[Circulation of West Nile virus (Flaviviridae, Flavivirus) and some other arboviruses in the ecosystems of Volga delta, Volga-Akhtuba flood-lands and adjoining arid regions (2000-2002)]. / Osobennosti tsirkuliatsii virusa Zapadnogo Nila (Flaviviridae, Flavivirus) i nekotorykh drugikh arbovirusov v ékosistemakh del'ty Volgi, Volgo-Akhtubinskoi poimy i sopredel'nykh aridnykh landshaftakh (2000-2002 gg.).

Comprehensive virological, serological as well as genetic studies of the ecology of West Nile Virus (WNV) as well as of some other arboviruses were undertaken in different ecosystems in the territories of the Astrakhan Region and of the Kalmyk Republic. The main carriers (mosquitoes, ticks, birds and mammals) were defined as involved in the circulation of viruses within the natural and anthropogenic biocenosis. Phylogenetic examinations of isolated strains and samples, which were positive in RT-PCR, showed an absolute predominance of genotype I virus that was most closely related to American and Israeli strains. At the same time, epidemic strains had up to 6% of nucleotide differences versus the historic strains isolated in the same region 20-30 years ago. Besides, the circulation of genotype IV was discovered; it was characterized by a lower pathogenicity, which, possibly, ensures the shaping of a pronounced immune interlayer bearing no epidemic consequences. An analysis of the study results on the WNV ecology denotes the epicenter of the endemic territory located in the middle part of the Volga delta.

West Nile virus and other zoonotic viruses in Russia: examples of emerging-reemerging situations.

Studies of the interactions of vertebrates, viruses and arthropod vectors of these viruses were monitored in terms of different ecological groups of viruses transmitted by mosquitoes and ticks in Northern Eurasia in an area encompassing more than 15 million km2. About 90 viruses were isolated, including 24 new to science. Newly recognized infections of vertebrates, including humans, were described. Many unusual epidemic situations were analysed. Permanent efforts were established to prevent bioterrorist activities and their consequences. Extensive epidemic outbreaks of West Nile fever (WNF; i.e., fever caused by West Nile virus) and Crimean-Congo hemorrhagic fever (CCHF) with unusual high mortality appeared in the last four years in southern Russia. We determined infection rates in humans, domestic and wild animals, mosquitoes and ticks from natural and synanthropic biocenoses [Editorial note: "synanthropic" means, roughly, all species living with (c.f. lice, fleas) or near people, such as in houses (c.f. house mice), parks (c.f. Rattus spp.), and the like, rather like "peridomestic", but not strictly so; "biocenosis" is the biome, the "totality of living populations in a particular habitat, which itself is only a part of the ecosystem".]. CCHF virus strains were phylogenetically similar to strains isolated in this area 35 years ago but different from Central-South-Asian and African strains. Before the outset of the current emergence of epidemic WNF, three genetic variants of this virus had been isolated in USSR, two African and one Indian. Phylogenetic analysis of complete genome sequences of epidemic strains demonstrated considerable similarity to strains from USA and Israel and differences from strains isolated in the same USSR areas 20-30 years before. In addition to strains of genotype 1, we isolated strains of second and third lineages and a strain of a fourth genetic variant. Nucleotide differences of these strains from all three genotypes was about 30%. The emerging WNF situation in Russia for the last 4 years probably has been the result of not only natural and social factors, but also to introduction of more virulent strains or by evolution of the virus.

[Sanitary and epidemiological provision of the personnel of the units and border formations of the North Caucasus Regional Command of the Border Guard Service of the Russian Federation]. / Sanitarno-épidemiologicheskoe obespechenie lichnogo sostava soedinenii i chastei Severo-Kavkazskogo Regional'nogo Upravleniia Federal'noi Pogranichnoi Sluzhby RF.

The factors affecting the environment of servicemen doing their duties in connection with the task of guarding the state frontier of the Russian Federation are presented. The main trends in the activity of the sanitary and epidemiological service, carried out under regular conditions and the period of the liquidation of the consequences of high floods in the Southern Federal District in 2002 with the aim of preventing the aggravation of the epidemical situation, were shown to be determined, and the corresponding measures taken, in due time, thus making it possible to prevent the growth of morbidity in enteric and other infections among the personnel of the units and formations of the North Caucasian Regional Command of the Federal Frontier-Guard Service of the Russian Federation.

[Analysis of new variants of West Nile fever virus]. / Analiz novykh variantov virusa likhoradki Zapadnogo Nila.

The complete nucleotide sequences for 6 strains of the West Nile fever virus were determined. For the first time the complete nucleotide sequences of the Indian isolate and Krsn190 strain, that is the most far phylogenetically from all isolates known at present time were established. The scheme for separation of virus variants into 4 groups and criteria for determination the group to which the isolate belongs are suggested.

[Genome analysis of hepatitis C virus strain 274933RU isolated in Russian Federation]. / Analiz genoma izoliata 274933RU virusa gepatita C, vydelennogo na territorii Rossiiskoi Federatsii.

Five overlapping cDNA fragments of hepatitis C virus (HCV) isolate 274933RU, obtained by RT-PCR, were amplified and cloned. Complete nucleotide RNA sequence has been determined. The genomic organization of 274933RU was, from 5' to 3' terminals, 5' UTR (341 nt), polyprotein ORF (9033 nt), 3' UTR (40 nt except for the poly(U-UC) and polypyrimidine stretch), and X-tail (98 nt). Phylogenetic analysis of the core and NS5 genes showed that the isolated strain belonged to HCV 1b subtype.

[Determination of hepatitis G virus markers in various risk groups]. / Opredelenie markerov virusa gepatita G v razlichnykh gruppakh riska.

Study of prevalence of hepatitis G virus (HGV) markers in different risk groups showed the presence of HGV RNA in 3.2% blood donors, 24.2% patients with hepatitis C (HCV), and 28% patients with hemophilia. HGV antibodies were detected in 11.3% donors, 16.0% patients with HCV, 13.4% patients with hemophilia, and 8.5% HIV-infected subjects. Anti-E1 HGV were more often detected in the absence of HGV RNA. Antibodies to HGV E2 protein were significantly more often detected in adult HCV patients but not in adolescent patients aged 8-15 years.

[Multiple forms of the NS1 protein as the main component of the nonvirion ("soluble") antigen of the tick-borne encephalitis virus]. / Mnozhestvennye formy belka NS1 kak osnovnogo komponenta nevirionnogo ("rastvorimogo") antigena virusa kleshchevogo éntsefalita.

The nonstructural virus-specific NS1 protein of tick-borne encephalitis (TBE) virus was found to be the main antigenic component of the nonvirion ("soluble") antigen which had been shown previously to present a complex protein structure closely associated with the infected cell membranes. In the presence of sodium dodecylsulphate, beta-mercaptoethanol and 8M urea NS1 protein could be detected in the form of oligomeric molecules which disintegrated to monomers after heating at 100 degrees C for 5 min. The infected cell membrane-associated NS1 protein was shown to differ in electrophoretic mobility from the NS1 protein released into the culture fluid in the course of virus infection. The conditions for detection of NS1 protein and its oligomeric forms by PAG electrophoresis and immune blotting were determined. Dimeric forms of NS1 protein were found to contain products of its proteolysis. NS5 protein was found together with NS1 protein in TBE nonvirion antigen and also possessed antigenic activity.