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Sidorenko M, Radzijevskaja J, Mickevičius S, Bratchikov M, Mardosaitė-Busaitienė D, Sakalauskas P, Paulauskas A. Phylogenetic characterisation of tick-borne encephalitis virus from Lithuania. PLoS One 2024; 19:e0296472. [PMID: 38324618 PMCID: PMC10849421 DOI: 10.1371/journal.pone.0296472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 12/13/2023] [Indexed: 02/09/2024] Open
Abstract
The Baltic states are the region in Europe where tick-borne encephalitis (TBE) is most endemic. The highest notification rate of TBE cases is reported in Lithuania, where the incidence of TBE has significantly increased since 1992. A recent study reported 0.4% prevalence of TBE virus (TBEV) in the two most common tick species distributed in Lithuania, Ixodes ricinus and Dermacentor reticulatus, with the existence of endemic foci confirmed in seven out of Lithuania's ten counties. However, until now, no comprehensive data on molecular characterisation and phylogenetic analysis have been available for the circulating TBEV strains. The aim of this study was to analyse TBEV strains derived from I. ricinus and D. reticulatus ticks collected from Lithuania and provide a genotypic characterisation of viruses based on sequence analysis of partial E protein and NS3 genes. The 54 nucleotide sequences obtained were compared with 81 TBEV strains selected from the NCBI database. Phylogenetic analysis of the partial E and NS3 gene sequences derived from 34 Lithuanian TBEV isolates revealed that these were specific to Lithuania, and all belonged to the European subtype, with a maximum identity to the Neudoerfl reference strain (GenBank accession no. U27495) of 98.7% and 97.4%, respectively. The TBEV strains showed significant regional genetic diversity. The detected TBEV genotypes were not specific to the tick species. However, genetic differences were observed between strains from different locations, while strains from the same location showed a high similarity.
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Affiliation(s)
- Marina Sidorenko
- Department of Biology, Faculty of Natural Sciences, Vytautas Magnus University, Kaunas, Lithuania
| | - Jana Radzijevskaja
- Department of Biology, Faculty of Natural Sciences, Vytautas Magnus University, Kaunas, Lithuania
| | - Saulius Mickevičius
- Department of Biology, Faculty of Natural Sciences, Vytautas Magnus University, Kaunas, Lithuania
| | - Maksim Bratchikov
- Department of Physiology, Biochemistry, Microbiology and Laboratory Medicine, Institute of Biomedical Sciences, Faculty of Medicine, Vilnius University, Vilnius, Lithuania
| | | | - Povilas Sakalauskas
- Department of Biology, Faculty of Natural Sciences, Vytautas Magnus University, Kaunas, Lithuania
| | - Algimantas Paulauskas
- Department of Biology, Faculty of Natural Sciences, Vytautas Magnus University, Kaunas, Lithuania
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Grygorczuk S, Dunaj-Małyszko J, Sulik A, Toczyłowski K, Czupryna P, Żebrowska A, Parczewski M. The Lack of the Association of the CCR5 Genotype with the Clinical Presentation and Frequency of Tick-Borne Encephalitis in the Polish Population. Pathogens 2022; 11:pathogens11030318. [PMID: 35335642 PMCID: PMC8955457 DOI: 10.3390/pathogens11030318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 02/24/2022] [Accepted: 03/01/2022] [Indexed: 11/16/2022] Open
Abstract
Background: The host factors influencing the susceptibility to and the severity of tick-borne encephalitis (TBE) are poorly defined. The loss-of-function Δ32 mutation in the chemokine receptor gene CCR5 was identified as a risk factor for West Nile encephalitis and possibly for TBE, suggesting a protective role of CCR5 in Flavivirus encephalitis. Methods: We studied the CCR5 genotype in 205 TBE patients stratified by a clinical presentation and 257 controls from the same endemic area (Podlasie, Poland). The genotype distribution between the groups and differences between TBE patients with different genotypes were analyzed. Results: There were 36 (17.6%) CCR5Δ32 heterozygotes and 3 (1.5%) homozygotes in the TBE group, with no statistically significant difference in comparison with the controls. The CCR5Δ32 allele did not associate with the clinical presentation or the severity of TBE. The cerebrospinal fluid (CSF) inflammatory parameters did not differ between the wild-type (wt/wt) and wt/Δ32 genotype patients. The TBE clinical presentation and CSF parameters in three Δ32/Δ32 homozygotes were unremarkable. Conclusions: The lack of association of CCR5Δ32 with the risk and clinical presentation of TBE challenges the suspected CCR5 protective role. CCR5 is not indispensable for the effective immune response against the TBE virus.
