The work is an overview of the data on application of loop-mediated isothermal amplification (LAMP) for the diagnosis of viral hemorrhagic fevers caused by pathogens belonging to the second pathogenicity group. The first part of the review provides a brief characterization of the main viral agents of hemorrhagic fevers from the families Nairoviridae, Phenuiviridae, Hantaviridae, and Flaviviridae. Special attention is given to the epidemiological significance of these pathogens and the challenges associated with their timely laboratory identification. The aim of the study was to analyze and systematize the data available in the literature sources on the use of LAMP as an alternative to polymerase chain reaction (PCR) for diagnosing hemorrhagic fevers caused by these agents. The review considers the principal methods for registering LAMP results, including the turbidimetric method, immunochromatographic assays, the use of fluorescent dyes, metal-based indicators and pH-sensitive dyes. A comparative analysis of the analytical characteristics of existing LAMP reagent kits for each of the described agents is also presented. It is noted that there are currently no registered and widely available commercial LAMP reagent kits for detecting the genetic markers of these viruses. This underscores the need for further research, since the implementation of rapid and reliable diagnostic methods suitable for field use is a prerequisite for effective epidemic control measures. Therefore, the development of appropriate reagent kits based on the LAMP method represents a promising objective.

The aim of the work was to analyze the epidemiological situation on cholera in the world and in Russia and to make its forecast for 2026. Proactive epidemiological surveillance data showed that over the period of 2016–2025 there was an upward trend in cholera incidence worldwide: 5,474,013 cases were documented in 91 countries. The proportion of patients was distributed among countries as follows: Yemen (53.4 %), Afghanistan (11.7 %), Democratic Republic of the Congo (6.3 %), Nigeria (4.7 %), Somalia (3.2 %), South Sudan (2.5 %), Sudan (2.5 %), and Haiti (2.4 %). In 2025, 42 countries reported 589,571 cases and 8,140 deaths (5.1 % more than in 2024). The increase in cholera cases in 2025, compared to 2024, amounted to 5.12 %. Population migration remained the main risk-forming factor for the spread of cholera to different countries. In the Russian Federation, monitoring of labor migration was introduced with the organization of medical observation of arriving persons for seven days after arrival from cholera affected countries. As a result of monitoring surface water bodies in 2025, 50 non-toxigenic strains of Vibrio cholerae O1 circulating in the territory of the Russian Federation and belonging to different genetic lines were isolated. A decrease in the number of acute intestinal infections was noted from 13 (2024) to 5 (2025), caused by non-toxigenic V. cholerae nonO1/nonO139. Forecast for 2026: the risk of cholera importation persists due to the expected increase in the intensity of labor migration. Registration of acute intestinal infections and extra-intestinal infections caused by non-toxigenic strains of V. cholerae nonO1/nonO139 is probable. Detection of non-toxigenic strains of V. cholerae O1 and their clonal complexes circulating in water bodies will continue. Stable epidemiological situation on cholera in the Russian Federation is predicted for 2026.

Small mammals (rodents, insectivores, and bats) are the main reservoirs for a wide range of zoonotic viruses. These include the agents of vector-borne infections transmitted via bites of blood-sucking arthropods (ixodid ticks, mosquitoes, sand flies) and non-vector-borne infections (orthohantaviruses and others). Natural foci of viral infections, the reservoir of which are small mammals, are of primary epidemiological significance in the Russian Federation: hundreds of cases are recorded annually, many of which are severe. The aim of this review was to summarize current data on the circulation of viral zoonotic pathogens in small mammal populations in natural foci in the Russian Federation and worldwide, as well as to identify key issues in epizootiological surveillance and the study of reservoir relationships between hosts, pathogens, and vectors. It has been shown that among the zoonotic viruses circulating with the participation of rodents and insectivores, along with the most significant and widespread, returning (re-emerging) pathogens that pose a serious global and regional threat are also of great epidemiological importance. These are representatives of the Flaviviridae family (tick-borne encephalitis virus, Omsk hemorrhagic fever virus, Kyasanur forest disease virus), Bunyaviridae (orthohantaviruses, Crimean-Congo hemorrhagic fever virus, and others), and Coronaviridae families. It was noted that small mammals acted not only as reservoir hosts for viruses but also as feeders, ensuring the maintenance of populations of vectors (ixodid and argasid ticks, mosquitoes and midges), thereby creating stable parasitic systems. The issue of zoonotic viruses circulating among small mammals remains urgent for both the Russian Federation and the global community. Analysis of global trends indicates that infectious diseases of animals are expanding their range, thereat many of them with zoonotic potential. The key drivers of this process are climate change, expansion of international trade and transformation of ecosystems, requiring improved epidemiological monitoring and an interdisciplinary approach to risk assessment.

