Manifestations Of Epidemic Process Research Articles

Analysis of epidemic process manifestations and detection of pathogens’ markers of tick-borne infections in the Tomsk region

BACKGROUND: Among the spectrum of the tick-borne infections, Lyme borreliosis (LB) and tick-borne encephalitis (TBE) are most often recorded in the Tomsk region, however it is obviously that possible range of the pathogens is not limited to these ones. AIM: is to assess epidemic process manifestations and detect frequencies of pathogen’s markers of tick-borne infections among adult patients applying serological and molecular genetic techniques in the Tomsk region during 2020–2023. METHODS: A single-center prospective sample study was conducted applying a comprehensive approach in peripheral blood specimens obtained from 197 patients with suspected tick-borne infections hospitalized during 2020–2023. To verify the diagnoses of TBE or LB, specific immunoglobulins of classes M and G to the antigens of TBE virus and Borrelia burgdorferi s. l. were determined in paired blood serum samples applying enzyme-linked immunosorbent assay (ELISA). Additionally, the polymerase chain reaction (PCR) was used to detect genetic markers of TBE virus, B. burgdorferi s.l., B. miyamotoi, Rickettsia spp., Coxiella burnetii, and Francisella tularensis. Epidemiological surveillance data of incidence rates of tick-borne infections obtained from official reports were analyzed as well. MS Office Excel 2010 software was used to calculate frequency morbidity measures. RESULTS: We verified the final diagnosis of TBE in 52 (26.4%) patients, LB in 116 (58.9%) patients, co-infection of TBE and LB 15 (7.6%) patients, hard tick relapsing fever caused by B. miyamotoi in 8 (4.1%) patients, coinfection of Q fever caused by C. burnetii with TBE or LB in 4 (2.0%) patients, and coinfection of tularemia with TBE or LB in 2 (1.0%) cases. We identified markers of TBE and LB pathogens by PCR in 3.6% and 4.1% of the patients. Most number of individuals with tick bites, and the highest LB and TBE incidence rates were recorded in the suburbs of Tomsk. The age groups of 40‒59 years, and elderly people 60 years and older were predominated among the patients. CONCLUSION: It was found out that, in addition to LB and TBE, there were such tick-borne infections as tick relapsing fever, Q fever, and tularemia in the Tomsk region in the 2020–2023 period.

Manifestation of epidemic process, clinical and epidemiological characteristics of adult patients in the early period of the COVID-19 epidemic in Russia

BACKGROUND: The COVID-19 pandemic became a challenge and caused significant social and economic damage to most countries. For the most objective assessment of the epidemiological and clinical features of COVID-19 during different periods of the epidemic, studies based on a large volume of data on patients identified throughout the Russian Federation are necessary. AIM: To analyze the epidemic process and clinical and epidemiological features of adult patients with COVID-19 identified during the first and second periods of the rise and decline in the incidence of COVID-19 in Russia. MATERIALS AND METHODS: This study included patients aged ≥18 years with a confirmed diagnosis of COVID-19 and identified in the periods from March 2, 2020, to June 30, 2020 (n=286,205) and from November 1, 2020, to January 31, 2021 (n=1 655 022), in Russia. RESULTS: At the early stage of the COVID-19 epidemic in Russia, two periods of the rise and fall in incidence were noted: March–August 2020 and September 2020–May 2021, using the Wald–Wolfowitz test. The median age of the patients with COVID-19 in the first and second periods were 50.0 [37–62] and 52.0 [39–64] years, respectively, and women accounted for 55.5 and 60.1% of the patients, respectively. The distributions of patients according to disease severity in the first and second periods were as follows: mild, 63.0 and 74.4%; moderate, 29.0 and 20.1%; severe, 4.9 and 3.5%; extremely severe, 3.1 and 2.1%, respectively. In the first and second periods, cases were dominated by patients aged 50–59 years (20.5%) and 60–69 years (20.5%), respectively. In both periods, the median duration from the onset of symptoms to diagnosis was 4 days, the median disease durations were 16.0 [12–21] and 13 [10–17], and the median duration of hospitalization were 15.0 [12–20] and 13.0 [10–18]. The hospitalization rates were 48.4 and 25.6% in the first and second periods; transfer rates to the ICU, 7.8 and 10.3%; and invasive mechanical ventilation rates, 5.6 and 7.7%, respectively. In both periods, the median age at death was 73 [66–82] years, with a higher proportion of men aged 30–39, 40–49, 50–59, and 60–69 years. The presence of one or more chronic diseases, as well as male sex, increased the likelihood of death (odds ratio = 10.2 and 1.3 in the first period; odds ratio = 16.0 and 1.6 in the second period). CONCLUSIONS: In the early period of the COVID-19 epidemic in Russia, related to the spread of the wild strain of SARS-CoV-2 and genetically closely related variants, the manifestations of the epidemic process and clinical and epidemiological characteristics of patients varied. In the second period with higher incidence and mortality rates than the first period, the frequency of severe and extremely severe COVID-19 and the frequency and duration of hospitalizations decreased; however, the frequency of transfers into the intensive care unit and artificial lung ventilation slightly increased.

