The epidemic process of tick-borne infections in Sverdlovsk region

Objective. To identify characteristics of the epidemic process of tick-borne infections in Sverdlovskaya Oblast (Russia) over a multi-year period, using the municipality of Alapaevsk as a case study. Materials and methods. Based on the state statistical reports from 2014 to 2023, the present study examines the incidence of tick-borne viral encephalitis (TBVE), Lyme borreliosis (LB), and tick bites among the local population. Results. The incidence of tick-borne viral encephalitis was found to be higher than that of Lyme borreliosis in Sverdlovskaya Oblast and the municipality of Alapayevsk. Both TBVE and LB show an annual incidence pattern in the region. In the municipality of Alapayevsk, TBVE was not recorded in the years 2014, 2018, and 2023, while LB was not registered in 2015 and 2021. The incidence rates for TBVE fluctuated between 2.30/0000 and 15.5 0/0000, while LB incidence ranged from 2.20/0000 to 13.30/0000. In the structure of morbidity, urban population predominated for both TBVE and LB, accounting for 81–87 %, with a majority being males. Notably, no cases of TBVE were registered among children. Conclusion. Sverdlovskaya Oblast and the municipality of Alapayevsk appear to be a natural focus of infection and faces the ongoing challenge with the incidence of tick-borne viral encephalitis and Lyme borreliosis, given the annual occurrences of population seeking medical assistance due to tick bites. The epidemic process of TBVE and LB involves primarily the adult population, predominantly males. In certain years, a dominance of one of the two parasitic diseases (TBVE or LB) has been observed.