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Affiliation(s)
- Sambor Grygorczuk
- Department of the Infectious Diseases and Neuroinfections, Faculty of Medicine, Medical University of Białystok, ul. Żurawia 14, 15-540 Białystok, Poland; (J.D.-M.); (P.C.)
- Correspondence:
| | - Justyna Dunaj-Małyszko
- Department of the Infectious Diseases and Neuroinfections, Faculty of Medicine, Medical University of Białystok, ul. Żurawia 14, 15-540 Białystok, Poland; (J.D.-M.); (P.C.)
| | - Artur Sulik
- Department of the Pediatric Infectious Diseases, Faculty of Medicine, Medical University of Białystok, ul. Jerzego Waszyngtona 17, 15-274 Białystok, Poland; (A.S.); (K.T.)
| | - Kacper Toczyłowski
- Department of the Pediatric Infectious Diseases, Faculty of Medicine, Medical University of Białystok, ul. Jerzego Waszyngtona 17, 15-274 Białystok, Poland; (A.S.); (K.T.)
| | - Piotr Czupryna
- Department of the Infectious Diseases and Neuroinfections, Faculty of Medicine, Medical University of Białystok, ul. Żurawia 14, 15-540 Białystok, Poland; (J.D.-M.); (P.C.)
| | - Agnieszka Żebrowska
- Regional Centre of Transfusion Medicine, ul. Marii Skłodowskiej-Curie 23, 15-950 Białystok, Poland;
| | - Miłosz Parczewski
- Department of the Infectious Diseases, Tropical Diseases and Acquired Immunodeficiencies, Pomeranian Medical University, ul. Arkońska 4, 71-455 Szczecin, Poland;
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Insights from experience in the treatment of tick-borne bacterial coinfections with tick-borne encephalitis. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 2022. [DOI: 10.1016/bs.armc.2022.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Deviatkin AA, Karganova GG, Vakulenko YA, Lukashev AN. TBEV Subtyping in Terms of Genetic Distance. Viruses 2020; 12:E1240. [PMID: 33142676 PMCID: PMC7692686 DOI: 10.3390/v12111240] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Revised: 10/24/2020] [Accepted: 10/29/2020] [Indexed: 01/07/2023] Open
Abstract
Currently, the lowest formal taxon in virus classification is species; however, unofficial lower-level units are commonly used in everyday work. Tick-borne encephalitis virus (TBEV) is a species of mammalian tick-borne flaviviruses that may cause encephalitis. Many known representatives of TBEV are grouped into subtypes, mostly according to their phylogenetic relationship. However, the emergence of novel sequences could dissolve this phylogenetic grouping; in the absence of strict quantitative criterion, it may be hard to define the borders of the first TBEV taxonomic unit below the species level. In this study, the nucleotide/amino-acid space of all known TBEV sequences was analyzed. Amino-acid sequence p-distances could not reliably distinguish TBEV subtypes. Viruses that differed by less than 10% of nucleotides in the polyprotein-coding gene belonged to the same subtype. At the same time, more divergent viruses were representatives of different subtypes. According to this distance criterion, TBEV species may be divided into seven subtypes: TBEV-Eur, TBEV-Sib, TBEV-FE, TBEV-2871 (TBEV-Ob), TBEV-Him, TBEV-178-79 (TBEV-Bkl-1), and TBEV-886-84 (TBEV-Bkl-2).
