Epidemiology and Infectious Diseases. Current Items

Objective. Evaluation of the role of viral hepatitis (VH) in the structure of infectious diseases in the Republic of Tatarstan and objective assessment of the prevalence of various nosological forms of VH to determine the strategy to combat them.

Materials and methods. The statistical observation forms №. 2 «Information on infectious and parasitic diseases» for the period from 2001 to 2023, annual reporting forms were used. Epidemiological and statistical research methods were applied.

Results. In the Republic of Tatarstan, in the structure of viral infections excluding respiratory viral infections, VH ranks second with a share of 18.8%. In the VH structure, chronic VH with a primary diagnosis account for 86.4%, the prevailing role among them belongs to chronic VH (75.3%). In 2001–2019, an average of 81.6±14.3% of patients with chronic VH were followed-up and underwent clinical and laboratory examinations. In 2020, the proportion of those who underwent follow-up monitoring decreased to 41.8%, which was associated with the introduction of anti-COVID restrictive measures in hospitals. A direct strong correlation between the first-time registered patients with chronic hepatitis and the proportion of patients with clinically expressed and latent forms of chronic hepatitis who underwent follow-up monitoring was established (r = 0.9999; p < 0.05).

Conclusion. In the Republic of Tatarstan, a decrease in the number of newly diagnosed clinically expressed and latent forms of hepatitis is observed. However, the lack of official registration of the latent course of the disease in HBsAg and anti-HCV carriers requires in-depth medical examination of such patients before diagnosis to organize anti-epidemic and preventive measures.

Objective. Assessment of the incidence and seasonality of norovirus infection (NVI) among children under 17 years of age in the Omsk region from 2017 to 2023.

Materials and methods. Official reporting forms with epidemiological data for 2017–2023 were used.

Results. The region has been experiencing a consistently high rate of confirmed cases of viral intestinal diseases (from 82.6% to 91.8%) among the entire population of the region for 7 years. The share of NVI increased from 8.1 to 25.1%, while the frequency of registration of cases of the disease in persons under 17 years of age ranged from 70.0 to 79.1%. Norovirus gastroenteritis was registered in children of all ages. The highest rates were observed in the age group from 1 year to 6 years, while cases of the disease were more common in children attending preschool institutions. Among children over 7 years of age, the incidence of norovirus infection decreased. Seasonality for NVI in the Omsk region was typical.

Conclusion. Most often, NVI affects organized preschool children, mainly in the cold season. The increase in the incidence of viral intestinal infections requires an expansion of the spectrum and volume of diagnostic virological studies.

Objective. Evaluation of the prospects for using integrative indicators based on laboratory data to analyze the completeness and objectivity of morbidity data, as well as comparative and operational assessment of the effectiveness of the epidemiological surveillance system for the new coronavirus infection (COVID-19).

Materials and methods. The calculation and analysis of integrative indicators was carried out based on the results of PCR studies for the presence of SARS-CoV-2 RNA according to the SOLAR (System of Laboratory Aggregation Result) platform and information on the incidence of COVID-19 in the constituent entities of the Russian Federation for the period 2022–2023.

Results. It is shown that the results of PCR studies can be used to assess the dynamics of the epidemic process. Methods for assessing the completeness and objectivity of morbidity data in the constituent entities of the Russian Federation using integrative indicators are proposed. The use of integrative indicators to identify regional characteristics in the diagnosis and recording of COVID-19 cases is substantiated.

Conclusion. Integrative indicators based on morbidity data and laboratory data can be successfully used as criteria for assessing the completeness and objectivity of information in epidemiological analysis. They can also serve as a basis for comparative and operational assessment of the effectiveness of the epidemiological surveillance system.

Objective. Evaluation of the efficiency of short PCR amplicons destruction using a continuous spectrum pulsed radiation source.

Materials and methods. Using a pulsed UV source, experiments were conducted on 117 bp DNA amplicons. The efficiency of decontamination was assessed based on the residual amount of amplicons in washes from work surfaces such as plastic, glass, and metal.

Results. High efficiency of pulsed UV radiation in combating DNA contamination was demonstrated, and the optimal irradiation time (10–12 min), sufficient for complete destruction of amplicons on various types of surfaces (plastic, glass, metal) was determined. The data obtained make it possible to reduce the time of room treatment and reduce the negative impact of UV radiation on laboratory equipment and premises.

