The Role of Climatic Factors in the Spread of Natural Focal Tick-Borne Infections in the Conditions of Climate Change in the North-West of Russia

Abstract

The purpose of this work is to study the dynamics of tick-borne infections morbidity in the North-West of the Russian Federation (detailed epidemiological characteristics on the example of Kaliningrad region) with a focus on the role of modern climatic changes and adaptation to them. Materials and methods. The study is based on the long-term monitoring of the incidence of tick-borne infections among the population of the Russian Federation, its separate regions including Kaliningrad region. We analyzed the long-term data on the average annual number, territorial and temporal distribution of the ticks', standardized indices of the incidence of tick-borne encephalitis (BE) and ixodine boreliosis (IBD); used statistical methods of time series studies with identification of trends and climate change anomalies. Results and discussion. The consequences of rapid climate variability affect the habitats of vectors and conditions of natural focal diseases, including tick-borne infections. Outbreaks of infectious diseases in Kaliningrad Region were registered in years with extremely high average annual air temperatures. At the same time, outbreaks were apparently contributed by climatically warm autumn and very warm winters in 2006-2007 with air temperature anomaly of 4.8°С and in 2014-2015 with air temperature anomalies of 5.1°С Conclusions. In the future the ranges, duration of ticks' season may change, but no statistically significant relationship between the increase in the incidence of tick-borne infections, in particular borreliosis and the average air temperature is found.