[Novel diagnostic kit on the basis of stained polymeric carriers for epidemiologic surveillance in natural foci of Crimean-Congo hemorrhagic fever].

AIM: To study diagnostic value of developed antigenic polymeric diagnostic kit for epidemiologic surveillance in natural foci of Crimean-Congo hemorrhagic fever (CCHF) in South federal district. MATERIALS AND METHODS: Novel antigenic diagnostic kit on the basis of polymeric microspheres for reaction of volume agglomeration was developed. The kit is designed for detection of virus-specific antibodies in human serum and in serum of agricultural animals. RESULTS: Laboratory and field trials of the kit showed its high diagnostic potency, it was included in methodical recommendations "Organization and accomplishment of measures against Crimean-Congo hemorrhagic fever on the territory of its natural foci in Russia". Use of antigenic polymeric kit for epidemiological surveillance allows for more complete and systemic understanding of CCHF epidemic process. CONCLUSION: At present, the diagnostic kit is successfully used, alongside with ELISA and PCR, on different levels of epidemiologic surveillance for CCHF in Rostov region.

[Genotypic heterogeneity and geographic diversity of collection strains of Francisella tularensis as determined using the VNTR variability analysis and DNA sequencing].

The analysis of the identification genotypes allowed the strains to be grouped into 61 variants from A to I with the incidence rate 0.002-0.142. The cluster analysis of the identification genotypes allowed the strains to be grouped into 9 clusters with different number of components. Actual existence of genotypic heterogeneity and geographic diversity of the F. tularensis strains was demonstrated in addition to territorial attribution of certain strains. The geoinformation system Tularemia was developed to provide spatioterritorial analysis of distribution of the genotypes of the strains. A specific feature of the geoinformation system is dynamic mode of its operation, which provides the ability of continuous addition of information not only by the expense of available data but also by the expense of creation of new layers. Any new information is automatically added to the geoinformation system, thereby providing both retrospective and operative analysis. The geoinformation system Tularemia should find promising application to the structure of the epidemiological method. The use of the system will bring the epidemiological control of tularemia to a qualitatively higher level.

[Vntr-genotyping of Francisella tularensis strains isolated in the former USSR territory and some European countries during epizootics in 1988 - 1989].

Retrospective VNTR-analysis of 159 Francisella tularensis subsp. holarctica strains isolated in December 1988 - February 1989 in former USSR and some European countries was carried out. Analysis of heterogenic genotypes of strains allow to subdivide them into 30 groups of variants by individual genotypes, while cluster analysis--to subdivide them in 7 clusters with different number of compositions. The predominance of genotype C1 strains isolated on the Rostov and Archangelsk regions and the Crimea was established. F. tularensis strains isolated in winter time 1988 - 1989 in different geographic regions were supposed to be resident cultures typical for their biotope in natural focus of disease.

[Genotyping of the Francisella tularensis strains isolated from natural foci of tularemia in the Rostov region by multilocus VNTR analysis]. / Genotipirovanie metodom mul'tilokusnogo VNTR-analiza shtammov Francisella tularensis, vydelennykh iz prirodnykh ochagov tuliaremii Rostovskoi oblasti.

On the basis of an analysis of the VNTR alleles' distribution in 109 strains of F. tularensis it was established that 19 genotypes of the disease causative agent circulated in the Rostov Region from 1945 to 2002. The microbe-provoked infection episodes can be divided into polyclonal, monoclonal and cluster ones. A retrospective analysis of the genotypes' distribution is indicative of that strains of similar or of closely-related genotypes circulate simultaneously in the studied territory. All investigated F. tularensis strains could be differentiated into two groups; strains, whose genotypes are encountered almost evenly within the entire Region's territory, belong to group 1; and strains of group 2 displayed a trend towards being geographically bound. Isolations of cultures with similar (close) genotypic features made in prolonged time periods suggest that a part of F. tularensis clones can persist for a long time in environmental foci. A set of strains described by genotype can provide a foundation for a database of the tularemic microbe culture within the geo-information system of the South Federative Okrug of Russia.

[Crimean hemorrhagic fever in the Rostov region: epidemiological zoning and the activity of natural foci]. / Krymskaia gemorragicheskaia likhoradka v Rostovskoi oblasti: épidemiologicheskoe raionirovanie i aktivnost' prirodnogo ochaga.

The epidemiological zoning of the territory of the Rostov region has been made with the use of the epidemic process patterns and the data indicating the links between the landscape and the natural focus of infection. The spread of infected ticks has been established. The participation of several carrier species in the circulation of Crimean-Congo haemorrhagic fever virus has been confirmed. The mosaic character of their distribution and different levels of their contamination is of great prognostic importance. These data will be used for the improvement of epidemiological surveillance in working out the tactics of epizootological surveys and organization of prophylactic measures.

[Noncultivatable forms of Francisella tularensis]. / Nekul'tiviruemye formy Francisella tularensis.

Conditions for the appearance of F. tularensis uncultivated forms and for their reversion into the initial state have been studied. As revealed in this study, the combined influence of stress factors (starvation and low temperature) may result in the transition of F. tularensis into the uncultivated state in which it persists in the environment during the period between epidemics. The reversion of F. tularensis uncultivated forms into the initial state has been carried out with the use of sensitive animals. The uncultivated state of F. tularensis should be regarded as the actual form of the existence of the causative agent of tularemia in soil and water ecosystems.

[Crimean-Congo hemorrhagic fever in Rostov Province: the epidemiological characteristics of an outbreak]. / Krymskaia-Kongo gemorragicheskaia likhoradka v Rostovskoi oblasti: épidemiologicheskie osobennosti vspyshki.

The results of the epidemiological analysis of the outbreak of hemorrhagic fever which was caused by Crimean-Congo hemorrhagic fever virus and occurred during the period of July 3-19, 1999, in the Oblivskaya district of Rostov Province are presented. The specific epidemiological features of the outbreak have been determined. The possible versions of the appearance of the focus of infection and the role of Ixodes ticks in the circulation of the infective agent are discussed.