In modern conditions, one of the urgent problems of epidemiology is the monitoring of the territorial distribution of natural focal infections, of which ixodic tick-borne borreliosis (ITB) is the most common in Russia. The aim of the work is a comparative assessment of epidemiological and epizootological characteristics of ixodid tick-borne borreliosis in different natural zones using the example of the European part of Russia. Based on the materials of state reports of the Federal Service and territorial departments of Rospotrebnadzor of the Russian Federation «On the state of sanitary and epidemiological well-being of the population» for 2011–2022, a comparative analysis of the incidence of Ixodid tick-borne borreliosis, the proportion of people bitten by ticks, and the infection of ticks with borrelia Ixodid tickborne borreliosis was carried out on the territory of various natural zones of the European part of Russia, united into three clusters. According to the results of the study, with an average long-term incidence of Ixodid tick-borne borreliosis in Russia of 4.61 per 100 thousand population, the value of this indicator in the taiga zone was 8.50, in the zone of mixed and broad-leaved forests — 3.96, forest-steppes and steppes — 2.50. A correlation dependence was found between the incidence rate of tick-bitten disease and the proportion of people bitten by ticks in all three natural zones, which was most pronounced in the taiga zone. The rate of tick infection with borrelia tick-bitten disease was highest in the taiga cluster and lowest in the forest-steppe and steppe cluster. The presented materials indicate the need to intensify measures to reduce the number of ticks and prevent their attacks on people, especially in areas with a high incidence rate of tick-bitten disease.

Opisthorchiasis invasion continues to be a serious problem in the structure of biohelminthiasis. Officially registered cases of opisthorchiasis, as a rule, do not reflect the full picture of the morbidity of the population. The aim of the study was to assess the degree of infection of the population and the contamination of environmental objects with the pathogen of opisthorchiasis in the Lipetsk region as part of epidemiological monitoring in the period 2019–2024. The study showed that the Lipetsk region is endemic for opisthorchiasis, which is confirmed by the identification of the parasite in fish samples caught in local freshwater reservoirs and the associated incidence of the population. The most disadvantaged areas are the areas located in the basin of the Don River. Carrying out preventive measures, including sanitary and educational work among the population, improving the system of sanitary and parasitological monitoring, including the introduction and practical use of new and modern methods of laboratory diagnostics, makes it possible to regulate the incidence of opisthorchiasis. At the same time, the current epidemiological situation requires constant monitoring by the concerned services and departments for the timely implementation of a set of preventive and anti — epidemic measures, as well as joint coordinated actions by medical, sanitary — epidemiological, veterinary and communal services of the region.

The relevance of the topic is determined by the insufficient development of the scientific substantiation of approaches to regulating the minimum age for young athletes to start playing sports and the requirements for the conditions of organizing classes that ensure a reliable level of prevention of health risks for young athletes. Assessment of the organization of classes with young athletes, providing conditions for achieving high sports results and key principles of safety of sports activities for children’s health. The method of questioning coaches was used, containing questions on the organization of training stages, including the average and maximum number of children engaged in groups at the same time, the duration and number of training sessions per day and per week, the use of sports equipment, inventory and ammunition. 411 children’s coaches from 22 constituent entities of the Russian Federation took part in the survey. Statistical analysis of the research materials was carried out using standard methods of descriptive statistics. It was found that 81.5 % of children’s coaches have higher specialized education, 14.8 % — secondary specialized education and 3.7 % did not have specialized education. When organizing training sessions with children in cyclic, complex coordination and game sports, the game form prevailed (from 58.8 to 85;7 %), in martial arts — competitive elements (61.5 %). The minimum age for children to start classes in gymnastics is below the optimal age to start classes, determined by the Federal Standards for Sports Training and is 3 years at the sports and health stage and 5 years at the initial stage of sports training, in figure skating (4 years — instead of 6 years), handball (8 — instead of 9 years), hockey (7 — instead of 8 years), which creates conditions for health problems. The results of the study confirm the need for practical development of issues of methodological support for children’s sports in terms of regulating the requirements for the conditions for playing sports, the optimal age to start classes, determining the maximum number of children in one group with a collective form of classes, which will reduce the health risks of young athletes.

