Morbidity Rate Forecasting for 2014 as Regards Tick-Borne Viral Encephalitis in the Territory of the Russian Federation Based on Multi-Factor Regression Models

Morbidity forecasting as regards tick-borne viral encephalitis has been carried out using three various methods. Demonstrated is the fact that variability consistency among the actual values accounting the numbers of seeking medical aid because of tick bites and estimated values within the current quasi-cycle is 31.4 %. Developed have been multi-factor regression models for medical aid encounters on the occasion of tick bites and for tick-borne viral encephalitis morbidity. Identified are the most significant factors which characterize specific prophylaxis, acaricide treatment, and abundance of infected ticks; estimated is the impact of the factors on the forecasting. Maximum level of interdependency has reached 78 %: in case with seroprevention it has come up to 64 %, vaccination - 11.5 %, acaricide treatments - 4 %, and abundance of infected ticks - 3%. It has been outlined that a 20 % extension of areas for acaricide treatments leads to a 5% decrement in medical aid encounters, while a 20% reduction - to an almost 7 % rise, respectively. Thus evaluation of the significance of the preventive and curative interventions is of a crucial importance while developing Territorial prevention programmes if undertaken along with consistent application of acaricide treatments

Assessment of indicators of specific humoral immune against COVID-19 in children during the distribution of a new coronavirus infection in the Irkutsk region (2020–2021)

Background. There are many aspects of the development of immunity to the SARSCoV-2 virus, that remain poorly understood, like the influence of age-related characteristics on the intensity of immunity and the course of the disease. Studies of the state of immunity are widely used, mainly in the adults. But questions of the patho- and immunogenesis in children remain unsolved. Determining the nature of seroconversion of antibodies to SARS-CoV-2 in this age group is important information for serological monitoring for targeted immunoprophylaxis of the population and forecasting the epidemic situation in the region.The aim. Evaluation of the dynamics of seroprevalence of specific antibodies to SARS-CoV-2 in children of the Irkutsk region during the pandemic of a new coronavirus infection.Materials and methods. Study was conducted among the child population of the Irkutsk region in the period June 2020 – December 2021 as part of the Rospotrebnadzor project to assess population immunity to SARS-CoV-2 in the population of the Russian Federation. The content of antibodies to SARS-CoV-2 was determined by ELISA using native commercial test systems.Results. Population immunity among the child population of the Irkutsk region was characterized by an upward trend from 7.8 % at stage 1 to 98.4 % at stage 6 of the study. IgG to SARS-CoV-2 remained in 72.8 % and formed in 25.6 % of previously seronegative children. Antibodies were detected in 66.1 % of cases and persisted for up to 10–15 months after COVID-19 infection. The proportion of asymptomatic forms of infection among seropositive volunteers was 69.5 %, which determines the high intensity of the latent epidemic process.Conclusion. The level of seroprevalence was 98.4%. The current results of serological monitoring serve as a scientific basis for adjusting the list and scope of management decisions on the organization of preventive anti-epidemic measures, including vaccination

Morbidity Rates as Regards Tick-Borne Viral Encephalitis in the Russian Federation and across Federal Districts in 2009-2013. Epidemiological Situation in 2014 and Prognosis for 2015

. The first group comprises the greatest number of entities with year on year minimal-change morbidity. Variability of morbidity rates in the second and third groups lays premises for the major changes of TBVE long-term annual average rate across the Russian Federation

Pathoanatomical Pattern of Brain Damage of White Mice Infected with Experimental Anthrax

