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Possibility to use blood dried on filter paper for serological testing on antibodies to tick-borne encephalitis (TBE). Sensitivity and specificity of specific IgM detection in dry stains of blood by lanthanide fluorescence immunoassay was 94.9% (86.9-100%) and 97.5% (94-100%) respectively, compared with results obtained in tests of sera. Agreement in positive and negative results of tests for IgM against TBE in 562 serum samples and dry blood stains was 95.3%. During analysis of both types of biomaterial high degree of correlation was observed between intensity of fluorescence when testing for both IgM (r=0.86700; p=0.05; n=562), and IgG (r=0.83883; p=0.05; n=337) toTBE virus. Use of this mildly invasive technique of blood draw is reasonable during conduction of large-scale population studies for seroepidemiologic monitoring, investigation of disease outbreaks, control of effectiveness of vaccination against TBE, assessing of level of specific immunity in population of endemic regions, control of treatment, and serologic diagnostics of acute TBE in hospitalized patients, in which blood draw is difficult to perform.

The paper shows variability of the functional activity of the superficial structures of three Far Eastern strains of tick-borne encephalitis (TBE) virus used to study the immunogenicity of different vaccines. The avidity antibodies to the study TBE virus strains were not detected in all of the persons vaccinated with different TBE vaccines even in the year of immunization. Two years after a course of vaccination, immune response and antibody avidity were decreased in the vaccinees. The persons vaccinated with "eastern" vaccines were better protected against Sofjin-like strain P-73 that had led to a fatal outcome in a patient with TBE. Those vaccinated with "western" strain vaccines were found to have a higher affinity for antibodies to the strains P-202 and P-69 that caused inapparent TBE in the year of immunization and 2 years later. A group of persons vaccinated with both "western" and "eastern" vaccines in different periods showed rather high antibody avidities.

A patient with diagnosed meningoencephalitis and a history of tick bite died in Mongolia in 2008. The purpose of this paper is to characterize the virus causing the ill person's death. The virus was identified using the phylogenetic analysis of the 520-bp fragment of the tick-borne encephalitis virus (TBEV) genome, which codes the fragment of TBEV protein E between 52-223 amino acids. TBEV RNA was detected in the samples of medulla oblongata, cerebral cortex, and pia mater of brain, but not in the cerebellar tissue. The study virus fragment was genetically closest to the representatives of the Far East subtype. Its closest relative was virus 740-84 (GenBank EU878282) isolated from large-toothed redback voles (Clethrionomys glareolus) in Buryatia and greatly differed from the Far East virus Soffin. Two amino acid substitutions (H86R and VI7A) were detected within the study protein E fragment. The paper is the first to describe the causative agent of tick-borne encephalitis on the territory of Mongolia and to discuss the evolution and pathogenicity of TBEV.

Emergency specific prevention of tick-borne encephalitis (TBE) by using homologous immunoglobulin is an important element in the package of controlling measures against this viral natural and focal infection. There are annually a few hundred thousand referrals for health care facilities for tick bites. Their maximum coverage tactics via immunoglobulin prevention is medically unreal and unjustifiable. The paper presents the results of a long-term application of another approach based on preliminary rapid studies of the ticks taken from victims or the blood of patients in the period of possible development of virusemia and preventive immunoglobulin use only in the persons bitten with TBE virus-infected ticks. Examination of the material available from more than 56 thousand referrals indicated the high epidemiological (more than 99%) and economic effectiveness of the target administration of an immunological drug. By taking into account the accumulated data on a wide spread of combined foci of TBE and other tick-borne infections and the authors' own experience, it is suggested that it is necessary to organize a comprehensive differential laboratory diagnosis and emergency prevention against the whole complex of Ixodes tick-borne infections.

The evolution of tick-borne encephalitis (TBE) is marked by the expanded nosological area, the transformation of landscapes, the formation of anthropurgic foci, the change of environmental systems, the increase of mortality rate mainly among urban dwellers, as well as pathomorphism. The evolution of natural TBE virus (TBEV) populations was studied in Eastern and Western Siberia, Middle Urals, and the European part of the nosological area. The paper first describes the types of evolutionary transformations of viral populations under the conditions of a varying environmental and epidemiological situation. These include: 1) the change of TBEV subtypes over 50-60 years; substitution of the Far-Eastern subtype for its Siberian subtype (the Sverdlovsk and Kemerovo regions); 2) the steady-state circulation of one Siberian subtype with mutanttypes being accumulated (the Vologda region); 3) co-existence of the Far-Eastern and Siberian subtypes with the common vector Ixodes persulcatus (the Yaroslavl and Irkutsk regions, etc.); 4) original mixed TBEV strains including the gene sites of proteins E and NSI of two subtypes. There is new evidence that the Siberian subtype is able to induce focal TBE forms, leading to death.

The paper discusses the prevention of tick-borne encephalitis (TBE) under the conditions of a varying epidemiologic situation. High mortality, a change in its structure, an expansion of a nosological area, an increase in the number of anthropurgic foci in the suburbs and towns and cities, the detection of combined foci and the development of mixed forms of tick-borne infections, and clinical pathomorphism suggest that novel approaches to preventing this severe viral disease are urgent. The comprehensive nature of a prophylaxis system should envisage the use of tried-and-true specific and nonspecific measures against the entire group of tick-borne infections. Cohort vaccination should be considered as a priority measure in high TBE endemic areas. The prophylaxis system should be differentiated and adequate to the specific epidemic situation in the endemic regions.

The discovery of tick-borne encephalitis (TBE) in the Far East of the USSR in 1937 is marked by investigators' heroism and tragedies--diseases in the members of the expedition and deaths when the first vaccine was designed in 1938. The head of the expedition L. A. Zilber and two specialists were arrested on a charge of subversive activities--spreading Japanese encephalitis in the guise of discovering a new virus. The paper presents the archival records and recollections of the members of the far-eastern expedition, which specify the history of TBE discovery.

The paper presents the data characterizing the epidemiological situation associated with tick-borne virus encephalitis (TBVE) in the Russian Federation in 2006. There is a 22.7% reduction in morbidity as compared with 2005; however, the situation is considered to be of strain; a rise in the incidence of TBVE is recorded in a number of subjects of the Russian Federation. There is a high activity of natural and anthropurgic foci of TBVE; there are as many as 250 recourses to a doctor for tick bites. In some regions, tick virus carriage has been established at 13-29%. TBVE vaccination coverage is quite insufficient; in many cases emergency prophylaxis is not made due to the fact that specific immunoglobulin is in short supply whereas some areas continue to unwarrantedly inject a serum for lack of rapidly tick virus-determining laboratories. There are essential faults in the organization of acaricidal measures and in the propaganda of knowledge of personal TBVE prophylaxis in the population. Tasks for increasing the level of comprehensive prophylaxis are defined to substantially reduce TBVE morbidity in the Russian Federation.

The paper deals with an investigation of an immune response in BALB/c mice immunized with tick-borne encephalitis (TBE) vaccine and infected with TBE virus and in non-immunized mice. The parameters of specific humoral (IgG and IgM) and cellular (gamma-interferon (IFN) and cell proliferation) immunities and the activity of cytokines (necrosis tumor factor-alpha, interleukin (IL)-1beta, IL-2, IL-6, IL-10, and IL-12) were studied. There were significant differences in the specific and nonspecific immune response of immunized and non-immunized animals. Noteworthy is the difference in the time course of changes in the levels of IL-6, IL-2, IL-12, and gamma-IFN in the immunized and non-immunized animals.