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Affiliation(s)
- Andrei A. Deviatkin
- Laboratory of Molecular Biology and Biochemistry, Institute of Molecular Medicine, Sechenov First Moscow State Medical University, 119048 Moscow, Russia;
| | - Galina G. Karganova
- Department of Organization and Technology of Immunobiological Preparations, Institute for Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University, 119991 Moscow, Russia;
- Laboratory of Biology of Arboviruses, Chumakov Institute of Poliomyelitis and Viral Encephalitides (FSBSI “Chumakov FSC R&D IBP RAS), 108819 Moscow, Russia
| | - Yulia A. Vakulenko
- Martsinovsky Institute of Medical Parasitology, Tropical and Vector Borne Diseases, Sechenov First Moscow State Medical University, 119435 Moscow, Russia;
- Department of Virology, Faculty of Biology, Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Alexander N. Lukashev
- Laboratory of Molecular Biology and Biochemistry, Institute of Molecular Medicine, Sechenov First Moscow State Medical University, 119048 Moscow, Russia;
- Martsinovsky Institute of Medical Parasitology, Tropical and Vector Borne Diseases, Sechenov First Moscow State Medical University, 119435 Moscow, Russia;
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Kovalev SY, Mukhacheva TA. Tick-borne encephalitis virus subtypes emerged through rapid vector switches rather than gradual evolution. Ecol Evol 2014; 4:4307-16. [PMID: 25540692 PMCID: PMC4267869 DOI: 10.1002/ece3.1301] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 09/27/2014] [Accepted: 10/01/2014] [Indexed: 12/20/2022] Open
Abstract
Tick-borne encephalitis is the most important human arthropod-borne virus disease in Europe and Russia, with an annual incidence of about 13 thousand people. Tick-borne encephalitis virus (TBEV) is distributed in the natural foci of forest and taiga zones of Eurasia, from the Pacific to the Atlantic coast. Currently, there are three mutually exclusive hypotheses about the origin and distribution of TBEV subtypes, although they are based on the same assumption of gradual evolution. Recently, we have described the structure of TBEV populations in terms of a clusteron approach, a clusteron being a structural unit of viral population [Kovalev and Mukhacheva (2013) Infect. Genet. Evol., 14, 22–28]. This approach allowed us to investigate questions of TBEV evolution in a new way and to propose a hypothesis of quantum evolution due to a vector switch. We also consider a possible mechanism for this switch occurring in interspecific hybrids of ticks. It is necessarily accompanied by a rapid accumulation of mutations in the virus genome, which is contrary to the generally accepted view of gradual evolution in assessing the ages of TBEV populations. The proposed hypothesis could explain and predict not only the formation of new subtypes, but also the emergence of new vector-borne viruses.
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Affiliation(s)
- Sergey Y Kovalev
- Laboratory of Molecular Genetics, Department of Biology, Ural Federal University Lenin Avenue 51, Yekaterinburg, 620000, Russia
| | - Tatyana A Mukhacheva
- Laboratory of Molecular Genetics, Department of Biology, Ural Federal University Lenin Avenue 51, Yekaterinburg, 620000, Russia
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Lindblom P, Wilhelmsson P, Fryland L, Sjöwall J, Haglund M, Matussek A, Ernerudh J, Vene S, Nyman D, Andreassen A, Forsberg P, Lindgren PE. Tick-borne encephalitis virus in ticks detached from humans and follow-up of serological and clinical response. Ticks Tick Borne Dis 2013; 5:21-8. [PMID: 24275477 DOI: 10.1016/j.ttbdis.2013.07.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Accepted: 07/14/2013] [Indexed: 12/20/2022]
Abstract
The risk of tick-borne encephalitis virus (TBEV) infection after a tick bite remains largely unknown. To address this, we investigated the presence of TBEV in ticks detached from humans in an attempt to relate viral copy number, TBEV subtype, and tick feeding time with the serological and clinical response of the tick-bitten participants. Ticks, blood samples, and questionnaires were collected from tick-bitten humans at 34 primary health care centers in Sweden and in the Åland Islands (Finland). A total of 2167 ticks was received from 1886 persons in 2008-2009. Using a multiplex quantitative real-time PCR, 5 TBEV-infected ticks were found (overall prevalence 0.23%, copy range <4×10(2)-7.7×10(6)per tick). One unvaccinated person bitten by a tick containing 7.7×10(6) TBEV copies experienced symptoms. Another unvaccinated person bitten by a tick containing 1.8×10(3) TBEV copies developed neither symptoms nor TBEV antibodies. The remaining 3 persons were protected by vaccination. In contrast, despite lack of TBEV in the detached ticks, 2 persons developed antibodies against TBEV, one of whom reported symptoms. Overall, a low risk of TBEV infection was observed, and too few persons got bitten by TBEV-infected ticks to draw certain conclusions regarding the clinical outcome in relation to the duration of the blood meal and virus copy number. However, this study indicates that an antibody response may develop without clinical symptoms, that a bite by an infected tick not always leads to an antibody response or clinical symptoms, and a possible correlation between virus load and tick feeding time.
