Despite the fact that databanks of genomic sequences have clear information links with biological samples, they are an independent intellectual resource in demand among many researchers. To deposit information obtained in the course of molecular genetic studies in Russia, the Virus Genome Aggregator of Russia (VGARus) databank was created.Aim. To evaluate data on the variability of genetic sequences of the Epstein-Barr virus (EBV), obtained as a result of Russian studies, and the possibility of their integration into the VGARus database forsubsequent use in epidemiological surveillance.Material and methods. A search for publications was carried out in the PubMed, eLibrary, Cyberleninka databases. In total, the study included 32 papers of Russian and external authors that meet the stated aim. Results. The number of studies containing data on the EBV genetic sequences in the Russian Federation is extremely small. The information presented in publications indicates geographical differences in the ratio of two EBV genotypes, the presence of a special LMP1 TatK gene variant in the Tatars of the Volga region, the difference between Russian EBV samples in the gene encoding the gp350 from those from other world regions. At the same time, information on the genomic sequences obtained in the studies was not deposited in the Russian gene bank in any case.Conclusion. Expanding the potential of the Russian VGARus platform by including information on the genomic sequences of all pathogenic microorganisms circulating in the Russian Federation will require largescale work that takes into account technical features, biological and information security requirements.

Identifying population groups at greatest risk of hepatitis C virus (HCV) infection is essential for targeting screening and treatment. We analyzed the seroprevalence of antibodies to HCV (anti-HCV) and HCV RNA in serum samples from 37,291 conditionally healthy volunteers collected between 2018 and 2022, and from 4764 individuals sampled in 2008, totaling 42,055 participants. In 2018–2022, anti-HCV prevalence varied by region, ranging from 1.1 to 1.4% in Belgorod, Moscow, and St. Petersburg to 1.8–2.1% in Dagestan, Tatarstan, Novosibirsk, Tyva, and southern Yakutia, and reaching 3.4–5.2% in Khabarovsk and the Arctic zone of Yakutia. In 2008, prevalence in Moscow, Rostov, Sverdlovsk, Tyva, and Yakutia ranged from 1.7% to 3.3%. A significant decline over time was observed: from a mean of 2.6 ± 0.5% in 2008 to 1.9 ± 0.1% in 2018–2022 (p < 0.01). In recent years, men were more frequently anti-HCV-positive than women (2.5 ± 0.2% vs. 1.5 ± 0.2%, p < 0.01), whereas no sex differences were noted in 2008. The age of a sharp prevalence increase shifted from the 20–29 cohort in 2008 to the 30–39 cohort in 2018–2022. Based on the demographic structure, we estimate ~3.23 million anti-HCV carriers in Russia. HCV RNA was detectable in only one-third of seropositive individuals, identifying them as candidates for antiviral therapy. Thus, in contemporary Russia, men aged over 30 years have the highest risk of HCV infection and should be prioritized for targeted screening.

Identifying population groups at greatest risk of hepatitis C virus (HCV) infection is essential for targeting screening and treatment. We analyzed the seroprevalence of antibodies to HCV (anti-HCV) and HCV RNA in serum samples from 37,291 conditionally healthy volunteers collected between 2018 and 2022, and from 4,764 individuals sampled in 2008, totaling 42,055 participants. In 2018–2022, anti-HCV prevalence varied by region, ranging from 1.1–1.4% in Belgorod, Moscow, and St. Petersburg to 1.8–2.1% in Dagestan, Tatarstan, Novosibirsk, Tyva, and southern Yakutia, and reaching 3.4–5.2% in Khabarovsk and the Arctic zone of Yakutia. In 2008, prevalence in Moscow, Rostov, Sverdlovsk, Tyva, and Yakutia ranged from 1.7% to 3.3%. A significant decline over time was observed: from a mean of 2.6 ± 0.5% in 2008 to 1.9 ± 0.1% in 2018–2022 (p < 0.01). In recent years, men were more frequently anti-HCV–positive than women (2.5 ± 0.2% vs 1.5 ± 0.2%, p < 0.01), whereas no sex differences were noted in 2008. The age of sharp prevalence increase shifted from the 20–29 cohort in 2008 to the 30–39 cohort in 2018–2022. Based on demographic structure, we estimate ~3.23 million anti-HCV carriers in Russia. HCV RNA was detectable in only one-third of seropositive individuals, identifying them as candidates for antiviral therapy. Thus, in contemporary Russia, men over 30 years have the highest risk of HCV infection and should be prioritized for targeted screening.

