Tick-borne encephalitis (TBE) is a natural focal viral neuroinfection vastly spread in the mid-latitude climate zone of theEurasia. Lethal cases and disability related to TBE determine its high epidemiological significance as well as underlie undiminished attention to prevent it in endemic territories. At the same time, TBE epidemiologic features significantly differ in various geographic areas. Importantly, Republic Sakha (Yakutia) is not among TBE endemic areas in theRussian Federation. However, in the last decade an increased incidence of ixodic tick bites was registered in the Republic Sakha. A pattern of pathogen-specific population immunity is one of the most valuable criteria for assessing magnitude of epidemic process in TBE foci. Hence, our study was aimed at assessing natural herd immunity TBEV in Republic Sakha associated with elevated incidence of tick bite visits. Here, we analyzed the data regarding the rate of tick attacks in the period of 2001–2007 in Republic Sakha. Residents and individuals unvaccinated against TBEV in the city ofYakutskas well as various administrative regions were examined to record the peak incidence of tick attacks. It was found that a range of the administrative regions recording with registered of ixodic tick attacks and elevated incidence of tick bites was expanded. Moreover, the top incidence of tick bites was annually recorded in the south regions of the republic Aldanian, Neryungri, Olyekminsk, Leninsk, Khangalassky districts, city ofYakutskand its suburbs. Furthermore, TBEV-specific immunoglobulins were detected in 5.7±0.68% of the residents examined suggesting about contacts with the pathogen. In addition, the peak count of seropositive people (8.9±1.85%) was identified in Namsky district located in the central part of the republic. Overall, detection rate of TBEV-specific antibodies among general adult population (6.9±0.95%) was significantly higher compared to those observed in children (3.9±0.89%, р < 0.05). no significant differences in urban (5.8±1.12%) vs. rural population (5.63±0.84%) was found.

Aim. To analyze current epidemiological and epizootological situation on cystic (hydatidiform) echinococcosis in constituent entities of the Far Eastern Federal District (FEFD) of the Russian Federation. Materials and methods. Data of the administrations of the Federal service for surveillance on consumers rights protection and human wellbeing as well as data of the FBIH «Center of hygiene and epidemiology» located in different constituent territories of the FEFD during 2013-2017 was used. A review of scientific papers concerning the topic of the current article was performed. Results. Mainly sporadic cases of the disease were registered in 7 out of 9 constituent entities of the FEFD during the 2013-2017. The Jewish Autonomous district and Kamchatka region were free of the echinococcosis during the 5-year observation period. Echinococcosis cases were registered annually in the Chukotka Autonomous district, Republic Sakha (Yakutia) and Primorsky region. Herewith, the incidence rates in Chukotka Autonomous district and Republic Sakha (Yakutia) notably exceeded the national average. No fatal outcomes due to cystic echinococcosis in the FEFD were registered. Conclusion. Implementation of immunoepidemiological surveillance of the population of different age groups and professions is recommended on the constituent entities with registered cases of cystic echinococcosis.