The paper presents an analysis of the formation and initial results of work of the Joint Russian-Burundian Center for the Study and Prevention of Infectious Diseases (hereinafter “the Center”), created in 2023 in Bujumbura at the premises of the National Institute of Public Health of the Republic of Burundi. It is shown that the establishing of the Center became a natural outcome of the strengthening bilateral relations between Russia and Burundi, including the signing of an interdepartmental Memorandum of Cooperation (December 2022), the opening of a Russian laboratory (February 2023), and the signing of the Center’s constituent documents within the framework of the Second Russia–Africa Summit (July 2023). A key feature of the Center is the integration of leading scientific institutions of the Rospotrebnadzor with national experts from Burundi, which enables fundamental and applied research on a wide range of infectious threats relevant to the East African region. The results of scientific research on natural-focal infections, the etiology of acute intestinal infections, the prevalence of HIV infection, and viral hepatitis markers among the population are presented. Considerable attention is also given to systematic personnel training – more than 130 Burundian specialists have been trained in modern methods of laboratory diagnostics, epidemiological monitoring, and biosafety. The experience of the Center represents an effective model of scientific diplomacy and practical public health, significant for strengthening biological security in the African region.

Epizootiological-epidemiological situation on tularemia in the Russian Federation in 2025 has been assessed and forecast for 2026 is provided. In 2025, 45 cases of human tularemia were registered in the Russian Federation (incidence rate of 0.03 per 100,000 population) across 16 regions of the country. The highest proportion of cases was recorded in the Stavropol Territory and the Khanty-Mansi Autonomous Region (21.6 and 16.2 %, respectively). Arkhangelsk Region and Republic of Karelia accounted for 10.8% each, the Kirov, Omsk and Chelyabinsk Regions – 8.1% each, Voronezh, Yaroslavl, Nizhny Novgorod Regions and the Krasnodar Territory – 2.7% each. The main share (48.9%) of all cases occurred in August and September. The urban population predominated in the morbidity structure – 62.2%. The incidence was characterized by a relatively even distribution by gender: men accounted for 55.6%, women – 44.4%. The largest share of the affected was among people of working age, but noteworthy is the significant proportion of sick children under 17 years of age – 24.5%. Ulceroglandular tularemia (A21.0) predominated, accounting for 71.1% of cases. A total of 871,599 people were vaccinated or revaccinated against tularemia. Nationwide, 28 cultures of Francisella tularensis were isolated from field material in 7 entities. High risk of epidemiological complications due to tularemia will persist in 20 regions of the Russian Federation: Arkhangelsk, Leningrad, Volgograd, Kirov, Novosibirsk, Omsk, Tomsk, Kherson and Zaporozhe Regions; the Republics of Karelia, Crimea, Mordovia, Tuva, Buryatia and Sakha (Yakutia); Stavropol and Altai Territories; Khanty-Mansi Autonomous Region; and the Donetsk and Luhansk People’s Republics.