The topic of epidemiologic surveillance is one of the basic concepts in the theory and practice of epidemiologic science. In Russia, generalization of the accumulated factual material and theoretical developments have allowed us to formulate a number of provisions on the nature of the epidemic process. The pandemic of a new coronavirus infection has forced adjustments in all spheres of society, including the activities of the infectious disease epidemiological surveillance system, requiring the development and implementation of innovative solutions. Based on the experience of prompt response to the tasks set by the COVID-19 pandemic, the authors raised the problem of development and implementation of a system of molecular genetic monitoring for pathogens of emerging and re-emerging infections as a priority vector of epidemiological surveillance development. The introduction of modern molecular biological technologies for the identification of pathogens with epidemic potential, taking into account their genetic diversity, into the system of epidemiologic surveillance has been substantiated based on the experience of using platform solutions created by the Central Research Institute of Epidemiology of Rospotrebnadzor. The strategy of genomic epidemiologic surveillance as a powerful tool to ensure readiness for response measures and management of the epidemic process by implementing and adjusting preventive and anti-epidemic measures was developed. The Russian platform for aggregation of information on virus genomes (VGARus) developed at the Central Research Institute of Epidemiology of Rospotrebnadzor as a technological, scientific, organizational and infrastructural base of genomic epidemiological surveillance, acting as an interdepartmental consortium, has been introduced into practice. The efficiency of VGARus was shown to assess the mutational variability of SARS-CoV-2, the influence of evolutionary development of circulating pathogens on the characteristics of the epidemic process, the implementation of operational and retrospective analysis of morbidity and prediction of the spread of genetic variants of pathogens.

Hepatitis B (HB) remains one of the serious medical and social health problems, and to assess the epidemiological situation, it is necessary to analyze the state of population immunity by collecting information on its intensity during serological studies. The aim of the work is to assess the level of population immunity against HB in the population of the Russian Federation in 2017 to 2022. Materials and methods. The results of serological monitoring for the presence of anti-HBs, provided by territorial laboratories of medical institutions of each subject of the Russian Federation in 2017 to 2022, were analyzed. The cohort of subjects in each subject of the Russian Federation consisted of persons in the age groups 3–4, 16–17, 20–29, 30–39, 40–49 years old, numbering at least 100 people each. The analysis of the obtained data for 6 years (2017–2022) was carried out using averaged data for every two years – 2017–2018, 2019–2020 and 2021–2022. The number of study cohorts during these time intervals was 88,151, 84,166 and 97,274 people, respectively. Results and discussion. The average values of the proportion of persons with immunity against HB were 69.0% in 2017–2018, 66.2% in 2019-2020 and 61.3% in 2021–2022. The highest proportion of people with protective immunity against hepatitis B was observed in the age group of 20-29 years. The proportion of children 3-4 years old who had anti-HBs detected at a concentration exceeding 10 IU/l was 65.8–72.5%, and 16–17 years old – 49.6–64.9%. The intensity of post-vaccination immunity against HB in children 16-17 years old should be considered insufficient. Conclusion. An analysis of serological studies results for the period from 2017 to 2022 showed that the potential of vaccine prevention of hepatitis B, carried out since 2006 within the framework of the priority National Project «Health», is not fully realized.