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Affiliation(s)
- Pontus Lindblom
- Division of Medical Microbiology, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
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Katargina O, Russakova S, Geller J, Kondrusik M, Zajkowska J, Zygutiene M, Bormane A, Trofimova J, Golovljova I. Detection and characterization of tick-borne encephalitis virus in Baltic countries and eastern Poland. PLoS One 2013; 8:e61374. [PMID: 23650497 PMCID: PMC3641128 DOI: 10.1371/journal.pone.0061374] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Accepted: 03/07/2013] [Indexed: 12/30/2022] Open
Abstract
Ticks were collected from the vegetation in the Baltic countries Estonia, Latvia, Lithuania and eastern Poland and analyzed for the presence of tick-borne encephalitis virus (TBEV) by amplification of the partial E and NS3 genes. In Estonia we found statistically significant differences in the TBEV prevalence between I. persulcatus and I. ricinus ticks (4.23% and 0.42%, respectively). In Latvia, the difference in TBEV prevalence between the two species was not statistically significant (1.02% for I. persulcatus and 1.51% for I. ricinus, respectively). In Lithuania and Poland TBEV was detected in 0.24% and 0.11% of I. ricinus ticks, respectively. Genetic characterization of the partial E and NS3 sequences demonstrated that the TBEV strains belonged to the European subtype in all countries, as well as to the Siberian subtype in Estonia. We also found that in areas where ranges of two tick species overlap, the TBEV subtypes may be detected not only in their natural vector, but also in sympatric tick species.
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Affiliation(s)
- Olga Katargina
- Department of Virology, National Institute for Health Development, Tallinn, Estonia
| | - Stanislava Russakova
- Department of Virology, National Institute for Health Development, Tallinn, Estonia
| | - Julia Geller
- Department of Virology, National Institute for Health Development, Tallinn, Estonia
- Department of Gene Technology, Tallinn University of Technology, Tallinn, Estonia
| | - Macije Kondrusik
- Department of Infectious Diseases and Neuroinfections, Medical University, Bialystok, Poland
| | - Joanna Zajkowska
- Department of Infectious Diseases and Neuroinfections, Medical University, Bialystok, Poland
| | - Milda Zygutiene
- Department of Epidemiological Surveillance, Centre for Communicable Diseases and AIDS, Vilnius, Lithuania
| | - Antra Bormane
- Infectious Diseases Surveillance and Immunisation Unit, Centre for Disease Prevention and Control of Latvia, Riga, Latvia
| | - Julia Trofimova
- Molecular Biology of Bacterial Infection Unit, Latvian Centre of Infectious Diseases, East University Hospital, Riga, Latvia
| | - Irina Golovljova
- Department of Virology, National Institute for Health Development, Tallinn, Estonia
- * E-mail:
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8
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Kovalev SY, Kokorev VS, Belyaeva IV. Distribution of Far-Eastern tick-borne encephalitis virus subtype strains in the former Soviet Union. J Gen Virol 2010; 91:2941-6. [PMID: 20810744 DOI: 10.1099/vir.0.023879-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
European and Asian viruses within the tick-borne encephalitis flavivirus complex are known to show temporal, spatial and phylogenetic relationships that imply a clinal pattern of evolution. However, the isolation of recognized Far-Eastern tick-borne encephalitis virus (TBEV) strains in the European region of the former Soviet Union (SU), i.e. thousands of kilometres west of the region in which they are considered endemic, appears to contradict this concept. Here, we present a parsimonious explanation for this apparent anomaly based on analysis of the dates and regions in which these non-endemic strains were isolated, together with their phylogenetic relationships and the records of redistribution of animals under the All-Union programme for acclimatization of game animals within the former SU. Our evidence supports the concept that the anomalous distribution of Far-Eastern TBEV strains in Europe and Siberia arose primarily as the result of the large-scale westward redistribution of game animals for economic purposes.
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Affiliation(s)
- S Y Kovalev
- Laboratory of Molecular Genetics, Department of Biology, Ural State University, Yekaterinburg, Russia.
