[The problem of natural foci of plague: the search for ways for its resolution]. / Problems prirodnoi ochagovosti chumy: poisk putei ee resheniia.

The paper deals with one of the most important problems of plague natural foci, namely the places and types of its bacillus persistence outside the parasitic system, as well as in the interepizootic period. It also discusses different hypotheses forwarded on the basis of field observations and experimental findings. In particular, it gives the materials suggesting that the plague bacillus can persist in the low-virulent form under natural conditions, as well as due to its transition to a L-form. The paper provides strong evidence for the long-term persistence of the plague bacillus in soil and hole substrates and discloses the adaptive mechanisms ensuring such persistence. Particular emphasis is placed on the complex symbiosis of the plague bacillus with soil microorganisms, including protozoa, and on their persistence in cysts of the latters. Tasks and a trend in further studies required to finally solve the problem are stated in the paper.

[The characteristic properties of Vibrio cholerae eltor isolated from environmental objects on the territory of the former USSR during the 7th cholera pandemic]. / Kharakteristika nekotorykh svoistv Vibrio cholerae eltor, vydelennykh iz ob''ektov okruzhaiushchei sredy na territorii byvshego SSSR vo vremia sed'moi pandemii kholery.

The properties of 22,382 V. eltor strains isolated from environmental objects on the territory of different climatic and geographical zones during the period of 1970-1988 were studied. The study was made on the morphology of their colonies, the agglutinability of the strains by cholera O serum, type-specific serum and RO serum, their capacity for being lyzed by V. eltor bacteriophage, their hemolytic activity and virulence. Differences in the occurrence of strains with any of the above-mentioned properties, depending on the object from which they were isolate, the climatic and geographical zone and the intensity of the epidemiological situation with regard to cholera.

[The ecological and geographical aspects of the spread of Vibrio cholerae in environmental objects]. / Ekologo-geograficheskie aspekty rasprostraneniia Vibrio cholerae v ob''ektakh okruzhaiushchei sredy.

The results of studies carried out over the period of 24 years have revealed that V. eltor is widely spread in different ecological systems over a considerable part of the territory of the former USSR in the temperate and subtropical climatic zones. The duration and seasonal character of the isolation of these bacteria depend on climatic and geographical conditions, and their isolation rate greatly depends on the epidemic situation. The intensity and seasonal character of the isolation of V. eltor have been shown to depend on the character of the ecological system. For some water reservoirs definite biotic and abiotic factors capable of influencing the isolation rate of V. eltor have been determined, but no general regularities involving the above-mentioned factors and constantly ensuring such influence have been established.

[The types of the epidemic manifestations of cholera on the territory of the USSR]. / Tipy épidemicheskikh proiavlenii kholery na territorii SSSR.

On the basis of the analysis of cholera cases for the period of 1965-1989 three main main types of epidemic manifestations of this infection on the territory of the USSR were determined with due attention to the complex of data, characterizing the intensity and types of the epidemic process, the danger of the outbreak and spread of cholera. This made it possible to differentiate and decrease the complex of prophylactic measures, depending on the type of the territory.

[The 7th cholera pandemic in the world and the USSR]. / Sed'maia pandemiia kholery v mire i SSSR.

1,713,057 cases of cholera were registered in the world during the seventh pandemic of the disease at the period of 1961-1989. The pandemic still continues, being the most prolonged pandemic in comparison with earlier ones. During the period of the seventh pandemic 10,723 cases of cholera were registered in the USSR. Great outbreaks occurred in 1965 and 1970-1974. At present sporadic cases of cholera can be registered, and wide circulation of mainly avirulent, nontoxigenic strains of cholera vibrios in environmental objects is characteristic of the epidemic situation.

[The practical performance of cholera control measures in the USSR during the 7th pandemic]. / Praktika provedeniia protivokholernykh meropriiatii v SSSR v period 7-i pandemii.