Relevance. It is known that the immune response to the administration of immunobiological drugs is variable and depends on the individual characteristics of the organism. Host immunogenetic factors have a significant impact on the effectiveness of vaccination. In this study, the frequencies of alleles of the HLA class I (HLA-A, B, C) and class II genes (HLA-DRB1, DPB1, DQB1) were studied in groups of participants with different levels of antibodies (anti-HBs) after vaccination against viral hepatitis B. Aims of the work was to determine the possible relationship between alleles of HLA genes and the intensity of post-vaccination immunity against hepatitis B. Materials and methods. The study included 271 apparently healthy adults who were divided into 3 groups depending on the specific concentration of post-vaccination antibodies (anti-HBs) using ELISA. All calculations were made relative to the groups anti-HBs >100 mIU/ml (n=82), 10-100 mIU/ml (n=98) (protective antibody level) and anti-HBs <10 mIU/ml (n = 91). To type alleles of the HLA class I (HLA-A, B, C) and class II (HLA-DRB1, DPB1, DQB1) genes, we used a panel we developed for whole-genome next-generation sequencing (NGS). Statistical analysis was performed using Pearson's χ2 goodness-of-fit test using the FDR multiple correction method with an initial target of p < 0.05. Results. When typing the six genes studied, the total number of alleles identified at least once was 189 variants that were distinct from each other. We identified 3 alleles (B*38:01:01, DQB1*06:03:01 and DRB1*13:01:01), which were significantly more common (FDR p < 0.05) in the group with a protective level of anti-HBsS. Also in this group there was an increased frequency of occurrence of alleles A*26:01:01, A*32:01:01, C*12:03:01, DPB1*04:01:01 and haplotypes DQB1*06:03:01 -DRB1*13:01:01 and B*38:01:01-C*12:03:01. In the group of seronegative patients, alleles A*02:01:01, A*03:01:01, B*44:02:01, B*44:27:01, C*07:04:01, DPB1*04 were more common :01:01, DQB1*05:01:01, DRB1*01:01:01 and DRB1*16:01:01. It was shown that the identified associations were more significant in the group of individuals with a concentration of post-vaccination anti-HBs above 100 mIU/ml. Conclusion. The results obtained indicate that the HLA alleles we identified may influence the level of anti-HBsS production, and that the genetic factor may, to a greater extent, determine whether the antibody level exceeds 100 mIU/ml. defined as an anti-HBS level of 10 mIU/ ml. The development of an integrated approach to the organization of vaccine prevention, including the determination of genetic markers, will improve the quality of immunization of the population. Information about the association of HLA gene alleles can be used to develop predictive scenarios for the development of the hepatitis B epidemic process.

Introduction. The World Health Organization considers the values of antibody titers in the hemagglutination inhibition assay as one of the most important criteria for assessing successful vaccination. Mathematical modeling of cross-immunity allows for identification on a real-time basis of new antigenic variants, which is of paramount importance for human health. Materials and methods. This study uses statistical methods and machine learning techniques from simple to complex: logistic regression model, random forest method, and gradient boosting. The calculations used the AAindex matrices in parallel to the Hamming distance. The calculations were carried out with different types and values of antigenic escape thresholds, on four data sets. The results were compared using common binary classification metrics. Results. Significant differentiation is shown depending on the data sets used. The best results were demonstrated by all three models for the forecast autumn season of 2022, which were preliminary trained on the February season of the same year (Auroc 0.934; 0.958; 0.956, respectively). The lowest results were obtained for the entire forecast year 2023, they were set up on data from two seasons of 2022 (Aucroc 0.614; 0.658; 0.775). The dependence of the results on the types of thresholds used and their values turned out to be insignificant. The additional use of AAindex matrices did not significantly improve the results of the models without introducing significant deterioration. Conclusion. More complex models show better results. When developing cross-immunity models, testing on a variety of data sets is important to make strong claims about their prognostic robustness.

The problem of biological safety is extremely relevant today for all countries of the world because of the real and potential threats caused by biological agents that are dangerous to public health and the environment. Modern microorganisms are becoming increasingly aggressive towards humans, as clearly demonstrated by the COVID-19 pandemic, which has affected all aspects of people's lives and exposed the vulnerability of the healthcare system. According to the Decree of the President of the Russian Federation «On the Fundamentals of the State policy of the Russian Federation in the field of chemical and biological safety for the period up to 2025 and beyond» and the Federal Law «On Biological Safety in the Russian Federation», the main objectives of state policy are to reduce the risks of negative effects of biological factors on the population and the environment. Antimicrobial resistance, the emergence of new infections and the overcoming of interspecific barriers by microorganisms are of particular concern. Infectious disease agents with epidemic potential, such as Ebola, Zika, Marburg, Lassa, MERS-CoV and SARS-CoV viruses, continue to pose a high threat. To counteract new biological threats, Russia has created a scientific concept of future biosafety, focusing on the development of genomic epidemiological surveillance, digital transformation and mobile technologies. Effective management of epidemic processes requires constant monitoring of genetic changes in infectious agents and prompt response to new threats, which allows the VGARus platform created in Russia to monitor virus mutations. Thus, genomic epidemiological surveillance is becoming a key element of ensuring biological safety and scientific and technological development in Russia.

