Chapter 12a: Epidemiology by country – an overview

Abstract

TBE is a flavivirus infection of the central nervous system (CNS), transmitted by ticks and in some rare instances by ingestion of unpasteurized milk. It is diagnosed in the forested belts of Northern Eurasia ranging from the UK, eastern France, The Netherlands and Norway down to Italy through central and Eastern Europe, Russia, Kazakhstan, and China to Japan. About 10,000 cases of TBE are reported annually, likely a significant underestimate as serological testing is more sporadic than complete and in some countries and, in some countries, (like Japan) not even available. The European Centre for Disease Prevention and Control (ECDC) have put TBE on their list of notifiable diseases. Their case definition requires clinical symptoms of CNS infection plus virological or serological confirmation of the infection, usually by detection of specific immunoglobulins IgG and IgM. Vaccination against TBE is on the World Health Organization's List of Essential Medicines. the safest and most effective medicines needed in a health system. Surveillance of TBE and the TBEV is incomplete. Reported incidences do not reflect actual risk since this fluctuates annually as a result of changes in exposure, vaccine uptake, intensity of case finding and reporting, climate factors, reservoir animals and ticks - just to mention the most relevant factors. For largely unknown reasons (including human behavior, improved diagnostics, or climate change) TBEV appears to be spreading north, east, west, even south and to higher altitudes to areas that were previously believed to be free of the virus.