Characterization of tick-borne enchephalitis virus from latvia

Viruses of the tick-borne encephalitis (TBE) antigenic complex, within the family Flaviviridae, cause a variety of diseases including uncomplicated fe brile illness, encephalitis, meningo: encephalitis, hemorrhagic fever and c hronic disease in humans, domesticated animals or wildlife species. TEE is a serious problem in Latvia with up to a 1,000 patients confirmed serologic ally annually 1994-1995. No previous data had been reported on the causativ e agent of TEE in Latvia. In the present-study, a virus was isolated from s erum of a patient with clinical symptoms of an acute TBE infection. Nucleot ide sequence information obtained by direct reverse transcription-polymeras e chain reaction (RT-PCR) and the serological characteristics of the isolat ed virus strain, designated TBE-Latvia-1-96, indicated a closer relationshi p to the Vasilchenko strain, isolated in Novosibirsk (Siberia, Russia), as compared to the western European or far eastern subtypes of TBE viruses. In a mouse neurovirulence assay, a significant difference in survival rates ( days) was shown between Latvia-1-96 and the western European TBE virus subt ype. J. Med, Virol. 60:216-222, 2000. (C) 2000 Wiley-Liss, Inc.