Relevance. In patients with circulatory system diseases, Klebsiella pneumoniae isolates carrying both hypervirulence and multidrug resistance are one of the most common causative agents of healthcare-associated infections (HAI). The main sequence types (ST395, ST307) of Klebsiella pneumoniae are shown, virulence marker genes (AbST, YbST and RmST), determinants of beta-lactam resistance (bla , bla , bla ), including carbapenems (bla , are identified.

Aim. To investigate the determinants of antibiotic resistance and virulence markers of clinical isolates of Klebsiella pneumoniae in patients with circulatory system diseases (CSD).

Materials and methods. We studied 69 isolates of Klebsiella spp., collected from November 2022 to October 2023 from samples of pathological materials from patients of two large centers for the treatment of patients with CSD who had registered cases of HAIs according to NASCI criteria. The species identity of isolates to the Klebsiella spp. genus confirmed by mass spectrometry. PCR was used to determine the presence or absence of carbapenemase and aerobactin genes for strain typing. Antibiotics susceptibility was determined by the disk diffusion method and broth microdilution method. The complete set of genes determining resistance and virulence was identified in 17 Klebsiella pneumoniae isolates using whole genome sequencing. Functional annotation of genomes was performed by the bioinformatic resource Kleborate v3. and Kaptiv.

Results. The studied Klebsiella pneumoniae strains were characterized by different degrees of phenotypic drug resistance: predominantly broad/extreme XDR) – 78.57 %, multiple (MDR) – 14.29 %, pan-resistance (PDR) –7.14 %. Klebsiella pneumoniae (n = 17) for which whole genome sequencing was performed belong to 4 sequence types: to ST395 – 11 isolates (64.71 %), to ST307 – 4 (23.53 %), and one of each to ST416 and ST6 (5.88 % each). Sequence-type ST395 isolates demonstrated the properties of resistance to classes 13–14 of antibiotics, ST307 to classes 9, ST416 and ST6 did not have resistance to antibiotics. A high prevalence of the hypervirulent Klebsiella pneumoniae (hvKP) pathotype was observed: rmpA2 (82.35 %), iucA (82.35 %), a hypermucoid phenotype (Hm, 58.93 %) and carbapenem resistance (mediated by OXA-48 carbapenemase, 64.71 %).

Conclusion. Analyzed Klebsiella pneumoniae isolates are represented by 4 sequence types, widespread in European countries. HvKP isolates characterized by XDR, PDR and simultaneously carrying carbapenem resistance genes require prompt and accurate diagnosis to effectively treat patients with CSD.

Relevance. In 1973, while searching for the causative agent of HFRS, virus strains were isolated from bank voles that exhibited no cytopathogenicity in continuous human, monkey, and porcine kidney cell cultures. The HFRS virus was not detected in these cell cultures. It was only in 2017 that S. V. Alkhovsky et al. established that bank vole viruses (BVVs) belong to the Paramyxoviridae family. The question of BVVs involvement in human pathology remained open.

Аim. Establish the involvement of BVV in human pathology based on the detection of antibodies to this virus among outpatients and donors in the Tula and several other regions of the European part of Russia.

Materials & Methods. Viruses: paramyxovirus RP-12 strain, GenBank # MP943130. Sera from patients with suspected HFRS, as well as donor sera from several regions of Russia, were investigated. Antibodies to the BV virus detected by ELISA and immunoblotting.

Results. The BVV virus circulation and its etiological role in human disease was established according to virological testing, PCR analysis of the organs of bank voles and serological examination of patients diagnosed with fever of unknown etiology and other categories of patients, in the Tula, Ryazan, Voronezh, Saratov, Lipetsk, Moscow, Ulyanovsk regions and the Republic of Bashkortostan.The distribution of this new infection, as well as its clinical and epidemiological characteristics in European Russia, are consistent with HFRS associated with the Puumala virus.

Conclusion. We discover the new zoonotic human infection associated with bank vole paramyxovirus similar in epidemic characteristics to HFRS. In addition, two genotypes of the BV virus identified in the forest zone of European Russia.

