1
|
Conde JN, Sanchez-Vicente S, Saladino N, Gorbunova EE, Schutt WR, Mladinich MC, Himmler GE, Benach J, Kim HK, Mackow ER. Powassan Viruses Spread Cell to Cell during Direct Isolation from Ixodes Ticks and Persistently Infect Human Brain Endothelial Cells and Pericytes. J Virol 2022; 96:e0168221. [PMID: 34643436 PMCID: PMC8754205 DOI: 10.1128/jvi.01682-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 10/06/2021] [Indexed: 11/20/2022] Open
Abstract
Powassan viruses (POWVs) are neurovirulent tick-borne flaviviruses emerging in the northeastern United States, with a 2% prevalence in Long Island (LI) deer ticks (Ixodes scapularis). POWVs are transmitted within as little as 15 min of a tick bite and enter the central nervous system (CNS) to cause encephalitis (10% of cases are fatal) and long-term neuronal damage. POWV-LI9 and POWV-LI41 present in LI Ixodes ticks were isolated by directly inoculating VeroE6 cells with tick homogenates and detecting POWV-infected cells by immunoperoxidase staining. Inoculated POWV-LI9 and LI41 were exclusively present in infected cell foci, indicative of cell to cell spread, despite growth in liquid culture without an overlay. Cloning and sequencing establish POWV-LI9 as a phylogenetically distinct lineage II POWV strain circulating in LI deer ticks. Primary human brain microvascular endothelial cells (hBMECs) and pericytes form a neurovascular complex that restricts entry into the CNS. We found that POWV-LI9 and -LI41 and lineage I POWV-LB productively infect hBMECs and pericytes and that POWVs were basolaterally transmitted from hBMECs to lower-chamber pericytes without permeabilizing polarized hBMECs. Synchronous POWV-LI9 infection of hBMECs and pericytes induced proinflammatory chemokines, interferon-β (IFN-β) and proteins of the IFN-stimulated gene family (ISGs), with delayed IFN-β secretion by infected pericytes. IFN inhibited POWV infection, but despite IFN secretion, a subset of POWV-infected hBMECs and pericytes remained persistently infected. These findings suggest a potential mechanism for POWVs (LI9/LI41 and LB) to infect hBMECs, spread basolaterally to pericytes, and enter the CNS. hBMEC and pericyte responses to POWV infection suggest a role for immunopathology in POWV neurovirulence and potential therapeutic targets for preventing POWV spread to neuronal compartments. IMPORTANCE We isolated POWVs from LI deer ticks (I. scapularis) directly in VeroE6 cells, and sequencing revealed POWV-LI9 as a distinct lineage II POWV strain. Remarkably, inoculation of VeroE6 cells with POWV-containing tick homogenates resulted in infected cell foci in liquid culture, consistent with cell-to-cell spread. POWV-LI9 and -LI41 and lineage I POWV-LB strains infected hBMECs and pericytes that comprise neurovascular complexes. POWVs were nonlytically transmitted basolaterally from infected hBMECs to lower-chamber pericytes, suggesting a mechanism for POWV transmission across the blood-brain barrier (BBB). POWV-LI9 elicited inflammatory responses from infected hBMEC and pericytes that may contribute to immune cell recruitment and neuropathogenesis. This study reveals a potential mechanism for POWVs to enter the CNS by infecting hBMECs and spreading basolaterally to abluminal pericytes. Our findings reveal that POWV-LI9 persists in cells that form a neurovascular complex spanning the BBB and suggest potential therapeutic targets for preventing POWV spread to neuronal compartments.