The Results of Work of Infectious Disease Specialists and Epidemiologists of the Rospotrebnadzor during the Outbreak of Acute Intestinal Infections in the Republic of the Congo (Brazzaville) in 2023

This paper provides an analysis of the results of joint work of Russian and Congolese infectious disease specialists and epidemiologists to decipher the etiology and causes of the outbreak of intestinal infections in Dolisie (Republic of the Congo) in the summer of 2023. It has been found that the increase in the incidence of intestinal infections was caused mainly by the agents of typhoid fever and dysentery; tropical malaria was a combined pathology. No cases of cholera patient detection were registered. Failure of water supply system, domestic disrepair, and low public awareness about prevention of intestinal infections contributed to the active transmission of pathogens. The combination of epidemic process manifestations testified to the aquatic nature of the outbreak. Also, cases of pathogen transmission through contact household route were recorded, food transmission was not excluded. Patients with severe and complicated forms of typhoid fever and shigellosis accounted for 50 % of those hospitalized. There was delay in seeking medical care. The available regimens of antibacterial therapy were ineffective, since there was no possibility of laboratory confirmation of the diagnosis with determination of sensitivity to drugs. Uncontrolled treatment facilitated the emergence of antibiotic resistance in pathogens, prolonged bacterial release and subsequent spread of infection. Infectious disease specialists and epidemiologists of the Rospotrebnadzor provided consulting and practical assistance to Congolese colleagues, developed and presented recommendations for optimizing anti-epidemic and therapeutic measures, taking into account the results of assessment of the causes for onset and development of the outbreak.

Similarities and Differences in the Manifestations of the COVID-19 Epidemic Process in Some Countries

Relevance. The pandemic of a new coronavirus infection has become an unprecedented challenge for modern society. It took the entire population of the Earth by surprise, changing the lives of millions of people in the world in record time. Governments of different countries have reacted differently to the pandemic. The list of preventive measures and the timeliness of their adoption differed. Comparing and evaluating the experience of different countries and emergency response systems will help in the future to use best practices and models to combat future biological threats. The aim of the study was to identify and describe the features of the manifestation of the COVID-19 epidemic process in a number of countries, taking into account the ongoing anti-epidemic and preventive measures, and to hypothesize about the main factors that could potentially influence the differences in the manifestation of the COVID-19 epidemic process. Materials and methods. The choice of countries was conditioned by the purpose to compare the manifestations of epidemic process in our country with the great powers and economies of the world - USA and China and countries (Republic of Belarus and Sweden), which did not introduce lockdown and did not follow all WHO recommendations. To achieve this goal, a descriptive research method was used based on open source data, an analysis of relevant Russian and foreign literature was carried out (scientific electronic libraries PubMed and Elibrary; open sources of statistical information: Yandex DataLens Public: Coronavirus: Dashboard, Johns Hopkins University website, United Nations Population Division, World Bank, Global Panel Database on COVID-19 Pandemic Policy (Oxford COVID-19 Government Response Tracker), as well as the website of the World Health Organization (WHO), Our World in Data, Rospotrebnadzor and some media). Conclusion. The lowest incidence rate is observed in China (on average 315.1 per 100 thousand population [95% CI 314.8–315.4]), and the highest is in the USA (9957.7 per 100 thousand population [95% CI 9954.5–9960.9]). In terms of the number of tests conducted, the United States and Russia are in the lead. To date, the highest vaccination coverage and vaccination rate are observed in the PRC and amount to 92.4% and 90.1%, respectively. In general, these indicators do not reach 95% in all countries, which requires improving the quality of immunoprophylaxis measures. Anti-epidemic measures in the studied countries differed in their set, scope and severity of implementation. In China, Russia and the USA were held in full, and in Belarus and Sweden only partially, some of the events were not held at all. Thanks to the rapid creation of effective vaccines in Russia and China, it was possible to delay the onset of pronounced increases in morbidity at a later date, which, in turn, helped to reduce the burden on the healthcare system. At the same time, despite the obvious relevance of COVID-19, the question of a comprehensive study of the alleged risk factors (biological, social and natural) is still open. There is a certain probability that the virus will now be permanently present in the global population (it will become a seasonal disease).