Background. Bacillus anthracis is a microorganism that causes anthrax. Because of irrational therapy, this particularly dangerous infectious disease leads to a systemic spread of bacteria in the body through histohematological barriers. Bacilli entering the brain subsequently lead to hemorrhagic meningitis. Despite intensive antibiotic therapy, that kind of meningitis is difficult to cure and therefore highly lethal. Studying characteristics of anthrax’s isolates of different origin and genotype is an actual area of research.The aim of the study is searching for pathomorphological and histological changes in the brain regions of experimental animals with anthrax infection, caused by B. anthracis with different plasmid spectrum.Materials and methods: The study was conducted on 200 certified white mice, three B. anthracis strains were used as research objects: B. anthracis I-323 (рХО1– /рХО2– ), B. anthracis I-275 (рХО1- /рХО2- ), and B. anthracis I-217 (рХО1+ / рХО2– ). The material for histological examination was the brain of mice, embedded in paraffin, and then sections were prepared using a microtome and stained with hematoxylin-eosin and Nissl toluidine blue. The degree of neuronal damage was assessed by calculating the semi-quantitative factor and determining the average size of the neuron nuclei, and the numerical density of cells in 1mm2 was studied. Microphotography and quantitative analysis was performed using the Motic Images Plus 2.0 application package. Statistical processing of the results was performed using the program “Statistica 6.0”.The results of the study showed that the brain of infected mice shows signs of hemorrhagic leptomeningitis, the manifestations of which are more pronounced in mice infected with weakly virulent plasmid strains of B. anthracis and fallen mice.Conclusion. Multicomponent exotoxin and specialized proteins, encoded in the pathogenicity plasmid of microorganisms, allow B. anthracis to easily overcome histohematological barriers and cause severe septic anthrax. The results obtained during the study supplement the available information on the pathogenesis of anthrax and indicate the need for further research in this direction

TICK-BORNE VIRUS ENCEPHALITIS IN THE RUSSIAN FEDERATION: FEATURES OF EPIDEMIC PROCESS IN STEADY MORBIDITY DECREASE PERIOD. EPIDEMIOLOGICAL CONDITION IN 2016 AND THE FORECAST FOR 2017

Epidemiological situation for tick-borne virus encephalitis (TBVE) in the Russian Federation is analyzed for the last twenty years (1997–2006 and 2007–2016). It is established that the last decade is characterized by decrease of the morbidity indicators in all constituent entities of the country attributed to the groups with high and middle intensity of the epidemic process, except for the Kirov region. Differences in the dynamics of morbidity decrease are revealed in groups of entities with various intensity of epidemic process in European and Asian parts of Russia. It is shown that at current period the epidemic process is the most intensive in the Asian part of nosoarea of TBVE. In short-term prospect the incidence rate is expected to be below average long-term indicators for 2007–2016 or slightly exceed them

Epizootiological and Epidemiological Situation on Leptospirosis in the Russian Federation over the Period of 2013–2022 and the Forecast for 2023

The aim of the work was to analyze the epizootic and epidemiological situation on leptospirosis in the territory of the Russian Federation in 2013–2022 and to forecast its development in 2023. The long-term dynamics of leptospirosis incidence in the Russian Federation tends to decrease. Cases were registered in 58 constituent entities of the Russian Federation, in all federal districts. The highest incidence rates were noted in the North-Western Federal District. When studying the material from small mammals using bacteriological, immunological and molecular-biological methods, Leptospira circulation was detected in 52 entities of the Russian Federation, in all federal districts. In 2023, sporadic cases of infection are to be expected in the territories of the North-Western Federal District, the Central Federal District, and the Southern Federal District; imported cases of infection from countries with subequatorial and equatorial climates are not excluded

Epidemiological Situation on Tick-Borne Viral Encephalitis in the Russian Federation in 2022 and Forecast of its Development for 2023

The aim of this review is to predict the incidence of tick-borne viral encephalitis (TBVE) in the Russian Federation for 2023 based on analysis of the epidemiological situation on TBVE during 2012–2022. Over the decade, the highest incidence of TBVE was registered in the Siberian, Volga and Ural Federal Districts. In 2022, the Ural Federal District took the second place, the share of the North-Western one decreased by almost two times. Ranking of territories according to the rate of TBVE incidence at the level of constituent entities has made it possible to attribute 16 of them to the group of regions with a high epidemic risk, 14 – to medium epidemic risk, and 18 – to a low epidemic risk. In 2022, the incidence of TBVE in Russia increased by 1.9 times compared to 2021, and amounted to 1.34 0/0000. Despite the increase in the incidence of TBVE in 2022, a significant downward trend has been retained. The rate of infection of ticks removed from humans in 2022 was below the long-term average values. PCR and ELISA were applied for tests. Infection rate of ticks from environmental objects when studied by PCR was higher than the multi-year average values, and lower when studied by ELISA. In 2022, 3.5 million people were immunized against TBVE (vaccinated and revaccinated). Emergency immunoprophylaxis with immunoglobulin covered 24.5 % of the people affected by tick bites (children accounted for 34.3 %). The forecast for TBVE incidence in Russia in 2023 remains favorable. It is expected to be reduced to (0.83±0.298) 0/0000. However, there was not only an increase in the number of TBVE cases, but also the proportion of clinical manifestations of the disease, as well as lethal outcomes among those who suffered from tick bites in 2022. If this pattern holds, the incidence of TBVE in 2023 will be higher than predicted, especially in the constituent entities where the share of individuals with manifest forms among those who suffered from tick bites has increased greatly