This review characterizes global epizootic and epidemic situation regarding brucellosis. Based on an expert assessment, a short-term forecast for incidence of the disease in the Russian Federation for 2026 is provided. Globally, there is an upward trend in human brucellosis incidence in regions with developed livestock farming within endemic areas, with the exception of European Union countries, where a decline in cases of brucellosis has been observed (though approximately half of these cases are linked to traveling to endemic countries or consumption of imported animal products). Over the past four years, the Russian Federation has seen an alarming 25–40 % increase in human brucellosis incidence compared to long-term average figures. Furthermore, a comparison of 2022–2025 period with 2016–2019 reveals (26.3 %) increase in the average number of constituent entities (primarily in the Central and Volga Federal Districts) reporting brucellosis outbreaks, indicating a geographical expansion of the infection. One of leading factors contributing to deterioration of epizootic situation regarding brucellosis is systemic crisis in veterinary monitoring and low effectiveness of control over livestock registration and movement. Given these trends, incidence rate in 2026 is projected to be 30–40 % higher than long-term average values. The number of human brucellosis cases in the Russian Federation is expected to remain consistent with 2024–2025 levels, falling within the range of 500–550 cases (0.35–0.38 per 100,000 population).

The aim of the review is to assess the Q fever situation in the Russian Federation based on official registration data and analysis of the epidemiological situation during 2013–2024, excluding the data for 2020 and 2021, the period of anti-epidemic measures to prevent COVID-19, and to determine the current aspects of the fight against this infection. The epidemic potential of Q fever in Russia and other countries, where an increase in the activity of its foci is observed, is evaluated. The regions of the Russian Federation with unfavorable Q fever status are ranked based on the incidence rates of registered cases. The incidence of Q fever in the Russian Federation in 2024 is analyzed and forecasts for 2025 are provided for affected territories. The paper presents an analysis of the results of Q fever monitoring in the Stavropol, Altai, Primorsky Territories, Astrakhan, Rostov and Omsk Regions in 2024. Proposals are made to clarify and stabilize the epidemiological situation on Q fever.

Results of monitoring and analysis of the epizootic situation in the Central Caucasus high-mountain natural plague focus in 2025 are presented. The aim of the study was to characterize the case of Yersinia pestis strain isolation in the Bityug-Tyube tract and assess the features of the epizootic process. The epizootic is characterized as a single sporadic case, along with the identification of the plague pathogen strain as belonging to the main subspecies, biovar medievalis, genetic lineage 2.MED0, isolated from the carcass of a mountain ground squirrel (Spermophilus musicus). Material and methods. Laboratory testing of field material for the presence of the plague pathogen was carried out in accordance with MU 3.1/4.2.4065-24 “Epidemiological surveillance in natural plague foci in the territory of the Russian Federation: monitoring, diagnosis, and prevention”. To estimate the possible number of infected animals, a probabilistic calculation using the sequential sampling without replacement method (employing an algorithm verified with Python code) was applied, as well as computer simulation modeling of the epizootic process. The use of artificial intelligence systems, with mandatory verification of results by specialists, allows for the rapid execution of complex, reproducible calculations based on empirical data for an in-depth understanding of epizootic processes. Results and discussion. The studies showed that the epizootic manifestation in 2025 was a sporadic one and of low-intensity, likely due to two factors: a relatively low abundance of flea vectors and high resistance of local mountain ground squirrel populations to plague. Using mathematical modeling, it was established that the maximum number of infected ground squirrels in the focus during the observation period did not exceed six specimens (0.1–0.2 % of the population). The hypothesis of a latent epizootic process in the highlands, with rare manifestations in the form of animal deaths due to the high resistance of local mountain ground squirrel populations to plague, is discussed. The conclusion is made about the necessity of assessing the epidemic hazard of such sporadic cases. As a preventive measure, annual preliminary disinsection in areas of mass stay of people is recommended.