Tick-borne infections in the south of Russia: modern epidemiological situation, new approach to create “forecasting” and “explaining” morbidity models (in astrakhan rickettsiosis fever and crimean-congo hemorrhagic fever)

The article presents a description of the current tick-borne infection epidemiological situation in the south of Russia from the years 2013 to 2022, proposes a new approach to develop forecasting models for morbidity dynamics of Astrakhan rickettsial fever (ARF) and Crimean hemorrhagic fever (СCHF) in the Astrakhan region and presents data assessing 2022 explaining models for the Stavropol Territory and Astrakhan Region. Materials and methods. A comprehensive research was performed using epidemiological analysis and non-parametric statistical methods. The data assessing tick-borne infections epidemic process manifestations were retrieved from ARF and CCHF morbidity databases (developed as a project) and documents of infectious disease focus epidemiological examination provided by the departments of Rospotrebnadzor in the subjects of the Southern and North Caucasian Federal Districts. Morbidity models were developed using the Bayes theorem and Walds sequential statistical analysis, with a preliminary calculation of indicators informativeness by the Kullback method. The values of climatic factors from the database of the Center for Collective Use IKI-monitoring of the Space Research Institute of the Russian Academy of Sciences were used. Results. The results of the study indicate persistence of serious epidemiological situation regarding rickettsiosis of the tick-borne spotted fever group, Q fever, tick-borne borreliosis and CCHF in the south of Russia. Almost all tick-borne infections nosological forms in children under 14 years (including young children and infants) were widely involved in the epidemic process, which belong to patients at risk for a complicated disease course due to complicated diagnostics and treatment. The annual registration of tick-borne infections cases in the resort areas, with the subsequent occurrence of imported cases in other, including non-endemic regions poses a serious problem. The proposed forecasting models allow to predict the CСHF and ARF morbidity for each administrative district of the Astrakhan region with up to 91.7% accuracy. The explaining models CСHF accuracy for the Stavropol Territory and Astrakhan Region, when tested in 2022, was 88.5 and 83.3%, respectively, for ARF 91.7%. Conclusions. The further continuation of forecasting and explaining models verification for planning preventive measures and propose similar steps for tick-borne borreliosis and Q fever to epidemiological tick-borne infections to stabilize situation in the south of Russia.

COVID-19 in Russia: Epidemiology and Molecular Genetic Monitoring

Background. The COVID-19 pandemic has exposed health problems, but at the same time has become a powerful impetus for the development of new scientific research in the field of epidemiology, clinic of infectious diseases, diagnostics, bioinformatics and digital methods. On the basis of the Central Research Institute of Epidemiology of Rospotrebnadzor, new unique test systems for the detection of SARS-CoV-2 RNA based on real-time PCR based on loop isothermal amplification (IT) technology have been developed, which allows you to examine samples 34 times faster than those developed previously. The Central Research Institute of Epidemiology of Rospotrebnadzor has developed and put into operation the Russian Platform for Aggregation of Information on Virus Genomes (VGARus). The VGARus database contains information about the nucleotide sequences of the SARS-CoV-2 viruses and their mutations, and the SOLAR Integration Platform has been created to quickly transfer the results of PCR studies to all interested citizens of the Russian Federation.
 Aims to study the manifestations of the epidemic process of COVID-19 and the prevalence of genovariants of the SARS-CoV-2 virus in the Russian Federation.
 Methods. A retrospective epidemiological analysis of the incidence of COVID-19 was carried out from March 30, 2020 to May 17, 2022 in the Russian Federation. The database was formed on the basis of the materials of the Rospotrebnadzor report form No. 970 Information on cases of infectious diseases in persons with suspected new coronavirus infection, data from the WHO, the domestic information portal Stopkoronavirus.rf and the Yandex DataLens data visualization and analysis service were used, information on SARS-CoV-2 genovariants in the VGARus database.
 Results. When analyzing the manifestations of the COVID-19 epidemic process in the Russian Federation for 20202022. Two stages have been identified. The first stage was characterized by the rapid spread of the SARS-CoV-2 virus from megacities to other regions of the country and the use of non-specific prevention measures. The beginning of the second was due to the evolution of the SARS-CoV-2 virus and a change in its biological properties, followed by a change in the prevailing genovariants on the territory of the Russian Federation.
 Conclusion. As a result of the study, it was found that with each subsequent increase in the incidence of COVID-19, there was a decrease in the severity of the course and the proportion of pneumonia in the structure of the clinical forms of the disease.