Background. Constant assessment of the dynamics of the main characteristics of the epidemic process is the basic function of epidemiological surveillance of infectious diseases. The search for factors that determine changes in the characteristics of the epidemic process makes it possible to develop timely management decisions and reduce the risk of an increase in the scale of the pandemic. Moscow is the main centre of attraction for the population of other Russian regions with the most complex structure of social links and the highest population density. The purpose of the study is to identify factors that potentially determine the trends of observed changes using a molecular epidemiological analysis of the main characteristics of the epidemic process of a new coronavirus infection (COVID-19). Materials and methods. For the analysis, the data of Russian national genome sequence database of SARS-CoV-2 virus (VGARus) were combined with information on morbidity and mortality presented at the official internet resources стопкоронавирус.рф and Yandex DataLens, the dynamics of vaccination, COVID-19 disease incidence and hospitalization from the portal Gogov.ru. A multicentre retrospective observational epidemiological study was conducted to examine the sex and age structure of hospitalised patients. Anonymized case histories of patients with COVID-19 collected at different follow-up periods in the institutions of Moscow (41,561 cases) served as a source of data for the sex and age structure analysis. Results. We identified 11 periods with significantly different complex epidemiological characteristics. A decrease in the incidence among young people of working age during the period of restrictive measures was revealed. In 3 out of 11 worsening of the epidemic situation coincided with the beginning of the circulation of a new genetic variant of the pathogen COVID-19 (variants Wuhan, Delta, Omicron). A decrease in the incidence in the summer period was noted, regardless of the circulating genetic variants. Conclusion. A significant part of the observed dynamics of the characteristics of the epidemic process in Moscow can be explained by the properties of the pathogen, seasonality and dynamics of magnitude of the herd immunity. The influence of the dynamics of the herd immunity indicators on the course of the epidemic process is to be studied further.

A neonatal vaccination against the Hepatitis B virus (HBV) infection was initiated in Russia 20 years ago, with catch-up immunization for adolescents and adults under the age of 60 years launched in 2006. Here, we have assessed the humoral immunity to HBV in different regions of Russia, as well as the infection frequency following 20 years of a nationwide vaccination campaign. We have also evaluated the role of immune-escape variants in continuing HBV circulation. A total of 36,149 healthy volunteers from nine regions spanning the Russian Federation from west to east were tested for HBV surface antigen (HBsAg), antibodies to HBV capsid protein (anti-HBc), and antibodies to HBsAg (anti-HBs). HBV sequences from 481 chronic Hepatitis B patients collected from 2018–2022 were analyzed for HBsAg immune-escape variants, compared with 205 sequences obtained prior to 2010. Overall, the HBsAg detection rate was 0.8%, with this level significantly exceeded only in one study region, the Republic of Dagestan (2.4%, p < 0.0001). Among the generation vaccinated at birth, the average HBsAg detection rate was below 0.3%, ranging from 0% to 0.7% depending on the region. The anti-HBc detection rate in subjects under 20 years was 7.4%, indicating ongoing HBV circulation. The overall proportion of participants under 20 years with vaccine-induced HBV immunity (anti-HBs positive, anti-HBc negative) was 41.7% but below 10% in the Tuva Republic and below 25% in the Sverdlovsk and Kaliningrad regions. The overall prevalence of immune-escape HBsAg variants was 25.2% in sequences obtained from 2018–2022, similar to the prevalence of 25.8% in sequences collected prior to 2010 (p > 0.05). The population dynamics of immune-escape variants predicted by Bayesian analysis have remained stable over the last 20 years, indicating the absence of vaccine-driven positive selection. In contrast, the wild-type HBV population size experienced a rapid decrease starting in the mid-1990s, following the introduction of mass immunization, but it subsequently began to recover, reaching pre-vaccination levels by 2020. Taken together, these data indicate that it is gaps in vaccination, and not virus evolution, that may be responsible for the continued virus circulation despite 20 years of mass vaccination.

