Biology of tick-borne encephalitis virus.

Tick-borne encephalitis (TBE) virus is an important human pathogen belonging to the genus Flavivirus within the family Flaviviridae. The genome of the TBE virus is a single-stranded RNA (ssRNA) molecule of positive polarity encoding all the viral proteins within a single open reading frame (ORF). TBE virus shares common physical and genetic characteristic of the flavivirus genus. Two subtypes of the TBE virus have been described: (1) European, endemic in many parts of Europe and transmitted by Ixodes ricinus ticks, and (2) Far Eastern (Russian spring summer encephalitis (RSSE) virus), endemic in Far East and transmitted by Ixodes persulcatus ticks.