COVID-19: the evolution of the pandemic in Russia. Report I: manifestations of the COVID-19 epidemic process

Background. The ongoing pandemic of a new coronavirus infection (COVID-19) determines the relevance of the analysis of epidemiological patterns of SARS-CoV-2 spread among the population of the Russian Federation.Aim — study of the manifestations of the epidemic process of COVID-19 in the Russian Federation in 2020–2022.Materials and methods. A retrospective epidemiological analysis of the incidence of COVID-19 in the Russian Federation was carried out from 03/30/2020 to 04/24/2022. The data from the Rospotrebnadzor report No. 970 “Information on cases of infectious diseases in persons with suspected new coronavirus infection”, information portal Stopcoronavirus.rf, etc. were used. The presence of SARS-CoV-2 RNA was confirmed by real-time RT-PCR.Results and discussion. The analysis of the manifestations of the epidemic process of COVID-19 in the Russian Federation in 2020–2022 showed the presence of two stages which differed depending on the influence of the biological factor and the ongoing anti-epidemic measures. There was a pronounced trend in the development of the epidemic process, starting from megacities (Moscow, Moscow region and St. Petersburg), which are major transport hubs and centers of migration activity of the population, to the regions of the Russian Federation. The SARS-CoV-2 pathogenicity has been shown to decrease with each subsequent cycle of the rise in the incidence of COVID-19 against the background of the increased contagiousness of the virus.Conclusion. As a result of the study, risk areas (megacities) and risk groups were identified.

Infectious Diseases in the Americas Region that Are Relevant to the Global Surveillance and Control

The aim of the work was information-analytical assessment of the epidemiological situation on infectious diseases that are potentially or truly dangerous in terms of occurrence of emergencies of sanitary-epidemiological nature in the Region of Americas.Materials and methods. The study was based on the official reports of the WHO, the Pan American Health Organization, the Centers for Disease Control and Prevention, the national Ministries of Health, data from the ProMED information portal, the Global Network for the Epidemiology of Infectious Diseases, and published scientific papers.Results and discussion. By the model of the Americas, regional epidemiological features have been established, including the endemicity (enzooticity) of territories according to the most relevant nosological forms and the intensity of the epidemic process manifestations. It is shown that the main epidemiological risks in the countries of Central, South America and the Caribbean are associated with dengue, Zika, Chikungunya fevers characterized by a wide territorial dissemination and the ability to cause large-scale epidemic outbreaks, in the countries of North America – West Nile fever. Other infections of international concern include: cholera, that twice caused epidemics of imported origin during the seventh pandemic, which changed the structure of world morbidity; plague, manifested in an annual incidence, including with a complication by the pneumonic form, which determines an increased potential danger of anthropogenic spread; malaria, demonstrating an upward trend in morbidity and the number of intra-continental imported cases; yellow fever, characterized by the activation of natural foci and the expansion of the territories of potential pathogen transmission. The data obtained can serve as a basis for assessing the risks of infectious disease introduction from the American Region into safe territories, improving epidemiological forecasting and validity in making managerial decisions when conducting sanitary and anti-epidemic (preventive) measures.

Development of an Approach to Integrated Epidemiological Zoning of West Nile Fever Endemic Territory (by the Example of the Volgograd Region)

Relevance . The widespread occurrence of West Nile fever (WNF) in the Russian Federation and the various intensity of epidemic process manifestations determine the relevance of developing a methodology for epidemiological zoning and differentiation of the country's territory by the level of potential epidemic hazard, which will optimize WNF pathogen monitoring and a set of preventive measures. Aims. To develop a methodology for differentiating the territory according to the degree of potential epidemic hazard of West Nile virus (WNV) infection and to test it by the example of the Volgograd region. Materials & Methods . The work used: information on the detection of WNF cases in the Volgograd region in 1999–2019, the results of serological and entomological monitoring for the 1999–2020 period, meteorological data (air temperatures in June-August, 1999–2020), vector maps of hydrography and land use. Results and discussion. As criteria for assessing the potential epidemic hazard of the territory, the following have determined: the number of patients, the number of years of case registration, the average air temperature during WNV transmission season, the identification of markers (antigens/RNA) of the pathogen in environmental objects (carriers, vectors, marker species of animals), the number of the main pathogen's vectors, positive results of serological screening of the population, as well as the level of organization of the epidemiological surveillance system and the level of preparedness of health authorities and institutions for the identification, diagnosis and treatment of patients with WNF. On the basis of the methodology developed by us using the spatial cluster analysis and the method of scoring indicators, an epidemiological zoning of the Volgograd region has carried out in terms of the WNV infection risk. As a result, more than 50% of the territory belongs to the zones of increased risk due to the combined action of biotic, abiotic and social factors. Conclusions . The results obtained indicate the need for targeted monitoring of the pathogen in the territories of the Volgograd region with unconfirmed WNV circulation (northeastern and northwestern regions). In the future, application the developed methodology in practice when carrying out zoning of WNV-endemic territories of the Russian Federation is planned, primarily the subjects of the Southern Federal District, which are characterized by the most intense course of the epidemic process.

