Vitalina V. Klushkina

Introduction. Genetic monitoring of hepatitis A virus (HAV) is an important tool for surveillance of this infection and the identification of hepatitis A outbreaks. The aim of the study was to analyze the genetic diversity of HAV variants involved in sporadic and cluster cases of hepatitis A in 2022–2025. Materials and methods. A total of 402 HAV VP1/2A partial sequences isolated from sporadic and cluster cases in 2022–2025 in various regions of the Russian Federation were analyzed. Phylogenetic trees were constructed using a Bayesian approach implemented in the Beast2 software package using HAV sequences isolated in regions of the Russian Federation and neighboring countries since 1998. To assess changes in genetic diversity, p-distance values were analyzed in four HAV sequence samples, divided based on virus genotype and the year the sequences were isolated — before or after 2020. Results. The persistent circulation of two HAV genotypes, IA and IIIA, was demonstrated. The share of genotype IA was 78.4%, genotype IIIA — 12.7%, and imported genotype IB — 8.9%. Both genotypes, IA and IIIA, contribute to both sporadic and outbreak cases. 98% of HAV genotype IA isolates belonged to a single lineage originating from the strain that caused the 2010 outbreak in Moscow. Analysis of p-distance values confirmed a decrease in HAV genetic diversity — for genotype IA before 2020, this indicator ranged from 0.000 to 0.316, and from 0.000 to 0.087 in 2020–2024. For genotype IIIA, a decrease in the p-distance indicator was also noted, from 0.000–0.080 before 2020 to 0.000–0.029 in 2020–2024. Conclusion. The obtained results indicate a decrease in the genetic diversity of HAV against the background of a decrease in hepatitis A incidence rates, and suggest that analysis of longer regions of the viral genome might be required for molecular surveillance and outbreak investigation in the future, if the trend of decreasing genetic diversity of the virus remain.

   The objective.  To increase and assess the awareness of Sechenov University students about hepatitis C using an educational video and a specially prepared questionnaire.    Materials and methods. An educational video and a questionnaire consisting of nine questions were prepared. A survey was conducted before and after viewing, the results were analyzed. Sample population: 155 students in their first to sixth years at the Institute of Sechenov University.    Results.  All respondents were divided into levels of awareness about hepatitis C. The survey was conducted before and after viewing the educational video. Before viewing, a high level of awareness was determined in 45.8 % of respondents; an average level in 36.8 %; and a low level in 17.4 %. After viewing: a high level of awareness was determined in 61.9 % of respondents; an average level in 31.6 %; and 6.5 % had a low level of awareness.    Conclusions.  The results of the survey showed that the awareness of Sechenov University students about hepatitis C increased after watching the educational video, but there was still a need for further education on this issue.

Introduction. A sharp increase in the registered incidence of chronic hepatitis C, exceeding the average country level by more than 3 times, was noted in Omsk Region since 2023. The objective of the study was to answer the question of whether the observed increase in incidence is a consequence of the recent sharp increase in cases of hepatitis C virus (HCV) transmission, using molecular genetic analysis. Materials and methods. Amplification of HCV core/E1 fragment and Bayesian phylogenetic analysis of corresponding nucleotide sequences were performed for serum samples from 344 patients with chronic hepatitis C diagnosed in 2022–2023, which accounted for 12.6% of all chronic hepatitis C cases diagnosed during this period in Omsk Region (n = 2730). Results. Phylogenetic analysis demonstrated the presence of regional HCV clusters formed in 1990–2000s (95% HPD 1980–2014). The majority (86.0%, 295 out of 343) of HCV genotype 1a, 1b, 2a, 2c, 2k and 3a sequences isolated in 2023–2024 belong to different lineages circulating in the region for at least 10 years, which, together with the absence of large, homogeneous clusters with a recent tMRCA suggests the absence of a recent epidemiological link between these HCV cases. However, 12 (3.5%) sequences formed pairs with divergence in 2021–2023 (95% HPD 2018–2024), which indicates recent infection and suggests the presence of an epidemiological link between these cases of infection. Such pairs were identified for HCV genotypes 1a, 1b, 2a and 3a. Conclusion. The observed upsurge in chronic hepatitis C incidence in Omsk Region apparently reflects the accumulated number of cases of HCV infection in the region resulted from transmissions occurred 10–20 or more years ago, and is a consequence of the increase in the HCV testing coverage. With an increase in the testing rates, especially in vulnerable groups where a significant number of undetected HCV infections are concentrated, an increase in the incidence of chronic hepatitis C can be expected in other regions of the country.