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9
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Kovalev SY, Chernykh DN, Kokorev VS, Snitkovskaya TE, Romanenko VV. Origin and distribution of tick-borne encephalitis virus strains of the Siberian subtype in the Middle Urals, the north-west of Russia and the Baltic countries. J Gen Virol 2009; 90:2884-2892. [PMID: 19656959 DOI: 10.1099/vir.0.012419-0] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Tick-borne encephalitis virus (TBEV) plays an important role in infectious human morbidity, particularly in Russia and the Middle Urals. The Siberian subtype of TBEV (S-TBEV) is dominant in the Middle Urals. Determining the origin of S-TBEV strains in this territory and also in the European part of Russia and the Baltic countries is very important for understanding the cause of its distribution. The surface glycoprotein E gene was partially sequenced in 165 S-TBEV isolates collected in the Middle Urals between 1966 and 2008. Nucleotide and amino acid sequence identity of the studied isolates is 94 and 97.4 %, respectively. Eighty per cent of them are represented by six clusters with identical amino acid sequences in the glycoprotein E fragment analysed. We have determined four types of isolate distribution in the explored territory: local, split, corridor and diffuse. The average rate of nucleotide substitutions per site year(-1) is estimated to be 1.56 x 10(-4). The age of the S-TBEV population was evaluated to be slightly less than 400 years. Phylogenetic analysis of the data and comparison with historical events indicate that the distribution of S-TBEV strains in the Middle Urals and the European part of Russia originated twice from different foci in western Siberia. This is related to the first land road into Siberia and the Trans-Siberian Way, which functioned at different times. The main reason for such rapid distribution of S-TBEV strains is the anthropogenic factor, i.e. human economic activity during the colonization of new territories in Siberia in the recent past.
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Affiliation(s)
- S Yu Kovalev
- Laboratory of Molecular Genetics, Department of Biology, Ural State University, Lenin Avenue 51, Yekaterinburg 620083, Russia
| | - D N Chernykh
- Laboratory of Molecular Genetics, Department of Biology, Ural State University, Lenin Avenue 51, Yekaterinburg 620083, Russia
| | - V S Kokorev
- Arbovirus Laboratory, Yekaterinburg Research Institute of Viral Infections, Letnyaya 23, Yekaterinburg 620030, Russia
| | - T E Snitkovskaya
- Laboratory of Viral Diseases, FSHI Sverdlovsk Oblast Hygiene and Epidemiology Centre, Otdel'nyi 3, Yekaterinburg 620078, Russia
| | - V V Romanenko
- Laboratory of Viral Diseases, FSHI Sverdlovsk Oblast Hygiene and Epidemiology Centre, Otdel'nyi 3, Yekaterinburg 620078, Russia
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Šikutová S, Hornok S, Hubálek Z, Doležálková I, Juřicová Z, Rudolf I. Serological survey of domestic animals for tick-borne encephalitis and Bhanja viruses in northeastern Hungary. Vet Microbiol 2009; 135:267-71. [DOI: 10.1016/j.vetmic.2008.09.082] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2008] [Revised: 09/23/2008] [Accepted: 09/29/2008] [Indexed: 11/29/2022]
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Unique signature amino acid substitution in Baltic tick-borne encephalitis virus (TBEV) strains within the Siberian TBEV subtype. Int J Med Microbiol 2008. [DOI: 10.1016/j.ijmm.2007.12.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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13
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Tick-borne encephalitis incidence in Central and Eastern Europe: consequences of political transition. Microbes Infect 2008; 10:209-16. [DOI: 10.1016/j.micinf.2007.12.005] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2007] [Accepted: 12/11/2007] [Indexed: 11/17/2022]
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Heinz FX, Holzmann H, Essl A, Kundi M. Field effectiveness of vaccination against tick-borne encephalitis. Vaccine 2007; 25:7559-67. [PMID: 17869389 DOI: 10.1016/j.vaccine.2007.08.024] [Citation(s) in RCA: 193] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2007] [Revised: 08/08/2007] [Accepted: 08/13/2007] [Indexed: 11/16/2022]
Abstract
Tick-borne encephalitis (TBE) is a vaccine-preventable disease caused by a flavivirus (TBE virus) that is endemic in many European countries and large parts of Central and Eastern Asia. In Europe, highly purified formalin-inactivated whole virus vaccines are in widespread use, but the vaccination coverage differs significantly between countries with TBE endemicity. Austria presents an exceptional situation because 88% of the total population have a history of TBE vaccination, with 58% being regularly vaccinated within the recommended schedule. In this study, we investigated the field effectiveness of TBE vaccination in Austria for the years 2000-2006 in different age groups on the basis of the documented numbers of hospitalized cases in unvaccinated and vaccinated people and the sizes of these population groups as revealed by representative inquiries. We show that the overall effectiveness in regularly vaccinated persons is about 99% with no statistically significant difference between age groups. It is at least as high after the first two vaccinations, i.e. before the completion of the basic vaccination scheme by a third vaccination, but is significantly lower (about 95%) in those with a record of irregular vaccination. Our data confirm the excellent performance of TBE vaccine under field conditions and provide evidence that, in Austria, about 2800 cases were prevented by vaccination in the years 2000-2006.