Manifestations of epidemic process of tuberculosis among HIV-infected patients and dependence of infection frequency on immunodeficiency level and HIV viral load

Objective. To assess the manifestations of the epidemic process of tuberculosis (TB) in HIV-infected persons and the frequency of infection depending on the level of immunodeficiency and viral load.
 Materials and methods. The epidemiological manifestations of TB incidence among HIV-infected and HIV-negative population of the Perm Region for 20142019 were studied. The frequency of TB in HIV-infected patients was determined depending on the level of immunodeficiency (96 patients) and viral load (61 patients).
 Results. On average, the incidence of TB among HIV-infected persons was by 36 times higher than that of noninfected persons. Among those infected and noninfected with HIV, TB was registered significantly more often among adults, and mainly men. The incidence of TB among HIV-infected persons is higher among urban population, while HIV-negative among rural residents. The incidence of TB in HIV-infected persons increases with an increase in the immunodeficiency and viral load.
 Conclusions. Persons with HIV infection are at risk for TB. The incidence of TB in HIV-infected persons increases with an increase in immunodeficiency and viral load.

West Nile fever in Volgograd Oblast: features of the epidemic process’s manifestations at the present stage

Objective: To study the regional features of the West Nile fever (WNF) epidemic process manifestations using the example of the territory with stable and long-term pathogen circulation (Volgograd Oblast).Materials and Methods: We used the data of the Reference Center for monitoring the WNF pathogen based on the Volgograd Research Anti-Plague Institute of Rospotrebnadzor over 1999–2021. The main method is a comprehensive epidemiological method.Results: The long-term changes in the WNF incidence in Volgograd Oblast is characterized by a cyclical nature with an interval of 1–8 years and a tendency to decrease. The maximum risk of infection occurs in August (58.8%), but there is an increase in the number of cases in September. The average duration of the epidemic season is 8.4 weeks. Case fatality rate is at the level of 4.3%; the prevalence of the number of deaths in the group of 70 years and older (75%), as well as among men (63.6%) has been established. The greatest contribution to the incidence rate is made by the age group of 60 years and older (37.7%). Features of the clinical presentation include the dominance of forms without damage to the central nervous system (91.1%) and moderate clinical course (72.3%). The prevalence of the urban population among the infected was noted (85.5%).Conclusion: A comparative analysis of the clinical and epidemiological WNF manifestations in Volgograd Oblast, territories with a stable circulation of the pathogen (Astrakhan and Rostov Oblasts) and, in overall, the Russian Federation, established differences in the duration of cyclical fluctuations in incidence, seasonality (Rostov Oblast), age structure of incidence (Astrakhan Oblast), distribution of cases by the severity of the clinical course, the site of the alleged infection and social status.

Новые подходы к оценке и прогнозу заболеваемости энтеровирусной (неполио) инфекцией в российской федерации с использованием математических моделей

At present it is impossible to develop epidemiologic surveillance and control over any infection regarding studies on dynamics of morbidity, seasonality and periodicity without using mathematical modeling techniques. Our research goal was to study regularities in manifestations of epidemic process for enterovirus (non-polio) infection (EVnI) in the Russian Federation over 14 years (2006–2019) using mathematical models (linear, logarithmic, power, and exponential approximation).An optimal mathematical model was selected using three statistical parameters, namely determination coefficient, Fischer’s exact test, and standard error. Periodicity of rises and falls in morbidity was calculated with Fourier one- dimensional spectral analysis. Intra-year dynamics of morbidity with EVnI was estimated basing on monthly spread of the disease cases on the RF territory. Classic seasonal decomposition, Census I technique, was applied to analyze time series of monthly morbidity. It was determined that EVnI epidemic process was unevenly spread over years in the RF in the examined period of time (2006–2019) and there were two opposite trends in it; the first one lasted from 2006 to 2010 when morbidity was declining and the second was from 2010 to 2019 when it was growing. Having analyzed manifestations of EVnI epidemi- ologic process in long-term dynamics given its uneven spread as per years, we established that it was advisable to use mathematical models approximated as per separate time periods. Average long-term morbidity with EVnI amounted to 8.09 0/0000 in the RF in 2010–2019 with growth rate being equal to 17.7 %. Maximum value was registered in 2017 (16.32 0/0000). An unfavorable prediction for further epidemic situation development was revealed for the examined pe- riod. The epidemic process was characterized with 4-year periodicity and summer-autumn seasonality with peaks usually occurring in August and September. Rates that characterized intensity of the trends in long-term morbidity dynamics and were calculated with mathematical models differed authentically from those obtained via conventional calculations of average values (χ=11.08; d.f.=1; p=0.0009).