Introduction. The design of studies aimed at finding the association between the genetic factor and the studied feature (disease) involves a comparison of the ratio of genotypes or allelic proportions in the study group with those in the control group. At the stage of determining the ratio of genotypes of the studied polymorphisms in the reference group, researchers meet a number of problems, which are the subject of the present work. Aim of the work is to provide scientific rationale for the feasibility of creating a national information system comprising genetic data of the relatively healthy population of Russia, incorporating its ethnic diversity. Materials and methods. The study group, total 1020 people, was genotyped for a number of single nucleotide polymorphisms of human genes. A comparative characteristic of the frequency distribution of the studied polymorphisms with those presented in international databases as reference data was carried out using χ2 index. Results. The frequency of SNP rs4986790 of the TLR4 gene significantly differs from the EUR population (p = 0.032) and the CEU subpopulation (p = 0.047). The allele frequencies of the rs1800795 (IL6) and rs1800896 (IL10) polymorphisms in the study population differ from the CEU subgroup (p = 0.030 and 0.012, respectively). The frequency of SNP rs2295119 (HLA-DPA2) in the study group is significantly different from the EUR population (p = 0.034). Conclusion. The analysis carried out in this work confirms the need to create a domestic information system containing data on the occurrence of SNP alleles and genotypes for a conditionally healthy population and in subgroups with various pathological conditions.

Currently, monitoring infectious morbidity, control and forecasting the epidemic process is a topical health problem.Aim. To analyze the capabilities of the biobank for serological monitoring of infectious diseases using the Epstein- Barr virus (EBV), which is associated with infectious mononucleosis, as well as somatic pathology, including cancer.Material and methods. Using the quantitative enzyme- linked immunosorbent assay for specific antibodies to various EBV proteins, we studied blood serum samples from healthy individuals (2010, 2016, 2019, 2020, 2021 and 2022) from the collection of the N. F. Gamaleya National Center of Epidemiology and Microbiology.Results. For the first time, the intensity of EBV epidemic process among apparently healthy adult residents of the capital was assessed using samples of biological material and a biobank information database. At the time of examination, 0,8% of individuals were not infected with EBV, and 9,4% suffered reactivation of a chronic infection. There were no significant changes in detection rate of markers over the years.Conclusion. Certified collections of blood sera can be effectively used to study population immunity, the prevalence of individual infections, population protection nationwide, etc.

Relevance. The identification of determinants of the human genome, such as single nucleotide polymorphisms (SNPs), in association with various disease patterns, including infectious diseases, is one of the most actively developing areas of scientific research in the world.. Hepatitis C (HC), which remains a serious global health problem, belongs to the number of infections that attract the attention of specialists. Aims. Determination of genetic markers of hepatitis C virus (HCV) natural elimination and assessment of their role as a monitoring parameter of the epidemiological surveillance system. Materials and methods . The study included 660 people divided into 2 groups: persons with chronic HC (CHC) and blood donors (indicator group of the healthy population). In the studied groups, the following SNPs were typed: rs1143634, rs1143627 (IL-1B); rs4251961, rs419598 (IL1RN); rs1800795 (IL6); rs1800896 (IL-10); rs4986790 (TLR4); rs4374383 (MERTK). The associative relationship between SNPs and CHC alleles was identified using logistic regression analysis within four models (codominant, dominant, recessive, and overdominant). Additionally, the significance of polymorphisms at the intragenic and intergenic levels was assessed using modern bioinformatic resources in the field of functional genomics. Results. In this study, genotypes associated with the natural elimination of HCV were identified. Paired combinations of IL 1RA/IL-1B genotypes associated with the probability of the formation of CHC have been established. It is shown that synonymous SNPs can be associated with any characteristics of the pathological process, which can be explained by disequilibrium in coupling with functionally significant alleles of other genetic loci. Conclusion. The detection of the association of SNPs with clinical manifestations of the pathological process is not final and requires further study taking into account ONP coupling groups.