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Affiliation(s)
- Franz X Heinz
- Institute of Virology, Medical University of Vienna, Kinderspitalgasse 15, AT-1095 Vienna, Austria.
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15
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Han X, Juceviciene A, Uzcategui NY, Brummer-Korvenkontio H, Zygutiene M, Jääskeläinen A, Leinikki P, Vapalahti O. Molecular epidemiology of tick-borne encephalitis virus in Ixodes ricinus ticks in Lithuania. J Med Virol 2005; 77:249-56. [PMID: 16121364 DOI: 10.1002/jmv.20444] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
In Lithuania, 171-645 serologically confirmed cases of tick-borne encephalitis occurred annually [Mickiene et al. (2001): Eur J Clin Microbiol Infect Dis 20:886-888] in 1993-1999, and the tick-borne encephalitis virus (TBEV) seroprevalence in the general population was found previously to be 3.0% [Juceviciene et al. (2002): J Clin Virol 25:23-27]. To assess the risk for TBEV virus infection in Lithuania and to characterize the agent a panel of 3,234 ticks combined into 436 pools [Juceviciene et al., 2005] were tested for presence of TBEV RNA by a nested RT-PCR targeting at the NS5 gene. Six pools were confirmed positive and the prevalence of the infected ticks was 0.2% (if one tick per pool [Juceviciene et al., 2005] was considered positive) and the proportion of positive tick pools was 1.4%. The prevalence of the infected ticks in the Panevezys, Siauliai, and Radviliskis regions (in central Lithuania) was 0.1%, 0.4%, and 1.7% corresponding with a higher TBE disease burden in these regions. The 252-nucleotide NS5-region amplicons, and a longer sequence (737 nucleotides) obtained from one sample from the PrM-E gene region, were sequenced. Phylogenetic analysis of the latter showed that all western type TBEV PrM-E sequences, including the Lithuanian strains, were monophyletic, showed no clustering and had very little variation. The NS5 sequences, although identical within one locality, did not show any mutations common to strains from the two Lithuanian regions, nor could any geographical clustering be found among western type TBEV strains from other areas.
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Affiliation(s)
- Xiuqi Han
- Department of Virology, Haartman Institute, University of Helsinki, Helsinki, Finland
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Golovljova I, Vene S, Sjölander KB, Vasilenko V, Plyusnin A, Lundkvist A. Characterization of tick-borne encephalitis virus from Estonia. J Med Virol 2005; 74:580-8. [PMID: 15484275 DOI: 10.1002/jmv.20224] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Tick-borne encephalitis virus (TBEV) is a severe problem in Estonia. In the present article the first genetic analysis of Estonian TBEV strains is described. In total, seven TBEV strains were isolated from ticks (Ixodes ricinus and I. persulcaus), rodents (Apodemus agrarius and Cletrionomys glareolus), and serum from a tick-borne encephalitis (TBE) patient. The nucleic acid sequences of the viral genome encoding almost the complete E protein (nt 41-1250) and the 3'-NCR-termini of the Estonian TBEV strains were determined by direct sequencing of RT-PCR products. The results showed that all three known TBEV subtypes, Western TBEV (W-TBEV), Far-Eastern TBEV (FE-TBEV), and Siberian TBEV (S-TBEV), co-circulate in Estonia. The Estonian TBEV strains of the S-TBEV and W-TBEV subtypes clustered with the previously reported strains from Latvia and Lithuania. Within the FE-TBEV subtype, however, the Estonian strain Est2546 clustered together with the strain Sofjin, originating from the Far-East of Russia, but not with the strain RK1424, isolated in the neighboring Latvia. This suggests a different evolutionary history for the Estonian and the Latvian strains in the FE-TBEV subtype. The Estonian TBEV strain (Est3535), which belonged to the S-TBEV subtype, had an organization of the 3'-NCR similar to that of strains from the Far-East of Russia (Irkutsk). The 3'-NCRs of Estonian strains of the W-TBEV subtype (Est3051, Est3053, Est3476, and Est3509) were very similar to those of the strain Ljubljana I from the Balkans. In the 3'-NCR sequence of the Estonian strain Est2546, which belonged to the FE-TBEV subtype, a deletion from position 10461 to 10810 extending approximately 10 nucleotides into the core element, was detected.