NEW APPROACHES TO ASSESSING AND FORECASTING MORBIDITY WITH ENTEROVIRUS (NON-POLIO) INFECTION IN THE RUSSIAN FEDERATION USING MATHEMATICAL MODELS

At present it is impossible to develop epidemiologic surveillance and control over any infection regarding studies on dynamics of morbidity, seasonality and periodicity without using mathematical modeling techniques. Our research goal was to study regularities in manifestations of epidemic process for enterovirus (non-polio) infection (EVnI) in the Russian Federation over 14 years (2006–2019) using mathematical models (linear, logarithmic, power, and exponential approximation).An optimal mathematical model was selected using three statistical parameters, namely determination coefficient, Fischer’s exact test, and standard error. Periodicity of rises and falls in morbidity was calculated with Fourier one- dimensional spectral analysis. Intra-year dynamics of morbidity with EVnI was estimated basing on monthly spread of the disease cases on the RF territory. Classic seasonal decomposition, Census I technique, was applied to analyze time series of monthly morbidity. It was determined that EVnI epidemic process was unevenly spread over years in the RF in the examined period of time (2006–2019) and there were two opposite trends in it; the first one lasted from 2006 to 2010 when morbidity was declining and the second was from 2010 to 2019 when it was growing. Having analyzed manifestations of EVnI epidemi- ologic process in long-term dynamics given its uneven spread as per years, we established that it was advisable to use mathematical models approximated as per separate time periods. Average long-term morbidity with EVnI amounted to 8.09 0/0000 in the RF in 2010–2019 with growth rate being equal to 17.7 %. Maximum value was registered in 2017 (16.32 0/0000). An unfavorable prediction for further epidemic situation development was revealed for the examined pe- riod. The epidemic process was characterized with 4-year periodicity and summer-autumn seasonality with peaks usually occurring in August and September. Rates that characterized intensity of the trends in long-term morbidity dynamics and were calculated with mathematical models differed authentically from those obtained via conventional calculations of average values (χ=11.08; d.f.=1; p=0.0009).

Effect of the natural and climatic factors on epidemiological situation related to natural focal infections

This article is dedicated to the analysis and generalization of the Russian and foreign research results on natural and climatic factors effect on the intensity of epidemic process manifestations and the natural focal infections pathogens vectors vital activity which are the most widespread in the Russian Federation. Over the past seven years tick-borne infections have been accounting for more than 50 per cent in the natural focal diseases general nosological structure. Among the diseases of this group Lyme borreliosis leads in prevalence and frequency of cases identification. Tick-borne viral encephalitis is still a serious danger for national health. Crimean-Congo hemorrhagic fever epidemiological situation remains unfavorable in the south of the European part of Russia. In addition to the annual patients identification, the demonstrable trend of shifting and expansion of the pathogen’s area in a northerly direction was established. It creates a risk for the spread of the Crimean-Congo hemorrhagic fever virus outside the southern regions of the country. High incidence of the dangerous vector-borne infection — West Nile fever — with the involvement of new subjects in the epidemic process and the emergence of local cases of infection in previously non-endemic territories is registered. Expansion of hemorrhagic fever with renal syndrome natural foci borders, which is the most widespread natural focal zoonosis of viral etiology in the Russian Federation and is the second by the frequency of patients identification after tick-borne infections, is noted. Research data for the dependence of the carriers pathogens number and the dynamics of the natural focal infections incidence on the values of climatic factors, confirmed using various methods of mathematical statistics (time-series analysis, autoregression integrated moving average, logistic regression, correlation analysis, one-way analysis of variance and other) were systematized. It was found that the temperature and humidity of the air and soil, the amount of precipitation, the height of the snow cover are the common abiotic factors for all of investigated infections. The values of these factors can be used for the subsequent epidemiological forecast. The further study of relationship between the incidence rate of the population, the number of arthropod vectors and small mammals with indicators of soil moisture and temperature at different depths, hydrothermal coefficient, normalized relative vegetation index, accumulated values of temperature and precipitation, as well as similar studies on other actual natural focal infections in the Russian Federation will be very promising.

