The experience of the organization and functioning of the laboratory network during the XXII Olympic Winter Games and XI Paralympic Winter Games of 2014 in Sochi is considered. Efforts to establish an effective system of laboratory support, the order of work and interaction of diagnostic laboratories involved in diseases control of population during the Olympic Games are analyzed.

Twenty-six patients with hemorrhagic fever with renal syndrome (HFRS) were revealed as a result of serological examination of 582 patients with fever living around Sochi town. Etiologic role of Dobrava virus subtype as the cause of HFRS was assessed by immunofluorescent and ELISA assays, and neutralization test. The principal host of this virus and source of infection for humans is Caucasian forest mouse Apodemus ponticus. HFRS morbidity was sporadic and not dependent from patients' occupation and season. Comparative analysis of clinical and laboratory data from HFRS cases caused by DOB/Sochi and DOB/Lipetsk subspecies, as well as Puumala virus showed higher proportion of severe forms of disease in patients with HFRS from Sochi.

The polymerase chain reaction (PCR) with and without pre-treatment of the samples of the fleas Citellophilus tesquorum with magnoimmunosorbents was used to detect the plague microbe in the samples containing 142, 168, 193 or more bacterial cells. PCR analysis reduced the time of tests of ectoparasites for plague to 6 hours. The use of a combination of PCR and magnoimmunosorbent simplified the most time-consuming and longest stage of isolation of plague microbial DNA from the suspensions of the fleas, which allows the time of a test to be reduced to 3 hours. The administration of an affine sorbent having magnetic properties during treatment of samples with plague-infected exoparasites for PCR analysis makes it possible to have a specific concentration of Yersinia pestis and to prevent the inhibitory effect of flea tissues on the polymerase chain reaction, to use the boiling method for isolating microbial DNA and for disinfecting the material to be tested.

The results of complete identification revealed the phenotypical similarity of V. cholerae strains isolated from surface water reservoirs im Grozny in 1995 and 2000. The strains under study proved to be atoxigenic, hemolysis-positive and phage resistant. The modified method of subculturing from peptone water 1 to peptone water 2 was more labor-consuming, but it was used in the bacteriological laboratory of the specialized antiepidemic brigade with the aim of more profound study of open reservoirs for the presence of V. cholerae with the positive result.

The typing of F. tularensis strains by four variable number of tandem repeats (VNTR) loci has been carried out. Among the strains isolated in the Stavropol and Krasnodar Territories seven genotypes have been detected and their spread in different natural foci has been analyzed. The data thus obtained suggest that the VNTR analysis may become an important instrument for studying the structure of the natural foci of tularemia and evolutionary relationships between individual areas of these foci.

The results of the epidemiological investigation of the outbreak of typhoid fever in Achkhoi-Martan region are presented. During the period from December 1999 to April 2000 the disease was diagnosed in 43 persons. The cases of the disease were registered in 3 settlements: Lermontov-Yurt, Kulary and Sernovodsk. The pronounced focal character of the disease was noted with the prevalence of family foci with two or more cases of the disease. This conclusion was based on the fact that at the initial stages of the formation of the foci the leading role belonged to the water factor of the transmission of the disease: water from irrigation ditches used by the population for both drinking and household needs. The unusual season when this outbreak took place (the cold time of the year) was due to highly unfavorable sanitary and hygienic conditions formed as the result of the antiterrorist operation.

The data obtained in the analysis of the epidemiological situation in tularemia in the zone of inundation in the Stavropol Territory in 2002 are presented. The current systematic epidemiological surveillance, as well as the data of urgent epizootological and epidemiological survey in the zone of inundation permitted the objective prognostication of the situation in tularemia and formed the basis for the rational planning and realization of prophylactic measures.

Thirty eight B. anthracis strains isolated on the territory of the former USSR from different sources at different periods were studied by the method of the multilocus analysis of 6 chromosomal and 2 plasmid regions of B. anthracis genome with a variable number of tandem repeats. The strains belonged to 18 different genotypes; of these, 14 genotypes were described for the first time. The analysis of the genetic relationship of the strains gave grounds to suggest that on this territory both closely related strains and strains whose genotypes were remote from those peculiar to the greater part of other strains could occur. The strains belonging to subgroup A1a of molecular variability were "endemic" for the European part of the former USSR. A modification of the method of gene typing was proposed, which permitted it to be made without the use of an automatic sequencer; this made it possible to greatly widen the circle of laboratories where this method of research could be used.

The experience of use of efforts and resources by the bacteriological section of the specialized antiepidemic brigade of the Stavropol Research Institute for Plague Control in the Chechen Republic during the period of 1999-2000 under the conditions of the emergency situation, formed as the consequence of carrying out the antiterrorist operation, is summarized. The work load falling of the bacteriological section in different shifts, the structure of bacteriological investigations, as well as some problems arising in the process of work, were analyzed. The experience showed the necessity of the complete accommodation of the bacteriological laboratory in specialized motor-vehicle modules having all necessary equipment for investigation works, disinfection, sterilization. The brigade sent to its mission should be given concrete tasks with a view to ensure the adequate supply of the bacteriological section with diagnostic preparations, materials and equipment.

The observations indicate that anthropogenic activities cause structural changes with time among tularemia pathogen carriers in the microfocus. The epizootic and epidemic values of animal species, such as dwarf hamsters and house mice, decrease while those of insect-eating animals, namely white-toothed shrews that refer to Group II increase, in terms of tularemia infection susceptibility. In white-toothed shrews, tularemia infection rates are 4-6-times greater than those in other small mammals that refer to Group I.

Vibrio cholerae eltor has been shown to exist in two variants: epidemic (V. cholerae eltor Hly-, tox+) and nonepidemic, or endemic (V. cholerae eltor Hly+, tox-); each of these variants determines the corresponding form of manifestation of the infection among the population and requires a differentiated complex of antiepidemic measures, as well as different tactics for the treatment of patients.

The surface water sources of some CIS territories have been screened for cholera toxin genes by the polymerase chain reaction. The vct-genes have been found in the majority of water samples indicating the presence of noncultivated vibrio cholerae cells of an epidemiologic significance. The bacteriological methods failed to isolate the active causative agent of cholera. Additional criteria are proposed for epidemiological typing of territories for cholera. The absence of long deletions or insertions in the vct-genes of noncultivated cholera vibrios has been shown in comparison with analogous gene of the active causative agent of cholera.

The genome polymorphism of the causative agents of sapronoses (Vibrio cholerae, Legionella and Leptospira) has been studied. The use of the method of genome fingerprinting [correction of dactyloscopy] has been shown to permit the differentiation of closely related strains of such causative agents. The epidemically significant strains of the causative agents of sapronoses, isolated in different geographical regions, have been found to be genotypically related, i.e., they are probably of clonal origin. Avirulent and nontoxigenic strains are genotypically heterogeneous and differ both from one another and from epidemically significant strains. Using V. cholerae as an example, the hypothesis of the appearance of potentially dangerous variants at the epidemic period in the absence of their release at the period between epidemics is considered.

Using the labeled DNA fragments containing the genes for cholera toxin the strains of cholera vibrios were studied for the presence of cholera toxin genes. Vibrio cholerae strains isolated from natural water reservoirs under the favourable epidemic situation do not contain the cholera toxin genes. The DNA hybridization method was compared with other methods used in research and practical work for estimation of epidemic importance of cholera vibrios.