Introduction. The WHO regularly updates influenza vaccine recommendations to maximize their match with circulating strains. Nevertheless, the effectiveness of the influenza A vaccine, specifically its H3N2 component, has been low for several seasons. The aim of the study is to develop a mathematical model of cross-immunity based on the array of published WHO hemagglutination inhibition assay (HAI) data. Materials and methods. In this study, a mathematical model was proposed, based on finding, using regression analysis, the dependence of HAI titers on substitutions in antigenic sites of sequences. The computer program we developed can process data (GISAID, NCBI, etc.) and create real-time databases according to the set tasks. Results. Based on our research, an additional antigenic site F was identified. The difference in 1.6 times the adjusted R2, on subsets of viruses grown in cell culture and grown in chicken embryos, demonstrates the validity of our decision to divide the original data array by passage histories. We have introduced the concept of a degree of homology between two arbitrary strains, which takes the value of a function depending on the Hamming distance, and it has been shown that the regression results significantly depend on the choice of function. The provided analysis showed that the most significant antigenic sites are A, B, and E. The obtained results on predicted HAI titers showed a good enough result, comparable to similar work by our colleagues. Conclusion. The proposed method could serve as a useful tool for future forecasts, with further study to confirm its sustainability.

Aim. To evaluate the safety of immunoglobulins (Ig) of different classes (IgA, IgM, IgG, IgE) under conditions of long-term low-temperature storage of blood serum samples. Material and methods. The work used samples of blood serum from the collection of the Department of Epidemiology, examined by enzyme immunoassay for antibodies of classes IgA, IgM, IgG, IgE twice as follows: immediately upon receipt in the laboratory and after storage at a temperature of -70о C for 8 years. Results. After the storage of seropositive sera, the level of IgA antibodies did not change significantly (p=0,7). For the remaining classes of immunoglobulins (IgM, IgG, IgE), a small (not >15%) but significant decrease (p<0,05), most pronounced for IgE, was observed. It was shown that the higher the antibody level in the samples during the first study, the more it decreased after long-term storage (correlation at p<0,05). This did not lead to false negative results, which is due to the greater accuracy in measuring small values. Conclusion. Long-term low-temperature storage of serum samples in biobank conditions ensures the safety of antibodies of different classes and is the basis for the reliability of future studies.

Introduction. Among the available scientific literature, there are no publications addressing processes of self-regulation in the parasite-host population systems with reference to chronic infections, including the infection caused by the EpsteinBarr virus (EBV infection). The aim of the study is to assess manifestations of the epidemic process of chronic EBV infection through the lens of the basic tenets of the theory of self-regulation of parasitic systems. Materials and methods. The study was performed using data from scientific publications selected from such database sources as Scopus, Web of Science, Cochrane Library, PubMed, CyberLeninka, RSCI, etc. The list of analyzed publications included published articles of the authors of this study, reporting the results of the retrospective epidemiological analysis of the incidence of infectious mononucleosis in Russia in general and in Moscow in particular, as well as the results of the laboratory tests regarding the detection frequency of specific antibodies to EBV proteins. Results. The chronic course of EBV infection promotes a close long-term interaction between the pathogen and the host. The genetic variability of the pathogen and the functions of specific and nonspecific human immune defense systems play a key role in the interaction between two heterogeneous populations and underlie their phasal self-transformation. A variety of social and natural factors (adverse chemical, physical, biological, climatic impacts, etc.) trigger the reactivation of chronic EBV infection, thus providing the continuous existence of additional sources of infection in the host population. Conclusion. The analysis of the manifestations of chronic EBV infection in the context of the theory of self-regulation of parasitic systems promotes the understanding of the factors underlying the unevenness of its epidemic process. The obtained data can be adjusted for other infections having similar transmission mechanisms and virus life cycles (including other herpes infections) to map out strategies to control the epidemic process of chronic infections spread by aerosol transmission of the pathogen.

To automate the aliquoting process, it is necessary to determine the required depth of immersion of the pipette into the blood serum. This paper presents the results of a study aimed at creating a vision system that makes it possible to determine the position and nature of the fractional interface based on the use of a convolutional neural network. As a result of training on photographic images of tubes ready for aliquoting, the neural network acquired the ability to determine the visible part of the tube, the upper fraction of its contents, and the fibrin strands with high accuracy, allowing the required pipette immersion depth to be calculated.