The critical analysis of anticholera measures carried out in the USSR since 1965 till the present time is presented. The grounds for the abolition or considerable reduction of a number of measures are considered from the viewpoint of their scientific substantiation, the adequacy of means and efforts spent for their realization and their antiepidemic effectiveness. Special attention is paid to the necessity of differentiated approach to these measures, depending on concrete local climatic and geographical, sanitary, hygienic and other factors which determine the epidemic potential of a given administrative territory.

[Quantitative parameters of the length of time of Vibrio eltor survival on household objects]. / Kolichestvennye parametry dlitel'nosti vyzhivaniia Vibrio eltor na nekotorykh predmetakh obikhoda.

On household articles contaminated with protein-containing excrements (as in the stool of cholera patients) V. eltor survive 4.6 times longer than on those contaminated with excrements without protein (as in the stool of vibriocarriers ). This is due to a lesser initial dose of vibrios and the absence of protein in the excrements of vibriocarriers . These differences in the survival time of V. eltor on household articles suggest that objects contaminated with the excrements of cholera patients are epidemiologically more dangerous than those contaminated with the excrements of vibriocarriers . The quantitative determination of the survival time of vibrios on household articles indicates that, probably, these articles merely play the role of intermediate factors in the transfer of V. eltor in the foci of cholera.

[NAG-vibrio serovar 2 causing a generalized infection]. / NAG-vibrion serovara 2, vyzvavshii generalizovannuiu infektsiiu.

A case of septicemia caused by NAG-vibrio, serovar 2, is described. In contrast to other vibrios, the strain under study was immobile at the moment of isolation and, when introduced enterally into suckling rabbits, showed the capacity of causing generalized infection.

[Serovars of NAG vibrios isolated from the water of open reservoirs]. / Serovary NAG-vibrionov, vydelennykh iz vody otkrytykh vodoemov.

Composition of serological types of NAG-vibrios isolated from the river water contaminated by effluents was found to be more varied than in uncontaminated water body. Vibrios of serological types 6, 8, 39, 41, 50, 53, 55 revealed frequently and in great amounts apparently inhabit the mentioned water bodies for prolonged periods.

[Effect of sulfide water from natural springs on the properties of Vibrino cholerae]. / Vliianie sul'fidnoi vody estestvennykh istochnikov na svoistva kholernykh embrionov.

The authors studied the properties of E1 Tor cholera vibrios isolated from sulfide water of the natural sources. There was demonstrated under experimental and natural conditions the influence of ecological conditions of sulfide water on such vibrio properties as cholerogenicity, sensitivity to diagnostic and typing phages, hemolytic activity and the value of the hemolysin-destructive factor. A short-liver stay of cholera vibrios in sulfide water was accompanied by some reduction of their virulence.

[Seasonal dynamics of the abundance of vibrios and related microorganisms in the Don River]. / Sezonnaia dinamika chislennosti vibrionov i rodstvennykh mikroorganizmov v reke Don.

The density of bacteria of the Vibrio, Aeromonas and Comamonas genera the Don river was subject to seasonal variations. The maximal vibrio concentration was recorded at the water temperature of 22 degrees C, and of Aeromonas and Comamonas--at lower temperature. Unlike Aeromonas, vibrios displayed a reverse dependence of the density on the extent of water contamination.

[Clinical cases of food poisoning caused by NAG-vibrios]. / Sluchai pishchevykh toksikoinfektsii, byzbannykh NAG-vibrionami

On the basis of bacteriological and serological studies carried out during two outbreaks of food poisoning it was found that the disease was caused by NAG-vibrios of the I Heiberg group, serotypes 5 and 34 after Sakazaki. The disease was accompanied by isolation of NAG-vibrios from feces and the washings from the stomach, it was characterized by symptoms of acute gastroenteritis and enteritis of mild and moderate severity. The incubation period lasted from 3 to 30 hours. There was an increase in the agglutinin titres to homologous strains of NAG-vibrios. Of the 6 strains tested 4 proved to be enteropathogenic in intraintestinal infection of rabbits in doses of 10(5) microbial cells.