Peculiarities of the Epidemiological Situation on Tick-Borne Viral Encephalitis in the Russian Federation in 2017 and the Forecast for 2018

The article presents the analysis of tick-borne encephalitis (TBE) epidemiological situation in the Federal Districts of Russia in 2017. Studied has been the effect of causative factors of epidemic process dynamics, such as: rate of people seeking medical help due to tick bites, contamination of ticks with the TBE virus revealed by immune-enzyme analysis and polymerase chain reaction, amount of people who were vaccinated, scope of emergency prophylaxis, the size of treated areas, and amount of funding for TBE-incidence decrease. Authors presented the incidence forecast for the endemic areas as regards TBE, as well as for the whole country for 2018, taking into account the presence or absence of change in its trends during 2008–2017. The values of the confidence interval are 95 % of the indicator fluctuations. Further gradual improvement of the epidemiological situation is expected

Tick-Borne Viral Encephalitis Incidence in the Constituent Entities of the Russian Federation. Communication 2. Verification of Conformity of the Forecast Data and Seasonal Monitoring of Actual Morbidity Rates

Abstract. Despite the decreasing TBE incidence trend in Russia, the disease is considered an ongoing challenge for the state’s public health and economics. Objective of our study was to describe the algorithm of short-term incidence forecast of TBE, to evaluate the conformity of these data to factual incidence and the results of annual strategic seasonal monitoring which takes place across all the entities of Russia. In the paper, we described the procedure for providing short-term extrapolation of TBE incidence forecast onto the Russian territories, depending on the absence or presence of incidence change trends.Materials and methods. Utilized were the State statistics, “The data on infectious and parasitic diseases” (Form No 2), as well as the information on strategic monitoring for a period of 2007–2018. In order to determine the multi-year trend of epidemic process development, regression analysis was applied. If the trend was identified, predictions were made on its basis, if not – through calculating the long-term annual average. In all the cases, 95 % confidence interval for incidence trend deviation was considered. Comparative analysis of actual morbidity rates and predicted ones and the data on strategic monitoring was conducted by Student’s criterion.The commutations were performed using Excel software tools.Results and discussion. The study has demonstrated that the expected rates of TBE incidence are not statistically different from the actual incidence or the data from strategic monitoring. The underestimation of the epidemiological risk is found only in 4 out of 49 entities (8,2 %), and it is of note that in 3 of them it was less than 16 %. The data from operational monitoring are downward biased by reference to actual incidence, which is probably due to inclusion of TBE cases confirmed and/or manifested upon termination of incubation period after expiration of terms of weekly observations. The unified and simple approach that we proposed to TBE-incidence forecasting within the territory of Russia provides for correct information on expected epidemiological risk assessment and timely planning of required preventative measures

Epidemiological Situation on Tick-Borne Viral Encephalitis in the Russian Federation in 2015 and Prognosis for 2016

Analyzed has been epidemiological situation and measures, performed for prophylaxis of tick-borne viral encephalitis in the territory of Russia in 2015. It is shown that the number of humans bitten by ticks increased in the majority of the constituent entities of the country. But specific and nonspecific preventive operations in 2015 were realized to a lesser extent as compared to 2014. Along with the natural factors, it might be the reason for increase in human tick-borne viral encephalitis morbidity rates. In total, 2116 patients with tick-borne viral encephalitis and 24 lethal cases were registered in the country. On the basis of the data regarding tick-borne viral encephalitis (TBVE) incidence rate among the population across the Federal Districts of Russia over a period of 2009-2015, forecasted have been intensive indicators of the clinical forms’ manifestations for 2016. TBVE morbidity rate in RF will amount to (1.90 ± 0.21)о/оооо. With 95 % probability it will be retained within a range of 1.4-2.4о/оооо