Intensity and Trends in Development of Epidemic Process of Ixodes Tick-Borne Borrelioses in the Russian Federation in 2002–2018 and Forecast for 2019

Abstract

Objective: to analyze the intensity and dynamics of Ixodidae tick-borne borreliosis (ITBB) incidence in Federal Districts and constituent entities of the Russian Federation (RF) in 2002–2018 and give a forecast of epidemic process development for 2019. The maximum number of cases of ITBB in 2002–2018 was registered in the Central Federal District (CFD); further on in a decreasing order, the Volga (VFD), Siberian (SiFD), North-West (NWFD), Ural (UFD), Far Eastern (FEFD), Southern (SoFD), and North Caucasian (NCFD) Federal Districts. The territories are distributed according to the incidence of ITBB, as follows (descending): NWFD, UFD, SiFD, VFD, CFD, FEFD, SoFD, NCFD. When assessing the dynamics of ITBB incidence, a reliable tendency towards decrease in the intensity of the epidemic process was found for the North-West Federal District and the Volga Federal District, in contrast to the Central Federal District, the Southern Federal District and the North-West Federal District, where there is a significant upward trend. For the UFD, the Siberian Federal District, Far Eastern Federal District, and the Russian Federation on the whole the variation in the incidence rates within the confidence intervals of the long-term annual average values is the most likely to be observed in the near future. The constituent entities of the Russian Federation were ranked according to the levels of ITBB morbidity; the trends in epidemic process development, depending upon the degree of epidemic hazard of the territory, were determined. In half of the 26 entities of the Russian Federation, with the average annual incidence rate above 6.5 о /оооо, a reliable trend in epidemic process intensity reduction was revealed. The exception is the Kemerovo Region and the Republic of Tuva, where further increase in ITBB incidence is probable. In the group of 15 entities of the Russian Federation with the average annual incidence of ITBB ranging from 2.9 о /оооо to 6.5 о /оооо, both the tendency towards growth and decrease or absence of a reliable trend in the intensity of the epidemic process is observed with approximately equal frequency. In the group of entities with the average annual incidence rates of ITBB less than 2.9 о /оооо, the increment of the indicator values in the future is highly probable.