Spatiotemporal spread of tick-borne encephalitis in the EU/EEA, 2012 to 2020

Abstract

Background Tick-borne encephalitis (TBE) is a vaccine-preventable disease involving the central nervous system. TBE became a notifiable disease on the EU/EEA level in 2012. Aim We aimed to provide an updated epidemiological assessment of TBE in the EU/EEA, focusing on spatiotemporal changes. Methods We performed a descriptive analysis of case characteristics, time and location using data of human TBE cases reported by EU/EEA countries to the European Centre for Disease Prevention and Control with disease onset in 2012–2020. We analysed data at EU/EEA, national, and subnational levels and calculated notification rates using Eurostat population data. Regression models were used for temporal analysis. Results From 2012 to 2020, 19 countries reported 29,974 TBE cases, of which 24,629 (98.6%) were autochthonous. Czechia, Germany and Lithuania reported 52.9% of all cases. The highest notification rates were recorded in Lithuania, Latvia, and Estonia (16.2, 9.5 and 7.5 cases/100,000 population, respectively). Fifty regions from 10 countries, had a notification rate ≥ 5/100,000. There was an increasing trend in number of cases during the study period with an estimated 0.053 additional TBE cases every week. In 2020, 11.5% more TBE cases were reported than predicted based on data from 2016 to 2019. A geographical spread of cases was observed, particularly in regions situated north-west of known endemic regions. Conclusion A close monitoring of ongoing changes to the TBE epidemiological situation in Europe can support the timely adaption of vaccination recommendations. Further analyses to identify populations and geographical areas where vaccination programmes can be of benefit are needed.

An Overview of Tick-Borne Encephalitis Epidemiology in Endemic Regions of Continental Croatia, 2017–2023

“…In a large European study that included the period from 2012 to 2020, 19 countries reported 24,974 TBE cases. Lithuania, Latvia, and Estonia had the highest reporting rates [ 1 ]. The continuing increase in the number of TBEV strains detected in I. ricinus in Europe and the westward spread of I. persulcatus and the more virulent TBEV European and Siberian strains is of great concern [ 4 , 5 ].…”

“…Tick-borne diseases are becoming an increasing public health problem. Tick-borne encephalitis (TBE) is the most widespread tick-borne viral disease in the Euro-Asia region and the second most common tick-transmitted disease in Europe [ 1 , 2 ].…”

“…Data from several European countries suggest that individuals over 50 years of age have the highest incidence of TBE. However, TBE in children may be significantly underdiagnosed due to its milder clinical course [ 1 ]. In addition, the incidence is generally higher in men, which may reflect more frequent exposure to tick bites during work or recreational outdoor activities [ 11 ].…”

Tick‐borne encephalitis: A comprehensive review of the epidemiology, virology, and clinical picture

“…In the recent years however there has been an increase in cases. [26][27][28] The rise in TBE cases is mainly due to environmental, ecological, and socioeconomic factors that increase the risk of human exposure to infected ticks. 29,30…”

“…One unique example when it comes to the change of cases is Austria, where for a long time the number of cases remained constant for a long time. In the recent years however there has been an increase in cases 26–28 . The rise in TBE cases is mainly due to environmental, ecological, and socioeconomic factors that increase the risk of human exposure to infected ticks 29,30 …”