Эффективность рекомбинантного интерферона альфа-2b при интраназальном применении для экстренной профилактики COVID-19 у медицинских работников

Healthcare workers are one of the main risk groups for COVID-19 infection and should be provided priority protection. Objective. To examine the development dynamics and epidemic process manifestations of COVID-19 in healthcare workers as well as to assess the efficacy of intranasal human recombinant interferon alpha-2b (Grippferon®) for emergency medicationassisted nonspecific prevention of novel coronavirus infection. Patients and methods. The incidence of COVID-19 in Perm healthcare workers was examined using official statistical data in the epidemic dynamics. The prophylactic efficacy of Grippferon® was assessed in the analytic cohort prospective study, involving 561 healthcare workers of infectious diseases hospital departments. Results. The incidence rate of COVID-19 among healthcare workers in Perm for the examined period from 09.03.2020 to 06.12.2020 was four times higher, than in the general population. Healthcare workers aged 30–59 years were found to be more likely to develop COVID-19. Physicians had the highest risk of infection compared to other medical professionals. The prophylactic efficacy of Grippferon® was shown to be high in physicians and nurses, who were in contact with COVID-19 patients. Conclusion. Recombinant interferon alpha-2b-based medication Grippferon® can be recommended for emergency prevention of novel coronavirus infection to ensure epidemiological safety of healthcare workers and patients during the COVID-19 pandemic. Key words: COVID-19, incidence rate, healthcare workers, recombinant interferon alpha-2b, Grippferon, intranasal use, prevention

Assessment of epidemiological situation of chronic hepatitis C in Samara Region

Research objective . Analysis of the features of the manifestations of the epidemic process of chronic hepatitis C (HCV) in Samara Region from 1997 to 2018. Materials and methods . The data of official statistics were analyzed: the materials of the Federal Service for Supervision in the Field of Consumer Protection and Human Welfare, the Office of the Federal Service for Supervision in the Field of Consumer Protection and Human Welfare in Samara Region. Results . From 1997 to 2016, in the Samara region there is a periodic wave-like increase in the incidence of HCV with small decreases in indicators from 5.2 to 58.0 0 ⁄ 0000 – by 11.16 times (p < 0.01). From 2017 to 2018 there was a slight decrease in the incidence of HCV in Samara Region from 58.0 to 56.2 0 ⁄ 0000 . The maximum incidence of HCV of the children's population of Samara Region was noted in 2002 and 2012 and amounted to 7.1 and 7.2 0 ⁄ 0000 . The minimum incidence rate of HCV was observed in 2017 at 1,9 0 ⁄ 0000 . Studying features of manifestation of epidemic process of chronic hepatitis, risk factors is necessary for the subsequent development of actions for prevention of growth of a disease and to forecasting of development of incidence.

Characteristic features of maxillofacial phlegmon morbidity with assessment of efficiency of detoxication therapy

Aim. To study the characteristic features of long-term facial phlegmon morbidity in Perm Krai with assessment of the efficiency of infusion therapy using indices of endogenous intoxication expression.&#x0D; Materials and methods. Manifestations of epidemic process of facial phlegmons were studied on the basis of a detailed retrospective analysis of sickness rate among the inhabitants of Perm Krai for the period of 2011–2016. In group 1, all patients besides standard therapy, underwent infusion therapy, and in group 2 – standard therapy alone. Prior to and after the therapy, peripheral blood cellular composition was assessed, and leukocytic indices of intoxication were calculated.&#x0D; Results. A long-term dynamics of facial phlegmon morbidity was established to show the irregularity of process expression according to years. Growth of the quantity of patients is provided by increase in the number of cases with complicated forms. Besides, males play a significant role in formation of sickness rate: the chances for the development of phlegmon among them are 1.49 times higher than in females. In the age structure of morbidity, prevail persons aged 21–30 and 31–50. A half of patients have endogenous intoxication. The course of infusion therapy essentially reduces the expression of endogenous intoxication.&#x0D; Conclusions. There is observed a tendency to growth of facial phlegmon morbidity that is probably connected with changes in etiological structure of pathogenic agents as well as with formation of pathosymbiosis of some opportunistic pathogenic microorganisms. As a rule, phlegmon is being developed against the background of endogenous intoxication, conditioned by both microbial metabolites and tissue destruction products. The efficiency of correction of endogenous intoxication using infusion therapy is shown.