Assessing the epidemiological potential of natural biotopes serves as the basis for predicting the risk of natural-focal infections and planning preventive measures. The traditional disease-specific approach fails to provide a comprehensive assessment of the epidemiological hazard posed by a specific biotope which determines its potential hazard – thereby precluding adequate planning for integrated prevention strategies in combined foci. The aim of this study was to develop and scientifically substantiate an algorithm for the integrated assessment of the epidemiological potential (hazard) of natural biotopes in the Krasnodar Territory regarding natural-focal infections. Materials and methods. Official statistical data covering five diseases (Ixodes tick-borne borreliosis, West Nile fever, hemorrhagic fever with renal syndrome, leptospirosis, and tularemia) from 2021 to 2025 were analyzed across 45 municipalities of the Krasnodar Territory. Results and discussion. A five-stage algorithm was developed to quantitatively assess the integrated epidemiological potential of biotopes; the process includes calculating long-term average incidence rates, min-max normalization, formalized weighting based on four clinical-epidemiological criteria, calculating an integrated index, ROC validation, and ranking the territories. Final weighting coefficients reflecting the epidemiological significance of the pathogens were substantiated as follows: West Nile fever – 2.0; hemorrhagic fever with renal syndrome – 1.5; leptospirosis – 1.2; Ixodes tick-borne borreliosis – 1.0; and tularemia – 0.8. The model’s predictive accuracy was determined to be 84%, with an AUC of 0.86 (95% CI: 0.74–0.95), demonstrating the index’s utility for reliably ranking territories based on their level of epidemiological potential. Based on a quantitative criterion, three zones of epidemiological potential (risk) for the biotopes were identified: red (II ≥ 8.50) – 18 municipalities (40.0%); yellow (1.0 ≤ II < 8.50) –19 municipalities (42.2%); and green (II < 1.0) – 8 municipalities (17.8%). Decomposition analysis revealed heterogeneity in the risk structure across different biotope types. The developed algorithm serves as a valid, reproducible, and practical tool for the quantitative assessment of the integral epidemiological potential of natural biotopes, establishing a scientific basis for transitioning to differentiated planning of preventive measures within a territory, taking into account its natural landscape characteristics.

The aim of the study was to assess the level of knowledge and behavioral attitudes of residents of the Amoron’i Mania region (Republic of Madagascar) regarding the risk of plague infection in order to develop scientifically based recommendations for improving the epidemiological surveillance system through optimization of outreach and public health education efforts. Materials and methods. The survey was conducted among 188 permanent residents of the region via personal interviews. The questionnaire covered the issues of risk awareness, knowledge of transmission routes and symptoms, as well as algorithms for action in the event of infection. The data were processed using descriptive statistics. Results and discussion. A high level of general awareness has been identified (88 %), but an imbalance in knowledge is found: anthropogenic transmission mechanisms (20 %) and the food route (13 %) are underestimated. A gap between knowledge and practice has been recorded: 44 % of respondents dispose of dead rodents on their own, which is a risk factor. At the same time, 85 % declare their willingness to consult a doctor. A request for additional information is expressed (88 %), and the preferred communication channel is personal consultation with a healthcare professional (62 %). Stabilization of the epidemiological situation requires a comprehensive approach. Systemic problems include fragmented knowledge, a contradiction between attitudes and behavior, and the persistence of risky practices in relation to plague sources. Implementing targeted health education measures based on survey data will help to develop sustainable safe behavior skills and create a reliable barrier to the spread of infection.