Relevance. Measles remains one of the most contagious infections in the world; despite the availability of an effective vaccine, disease outbreaks continue to be reported in both lowand high-immunization-coverage countries. The COVID-19 pandemic caused disruptions in healthcare systems and led to the accumulation of a susceptible population, making a comparative analysis of the epidemic process in countries with different social and climatic conditions, such as Vietnam and the Russian Federation, relevant for understanding common patterns and regional features.

Aim. To compare the main epidemiological characteristics of measles in Vietnam and the Russian Federation from 2000 to 2024.

Materials and Methods. A descriptive epidemiological study was conducted based on statistical data from open sources of the WHO (JRF, WUENIC) and national epidemiological surveillance systems. Incidence rates per 100,000 population, coverage rates for one and two doses of the measles-mumps-rubella (MMR) vaccine were analyzed.

Results. In both countries, cyclical patterns in the epidemic process persist with intervals of 2–5 years. In Vietnam, against a background of high (94 ± 3.33 %) but unstable vaccination coverage, a general trend towards decreasing incidence after 2007 is observed. In the Russian Federation, with more stable and high coverage (97.9 ± 0.26 % for MMR-1), an increasing incidence phase has been observed since 2008 (average annual growth rate of 25.2 %), reaching its maximum for the entire observation period in 2024 (15.51 per 100,000). The age structure of incidence in both countries is characterized by predominant involvement of children under 1 year and 2–4 years; however, in the Russian Federation, the most recent upsurge also involved children aged 5–9 years. A relative synchronicity of rises and declines in incidence was identified between the two countries, including a decline during the COVID-19 pandemic (2020–2022) and a subsequent sharp increase in 2023–2024.

Conclusion. Despite differences in vaccination schedules and climate, the measles epidemic process in Vietnam and the Russian Federation is characterized by similar cyclical patterns. Consistently high national average vaccination coverage does not guarantee the absence of outbreaks and may mask local immunity gaps. The increasing incidence in the Russian Federation, despite high coverage, may be associated with the accumulation of non-immune populations among adults, imported cases, and vaccination deficiencies in certain groups. The obtained data justify the need for monitoring immunization at the subnational level, catch-up vaccination, and considering adjustments to the immunization schedule (towards earlier initiation of vaccination) to reduce incidence among young children. 

Relevance. Pertussis, despite long-term mass vaccination, remains an urgent health problem, which is largely due to the difficulties of clinical diagnosis, especially in young children and with atypical forms of the disease.

Aims. To identify factors influencing the diagnostic performance of the molecular genetic method (PCR) and enzyme-linked immunosorbent assay (ELISA) in laboratory diagnosis of pertussis in children and adults in 2024–2025.

Materials and methods. The study was based on clinical analysis and analysis of medical records of patients diagnosed with pertussis hospitalized in an infectious diseases hospital in Moscow. Laboratory diagnostics were carried out by PCR and ELISA methods, taking into account the age of patients, the duration of the disease and the severity of the clinical course.

Results. It has been established that the diagnostic effectiveness of the methods significantly depends on the age and timing of the examination. PCR was shown to be highly informative in children under 1 year of age (92.4 ± 2.4 %), while in children over 1 year of age in 29.7 ± 4.3 % of cases (p < 0.001). The diagnostic significance of ELISA increased by the age of patients (in children under 1 year of age, diagnostically significant levels of anti-pertussis antibodies were detected in 29.0 ± 3.1 % of cases, then in children over 1 year of age in 85.6 ± 3.3 % of cases (p < 0.001)). A high PCR efficiency was established in weeks 1–3 of the disease in children under 1 year of age (88.9 ± 3.2 %), while at weeks 4–5 there was a decrease (to 60.8 ± 10.2 %). A correlation was found between the severity of the clinical course and the effectiveness of PCR (80.8 % for moderate forms and 52.6 % for lungs, p < 0.001). ELISA is highly effective in adults (97.3 %). Age-related features of the humoral immune response were revealed, characterized by the predominance of IgM antibodies in young children and the formation of a complex antibody response in older children.