Conclusion. The feasibility of using pulsed units generating high-intensity continuous spectrum UV radiation flows for the destruction of amplicons on various surfaces was demonstrated.

Background. The frequency of infectious complications in cardiac surgery varies widely, and the mortality rate reaches 30%. Active implementation of risk-oriented technologies requires ensuring a high level of epidemiological safety.

Objective. Evaluation of the effectiveness of epidemiological monitoring technology for assessing the risk of infection.

Materials and methods. For 153 days, all 111 patients admitted for planned coronary artery bypass grafting underwent continuous prospective epidemiological observation with microbiological monitoring of colonization of the main loci. Biological material was collected from three loci at five stages of the patient’s stay in the hospital. The quality of disinfection was controlled by washings from environmental objects (764 samples). 242 samples of various materials and instruments were tested for sterility.

Results. The most common microorganisms were Klebsiella pneumoniae, Staphylococcus aureus, Enterobacter cloacae. During microbiological monitoring, colonization of patients with Klebsiella pneumoniae at the stage of surgery was revealed during transesophageal echocardiography, which increased the likelihood of infection by 9.58 times. An analysis of discrepancies and their correction were performed, which excluded the transmission of the pathogen during the procedure.

Conclusion. Epidemiological monitoring technology is an effective diagnostic measure for assessing the risk of healthcare-associated infections. Epidemiological monitoring with microbiological control provides assessing the risk of infection and suggesting measures to minimize it.

The article considers unsolved problems of scientific and applied nature concerning complex comorbidity as a marker of aging, poor study of co-infections in human reproductive function disorders, problems of diagnostics and especially treatment of patients with complex comorbidity. The article considers in detail unsolved issues of epidemiology, microbiology, immunology and organizational nature, as well as the reasons for the formation of combined multicomponent pathology and problems of training personnel in this area of epidemiology.

Objective. Evaluation of the prevalence and dynamics of respiratory syncytial virus (RSV) circulation in the post-pandemic years in Russia, as well as assessment of the genetic diversity of the virus based on the G gene sequence according to the classification proposed in 2024.

Materials and methods. The analysis of summary data of selective laboratory studies in the weekly dynamics of biomaterial of 4,667,302 patients with acute respiratory infection from 89 regions of Russia was carried out. Children under 6 years of age accounted for 38.5% of the total number of examined patients. Differentiation of RSV-A and RSV-B was carried out using the developed method of amplification of the G gene with real-time detection. The coding region of the RSV G gene was sequenced by the Sanger method for 32 samples of viral RNA detected in different epidemic seasons in patients in Moscow. The nucleotide sequences were deposited in the Russian VGARus (Virus Genome Aggregator of Russia) database and the international GISAID database. Phylogenetic analysis was performed using the MEGA7 program by the TN93+G algorithm, bootstrap 1000.

Results. The highest frequency of RSV detection in all seasons was recorded in infants and, in aggregate, in young children, the lowest – in individuals aged 16–25 and 26–64 years. Over the years of follow-up, RSV has been detected year-round with periods of rise and decline. In individuals over 65 years old, RSV was detected more often than in the group of individuals aged 26-64 years. In the 2021–2022 season, there were no clearly defined peaks; RSV-A, clydes A.D.3 and A.D.5.1 circulated. In the post-pandemic season of 2022–2023, as well as in Europe, an increase in the incidence of RSV infection was noted in the autumn months. At this time, there was a change in the circulation of RSV-A to RSV-B (clyde B.D.E.1). In the 2023-2024 season. a shift in the incidence rate to the winter period with a sharp jump of more than 2 times at the peak (week 9, 2024) was noted, which was associated with the emergence of RSV-A and, apparently, its genetic variant A.D.5.2, which was new to Russia, with the preservation of previously circulating antigenic variants of subtype A (A.D.1, A.D.3) and subtype B (B.D.E.1).

Conclusion. The developed protocol for differentiating the RSV-A and RSV-B subtypes does not require labor-intensive virological studies and can be proposed to improve the epidemiological surveillance of RSV infection. During the follow-up period, RSV was detected year-round, against this background, 2 sharp peaks in the incidence of RSV infection were noted, which, as our study showed, were associated with the alternation in circulation of RSV-B and RSV-A and the emergence of new genetic variants that are not endemic, but have also been detected in other countries of the world. Similar to influenza viruses, RSV evolution is a global process of spreading genetic variants around the world, so a single immunization strategy can be used to prevent severe infection in risk groups.

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