The aim of the study was to perform a comprehensive phenotypic and genetic study of clinical strains of Vibrio paracholerae isolated in the Russian Federation and neighboring countries. Materials and methods. We used 210 nucleotide sequences of complete genomes of V. cholerae nonO1/nonO139 and 12 strains of V. paracholerae that caused acute intestinal infections in 1975–2014. Motility, production of soluble hemagglutinin/protease, phospholipase, and hemolysin were determined using specialized media; antibiotic sensitivity - applying the disk diffusion method. BLAST, BioEdit (v.7.7.1), ABRicate, and the VFDB and CARD databases were used for bioinformatics analysis; fastANI v.1.34 – to calculate ANI. Results and discussion. The analysis of 210 V. cholerae nonO1/nonO139 genomes has revealed 12 genomes containing specific markers of V. paracholerae and lacking the loci characteristic of V. cholerae. Determination of the average nucleotide identity of the genomes confirmed their relationship to V. paracholerae. It has been established that paracholera vibrios, like cholera vibrios, are motile and produce pathogenic enzymes and hemolysin. All strains are sensitive to tetracycline, azithromycin, aminoglycosides, cephalosporins, and third-generation fluoroquinolones, but resistant to rifampicin (100 %), ampicillin (58.3 %), trimethoprime/sulfamethaxazole (25 %), and second-generation fluoroquinolones (16.7 %). Genomic analysis has revealed the absence of the CTXφ prophage and the VPI-1 pathogenicity island. A number of strains possesses isolated genes for the VSP-I and VSP-II pandemicity islands. Loci encoding additional pathogenicity determinants have been identified: hemolysin HlyA, soluble hemagglutinin protease HapA, MARTX toxin, type VI secretion system proteins, and cholyx toxin ChxA (in 75 % of isolates). All strains have RND-type efflux system loci, and 85.7 % of ampicillin-resistant isolates harbored carb β-lactamase genes. Thus, in terms of phenotypic characteristics and genetic structure, clinical isolates of V. paracholerae are similar to aquatic vibrios; pathogenicity factors specific to this group could not be identified. Despite the presence of multidrug-resistant isolates, sensitivity to most antibiotics used in the treatment of intestinal infections was noted.

The aim of the study was to describe the experience in introduction, systematization and thematic analysis of the implemented programs of the Rospotrebnadzor for specialists of the Republic of Burundi (2023–2025) in the field of laboratory diagnostics, epidemiological monitoring and biosafety as part of the strategy to strengthen the biological sovereignty of African states. Materials and methods. The study is based on the analysis of reporting documents and educational materials from 15 advanced training courses and field exercises conducted for the staff of the National Institute of Public Health of Burundi (INSP) in 2023–2025. The training was delivered in English using adapted educational programs. Descriptive statistics and content analysis of course topics were employed. Results and discussion. During the reporting period, 16 educational events were conducted, over 130 specialists were trained. The programs covered such key areas as: general laboratory practice and biosafety (PBA of II–IV pathogenicity groups), molecular diagnostics (including third-generation sequencing on the MinION platform and LAMP), serological screening (ELISA diagnostics of natural-focal and hepatotropic infections), bacteriology of food-borne infections, zoological and entomological surveillance, as well as specific pathology (HIV infection, mpox). In October 2024, field exercises using a mobile laboratory for indication and monitoring of particularly dangerous infections (MLIM) were carried out. It is shown that systemic transfer of competencies, rather than one-time equipment supplies, forms the basis for autonomous response to biological threats. The implemented programs have confirmed the effectiveness of systematic approach to personnel training as a tool for strengthening the national laboratory network. The coverage of modern diagnostic methods meets the current needs of the republic. The developed educational modules have potential for duplication in other developing African countries.

The aim of the study was to construct an erythrocyte immunoglobulin diagnostic kit for the rapid detection of the plague pathogen (Yersinia pestis) using an indirect hemagglutination assay and to assess its analytical performance. The scientific innovation consisted in developing a new approach to producing an erythrocyte immunoglobulin plague diagnostic kit based on targeted adjustment of pH and surfactant concentration to optimize the interaction of antibodies with formalinized erythrocytes. Materials and methods. The diagnostic preparations were obtained using formalinized sheep erythrocytes conjugated with plague IgG in the presence of sodium lauryl sulfate (SLS). The pH of the medium (4.0…5.0 ± 0.05) and SLS concentration (0.20…0.45 ± 0.001 %) were adjusted to determine the optimal conjugation conditions. Analytical sensitivity and specificity were assessed in IHA using homologous and heterologous microbial strains. Statistical processing was carried out using a two-factor analysis of variance with a significance level of p<0.05. Results and discussion. A significant effect of pH and SLS concentration on the sensitivity of the diagnosticum (p<0.001), as well as their interaction (p<0.001), has been established. The optimal parameters are SLS concentration of (0.21±0.001) % and erythrocyte suspension pH of 4.3±0.05. Under these conditions, the diagnostic preparation demonstrated an analytical sensitivity of (1.95…3.90)·10⁵ cells/ml, no cross-reactions with heterologous strains, and stability during one year of storage. The developed technology provides a highly specific, stable, and reproducible preparation suitable for rapid serological detection of plague, which is of practical importance for epidemiological surveillance and laboratory diagnostics of natural-focal particularly dangerous infections.

