Tularemia is a widespread bacterial zoonotic infection in the world, the causative agent of it in our country is classified as pathogenicity group 2, which corresponds to group 3 according to the international classification for laboratory services. F. tularensis is considered a potential agent of category A bioterrorism. The review presents current information about the causative agent of tularemia, the features of the clinical course of the infection and the incidence rate associated with its different subtypes. The possibilities of treatment and prevention of the disease are highlighted. The material is presented from the point of view of whether the infection meets the criteria for a particularly dangerous disease. The species includes 4 subspecies, of which only one, present only in some states of the United States and probably the evolutionarily oldest, is assessed as highly virulent. The subspecies most widespread on the European continent is classified as moderately virulent and causes diseases that do not meet the criteria for a particularly dangerous disease in terms of severe and mortality rate. There is a list of drugs that are quite effective against the causative agent of tularemia, provided they are prescribed in a timely manner. The incidence of tularemia in countries where it is registered does not exceed sporadic levels. However, a feature of the pathogen is plasticity in the external environment which determines the long-term preservation of the epizootic potential of natural foci. In some years large outbreaks of infection occur, often in the absence of visible risk factors. The possibilities of specific and nonspecific prevention are limited and can reduce the risk of infection of the population only with a timely, quick and adequate response to changing situations. In various countries work is underway to create vaccines on different technological platforms, but currently only Russia, Belarus and Kazakhstan use the live attenuated vaccine. Although by wild strains is not a particularly dangerous disease, it requires close surveillance.

A prospective randomized observational study was conducted in cohorts of vaccinated and unvaccinated patients hospitalized in one of the Moscow hospitals and diagnozed with COVID-19 in the period from 06.23.2021 to 01.05.2022.

The purpose of the study was to identify the epidemiological features of COVID-19 in vaccinated people and to present scientifically based data on the need for vaccination and its importance in stopping the epidemic process.

Materials and Methods. The samples were studied in comparison for a number of indicators: age, clinical condition at admission, the presence and number of concomitant systemic chronic diseases as well as disease outcomes.

Results. It was proven that the risk of COVID-19 morbidity in vaccinated people decreased by 1.5 times, mortality by 1.5 times, and hospitalization due to the severity of the condition by 3.1 times. The mortality risk among vaccinated patients shifted to older age (76.9 years), while among unvaccinated patients, the mortality risk was higher for older people (73.7 years), which indicates an increase in life expectancy of vaccinated people.

The inhabitants of the planet in the XXI century are experiencing a second pandemic. The new coronavirus SARSCoV-2 is distinguished not only by its ubiquitous spread, but also by the possibility of developing adverse outcomes, which does not cause anyone doubts today.

Aim. To present the dynamic characteristics of children’s health depending on the form of severity of the new coronavirus infection (COVID-19).

Material and methods. A prospective single-center clinical study of the complex state of health of children hospitalized in a monoinfective hospital on the basis of the GUZ “City Clinical Hospital” was conducted. The observation included 86 convalescents of a new coronavirus infection aged 7 to 14 years. Dynamic monitoring was carried out for children for 1.5 years from the moment of infection with SARSCoV-2, control visits were performed 1, 6 and 18 months after the disease.

Results and discussion. According to the results of a comprehensive assessment of the health status of children after COVID-19, an increase in the number of registrations of recurrent upper and lower respiratory tract infections in convalescents of a moderate form of a new coronavirus infection was found. In 35 (41%) children after infection with SARSCoV-2, concomitant diseases were recorded, in contrast to 23 (26.7%) cases recorded before the pandemic. The structure of concomitant pathology in COVID-19 convalescents is represented by endocrine pathology in 30.2% of cases, in patients after moderate forms of the disease, the frequency of eating disorders (19.8%) increased by 2 times relative to the period before COVID-19, type 1 diabetes mellitus was first detected in 1 (1.2%) child. Diseases of the nervous system (20.9%) were 1.9 times more likely to be diagnosed after COVID-19. Diseases of the eye and its accessory apparatus were registered in 16.3% of children, more often after a moderate form of the disease. The number of cases of gastrointestinal pathology has not changed. Diseases of the respiratory system were recorded in 4.7% of patients, skin and subcutaneous tissue – 3.5% of the examined.