In the Russian Federation, the automotive industry is one of the most important sectors of the economy, employing tens of thousands of employees. The production environment in the workplaces of the automotive industry is characterized by the impact of a combination of negative factors, the combination of which often causes the development of disorders in the work of various organs and body systems, classified as both production-related and professional. The aim is to develop an algorithm for the formation of a «risk» group with signs of occupational diseases in automotive workers in order to optimize professional fitness and develop preventive measures. To achieve this goal, the results of periodic medical examinations, hygiene studies, production control data (350 maps) and a special assessment of working conditions (103 maps) conducted at automotive enterprises located in the Republic of Bashkortostan were used. Algorithms for the formation of a «risk» group with occupational vibration disease and hearing organ damage have been developed. The proposed algorithms make it possible to quickly and cost-effectively identify people with signs of occupational diseases during periodic medical examinations, determine with a high degree of efficiency the capabilities of an employee working in certain conditions, and choose the optimal strategy when choosing diagnostic and therapeutic measures aimed at detecting and preventing health disorders at an early stage. The introduction of the principles of effective professional selection, taking into account the severity of clinical manifestations of pre-nosological and nosological forms of diseases, will improve the quality of preliminary (when applying for a job) and periodic medical examinations and resolve issues of professional suitability in a more differentiated and reasonable manner.

Conducting long-term clinical studies against the background of stressful combined effects of physical and chemical factors makes it relevant to use 6‑month-old Wistar rats as an accessible experimental model, which allows experimentally establishing markers of accelerated aging. Evaluation of the indicators of clinical urinalysis in laboratory animals that have been under periodic combined exposure to physical and chemical factors for a long time can help identify markers of cellular aging that determine the pathogenetic features of the effects of these factors on the body. Objective: to evaluate the combined effects of physical and chemical factors on the indicators of clinical urinalysis in Wistar rats in a chronic experiment characterizing the stages of the adaptation process. The object of the study: white laboratory rats of the Wistar line (n=90), grouped into three groups: two experimental ones, kept under conditions of periodic combined exposure to physical (vibration, noise), as well as physical (vibration, noise) and chemical (4‑component mixture of aromatic hydrocarbons) factors at the level of 1.5 MPC, MPC, and one control (intact animals) — in comfortable conditions (normal photoperiodism and temperature +22–24 °C). Clinical urinalysis was performed using a DIRUI H-100 analyzer (manufactured in China) with a built-in thermal printer. The statistical analysis was carried out using standard Statistica 10.0 application programs with the calculation of the median (Me) and the percentile interval. The probability of differences of 95 % or higher (p<0.05) was considered an acceptable level of reliability of the results. During the study of urine clinical parameters in Wistar rats, the limits of variability were determined depending on the duration and type of combined exposure to physical and chemical factors in comparison with the control group. Biomarkers of premature aging (increased levels of urobilinogen, bilirubin, protein, ketone bodies, erythrocytes, leukocytes, glucose, acidity and density of urine) were established in the experimental groups, compared with the control. The results of a clinical urine analysis of Wistar rats in a chronic experiment to study the combined effects of physical and chemical factors (at the level of 1.5 MPC and MPC) indicate the development of stress-induced pathological conditions in animals of experimental groups on the 180th day of the experiment, which may increase the risks of accelerated aging of various biological systems and negatively affect their vital functions, according to compared to intact animals.

The population of the Russian Federation is decreasing. The number of regions with high fertility is decreasing and the number of regions with low fertility is increasing. In 2023, two regions appeared with a fertility rate of 5.8 people per 1,000 population per year. The number of regions with a fertility rate of 5.8 to 7.9 people per 1,000 population per year increased 3‑fold from 2020 to 2023, and decreased 2.7 — fold from 10.0 to 19.0 people. The demographic situation is influenced by many factors: legislative and administrative, economic, socio-psychological. According to many experts, economic factors are the main influencing factors. The analysis of factual materials has shown that with an increase in the standard of living of the population, the birth rate increases. To improve the demographic situation, it is necessary to continue implementing measures aimed at improving the standard of living of the population, paying special attention to young low-income families. Improving medical care for the population, actively combating the growth of crime, drug addiction, and dangerous infectious diseases can also contribute to an increase in the birth rate. It is also very important to carry out educational work among the younger generation, prevent early pregnancy, and the importance of creating a strong, reliable family.