Inferring Evolutionary Timescale of Omsk Hemorrhagic Fever Virus.

Until 2020, there were only three original complete genome (CG) nucleotide sequences of Omsk hemorrhagic fever virus (OHFV) in GenBank. For this reason, the evolutionary rate and divergence time assessments reported in the literature were based on the E gene sequences, but notably without temporal signal evaluation, such that their reliability is unclear. As of July 2022, 47 OHFV CG sequences have been published, which enables testing of temporal signal in the data and inferring unbiased and reliable substitution rate and divergence time values.

Delimitation of the tick-borne flaviviruses. Resolving the tick-borne encephalitis virus and louping-ill virus paraphyletic taxa.

The tick-borne flavivirus (TBFV) group contains at least 12 members where five of them are important pathogens of humans inducing diseases with varying severity (from mild fever forms to acute encephalitis). The taxonomy structure of TBFV is not fully clarified at present. In particular, there is a number of paraphyletic issues of tick-borne encephalitis virus (TBEV) and louping-ill virus (LIV).

Phylogeography and Re-Evaluation of Evolutionary Rate of Powassan Virus Using Complete Genome Data.

In this paper, we revealed the genetic structure and migration history of the Powassan virus (POWV) reconstructed based on 25 complete genomes available in NCBI and ViPR databases (accessed in June 2021). The usage of this data set allowed us to perform a more precise assessment of the evolutionary rate of this virus. In addition, we proposed a simple Bayesian technique for the evaluation and visualization of 'temporal signal dynamics' along the phylogenetic tree.

[Biological properties and phylogenetic relationships of tick-borne encephalitis virus (Flaviviridae, Flavivirus) isolates of siberian subtype isolated in the south of East siberia in modern period].

Introduction: Tick-borne encephalitis virus (TBEV) is medically most important representative of the same-name serogroup of genus Flavivirus (Flaviviridae). In the view of various researchers there are 3 to 5 TBEV subtypes, of them siberian being the most prevalent. The aim of the work is to compare the biological properties and to reveal phylogenetic relationships of large group of modern (2006-2019) TBEV isolates of siberian subtype from natural foci in southern East Siberia.

Analysis of effectivity of the tickborne encephalitis virus detection methods in ixodid ticks.

Tick-borne encephalitis (TBE) is transmissible viral disease widely common in temperate zone of Eurasia. ELISA and PCR are used for express identification of the vector's infection, but the results of the two methods often do not agree. Aim of the work is comparative analysis for TBE virus of Ixodid ticks from nature using complex of methods, including ELISA, PCR, and isolation of the virus in laboratory mice.

Reporting of New tick-borne encephalitis virus strains isolated in Eastern Siberia (Russia) in 1960-2011 and explaining them in an evolutionary context using Bayesian phylogenetic inference.

Tick-borne encephalitis virus (TBEV) is one of the main tick-borne viral pathogens of humans. Infection may induce signs of meningitis, encephalitis, paralysis and high fever. TBEV is well studied by molecular phylogenetic methods.

Fox rabies outbreaks in the republic of Buryatia: Connections with neighbouring areas of Russia, Mongolia and China.

The Republic of Buryatia (RB) is located southeast of Lake Baikal and shares a long border with Mongolia. This region of Russia was rabies-free from 1982 to 2010. The first outbreak of fox rabies in RB was identified in 2011, about 30 km from the Russian-Mongolian border.

"886-84-like" tick-borne encephalitis virus strains: Intraspecific status elucidated by comparative genomics.

Tick-borne encephalitis virus (TBEV) can cause severe meningitis, encephalitis, and meningoencephalitis. TBEV represents a pathogen of high zoonotic potential and an emerging global threat. There are three known subtypes of TBEV: Far-Eastern, Siberian and European.

[PLAGUE IN MANCHURIA (1910-1911) AND EBOLA VIRUS DISEASE IN WEST AFRICA (2014-2015): COMMON PREREQUISITES FOR THE DEVELOPMENT OF EPIDEMICS].

The paper gives the results of a comparative analysis of the prerequisites for the emergence and spread of epidemics of particularly dangerous infections, by using plague in Manchuria (1910-1911) and Ebola virus disease in West Africa (2014-2015) as examples. Analysis of literature and archival data and online information could reveal a number of common factors and conditions, which substantially contributed to the epidemics. Organization of anti-epidemic (preventive) measures in cases of the threatening epidemic spread, of particularly dangerous diseases must be based on the minimization, of the influence of the specific factors and conditions, which facilitate disease transmission in a given area in a given time.

[POLYMORPHISM IN THE PHENOTYPIC STRUCTURE OF A POPULATION OF TAIGA TICK AND ITS EPIDEMIOLOGICAL SIGNIFICANCE].