Conclusion. A comprehensive assessment of the health status of children after COVID-19 for 1.5 years allows us to establish a decrease in the response of the child’s macroorganism to acute respiratory infections, an increase in the number of registered comorbidities, the relationship between the severity of COVID-19 and its consequences for children.

Purpose. To evaluate the tolerability, safety and immunogenicity of influenza inactivated split flu vaccine Flu-M during single immunization of children aged 6 to 17 years.

Materials and methods. A multicentre double-blind comparative randomised clinical trial of influenza inactivated split vaccine Flu-M for immunisation of children aged 6 to 17 years (the reference agent – Ultrix vaccine) was conducted. Children aged 12 to 17 years inclusive (300 children) were studied at stage I, and children aged 6 to 12 years (300 children) at stage II. Volunteers of each age category were randomised 1:1 into 2 groups comparable in sex and age, one was vaccinated with Flu-M vaccine and the other with Ultrix vaccine. The follow-up, including various laboratory and clinical tests, lasted for 28 days from the time of vaccination.

Results. Both vaccines were well tolerated by children aged 12 to 17 years and by children aged 6 to 12 years. There were no severe or serious adverse events. By all criteria of immunogenicity evaluation, vaccine Flu-M was not inferior to the comparison vaccine Ultrix.

Conclusion. Influenza inactivated split Flu-M vaccine produced by SPbNIIVS is approved for use for specific prophylaxis of influenza in children aged 6 to 17 years in the Russian Federation, the Republic of Belarus, Latin America and the Caribbean.The trial is registered at ClinicalTrials. gov (NCT 05317767).

Relevance: the annual incidence of acute respiratory infections (ARI) is in the lead in the structure of infectious pathology in the Russian Federation. One of the main issues is the development of optimal strategies for prevention of these diseases in high-risk groups.

Aim: to evaluate the preventive and clinical efficacy as well as safety of various dosage forms of interferon alpha-2b in relation to ARI in young adults from organized groups.

Materials and methods: our study included 300 volunteers aged 18 to 20 years, 100 of them were prescribed interferon alpha-2b in the form of a gel in addition to non-specific methods for the prevention of ARVI, 100 participants received interferon alpha-2b in the form of an ointment, 100 participants did not receive antiviral drugs.

Results: the use of interferon alpha-2b ointment for prevention of ARI in organized groups significantly reduced the number of people who had ARVI and cases of ARI during the observation period. Among those who used interferon alpha2b no pneumonias occurred, the duration of hospitalization was statistically significantly reduced compared to the group of volunteers who used only non-specific prophylaxis methods. Participants who received interferon alpha-2b ointment had ARVI mainly in a mild form. No adverse events that could be associated with the use of the study drug were recorded during the observation period.

Conclusion: the use of interferon alpha-2b in the form of ointment showed preventive and clinical efficacy against ARI in young adults from organized groups.

Objective: to study polymorphic variants of TLR3 (rs3775291) and TLR9 (rs352140) genes in patients with COVID-19 depending on the severity of the disease and their significance for determining the risk of severe course of COVID-19.

Materials and Methods: genetic analysis of polymorphism of TLR3 (rs3775291) and TLR9 genes (rs352140) was performed in 164 patients with COVID-19, who were divided by degree of severity into three groups: Group 1 with mild, Group 2 with moderate and Group 3 with severe and extremely severe degrees of severity. The control group consisted of 40 healthy donors. Statistical processing of the obtained results was carried out using STATISTICA 12.0 programs (Stat Soft, USA). To assess the difference of groups by qualitative characteristics, the χ2 criterion with Yates correction was used, and in case of violation of its conditions, the χ² criterion was applied. Yates correction, and if the conditions of its applicability were violated, the two-sided Fisher’s two-sided criterion (RF). The difference between the groups was considered statistically significant at р<0,05. The strength of associations was evaluated in the values of the odds ratio index odds ratio (OR) and 95% confidence interval.> ˂ 0,05. The strength of associations was evaluated in the values of the odds ratio index odds ratio (OR) and 95% confidence interval.

Results: the frequency of the ST genotype was significantly higher and the frequency of the TT genotype of the rs3775291 allele of the TLR3 gene was significantly lower in patients with the manifest form of COVID-19 compared with the control group. Frequency analysis of TLR9 (rs352140) in COVID-19 patients showed significantly higher values of the ST genotype and lower values of the CC genotype compared to healthy individuals. Comparative analysis between groups of hospitalized patients depending on severity revealed higher frequency of ST genotype and lower frequency of TT genotype of TLR3 (rs3775291) and TLR9 (rs352140) genes in patients with severe and extremely severe condition.