Conclusion. The results obtained confirm the feasibility of a differentiated approach to choosing a method for laboratory diagnosis of pertussis, taking into account the patient's age and the duration of the disease. 

Relevance: Vaccination is an effective method of prevention for many infectious and non-infectious diseases. However, distrust in immunization has become a global public health challenge. Personalized tools for assessing attitudes toward vaccination are necessary to improve population adherence to vaccination programs.

Aims. To develop a binary logistic regression model for personalized assessment of an individual's attitude toward immunization.

Materials and methods. The study utilized results from an anonymous survey of 3,082 respondents (2,087 medical students and 995 non-medical students). The data were split into training (80 %) and testing (20 %) datasets. A binary logistic regression model was constructed based on responses to seven survey questions. Model evaluation was performed using ROC analysis, sensitivity, specificity, accuracy, and the F1-score.

Results. The developed model is statistically significant (p < 0.001) and explains 50.1 % of the variance in attitudes toward vaccination. The area under the ROC curve (AUC) was 0.888, indicating high discriminative ability. On the test dataset, the model demonstrated a sensitivity of 82.3 %, specificity of 86.7 %, and accuracy of 83.3 %.

Conclusion. The developed binary classifier exhibits high predictive capability for personalized assessment of an individual's attitude toward immunization. Its application can enable healthcare professionals to effectively identify individuals with uncertain or negative attitudes toward vaccination and conduct targeted educational interventions to improve vaccination adherence. To enhance the model's universality and accuracy, further training incorporating representatives of various social groups is required.

Relevance. The high contagiousness of measles makes organized groups of children and adults epidemiologically significant due to the ease of aerosol transmission and the risk of persistent secondary transmission. The literature describes various measles outbreaks, varying in duration and number of cases. The evaluation of the anti-epidemic measures implemented in these outbreaks was assessed based on the timeliness of the initiation of anti-epidemic measures, including vaccination of contacts of eligible individuals, the outbreak duration, the ratio of outbreaks with one case to outbreaks with spread of infection, and the number of cases in absolute and relative terms. However, we did not find any studies evaluating the quality of anti-epidemic measures in terms of the magnitude of prevented financial losses and the number of prevented cases.

Aims. To evaluate the effectiveness of antiepidemic measures using the example of a measles outbreak among university students.

Materials and methods. The materials used for this study included emergency notifications, a report on the investigation of the outbreak with the establishment of a cause-and-effect relationship, «Epidemiological Investigation Cards for Measles Cases and Suspected Cases», and laboratory test results for the presence of IgM and IgG to the measles virus. The study utilized descriptive retrospective epidemiological analysis, serological, and statistical methods.

Results. A measles outbreak was recorded in May-June 2024 among 266 dormitory residents. The total number of contacts, including the university, was 502 and was small relative to the total number of students and staff. This was due to the end of academic term and the academic exam period from May 12th to 30th, followed by examinations from June 3rd. Immediately after receiving the emergency notification, an epidemiological investigation was initiated and anti-epidemic measures were implemented. The contact circle and the boundaries of the outbreak were determined. Since the source of infection for the first three simultaneous cases of measles was unclear and all contacts had been vaccinated against measles twice, serological testing was conducted using the ELISA method to detect M antibodies and G anti-measles antibodies. The suspected source of infection was identified among the international students in the dormitory who had not sought medical care. 48 students with questionable G antibody results were vaccinated, and a restrictive measure in the form of distance learning was introduced.

Discussion. Although serological testing of contacts is not included in the list of mandatory anti-epidemic measures, given the risk of infection spread, it was conducted. This allowed us to identify not only suspected sources of infection but also individuals who were conditionally seronegative for the measles virus but had been vaccinated against it. This study is the first to use an objective approach to assessing the effectiveness of anti-epidemic measures, expressed in economic terms as the amount of losses prevented. We believe this is very important and promising.