The aim of the study was to investigate the features of prevalence of vector-borne infection pathogens transmitted by Ixodidae ticks in the Vladimir Region. Materials and methods. The analysis of the data on the incidence of tick-borne borreliosis for 2005–2022 and the number of people who sought medical help because of tick bites in 2013–2022 has been carried out. The results of laboratory studies of Ixodidae ticks collected by a medical entomologist in various administrative districts of the Vladimir Region or removed after biting humans and animals and delivered to the laboratory of natural-focal and particularly dangerous infections of the Center of Hygiene and Epidemiology in the Vladimir Region are presented. A total of 7417 ticks were examined. Of these, 6389 were tested using ELISA (for TBE) and 1028 using PCR (for four infections). Results and discussion. The fauna of Ixodidae ticks in the region is represented by three species: Ixodes ricinus, Ixodes persulсatus, Dermacentor reticulatus. It has been established that the following tick-borne infections foci function in the Vladimir Region: Ixodidae tick-borne borreliosis, viral tick-borne encephalitis, human granulocytic anaplasmosis and human monocytic ehrlichiosis. Vectors of mix infections have been found. This circumstance necessitates the diagnosis of all pathogens identified in endemic territories. Among tick-borne infections in the region, only tick-borne borreliosis is registered in the population. Due to the uneven distribution of tick-borne infection foci, a modern safety provision strategy must take into account the specifics of the epidemic situation, including at the regional level. Differentiating between regions by tick-borne infection incidence allows for a more specific strategy, tactics, and scope of preventive measures.

The aim of the study was to perform a detailed molecular-genetic characterization of the toxigenic Vibrio cholerae nonO1/nonO139 strain isolated from the Don River in the Rostov Region in 2024. Materials and methods. Whole-genome sequencing was carried out on the MiSeq Illumina and Oxford Nanopore platforms. Primary assembly was performed de novo through the Canu software based on long reads, and subsequent alignment was carried out using short reads with the Pilon program. Vector NTI package, BLASTN, BLASTP, BioEdit, Ugene, abricate (CARD database) and SnapGene Viewer were used in the bioinformatics analysis of genomes. The search for the limits of wb* clusters and comparison of their genes were conducted by means of the author’s program “O-cluster”. The phylogenetic tree was constructed using the roary and FastTree software. Results and discussion. A toxigenic strain of NAG-vibrio has been identified for the first time in Russia. The sequences of both chromosomes of the studied strain have been determined via hybrid genome assembly. Based on the analysis of the O-antigen biosynthesis region, the strain has been classified into serogroup O105 and it shows a high degree of closeness to clinical strains of this serogroup previously isolated in China. Bioinformatic analysis has revealed the presence of tandems of two identical copies of CTX and RS1 prophages on the large chromosome, which are notably distinct from their prototypes. The ctxB gene is represented by the ctxB12 allele, and all RS1 genes, except for rstC, show no similarity to canonical sequences. A VPI-1 island with an alternative tcpA allele, a T3SS cluster within the VPI-3 island, and the cholix toxin gene have been identified, which constitutes a rare combination within a single strain’s genome. The set of intact determinants of other pathogenicity factors is sufficient for the realization of pathogenic potential. The presence of a number of antibiotic resistance determinants in the genome did not always correlate with the phenotypic manifestation of resistance/susceptibility to antimicrobial agents in vitro. The genome structure of the strain and its close relationship to clinical isolates indicate a potential capacity to cause acute intestinal infections. Since there is a possibility of new introductions of such strains into the Russian Federation, their detection in water bodies necessitates the implementation of a set of anti-epidemic measures.

