Pathogenesis and origin of tick-borne encephalitis virus isolated in Japan

为确定森林脑炎流行区域，评价森林脑炎病毒北海道株的致病性，并检测欧洲森林脑炎疫苗对北海道森林脑炎病毒的免疫效果。我们还对TBE病毒北海株进行了系统发育研究，从狗和马血清的抗体阳性结果来看，TBE病毒分布在北海道南部。从病毒分离结果中发现北海道地区TBE病毒的宿主动物为红腹隐翅虫和大姬鼠。TBE病毒北海道株具有TBE毒株共有的致病性。北海道病毒株几百年前从远东的祖先病毒分化而来。TBE病毒西伯利亚亚型的另一亚型分布于俄罗斯西伯利亚地区。欧洲型TBE病毒疫苗对北海道、远东和西伯利亚株的TBE病毒具有良好的免疫效果。制备了抗TBE病毒北海道株的单抗，可用于诊断。

We conducted epidemiclogical study to specify the endemic area of tick-borne encephalitis (TBE), evaluated the pathogenicity of TBE virus Hokkaido strain and tested the efficacy of European TBE vaccine to Hokkaido TBE virus strain. We also performed phylogenetic study of TBE virus Hokkai strains to estimate the origin.The results showed that TBE virus distribute in southern part of Hokkaido from the positive antibody results in dog and horse sera. Reservoir animals of TBE virus in Hokkaido were found to Clethrionomys rufocanus and Apodemus speciosus from virus isolation result. TBE virus Hokkaido strains possessed common pathogenicity shared among TBE virus strains. TBE virus Hokkaido strain diverged from ancestor virus in Far East several hundred years ago. Another subtype of TBE virus Siberian subtype was found to distribute in Siberian area of Russia. European type TBE virus vaccine was found to be efficacious to TBE virus Hokkaido, Far Eastern and Siberian strains. Monoclonal antibodies against TBE virus Hokkaido strain were produced and found to be useful for diagnosis.