Conclusion. The anti-epidemic measures proved effective, limiting the outbreak to 13 days, preventing the infection of 1,822 people, and preventing losses totaling 173,454 rubles.

Relevance. The world has seen an activation of the epidemic process of measles last decade. Medical workers are at an increased risk of infection with measles due to their professional activities.

Objective. To assess the epidemic situation of measles among medical workers in the Voronezh Region during the activation of the epidemic process (2012–2024).

Materials and methods. The study material were: forms No. 2 of Rosstat, cards of epidemiological investigation of measles cases in the territory of the Voronezh Region for 2012–2024, extraordinary reports on cases of “controlled” infections for 2023–2024, act of epidemiological investigation of an infectious (parasitic) disease focus with establishment of a causal relationship and annual reports of medical organizations on immunization against measles for 2014–2024. Antibodies were detected in contact persons during the investigation of a hospitalacquired infection in Voronezh, using the ELISA method.

Results. During the analyzed period, measles among medical workers in the Voronezh region was registered only in the years of the greatest increase of infection among the total population; 7 medical workers fell ill, foci with single cases were registered mainly ; medical workers, who fell ill, had completed the vaccination course in 42.86 % of cases. Including 2023th year, no significant differences were found in the incidence rates of the total population and healthcare workers in the Voronezh region. In 2024, the incidence rates of the total population were significantly higher than those of healthcare workers – 16.50 cases per 100,000 compared to 2.60 cases per 100,000, respectively, p < 0.01. Analysis of the maps of epidemiological investigation of measles cases, extraordinary reports on cases of "managed" infections until 2023 inclusive, indicates the absence or insufficient volume of supervisory and control measures carried out in the foccies with involved medical staff. According to the results of selective serological monitoring of the level of antibodies to measles among medical staff, only 88.76 % of the documented vaccinated persons had a protective level of antibodies. At the same time, according to official reports from medical organizations in the Voronezh Region on measles immunization (2014–2024), the proportion of healthcare workers who are potentially immune to measles (vaccinated, previously infected, or have a protective level of measles antibodies in their serological tests) averaged 99.4 % during the analyzed period of 2014–2024.

Conclusion. The conducted study allows us to consider the epidemic situation of measles among medical workers in the Voronezh Region to be favorable. The active decline of post-vaccination immunity to measles necessitates the determination of antibody levels for all medical workers as part of routine serological monitoring to address the issue of timely vaccination.

Relevance. Imported malaria cases are registered annually in Russia, mainly originating from African and Southeast Asian countries. Although there has been no local transmission of the disease within the country since 2018, the risk of importation and spread of the infection remains. This necessitates reliable diagnostic methods for rapid response. Globally, malaria remains one of the most significant public health threats in endemic regions. Since 2007, World Malaria Day has been observed on April 25, underscoring the importance of consolidating efforts in the diagnosis, prevention, and treatment of the disease. Current diagnostic methods, such as microscopy and immunochromatographic tests, have limitations in terms of sensitivity, specificity, and suitability for mass screening.

Aims. To develop and validate a reagent kit for malaria diagnosis based on loop mediated isothermal amplification (LAMP) method, and to assess its diagnostic performance.

Materials and methods. This study presents the development and validation of the AmpliSens® Plasmodium-IT reagent kit for the qualitative detection of DNA from pathogenic malaria Plasmodium species (P. falciparum, P. vivax, P. malariae, P. ovale, P. knowlesi) using LAMP with real-time fluorescent detection. Detection limit was assessed using serial dilutions of Plasmodium DNA. The diagnostic sensitivity and specificity were evaluated using clinical samples of whole venous blood characterized by PCR.

Results. The developed reagent kit demonstrates high analytical sensitivity (detection limit: 103 GE/mL), 100 % diagnostic sensitivity, and 100 % specificity when tested on clinical whole-blood samples. The analysis time is 25–30 minutes, and a positive signal in cases of high parasitemia is detected within 3–12 minutes.

