Siberian subtype tick-borne encephalitis virus in Ixodes ricinus in a newly emerged focus, Finland

Anu Jääskeläinen; Elina Tonteri; Ilkka Pieninkeroinen; Tarja Sironen; Liina Voutilainen; Markku Kuusi; Antti Vaheri; Olli Vapalahti

doi:10.1016/j.ttbdis.2015.10.013

Siberian subtype tick-borne encephalitis virus in Ixodes ricinus in a newly emerged focus, Finland

Ticks Tick Borne Dis. 2016 Feb;7(1):216-223. doi: 10.1016/j.ttbdis.2015.10.013. Epub 2015 Oct 19.

Authors

Anu Jääskeläinen¹, Elina Tonteri², Ilkka Pieninkeroinen³, Tarja Sironen⁴, Liina Voutilainen⁵, Markku Kuusi⁶, Antti Vaheri⁷, Olli Vapalahti⁸

Affiliations

¹ Department of Virology, University of Helsinki, P.O. Box 21, FI-00014 Helsinki, Finland. Electronic address: anu.jaaskelainen@helsinki.fi.
² Department of Virology, University of Helsinki, P.O. Box 21, FI-00014 Helsinki, Finland. Electronic address: elina.rintala@helsinki.fi.
³ Kymenlaakso Central Hospital, Kotkantie 41, FI-48210 Kotka, Finland. Electronic address: ilkka.pieninkeroinen@fimnet.fi.
⁴ Department of Virology, University of Helsinki, P.O. Box 21, FI-00014 Helsinki, Finland. Electronic address: tarja.sironen@helsinki.fi.
⁵ Department of Virology, University of Helsinki, P.O. Box 21, FI-00014 Helsinki, Finland; Natural Resources Institute, Vantaa Unit, P.O. Box 18, FI-01301 Vantaa, Finland. Electronic address: liina.voutilainen@helsinki.fi.
⁶ Department of Infectious Diseases, National Institute for Health and Welfare, P.O. Box 30, FI-00271 Helsinki, Finland. Electronic address: markku.kuusi@thl.fi.
⁷ Department of Virology, University of Helsinki, P.O. Box 21, FI-00014 Helsinki, Finland; Department of Virology and Immunology, HUSLAB, Helsinki University Hospital, P.O. Box 400, FI-00029 Helsinki, Finland. Electronic address: antti.vaheri@helsinki.fi.
⁸ Department of Virology, University of Helsinki, P.O. Box 21, FI-00014 Helsinki, Finland; Department of Virology and Immunology, HUSLAB, Helsinki University Hospital, P.O. Box 400, FI-00029 Helsinki, Finland; Department of Veterinary Biosciences, University of Helsinki, P.O. Box 66, FI-00014 Helsinki, Finland. Electronic address: olli.vapalahti@helsinki.fi.

PMID: 26548609
DOI: 10.1016/j.ttbdis.2015.10.013

Abstract

The first tick-borne encephalitis (TBE) cases in Kotka, Finland appeared in 2010. Altogether ten human cases have been diagnosed by 2014. Four had long-lasting sequelae. We collected 195 Ixodes ricinus ticks, nine rodents, and eleven shrews from the archipelago of Kotka in 2011. Three Siberian subtype TBE virus (TBEV) strains were isolated from the ticks and three mammals were positive for TBEV antibodies. The archipelago of Kotka is a newly emerged TBE focus of Siberian subtype TBEV circulating notably in I. ricinus. The patients had on average longer hospitalization than reported for the European subtype infection.

Keywords: Ixodes ricinus; Siberian subtype; TBE; Tick; Tick-borne encephalitis; Tick-borne encephalitis virus.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adolescent
Adult
Aged
Aged, 80 and over
Animals
Encephalitis Viruses, Tick-Borne / genetics*
Encephalitis Viruses, Tick-Borne / isolation & purification
Encephalitis, Tick-Borne / epidemiology*
Encephalitis, Tick-Borne / virology*
Finland / epidemiology
Humans
Islands
Ixodes / virology*
Middle Aged
RNA, Viral
Young Adult

Substances

RNA, Viral