The aim of the study was to comprehensively assess the cholera epidemiological situation in the Republic of Zimbabwe during the 2023–2025 epidemic surge, the organization of medical care, and sanitary-technical infrastructure, as well as the prospects for implementing modern diagnostic methods, including the use of mobile laboratory units. Materials and methods. The epidemiological situation was analyzed based on patient medical records, laboratory test protocols for patient samples, official reports on cholera and other acute intestinal infections published by the Ministry of Health and Child Protection of the Republic of Zimbabwe, and WHO data. Visits to hospitals designated for cholera treatment included assessments of the quality of medical care, laboratory testing capacities, and the condition of engineering systems. Results and discussion. The data confirm that the adverse cholera situation was driven by a complex interplay of sanitary-technical, environmental, social, and organizational factors. Similar patterns have been observed during cholera outbreaks in other African countries, where the spread of infection is closely linked to inadequate water supply and sanitation systems, high population density, seasonal climatic fluctuations, and limited healthcare system capacity. Most cases during the outbreak in question were characterized by a mild course, the absence of severe dehydration, and rapid improvement following the restoration of water-electrolyte balance. The assessment of laboratory capacities revealed several issues: a shortage of diagnostic reagents and a lack of experience in determining the toxigenicity and biovars of isolated Vibrio cholerae cultures in laboratory practices, as well as a lack of monitoring studies aimed at detecting the cholera pathogen in epidemiologically significant environmental samples. It should be noted that medical institutions in the Republic of Zimbabwe have accumulated extensive experience in organizing diagnostic and therapeutic care for cholera patients and implementing preventive measures, which helps contain the spread of the infection and save patients’ lives. To foster cooperation between the Russian Federation and the Republic of Zimbabwe in combating particularly dangerous infectious diseases, it is essential to conduct training courses on the epidemiology, diagnosis, and prevention of cholera and other acute intestinal infections; supply mobile laboratories, equipment, and diagnostic reagents; and organize joint, systematic monitoring of environmental objects.

The aim of the study was to evaluate the involvement of the small white-toothed shrew, Crocidura suaveolens, in the circulation of pathogens of natural-focal infections: tularemia, Lyme borreliosis (LB), Crimean-Congo hemorrhagic fever (CCHF), and hemorrhagic fever with renal syndrome (HFRS) in the southern part of the East European Plain in the Rostov Region (RR). Materials and methods. The findings of the epizootiological monitoring of natural-focal infections in the Rostov Region in 2019–2024 were used for the analysis. 280 specimens were caught during the specified period; 108 samples were formed, which were examined using bacteriological, molecular-genetic and immunological methods. Results and discussion. It has been found that over the past five years, the index of dominance of the small white-toothed shrew in captures has changed from a minimum (0.86 %) in 2021 to a maximum (12.10%) in 2024. It is established that the proportion of positive samples of small white-toothed shrew infected with tularemia pathogens, LB, CCHF and HFRS viruses differs in catches. During the observation period, the highest infection rate of the small white-toothed shrew was noted in regard to tularemia – 8 (7.4±2.5%) and CCHF – 6 (5.6±2.2%), the lowest – to LB – 4pathogens (3.7±1.8%) and HFRS – 3 (2.8±1.6%). According to the cartographic analysis, the administrative districts, where positive findings were identified, are located in the southwestern part of the RR (Rodionovo-Nesvetaisky, Matveevo-Kurgansky, Neklinovsky, Azovsky districts), in the northwestern part (Millerovsky district), and in the southeast (Remontnensky district). The research has showed the need for further study of significance of the small white-toothed shrew species for the circulation of pathogens of natural-focal infections as a species with high phenotypic adaptability.