Conclusion: reliable differences in the frequency of occurrence of genotypes of TLR3 (rs3775291) and TLR9 (rs352140) genes in patients with the manifest form of COVID-19 compared to healthy people were revealed. The analysis of nucleotide sequence variants of the studied genes in hospitalized patients depending on the degree of severity also showed significant differences in the frequency of genotypes. Thus, in patients with severe and extremely severe COVID-19, a significant difference in the frequency of occurrence of ST and TT genotypes of TLR3 (rs3775291) and TLR9 (rs352140) genes was revealed compared to patients with mild and moderate COVID-19, which may further have prognostic value in assessing the severity of the disease.

Aim: To evaluate the diagnostic significance of the relationship between the level of microRNA-122 expression and liver fibrosis during HDV infection.

Materials and methods. The expression of microRNA-122 was determined in 203 blood samples. Blood sampling was done from 53 patients with chronic viral hepatitis D, 49 patients with liver cirrhosis of HDV etiology, and 69 patients with newly diagnosed HBs antigenemia. The control group consisted of practically healthy individuals (n=32).

Results. In patients with negative RNA HDV levels, the level of microRNA-122 in the blood serum was significantly higher than in samples with positive RNA HDV levels (14.0±2.8 2^-ΔΔCt and 1.6±0.17 2^-ΔΔCt) (p ˂ 0.005). Meanwhile, in healthy individuals, the expression of microRNA-122 was statistically significantly lower – 1.3±0.03 2^-ΔΔCt (p ˂ 0.005). Undetectable levels of HDV RNA in the serum were accompanied by a high HBV viral load and a significantly higher level of microRNA-122, which was 8.7 times higher than in the group of HDV RNA-positive patients (p<0.005). In patients with liver fibrosis F1, the expression of microRNA-122 was higher than in patients with liver fibrosis F2, F3, F4 (p = 0.0001). The lowest levels of microRNA-122 were observed in liver fibrosis F4. Conclusion. The expression level of microRNA-122 in blood serum during HDV infection decreases as liver fibrosis progresses. The development of cirrhosis is accompanied by a 3.7-fold drop in the level of microRNA-122 compared to the group of patients with chronic hepatitis D. MicroRNA-122 can be used in laboratory monitoring of patients with various stages of HDV infection as an indicator of the activity of the process, assessing the severity of liver damage and the rate of progression of liver fibrosis.> ˂ 0.005). In patients with liver fibrosis F1, the expression of microRNA-122 was higher than in patients with liver fibrosis F2, F3, F4 (p = 0.0001). The lowest levels of microRNA-122 were observed in liver fibrosis F4.

Conclusion. The expression level of microRNA-122 in blood serum during HDV infection decreases as liver fibrosis progresses. The development of cirrhosis is accompanied by a 3.7-fold drop in the level of microRNA-122 compared to the group of patients with chronic hepatitis D. MicroRNA-122 can be used in laboratory monitoring of patients with various stages of HDV infection as an indicator of the activity of the process, assessing the severity of liver damage and the rate of progression of liver fibrosis.

The stable increase in morbidity and mortality of the population of the Republic of Sakha (Yakutia) from causes related to HIV infection indicates an unfavorable epidemiological situation in the region. Especially it affects industrial areas and large settlements of Yakutia. In the near future, an increase in the number of HIV-infected patients in the republic is expected, which is alarming. The HIV epidemiological situation is aggravated by the unequal distribution within the region with extremal environmental conditions and underdeveloped transport infrastructure. All this makes it much more difficult to provide medical care to this category of people, some of whom later move outside the territory of the Republic.

Aim: Improvement of effective preventive measures and organization of medical care in the Arctic regions of the Republic of Sakha (Yakutia) based on the analysis of morbidity and mortality from HIV infection.

Materials and methods: The materials of official statistics of the Department of the Federal Service for Supervision of Consumer Rights Protection and Human Welfare in RS(Ya) and data from official governmental medical reports (forms № 61 and № 4) were used in the work.