A serious problem on the way to creating population immunity is the anti-vaccination movement and medical diversions from immunization. The increase in the number of parental refusals to vaccinate is due to a number of reasons, one of which is the passive position of medical workers in promoting vaccination among the population, which is the result of insufficient awareness of this issue. In addition, the active activity of a mass and aggressive media campaign about the dangers of vaccinations also deals a blow to the creation of collective immunity. The purpose of the study: to identify the causes that affect the negative attitude of the population and medical workers to vaccination work and to evaluate measures aimed at an adequate attitude to vaccination. As part of the European Immunization Week, a survey of the population on immunoprophylaxis was conducted. It has been found that health workers are more committed to immunization for themselves and their children. At the same time, it is noted that persons with medical education can conduct subjective overdiagnosis, identifying unjustified contraindications to vaccination and signs of adverse reactions in themselves and their children. When comparing the causes of negative attitudes towards vaccination among medical workers and the population without medical education, it was revealed that for doctors the main causes are adverse reactions and post — vaccination complications that may appear after vaccination or have already been observed in the respondents. Thus, the conducted research made it possible to characterize the factors influencing the commitment of the Moscow population to immunoprophylaxis and identify priority areas for overcoming the formation of public opinion aimed at refusing preventive vaccinations.

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.

Background. The ongoing pandemic of a new coronavirus infection (COVID-19) determines the relevance of the analysis of epidemiological patterns of SARS-CoV-2 spread among the population of the Russian Federation.Aim — study of the manifestations of the epidemic process of COVID-19 in the Russian Federation in 2020–2022.Materials and methods. A retrospective epidemiological analysis of the incidence of COVID-19 in the Russian Federation was carried out from 03/30/2020 to 04/24/2022. The data from the Rospotrebnadzor report No. 970 “Information on cases of infectious diseases in persons with suspected new coronavirus infection”, information portal Stopcoronavirus.rf, etc. were used. The presence of SARS-CoV-2 RNA was confirmed by real-time RT-PCR.Results and discussion. The analysis of the manifestations of the epidemic process of COVID-19 in the Russian Federation in 2020–2022 showed the presence of two stages which differed depending on the influence of the biological factor and the ongoing anti-epidemic measures. There was a pronounced trend in the development of the epidemic process, starting from megacities (Moscow, Moscow region and St. Petersburg), which are major transport hubs and centers of migration activity of the population, to the regions of the Russian Federation. The SARS-CoV-2 pathogenicity has been shown to decrease with each subsequent cycle of the rise in the incidence of COVID-19 against the background of the increased contagiousness of the virus.Conclusion. As a result of the study, risk areas (megacities) and risk groups were identified.

Relevance. Hepatitis B is a global problem of global and Russian public health due to its high prevalence and the possibility of forming a chronic form of the disease with the development of cirrhosis and hepatocellular carcinoma.  Aims. Assessment of the herd immunity to hepatitis B in the population of the Russian Federation in 2017‒2019.Materials and methods. The research was carried out at the Central Institute of Epidemiology within the framework of a large-scale program to assess herd immunity to hepatitis B in the population of the Russian Federation. The results of studies for the presence of anti-HBs in various subjects of the Russian Federation in 2017 to 2019, which were performed in accordance with MU 3.1.2943-11, were analyzed. Additionally, as a reference study in 2020, a survey of donors in Moscow (n = 427) was conducted for the presence of anti-HBs. Standard methods of descriptive statistics Microsoft Excel and STATISTICA 12.0 (StatSoft, USA) were used for statistical processing. The mean values were estimated taking into account the 95% confidence interval [95% CI] (according to the Klopper-Pearson method (exact method).Results. The average annual values of the proportion of persons with protective immunity against hepatitis B for 2017, 2018 and 2019 were 70.03%, 67.95% and 66.36%, respectively. Significant differences were revealed in the average values of the proportion of persons with a protective level of anti-HBs in the Federal Districts (FD): higher than the average Russian indicators were found in the Northwestern (74.2%), Southern (71.0%) and Far Eastern FD (70.7%). In 44 subjects of the Russian Federation during the observation period, the proportion of persons with protective immunity against hepatitis B was less than 60%.Conclusion. The necessity of optimizing the system of serological monitoring of post-vaccination immunity against hepatitis B is substantiated, which will increase the effectiveness of preventive measures nationwide