Bone marrow recipients are the most immunocompromizied patients who are susceptible to multiple infections. It is especially true for long-term episodes of drug-associated granulocytopenia. Our research goal was to identify risk factors of healthcare-associated infections (HAIs) in patients after bone marrow transplantation (BMT). Risk factors of developing HAIs were identified by accomplishing an analytical epidemiological “case – control” study with 973 patients participating in it. They all underwent BMT in the Hematology, Chemotherapy and Bone Marrow Transplantation Department of the Pirogov National Medical and Surgical Center on a period from 2015 to 2018. The following diseases were diagnosed in them: lymphoma (n = 158), multiple myeloma (n = 96), and multiple sclerosis (n = 719). HAIs cases were selected based on the standard (epidemiological) case definition in accordance with the Federal Clinical Recommendations on Epidemiological Surveillance over HAIs approved by the National Association of Experts responsible for Control over Healthcare-Associated Infections. Retrospective analysis established 75 HAIs cases or 7.7 % of the total number of the analyzed patients after BMT. Catheter-related bloodstream infections took the leading place among all the HAIs accounting for 52.0 ± 2.4 %. They were followed by bloodstream infections, 28.0 ± 3.1 %; lower respiratory tracts infections, 17.0 ± 3.2 %; and post-injection complications, 3.0 ± 0.6 %. Oncological diseases were established to cause HAIs in bone marrow recipients more frequently (ОR = 5.603; 95 % CI = 3.422÷9.174) than multiple sclerosis (ОR = 0.178; 95 % CI = 0.109÷0.292). This indicates that an underlying disease has its influence on a risk of infectious complications. We established a direct correlation between HAIs frequency and contamination with opportunistic microorganisms detected in objects in the hospital environment (r = 0.79, p = 0.01). This calls for implementing up-to-date disinfection provided for such objects.

The review presents information on the role of hepatitis B virus (Hepadnaviridae: Orthohepadnavirus: Hepatitis B virus) (HBV) X gene and the protein it encodes (X protein) in the pathogenesis of viral hepatitis B. The evolution of HBV from primordial to the modern version of hepadnaviruses (Hepadnaviridae), is outlined as a process that began about 407 million years ago and continues to the present. The results of scientific works of foreign researchers on the variety of the influence of X protein on the infectious process and its role in the mechanisms of carcinogenesis are summarized. The differences in the effect of the X protein on the course of the disease in patients of different ethnic groups with regard to HBV genotypes are described. The significance of determining the genetic variability of X gene as a fundamental characteristic of the virus that has significance for the assessment of risks of hepatocellular carcinoma (HCC) spread among the population of the Russian Federation is discussed.

In order to assess the clinical eff ectiveness of COVID-19 complex therapy in adults, 140 patients with a confi rmed diagnosis of a new coronavirus infection, clinical symptoms and lung damage from 25 to 75 % (mild and moderate form) hospitalized in budgetary healthcare institutions of the Omsk region were included in an open prospective observational study. Patients were evenly divided into two groups: 1 — received standard therapy in accordance with the Temporary Guidelines "Prevention, diagnosis and treatment of new coronavirus infection (COVID-19)" approved by the Ministry of Health of the Russian Federation and interferon alpha-2b preparations (Viferon ® rectal suppositories 3,000,000 IU and Viferon ® gel for external and topical use of 36,000 IU/g); 2 — received only standard therapy. In group 1 patients, elimination of the SARS-CoV-2 antigen from the nasopharyngeal mucosa occurred 2 days earlier than in group 2 patients. Also, patients receiving standard therapy and interferon alpha-2b preparations improved on average 4.5 days earlier, most of the main symptoms of the disease were stopped by the 6th day of therapy. It was noted that in patients receiving complex standard therapy with adding of interferon alpha-2b preparations, a more pronounced regression of lung tissue damage was observed, especially in patients with a high degree of their lesion according to CT data before hospitalization. By the end of treatment in group 1, the proportion of patients with lung tissue lesions of grade CT-3 signifi cantly decreased by 17%, while in group 2, the proportion of patients with CT-3 increased by 13 %. Analysis of the dynamics of laboratory parameters and the main markers of infl ammation in the therapy groups also confi rms the positive eff ect of the inclusion of interferon alpha-2b drugs in the standard therapy. No adverse events associated with the use of interferon alpha-2b preparations were registered. Thus, in patients receiving standard therapy and interferon alpha-2b preparations, recovery occurred in a shorter time. In the end, this contributed to a faster discharge from the hospital and a reduction in the burden on the bed fund and medical staff . The results obtained give grounds to recommend the inclusion of interferon alpha-2b preparations (Viferon ® rectal suppositories 3,000,000 IU and Viferon ® gel for external and topical use 36,000 IU/g) in standard COVID-19 therapy regimens in adult patients with mild and moderate forms of the disease.