Conclusion. The developed reagent kit is a fast and accurate tool for malaria diagnosis, suitable for use in stationary laboratories for epidemiological surveillance and screening.

Relevance. COVID-19 continues to be a significant burden on global healthcare. For aerosol-transmitted infections, including COVID19, vaccination is recognized as the most effective protective measure. The accumulation of an immune layer causes changes in the SARS-CoV-2 virion surface protein and its antigenic properties. The epidemiology of the infection, as well as preparation for future pandemics, require studies of the prophylactic properties of vaccines in the context of the circulation of antigenically distinct virus variants.

Aims. To study the prophylactic efficacy of an inactivated whole-virion vaccine for the prevention of coronavirus infection, prepared using the prototype B.1.1 strain, in the context of the circulation of a heterologous virus variant.

Materials and Methods. The prophylactic efficacy of the vaccine was studied in an open, non-comparative, multicenter prospective study involving volunteers aged 18–60 years for 6 months after the vaccination course (two doses/two doses + booster/three doses). The comparison group consisted of unvaccinated infected individuals from a large industrial city.

Results. Among fully vaccinated individuals, cases of COVID-19 were registered less frequently, and these cases were mostly mild (1.2 times more often), less often lasted more than 18 days (1.7 times less often), and less often led to hospitalization (not a single patient among the vaccinated was hospitalized). The prophylactic efficacy of the studied inactivated whole-virus vaccine against coronavirus infection was 51.1 % [95 % CI 46.0–56.8 %].

Conclusion. A full course of vaccination helps to reduce the number of COVID-19 cases, as well as the proportion of moderate and severe forms, as well as the proportion of patients with prolonged infection and the number of hospitalizations.

Introduction. Frequent hospitalization of immunocompromised patients, the use of invasive devices, and antibacterial therapy contribute to the nosocomial spread of invasive candidiasis pathogens, including hospital outbreaks.

Objective. To characterize, based on published data, the epidemiological features of healthcare-associated outbreaks of invasive candidiasis caused by different yeast species and the measures used for their control.

Materials and methods. We analyzed data from online databases (Outbreak Database, PubMed, eLibrary) using the keywords “Candida,” “outbreak,” “nosocomial,” and “healthcare-associated infections”.

Results. A total of 82 outbreaks reported between 1977 and 2025 were included. The etiological profile of published outbreaks shifted from the predominance of C. albicans to the dominance of C. parapsilosis and, since 2016, C. auris. Outbreaks caused by C. auris and C. parapsilosis were characterized by prolonged duration and a wide range of contributing factors. Outbreaks caused by fluconazole-resistant strains were associated with longer duration and higher mortality. The main transmission factors included healthcare workers’ hands and parenteral nutrition solutions. The most effective control measures included epidemiological surveillance, hand hygiene monitoring, thorough environmental decontamination, isolation and restriction measures, and specialized strategies for C. auris.

Conclusion. Healthcare-associated outbreaks of invasive candidiasis caused by different yeast species differ in duration, mortality, and transmission patterns depending on the pathogen species and their susceptibility to antifungal agents. Their prevention and control depend on timely detection of colonized and infected patients, species-level identification of the pathogen, and appropriate selection of infection control measures depending on the pathogen species.

Relevance. In the world, the study of many aspects of hepatitis C (HC) – epidemiology, diagnostics, clinic, immunology, etc. – the infection remains largely an unresolved problem of public health due to the high prevalence, the difficulty of diagnosing the acute stage of the disease, frequent unfavorable outcomes.

Aims. Analysis of scientific publications concerning the problem of hepatitis C in children.

Material. The review used scientific information databases (eLIBRARY.RU, Cyberleninka, Federal electronic medical library, PubMed). The depth of study is 5 years, with a 20-year retrospective.

Conclusion. The problem of HCV is currently the subject of widespread attention and in-depth study in many countries. In particular, in the Russian Federation, as part of the implementation of the National Strategy for the Elimination of Hepatitis C, a plan has been developed and adopted aimed at a sharp decrease in the incidence of this infection by 2030.