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.

Aim. Identification of epidemiological patterns of the SARS-CoV-2 spread among the population of St. Petersburg during the one-year COVID-19 pandemic period.Materials and methods. The performed analysis focused on the dynamics of COVID-19 cases in St. Petersburg from 2/3/2020 to 4/4/2021 and on the gender-age profile of patients. The information about patients (age, gender, type of the disease, hospitalization, social, and occupational status) was obtained from the database containing the materials from statistical data form No. 058/u.Results. After one year, the dynamics of reported cases of COVID-19 in St. Petersburg shows two cycles of seasonal surge (spring and autumn-winter) and 8 epidemic periods. It has been found that there are no gender-age differences among COVID-19 patients, which can be seen from the relatively similar number of cases among men and women per 100,000 people in each age group during specific epidemic periods. The strong association between clinical manifestations of COVID-19 and the patients' age was detected: Severe cases were more frequently diagnosed in patients over 70 years, regardless of their gender identity. Based on the social and occupational status, the people who were most exposed to the COVID-19 epidemic process were retirees and people whose occupation was associated with health and safety of St. Petersburg. Among the COVID-19 patients, retirees accounted for 13.69% (men) and 17.67% (women). The proportion of healthcare workers was 3.67% (men) and 9.41% (women).Conclusion. It has been assumed that COVID-19 tends to be a seasonal disease featuring annual autumn-winter epidemic cycles. The study addressed prospects of preventive vaccination against COVID-19 in Russia and the importance of tracking the complications pathogenetically associated with the acute phase of the disease in the system of epidemiological surveillance.

Background.The COVID-19 epidemic in the Russian Federation, which began in March 2020, caused serious damage to health of the population and led to severe economic losses. By December 28, 2020, 3 078 035 cases of COVID-19 and 55 265 lethal outcomes were registered in the country. The population of all territorial subjects of the country is involved in the epidemic process of COVID-19. The severe epidemiological situation made it necessary to conduct an analysis to identify the factors that determine the high intensity of the epidemic process, as well as the population groups with the highest risk of SARS-CoV-2 infection. Aims to study the patterns of SARS-CoV-2 spread and the epidemiological features of the initial stage of the COVID-19 pandemic in the Russian Federation in 2020. Methods.An epidemiological analysis of the COVID-19 situation in the Russian Federation was carried out to determine the dynamics of morbidity, the gender proportion and age structure of patients, the proportion of hospitalized patients, the ratio of various forms of infection, the social and professional status of patients. Standard methods of descriptive statistics Microsoft Excel and STATISTICA 12.0 (StatSoft, USA) were used for statistical processing. The mean values were estimated with a 95% confidence interval [95% CI] (the exact Klopper Pearson method). Results.During the observation time (2020), several periods were identified in the dynamics of the new COVID-19 cases detection: the period of importation of SARS-CoV-2 and the increase in morbidity, the period of epidemic decline, the period of autumn growth, the period of sustained high incidence of COVID-19. It was found that people over 70 years of age are the group with the highest risk of infection and a more severe course of COVID-19. The presence of target contingents among social and professional groups of the population, which should include medical workers, retired person, employees of educational institutions, law enforcement agencies, transport, who require special attention and medical and social support, was shown. Conclusions.The analysis showed that the large-scale spread of COVID-19 requires in-depth epidemiological studies and the development of additional disease control measures, taking into account the dynamics of the incidence of this socially significant infection.