Prevalence and phylogenetic analysis of tick-borne encephalitis virus (TBEV) in field-collected ticks (Ixodes ricinus) in southern Switzerland

Particle and Fibre Toxicology

Maarten J Voordouw³  Olivier Péter²  Lise Gern⁴  Séverine Arcioni⁶  Caio C M Freire⁵  Stéphane Bressanelli¹  Nadia Rieille³ 

[1] Laboratoire de Virologie Moléculaire et Structurale, CNRS UPR3296, 1 avenue de la Terrasse, 91198 Gif-sur-Yvette cedex, France;Central Institute of Valais Hospitals, Infectious diseases, Av Grand Champsec 86, Sion, Switzerland;Laboratory of Ecology and Evolution of Parasites, Institute of Biology, University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland;Laboratory of Eco-Epidemiology of Parasites, Institute of Biology, University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland;Inter-institutional Grad Program on Bioinformatics, University of Sao Paulo, Matao Street 1010, Sao Paulo, Brazil;Central Institute of Valais Hospitals, Genetics, Av Grand Champsec 86, Sion, Switzerland

关键词: Tick-borne disease;    Tick-borne encephalitis virus;    Tick;    Switzerland;    Ixodes ricinus;    Flavivirus;    Envelope protein;   

Others  :  1150089
DOI  :  10.1186/1756-3305-7-443

 received in 2014-05-06, accepted in 2014-09-13,  发布年份 2014

【 摘 要 】

Background

Tick-borne encephalitis is the most common tick-borne viral infection in Europe with 3,000 human cases reported each year. In Western Europe, the castor bean tick, Ixodes ricinus, is the principal vector of the tick-borne encephalitis virus (TBEV). TBEV appears to be spreading geographically and was recently detected for the first time in Canton Valais in the southern part of Switzerland. The purpose of the present study was to survey the I. ricinus tick populations of Canton Valais for TBEV.

Methods

We collected a total of 19,331 I. ricinus ticks at 45 different sites in Canton Valais between 2010 and 2013. Ticks were processed in pools and tested for TBEV using reverse transcription quantitative PCR. The NS5 gene and the envelope gene of the TBEV isolates were partially sequenced for phylogenetic analysis.

Results

TBEV was detected in tick populations at six of the 45 sites. These six sites were all located in a 33 km transect along the Rhône River. TBEV was detected in two sites for three of the four years of the study showing the temporal persistence of the pathogen. Prevalence of TBEV in the six positive sites ranged from 0.16% to 11.11%. Phylogenetic analysis found that all TBEV isolates from Canton Valais belonged to the European subtype. Genetic analysis found two distinct lineages of TBEV suggesting that Canton Valais experienced two independent colonization events.

Conclusions

TBEV appears to be well established at certain locations in Canton Valais.

【 授权许可】

   
2014 Rieille et al.; licensee BioMed Central Ltd.

【 图 表 】

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