Comparative analysis of virulence of the Siberian and Far-East subtypes of the tick-born encephalitis virus
Pogodina, V.V.; Bochkova, N.G.; Karan', L.S.; Frolova, M.P.; Trukhina, A.G.; Malenko, G.V.; Levina, L.S.; Platonov, A.E.
Voprosy Virusologii 49(6): 24-30
2004
ISSN/ISBN: 0507-4088 PMID: 15597957 Document Number: 583666
The Siberian subtype of the tickborne encephalitis virus (TEV) was different from the Far-East subtype by being moderately virulent in Siberian hamsters and by having a low infection development rate (100 strains were compared). No differences regarding neuroinvasiveness were observed. Clinical findings and experiments with monkeys showed the ability of the Siberian subtype to provoke severe forms of tickborne encephalitis (TBE). Inflammation and degenerative changes were localized in the brain cortex, subcortical ganglia, nuclei of medulla oblongata, cortex and nuclei of cerebellum, and anterior horns of the spinal cord. 18 TBE cases, including 7 acute (5 were lethal) and 11 chronic cases, caused by the Siberian TEV subtype in residents of Western and Eastern Siberia and of Central Russia (Yaroslavl Region), were analysed. The viral RNA was found in the cortex, medulla oblongata, and horn of cervical spinal cord of acute TBE cases. The sequences of genotyped strains were deposited to GenBank/NCBI under the accession numbers AY363846-AY363865.