Characterization of human TBEV-strains from Sweden and a short review of the phylogenetic relationships within TBEV and Louping Ill.

Mats Haglund

Department of Infectious Diseases, Kalmar County Hospital, Kalmar, Sweden.

The aim of our study was to isolate swedish human TBEV-isolates with following characterization. We used serological and molecular methods including phylogenetic analysis, in both cases we used TBEV-strains from Europe and Russia in comparison (western and far-eastern subtypes). No previous characterization of swedish TBEV-isolates has been performed.

From 24 patients sampled (30 sera, 10 CSF) during the first viremic phase of disease we could obtain 14 isolates by intracerebral inoculation of babymice. None of the CSF-samples were positive. Three older swedish isolates (1950´s-60´s) were also included in the study.

The antigenic characterization (immunofluorescence using a panel of TBEV E-protein specific Mab´s and cross-neutralization using rapid fluorescent focus inhibition test [RFFIT]) verified the close antigenic relationships between the swedish strains and all the other strains used in the study. But the methods were not sensitive enough to discriminate between the western and far-eastern subtypes.

Sequence analysis of the RT-PCR generated fragment of the E-gene from the swedish strains revealed a high degree of homology (nucleotide sequence identity 98%). The sequence identities of the strains compared to western, far-eastern and louping-ill subtypes were 98%, 86% and 90% respectively. When the major part of the complete E-gene sequence obtained from two swedish strains were compared with the vaccine strain Neudoerfl only one conservative aminoacid substitution was found. A good protection of the available vaccines against TBEV in Sweden can be assumed.

We found no correlation between clinical data and phylogenetic data or geographical origin. But we could see a possible correlation between the phylogenetic relationships and geographical origin.

These data will be presented including some remarks describing other available data concerning the phylogeny, dispersal and evolution within the TBEV-complex.

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Bladh L et al.: Rapid detection and quantification of RNA of Crimean-Congo Hemorrhagic Fever Virus by Real-Time Reversed Transcription-PCR

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Haglund M: Characterization of human TBEV-strains from Sweden and a short review of the phylogenetic relationships within TBEV and Louping Ill.

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Olsson G et al.: Hot zones in time and space on human hantavirus infections in northern sweden

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