The paper presents the results of 10-year (2005-2014) observations of an Ixodespersulcatus Schulze population. The purpose of this investigation was to trace long-term changes in the structure of the taiga tick population from the proportion of specimens with external skeletal anomalies and to assess a relationship between the pattern of imago phenotypic variation and the virus percentage of a carrier. There were a total of reports of the external skeletal structure of 1123 females gathered from plants to a flag in an area at 43 km from the Baikal Road connecting Irkutsk and the settlement of Listvyanka (Irkutsk Region).

Tick-borne encephalitis virus isolates from natural foci of the Irkutsk region: clarification of the genotype landscape.

The Irkutsk region is the unique territory where all known subtypes of tick-borne encephalitis virus (TBEV) circulate. In the last years, the phenomenon of changes in TBEV subtypes (substitution of the Far-Eastern subtype by the Siberian one) was noted in some regions of the Russian Federation. The results of individual investigation of 11522 Ixodes persulcatus ticks and brain specimens from 81 small mammals collected in natural foci of the Irkutsk region during 2006-2014 are presented in the article.

Complete Genome Sequences of Four European Subtype Strains of Tick-Borne Encephalitis Virus from Eastern Siberia, Russia.

Three tick-borne encephalitis virus (TBEV) strains were isolated from Ixodes persulcatus ticks, and one was isolated from a shrew in the territory of eastern Siberia (Russia). The level of sequence identity compared to Neudoerfl (the European prototype strain) is 97.2 to 97.

[Monitoring of enterovirus circulation in Irkutsk region].

Aim: Monitoring of circulation of enteroviruses (EVI) in Irkutsk Region and study of regional specter of circulating enteroviruses.

Materials And Methods: 1419 samples from patients with suspected EVI, contact in foci ofenterovirus infection, acute intestine infections and 964 samples of sewage water were studied in total. In 2011 isolation of viral agents from 97 samples positive on enterovirus by RT-PCR from patients with preliminary EVI diagnosis and 5 samples of sewage water of Irkutsk city was carried out.

[Epidemiological situation and prophylaxis of zoonotic and natural-focal infectious diseases in Siberia and the Far East].

Analysis of zoonotic and natural-focal infectious disease morbidity in 2009 - 2011 in Siberia and the Far East is presented, and a complex of measures aimed at their prophylaxis is proposed. Analysis is carried out based on the data received by Reference Center of Monitoring of Natural-Focal Infection Causative Agents and Regional Center of Monitoring of I-II Pathogenicity Group Causative Agents at the Irkutsk Research Institute of Plague Control from departments and Centers of Hygiene and Epidemiology of Siberian, Far Eastern, 3 subjects of Urals Federal District and 5 Stations of Plague Control of Federal Service for Control in the Sphere of Protection of Consumers' Rights and Well-Being of Humans. In the morbidity structure in this region "tick-borne" infections were established to predominate--69.

[Polytypic strains in the genofund of tick-borne encephalitis virus].

Eighteen polytypic tick-borne encephalitis virus (TBEV) strains containing the fragments of E and NS1 protein genes of Siberian and Far Eastern, occasionally Siberian and European subtypes were isolated in the European and Asian parts of the tick-borne encephalitis (TBE) area. They were identified using real-time polymerase chain reaction, hybridization-fluorescence detection with genotype-specific probes, restriction fragment length polymorphism analysis, and E protein sequencing. The polytypic strains were isolated from individual Ixodes persulcatus ticks, their pools, from the blood of patients and the brain of dead patients.

Tick-borne encephalitis virus in Eastern Siberia: complete genome characteristics.

Tick-borne encephalitis (TBE) is one of the most important arboviral diseases across Eurasia. TBE virus (TBEV) is transmitted by tick bite and causes a potentially fatal neurological infection in humans. In the Russian Federation, TBE is endemic in most regions, with 3000-5000 cases of the disease annually.

[Evolution of tick-borne encephalitis and a problem of evolution of its causative agent].

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.

[Dynamics of expression of Marburg and Ebola virus antigens in infected Vero cells ].

Time course of Marburg and Ebola virus antigens expression in Vero cells was studied by indirect immunofluorescence test. The maximum accumulation of virus specific antigens in Vero cells infected with a high dose was observed after 48-54 h of incubation. It is essential for laboratory diagnosis that virus specific antigens can present as incorporations of different shape and size, starting from small hardly discernible granules (immediately after the virus adsorption) to large lumps, cords, accumulations, and diffuse fluorescence.

[Ebola virus reproduction in cell cultures].

Ebola-Zaire virus production in Vero and BGM cells was studied. The CPE developed in both cell cultures. The cell monolayer destruction by 80-90% was seen at a low multiplicity of infection in 7-8 days after virus inoculation.