction in the lymphoid tissue of the large intestine, has been found. The reactivity of the lymphoid tissue of the intestine in such patients is a risk factor contributing to the development of prolonged dysentery or chronic postdysenteric colitis.     

The cause of the activation of an epidemic process of intestinal infections in the 70s]

In the seventies a considerable rise in dysentery morbidity was observed in all republics of the USSR, in the whole of the USSR, in Bulgaria and in the German Democratic Republic. An increase in cholera morbidity in the world, as well as in the number of countries affected by this infection, was registered. A tendency towards a rise in virus hepatitis incidence was observed in the USSR. The dynamic study of the ozone content in the stratosphere, solar activity, disturbances in the magnetic field of the Earth, air temperature for the period of 1967-1980 was carried out. Strong and moderate correlation between dysentery and air temperature in summer was established. The maximum morbidity level in the USSR in 1972 was probably the consequence of unusually high air temperature in summer.     

Nature of the epidemic process in Sonne and Flexner dysenteries and the causes of its induction

A comparative study of the epidemic process in Sh. sonnei and Sh. flexneri dysentery in different regions of the USSR revealed that the morbidity level of Sh. sonnei dysentery changed simultaneously in the regions under study at intervals of 2-3 years. Sh. flexneri dysentery showed morbidity rises occurring at intervals 6-8 years, and their occurrence did not coincide with the periods of elevated morbidity in Sh. sonnei dysentery. The data obtained in the cohort analysis and in the study of recurrent morbidity suggest that Sh. flexneri dysentery produces more pronounced postinfection immunity than Sh. sonnei dysentery, and the immunological factor probably affects the dynamics of the epidemic of these Shigella infections.     

Etiologic structure of bacterial dysentery in the USSR in 1983-1985

The etiological structure of dysentery in the USSR in 1983-1985 is characterized. Sonne dysentery was found to prevail in the territories with adequate water supply, while dysentery caused by Shigella flexneri prevailed at the territories with unsatisfactory water supply. S. dysenteriae and S. boydii were found to play a limited role in the etiology of dysentery. In the presence of global pandemic, an increase in the isolation rate of S. dysenteriae I in the USSR is observed. The data on the biochemical structure of S. sonnei are presented.     

Detection of Shigella antigens in the feces of patients with acute intestinal diseases using a coagglutination reaction

A total of 113 patients with acute intestinal diseases have been examined with the use of the coagglutination test. 84.95% of the patients showed the presence of different Shigella antigens. In patients with bacteriologically confirmed dysentery the corresponding Shigella antigens were detected in 96.97% of cases in S. sonnei dysentery, in 90% of cases in S. flexneri dysentery, in 75% of cases in S. newcastle dysentery and in 100% of bases in S. boydii dysentery. In 81.6% of patients with acute intestinal diseases of unknown etiology the coagglutination test revealed the presence of various Shigella antigens.     

Seeding efficiency of the causative agent of dysentery as an index of the intensity of the epidemiologic process]

A study was made of the character and extent of interrelationship between the indices of dysentery morbidity and the indices of the seeding efficiency of dysentery bacilli persons who did not apply for medical aid. Establishment of such interrelationship permitted the authors to suggest the use of a more objective index of the seeding efficiency of dysentery bacilli, along with morbidity indices, for the assessment of the intensity of the epidemic process in this infection. On the basis of investigations carried out the authors came to the conclusion that a tendency to the increase of dysentery incidence the last few years chiefly bore a "statistical" character and was due to the improved detection of patients and carriers.