[Tick-borne encephalitis, an emerging disease in Europe: State of the art, perspectives and future challenges]

TTick-borne encephalitis (TBE), caused by the tick-borne encephalitis virus (TBEV), is primarily transmitted to humans through Ixodes tick bites. TBEV comprises three main subtypes describing distinct severity and clinical course: European (TBEV-Eu), Siberian (TBEV-Sib), and Far Eastern (TBEV-Fe). Over the past decade, TBE epidemiology significantly changed in Europe, with an increasing incidence in endemic countries and the discovery of new human case foci and areas of virus circulation. This emergence involves many factors whose impact is not easily determined. While most TBEV-Eu infections are asymptomatic, some patients develop meningitis, or meningoencephalitis, associated with post-infectious sequelae. Several studies recently evaluated the burdens of these sequelae and their associated medical costs. During the complex TBE neuropathogenesis, the antagonism between viral and immunological factors is not clearly identified, nor are the predictive factors of clinical severity. New diagnostic tools are being developed. While TBE treatment is currently only symptomatic, several antiviral treatments are under study.