THE CHARACTERISTICS OF MANY YEARS DYNAMICS OF MORBIDITY OF INFECTIONS RELATED TO MEDICAL CARE SUPPORT IN THE REPUBLIC OF TATARSTAN

The retrospective epidemiological study was carried out concerning infections related to medical care support registered in population on the territory of the Republic of Tatarstan in 2002-2015. The reason of such a study was because of late identification and registration of infections related to medical care support, significant damage to population health, development of complications in significant percentage of hospitalized patients and necessity of investigation of patterns of development and outspread of nosocomial infections. The epidemiological analysis was implemented using report form of the Federal statistical observation № 2 of the Federal service of control of sector of defense of rights of consumers and human well-being “The data of infectious and parasitic infections”. The dynamics, structure of many years morbidity and main parameters of manifestation of epidemic process were investigated. The derived data was used as a basis to provide epidemiological characteristic of many years' dynamics of various classes of infections related to medical care support. The indices of morbidity are calculated with consideration for average annual population size. The priority nosologic forms of infections related to medical care support were established concerning newborns (pyodermatitis, conjunctivitis, pneumonia, omphalitis, sepsis, etc.), puerpera (pyo-septic infections, mastitis, sepsis), adult population (postoperative and post-injection complications, infections of urinary tracts, nosocomial pneumonia, viral hepatitis, etc.) which dynamics was characterized by positive and negative rate of increment of indicator. The obtained data was compared with indices represented in national and foreign publications. The implemented study testifies the necessity of development of measures epidemiological monitoring of decreasing of morbidity because of infections related to medical care support in medical organizations.

Vaccination Effect on Epidemic Process of Viral Hepatitis B In Republic of Belarus

Relevance.Hepatitis B (HB) has a global range of spread; in the WHO European Region alone, approximately 15 million people suffer from a chronic form of infection, which in 20–30% of patients can lead to cirrhosis and liver cancer. The aim of this paper was to analyze the of the HBV epidemic process manifestations on territory of Republic of Belarus from 1965 to 2017 and to assess the epidemiological effectiveness of vaccine prevention.Materials and methods.To assess the incidence and coverage of prophylactic vaccinations against HB-infection in the general population and its individual groups, data from the state statistical reporting «Report on certain infectious and parasitic diseases and their carriers», «Report on prophylactic vaccinations», and other medical documentation were used. Results and discussion. Introduction of hepatitis B vaccination of newborns and certain adults groups allowed reducing incidence hepatitis B (HB) rate among total population by 5.4 times in 2017 (14.93 cases per 100,000 population). Incidence rate among child population decreased by 82,8 times (from 4.97 cases per 100,000 child population to 0.06 in 2016). There is direct correlation was established between acute viral hepatitis incidence rate and vaccination coverage level (r = –0.85, p ≤ 0.05). In the last 5 years, the maximum incidence rate of all forms of HB has been marked in group of 30–39 years (68.3% of all registered cases), vaccination coverage of necessary groups is 27.9%. The total populational vaccination coverage by 01.01.2018 is 37.1%, child population is 98.0%.Conclusion.However, a certain number of children remains unvaccinated due to long-term and permanent contraindications or vaccine refuse. If achieved levels of HB vaccination are maintained over the next 20 years, population up to 40 years old will have a recommended level of immunization coverage above 98%, and population up to 45 years old – 96%. Such vaccination coverage will provide background and conditions for HB epidemic situation changing.

Epidemic Process Manifestations and Leading Factors of Transmission of The Pathogenes of the Enterovirus Infection Basic Clinical Forms

Relevance .The urgency of the problem of non-polio enterovirus infection is determined by the wide spread of pathogens, the occurrence of outbreak of morbidity, polymorphism of clinical manifestations and the lack of specific prophylaxis. Most often non-polio enterovirus infection is asymptomatic. Clinically expressed forms can be serous meningitis, herpetic sore throat, eczematous fever, vesicular pharyngitis, gastroenteritis, epidemic myalgia (pleurodynia), tonsillitis, myocarditis, pericarditis, hemorrhagic conjunctivitis, uveitis, etc. The aim of the work is a comparative evaluation of the epidemic process manifestations and the leading factors of serous meningitis (SM) pathogens, enterovirus etiology herpetic angina (HA) transmission and enterovirus etiology gastroenteritis (GE). Materials and methods . Manifestations of the epidemic process of SM and HA were studied according to the official registration of the incidence of the population of Perm for the 2010–2017. In conditions of analytical «case-control» method the epidemiological survey of 350 epidemiological focuses of SM and 142 focuses of HA and 61 focuses of GE were conducted. Results . According to official registration data, the incidence rates of NEVI in the population of Perm during the last 7 years (2010–2017) ranged from 0.3 to 21.5, averaging 5.4 per 100 thousand population. There were mainly three clinical forms registered - serous meningitis, herpetic sore throat, gastroenteritis, the proportion of which was 45.3; 36.6 and 12.4%, respectively. The findings clearly demonstrate that it is similarity between epidemic process manifestations of SM, HA and enterovirus etiology gastroenteritis. Conclusion . In both clinical variants of enterovirus infection the priority role is the water way of transmission of the pathogen by drinking water from centralized and decentralized sources of water system, as well as swimming in surface water.