Results: The number of HIV-infected people on the territory of the Republic of Sakha (Yakutia), including in the Arctic regions, is growing in recent years. Thus, from 1998 to 2022, 77 new cases of HIV infection were detected in the Arctic regions, more than half of which (54.5%) were registered in the period from 2016 to 2022. The tendency of growth of the indigenous population affected by HIV infection, including in remote areas of the region, that dictates the need for mandatory HIV screening of all persons arriving for shift work both from neighboring countries and from other regions of the Russian Federation.

Conclusion: Preventive measures, HIV testing and organization of medical care are the basis for effective fight against this disease, especially in remote Arctic regions of the Republic of Sakha (Yakutia).

The study’s objective was to reveal trends in infections transmitted by ixodes ticks epidemic processes and the level of seroprevalence of the population to the tick-borne encephalitis virus, Borrelia burgdorferi sensu lato, Coxiella burnetii, Anaplasma phagocytophilum and Ehrlichia chaffeensis/ E. muris in the Leningrad Oblast.

Materials and methods. A retrospective epidemiological analysis of the tick-bite incidence rate, the ixodic tick-borne borreliosis, tick-borne encephalitis, Q fever, human granulocytic anaplasmosis and human monocytic ehrlichiosis incidence rates, as well as vaccination against tick-borne encephalitis of the population of the Leningrad Oblast in 20112020. The official data of the tick-bite incidence rate, infections transmitted by ixodes ticks incidence rates and vaccination of the population was taken from the forms of federal statistical observation No. 2 and No. 5. Blood was sampled in 2019-2020 from randomly selected donors. Blood serum samples were examined by enzyme-linked immunosorbent assay for the presence of IgG antibodies to the pathogens of the studied infections using commercial test systems according to the manufacturer’s instructions.

Results. In the Leningrad Oblast, in 2011-2020, there was a downward trend in the tick-bite incidence rate, as well as in the incidence rates of infections transmitted by ixodic ticks. The long-term average tick bite incidence rate was 369.0. The long-term average incidence rate of ixodic tick–borne borreliosis was 4.1; tick–borne encephalitis was 1.4; Q fever was 0.02. During the analyzed period, no cases of human granulocytic anaplasmosis and human monocytic ehrlichiosis were reported. The seroprevalence to tick-borne encephalitis virus was 1.7%; to B. burgdorferi s. l. – 3.7%; to C. burnetii – 1.8%; to A. phagocytophilum – 1.0%; to E. chaffeensis/ E.muris – 3.2%.

Conclusion. The results obtained indicate the existence of active natural foci of infections transmitted by ixodes ticks, fairly frequent contact of the residents with these foci, and possible significant hypodiagnosis of these infections in the Leningrad Oblast.

A brief scientific biography of Professor V.G. Bochorishvili is presented, his contribution to the development of the science of infection and the role of the forerunner in the formation of the scientific concept of “infectology” is shown.

A clinical case of the course of malaria in a pregnant woman in the second trimester of pregnancy who returned from the Republic of Ghana is described. A multidisciplinary approach to the treatment of the disease made it possible to avoid the death of a woman. However, the extremely severe course of infection and the complications of this disease that have arisen have led to intrauterine fetal death.

A description of a clinical case of a severe, protracted course of coronavirus infection (COVID-19) in a patient with advanced stage HIV infection, characterized by prolonged release of the SARS-CoV-2 virus and the formation of pulmonary fibrosis against the background of an active viral infection, is presented. COVID-19 infection occurred in an immunosuppressed patient without ART. During the period of inpatient treatment, a comprehensive examination was carried out to exclude HIV-associated lung lesions; no evidence of viral, fungal, or bacterial pathology was obtained; mycobacterial infections were also excluded. Despite two courses of antiviral therapy, the use of anti-Covid plasma and complex pathogenetic therapy, persistence of SARS-CoV-2 replication was observed for eight months, with a steady progression of the disease, ending in death.

Complications after the introduction of the tuberculosis vaccine develop extremely rarely. They become accidentally vaccinated infants with undiagnosed severe immunodeficiency. The article considers a clinical case of the course of disseminated BCG infection with multiple organ damage in congenital immunodeficiency in a 9-month-old boy. The disease manifested itself acutely, the child’s condition worsened within a week, and its outcome was the death of the baby. Primary immunodeficiency was confirmed by the results of a pathoanatomic examination. The discussion provides a classification of complications after the introduction of BCG vaccine, the algorithm of the doctor’s actions in case of a suspected complication after vaccination, and also describes the main signs of immunodeficiency.