The aim of the work is to divide the administrative-territorial units (ATU) of the Krasnoyarsk Territory into groups with different levels of epidemiological risk of tick-borne viral encephalitis (TBVE) in order to identify areas requiring special attention from the Rospotrebnadzor and health authorities. Materials and methods. Retrospective epidemiological analysis of manifestations of the TBVE epidemic process in Krasnoyarsk Territory is based on the data from the Rospotrebnadzor Administration in the Krasnoyarsk Territory, the Reference Center for Monitoring Tick-Borne Viral Encephalitis at the premises of the Irkutsk Research Anti-Plague Institute of the Rospotrebnadzor, and materials from state statistical reporting form No. 2 “Information on Infectious and Parasitic Diseases” for 2009–2024. To identify groups of territories with different levels of epidemiological risk, the method of finding the limits of the 95% confidence interval for the average long-term incidence of TBVE for 2015–2024 was used. Results and discussion. Since the beginning of the 21st century, the incidence of TBVE in the Krasnoyarsk Territory has shown a pronounced downward trend. Differentiating the ATUs that are part of Krasnoyarsk Territory has revealed six groups of units: non-endemic (4), with low (30), medium (14), high (10), and very high (2) levels of epidemiological risk for TBVE; the administrative center of the constituent entity, Krasnoyarsk, was considered as a separate unit. Each group is characterized by absolute and relative indicators of TBVE incidence, appeals to medical institutions regarding tick bites, and the volume of preventive measures. The division of ATUs by the level of epidemiological risk associated with TBVE, in combination with the analysis of data on key factors influencing the epidemic process, should contribute to a more accurate distribution of the volumes of preventive (anti-epidemic) measures, increasing their targeting and effectiveness.

Ixodidae ticks are the main reservoir and vector of the tularemia pathogen (Francisella tularensis), ensuring the long-term persistence of natural foci of the foothill-stream type. Given the micro-focal structure of the Dzhungar focus, the lack of a standardized scale of vector abundance limits the capability to accurately predict epizootic activity. The aim of this study was to develop an objective regional scale for grading the abundance of pasture ticks and to conduct a retrospective analysis of the relationship between their abundance and the intensity of tularemia epizootics in the Dzhungar focus. Materials and methods. The results of 270 counts of adult ticks of the genus Dermacentor, Ixodes, Hyalomma and Haemaphysalis (the “flag-hour” method), conducted in 2010–2025, were analyzed. Statistical processing was performed using PAST 4.11 and Microsoft Excel software. To construct a 5-level gradation scale (from “very low” to “very high”), we used a logarithmic data transformation followed by quintile analysis to stabilize the variance of the non-parametric sample. Results and discussion. The abundance distribution was found to be characterized by pronounced right-sided asymmetry (range – 0–156 individuals/flag-hour, median 17.0, mean 23.9). The developed scale allowed us to classify abundance as follows: <8 (very low), 8–13 (low), 13.1–22 (medium), 22.1–38 (high), and >38 (very high). A retrospective analysis revealed a paradox: maximum epizootic activity (isolation of 32 F. tularensis strains in 2018) was observed at “medium” vector abundance, while only sporadic occurrences were recorded at “very high” abundance (2022 and 2025). Hypotheses regarding increased mortality of infected specimens and the presence of specific tick haplotypes in high-infestation zones are discussed.

The paper describes the work of the Rostov-on-Don Anti-Plague Institute of the Rospotrebnadzor as the main institute for the control and prevention of cholera and the Reference Center for monitoring this infection. Based on the analysis of previous experience and the results of work in the modern period, the contribution of the Rostov-on-Don Anti-Plague Institute, as coordinator of cholera prevention measures, and the Reference Center for monitoring this infection, into ensuring the sanitary and epidemiological well-being of the country’s population for 55 years has been defined. Annually, activities to ensure external quality control of laboratory diagnostics for cholera in the Rospotrebnadzor institutions, to assess the readiness of the hospital and laboratory bases of medical facilities and centers of hygiene and epidemiology in the constituent entities of the Russian Federation, and to provide professional training for personnel are organized. New rapid molecular diagnostic tests and computer programs for conducting bioinformatics analysis of nucleotide sequences are being developed and implemented into practice. The coordinated efforts of the Reference Center with the organizations of the Rospotrebnadzor and the Ministry of Health of Russia make it possible to carry out effective proactive epidemiological surveillance of cholera in the Russian Federation.