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Haglund M, Vene S, Forsgren M, Günther G, Johansson B, Niedrig M, Plyusnin A, Lindquist L, Lundkvist A. Characterisation of human tick-borne encephalitis virus from Sweden. J Med Virol 2003; 71:610-21. [PMID: 14556277 DOI: 10.1002/jmv.10497] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Viruses of the tick-borne encephalitis (TBE) antigenic complex, within the family Flaviviridae, cause a variety of diseases including uncomplicated febrile illness, meningo-encephalitis and haemorrhagic fever. Different wildlife species act as reservoir hosts with ixodid tick species as vectors. TBE virus (TBEV) causes 40-130 cases confirmed serologically in Sweden each year. Characteristics of TBEV strains circulating in Sweden have not been investigated previously and no viral sequence data has been reported. In the present study, virus strains were isolated from serum of patients with clinical symptoms consistent with acute TBEV infection. Serologic characterisation, using a panel of E-specific monoclonal antibodies and cross-neutralisation tests, indicated that the Swedish strains of TBEV, isolated 1958-1994, all belonged to the Western TBEV subtype, which includes the Austrian vaccine strain Neudoerfl. Genetic analysis of a partial E-sequence confirmed this close relationship: all Swedish TBEV strains belonged to the European lineage of the Western TBEV subtype, which includes the previously characterised strains Neudoerfl, Hypr, and Kumlinge. Further, three Swedish strains showed partial E-sequences identical to that of the Finnish Kumlinge strain, ten Swedish strains formed a well-supported separate cluster, whereas four others did not show any real clustering. No apparent correlation was observed in comparison of clinical parameters with genetic data or geographic origin of the strains.
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Affiliation(s)
- Mats Haglund
- Division of Infectious Diseases, Department of Medicine, Karolinska Institutet, Huddinge University Hospital, Stockholm, Sweden.
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Mickiene A, Laiskonis A, Günther G, Vene S, Lundkvist A, Lindquist L. Tickborne encephalitis in an area of high endemicity in lithuania: disease severity and long-term prognosis. Clin Infect Dis 2002; 35:650-8. [PMID: 12203160 DOI: 10.1086/342059] [Citation(s) in RCA: 162] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2001] [Revised: 04/10/2002] [Indexed: 11/04/2022] Open
Abstract
Of 250 consecutively admitted patients with central nervous system (CNS) infections who were treated during a 1-year period, all 133 patients with tickborne encephalitis (TBE) were included in a prospective follow-up study. TBE presented as mild (meningeal) in 43.6% of patients and as moderate or severe (encephalitic) in 43.6% and 12.8% of patients, respectively. Paralytic disease was observed in 3.8% of the subjects, and cranial nerve injury was observed in 5.3%. One patient died of TBE. Permanent CNS dysfunction after 1 year was found in 30.8% of patients; in 8.5% of all TBE cases, severe disabilities required adjustment of daily activities. Corticosteroid treatment did not seem to improve outcome. A progressive course of TBE was noted in 2 patients. The risk of incomplete recovery was significantly higher among patients with the encephalitic form of TBE (odds ratio, 4.066; 95% confidence interval, 1.848-8.947). In conclusion, TBE is an important pathogen in CNS infection in the Kaunas region of Lithuania, and it causes long-lasting morbidity in one-third of cases.
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Affiliation(s)
- Aukse Mickiene
- Clinic of Infectious Diseases, Kaunas University of Medicine, 3021 Kaunas, Lithuania.
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