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

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

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

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

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

Epidemiological Situation on Tick-Borne Viral Encephalitis in the Russian Federation in 2019 and Forecast for 2020

Tick-borne encephalitis is a transmissible natural-focal disease which occurs in some countries across Europe and Asia. The observation of epidemic process dynamics of TBVE in Russia covers an 80-year long period and it’s the world longest. The existence of extensive records, various data from different geographic and administrative areas opens the way to interpretation of certain ecological and social factors and their role in the regional epidemiological situation. The targeted measures against TBVE are feasible only when the role of basic predictors of decreasing incidence is defined. Objective: analysis of TBVE incidence among the population and preventive measures in the Districts and constituent entities of Russia in 2019, forecast for 2020 based on the data collected in 2010–2019. The article shows a continued downward trend in TBVE incidence, noted in recent years. However, cases of infection were registered in 6 Federal Districts and 46 regions just like in the past. The number of patients amounted to 1559 (the incidence rate is 1.02 per 100000 people), of whom 23 have died. The rate of seeking medical care among those who were bitten by ticks increased. Specific preventive measures against TBVE haven’t significantly changed by volume and focus compared to the previous period. The scope of acaricide treatments has declined. The article also presents the data concerning TBVE carriers’ infection rate, and the laboratory study results in districts and regions across the country. It is recognized that the epidemiological situation on TBVE in Russia is still unfavorable. It requires the constant attention of health facilities and Rospotrebnadzor and management decisions aimed at further decrease in the incidence by improved prevention especially in the regions with high TBVE incidence

Tick-Borne Viral Encephalitis Morbidity Rates in the Constituent Entities of the Russian Federation. Communication 1: Epidemiological Situation on Tick-Borne Viral Encephalitis in 2018 and Forecast for 2019

Epidemiological situation on tick-borne viral encephalitis in the Russian Federation in 2018 was analyzed. Dynamics of the incidence, medical aid appealability among persons who suffered from tick suction, virus carriage of the vector; vaccination volumes, seroprophylaxis; acaricide treatment are reported in the paper. Utilized were the data on operative monitoring performed by the Rospotrebnadzor Institutions in the constituent entities of the Russian Federation and form data from the Federal statistical survey «Data on Infectious and Parasitic Diseases» over the period of 2009–2017, and also information from the operative monitoring, 2018. The increase in medical aid appealability among the population due to tick suctions was observed in all endemic Federal Districts (FD) of the European part of the Russian Federation during the epidemic season, 2018. The total of 1508 cases in 46 constituent entities of the country was registered: Siberian FD – 44.3 % of the cases, Privolzhsky FD – 22 %, Ural FD – 14.7 %, Northwest FD – 12.6 %,Central FD – 3.7 % , and Far Eastern FD – 1.7 %. Twenty two cases had lethal outcomes. Nation average infection rate of ticks taken off from humans was 1.38 %, from environment objects – 0.61 %. General level of tick infectivity was 1.5 times lower in 2018 as compared to 2017. The forecast of the incidence for 2019, taking into account the presence or absence of the trend fluctuations in the constituent entities in 2009–2018 and the values of the 95 % confidential interval of the possible parameter variations, is presented. The further gradual improvement of the epidemiological conditions for tick-borne viral encephalitis is expected. According to estimates, in 2019, morbidity rates will be 0.19 0/0000 in CentralFD, with value fluctuations ranging between 0.128 to 0.247 cases, in Northwest FD – 1.12 0/0000 (0.112 to 2.122 0/0000), Privolzhsky FD – 0.67 0/0000 (0↔1.649), Ural FD – 1.2 0/0000 (0↔4.590), Siberian FD – 3.4 0/0000 (1.319↔5.471), and Far Eastern – 0.65 0/0000 (0.522↔0.770)

Trends in Epidemic Process Development of Tick-Borne Encephalitis in the Russian Federation, Laboratory Diagnosis, Prophylaxis and Forecast for 2021

Tick-borne encephalitis is a natural-focal infection damaging central nervous system, caused by the similarly-named virus transmitted by several species of ixodic ticks. Natural foci of tick-borne encephalitis (TBE) are widely spread in the forest and forest-steppe landscape zones of the temperate climate belt in the vast territory of Eurasia from the Atlantic to the Pacific Ocean. New TBE-endemic territories have been recently identified in Japan, the Netherlands, and in the UK – in 2019. The increasing risk of infection due to the development of tourism and visits to natural foci of TBE became a public health issue of international concern. The aim of the study is to identify modern features of TBE incidence dynamics in the Russian Federation, the state of laboratory diagnostics and prevention and to predict the incidence for 2021. The paper shows that there is a persistent downward trend in TBE-cases in Russia, which is observed through the past few years. The characteristic feature of the epidemic season-2020 was a significant reduction in the incidence of TBE: 989 cases were registered in 33 constituent entities of the Russian Federation (morbidity rate – 0.67 per 100 000 of the population). The sharp decrease of TBE cases in 2020 as compared to 2019 against the background of a decrease in vaccination can be explained, along with natural factors, by the introduction of restrictive measures during the COVID-19 epidemic. The paper also reflects the dynamics of morbidity, seeking the medical services because of tick bites, the infection rate of the carrier, the scope of vaccination, seroprophylaxis, acaricide treatments. The coverage of express-diagnostic tests of ticks for markers of associated pathogens and its availability for the population are presented. It is recognized that the epidemiological situation on TBE in the Russian Federation remains unfavorable. It demands constant attention on the part of healthcare organizations and Federal Service for Surveillance in the Sphere of Consumers Rights Protection and Human Welfare, as well as management decision making aimed at further decrement in TBE incidence through the improvement of prevention measures, specifically in the entities that are characterized by high TBE incidence. The situation requires monitoring of natural foci of infection, enhancement of prophylaxis and treatment of TBE. The paper provides the forecast of TBE incidence for 2021 and values of the 95 % confidence range of the indicator fluctuation, taking into account the presence or absence of trends in its changes in the territory of federal districts and constituent entities of the Russian Federation in 2011–2020