Collapse
Affiliation(s)
- Jonas N. Conde
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
- Center for Infectious Disease, Stony Brook University, Stony Brook, New York, USA
| | - Santiago Sanchez-Vicente
- Center for Infection and Immunity, Mailman School of Public Health, Columbia University New York, New York, USA
| | - Nicholas Saladino
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
- Center for Infectious Disease, Stony Brook University, Stony Brook, New York, USA
| | - Elena E. Gorbunova
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
- Center for Infectious Disease, Stony Brook University, Stony Brook, New York, USA
| | - William R. Schutt
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
- Center for Infectious Disease, Stony Brook University, Stony Brook, New York, USA
| | - Megan C. Mladinich
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
- Molecular and Cellular Biology Program, Stony Brook University, Stony Brook, New York, USA
- Center for Infectious Disease, Stony Brook University, Stony Brook, New York, USA
| | - Grace E. Himmler
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
- Molecular and Cellular Biology Program, Stony Brook University, Stony Brook, New York, USA
- Center for Infectious Disease, Stony Brook University, Stony Brook, New York, USA
| | - Jorge Benach
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
- Center for Infectious Disease, Stony Brook University, Stony Brook, New York, USA
| | - Hwan Keun Kim
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
- Molecular and Cellular Biology Program, Stony Brook University, Stony Brook, New York, USA
- Center for Infectious Disease, Stony Brook University, Stony Brook, New York, USA
| | - Erich R. Mackow
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
- Molecular and Cellular Biology Program, Stony Brook University, Stony Brook, New York, USA
- Center for Infectious Disease, Stony Brook University, Stony Brook, New York, USA
| |
Collapse
|
2
|
Ličková M, Fumačová Havlíková S, Sláviková M, Klempa B. Alimentary Infections by Tick-Borne Encephalitis Virus. Viruses 2021; 14:56. [PMID: 35062261 PMCID: PMC8779402 DOI: 10.3390/v14010056] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 12/23/2021] [Accepted: 12/28/2021] [Indexed: 12/30/2022] Open
Abstract
Tick-borne encephalitis virus (TBEV) causes serious the neurological disease, tick-borne encephalitis (TBE). TBEV can be transmitted to humans by ticks as well as by the alimentary route, which is mediated through the consumption of raw milk products from infected ruminants such as sheep, goats, and cows. The alimentary route of TBEV was recognized in the early 1950s and many important experimental studies were performed shortly thereafter. Nowadays, alimentary TBEV infections are recognized as a relevant factor contributing to the overall increase in TBE incidences in Europe. This review aims to summarize the history and current extent of alimentary TBEV infections across Europe, to analyze experimental data on virus secretion in milk, and to review possible alimentary infection preventive measures.
Collapse
Affiliation(s)
| | | | | | - Boris Klempa
- Biomedical Research Center, Institute of Virology, Slovak Academy of Sciences, 84505 Bratislava, Slovakia; (M.L.); (S.F.H.); (M.S.)
| |
Collapse
|
3
|
Abdiyeva K, Turebekov N, Yegemberdiyeva R, Dmitrovskiy A, Yeraliyeva L, Shapiyeva Z, Nurmakhanov T, Sansyzbayev Y, Froeschl G, Hoelscher M, Zinner J, Essbauer S, Frey S. Vectors, molecular epidemiology and phylogeny of TBEV in Kazakhstan and central Asia. Parasit Vectors 2020; 13:504. [PMID: 33023633 PMCID: PMC7539389 DOI: 10.1186/s13071-020-04362-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 09/15/2020] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND In the South of Kazakhstan, Almaty Oblast' (region) is endemic for tick-borne encephalitis, with 0.16-0.32 cases/100,000 population between 2016-2018. The purpose of this study was to determine the prevalence and circulating subtypes of tick-borne encephalitis virus (TBEV) in Almaty Oblast' and Kyzylorda Oblast'. METHODS In 2015 we investigated 2341 ticks from 7 sampling sites for the presence of TBEV. Ticks were pooled in 501 pools and isolated RNA was tested for the presence of TBEV by RT-qPCR. For the positive samples, the E gene was amplified, sequenced and a phylogenetic analysis was carried out. RESULTS A total of 48 pools were TBEV-positive by the RT-qPCR. TBEV-positive ticks were only detected in three districts of Almaty Oblast' and not in Kyzylorda Oblast'. The positive TBEV pools were found within Ixodes persulcatus, Haemaphysalis punctata and Dermacentor marginatus. These tick species prevailed only in Almaty Oblast' whereas in Kyzylorda Oblast' Hyalomma asiaticum and D. marginatus are endemic. The minimum infection rates (MIR) in the sampling sites were 4.4% in Talgar, 2.8% in Tekeli and 1.1% in Yenbekshikazakh, respectively. The phylogenetic analysis of the generated sequences indicates that TBEV strains found in Almaty Oblast' clusters in the Siberian subtype within two different clades. CONCLUSIONS We provided new data about the TBEV MIR in ticks in Almaty Oblast' and showed that TBEV clusters in the Siberian Subtype in two different clusters at the nucleotide level. These results indicate that there are different influences on the circulating TBEV strains in south-eastern Kazakhstan. These influences might be caused by different routes of the virus spread in ticks which might bring different genetic TBEV lineages to Kazakhstan. The new data about the virus distribution and vectors provided here will contribute to an improvement of monitoring of tick-borne infections and timely anti-epidemic measures in Kazakhstan.
Collapse
Affiliation(s)
- Karlygash Abdiyeva
- Center for International Health, Ludwig-Maximilians-Universität, Munich, Germany
- National Scientific Center for Highly Dangerous Infections, Almaty, Kazakhstan
| | - Nurkeldi Turebekov
- Center for International Health, Ludwig-Maximilians-Universität, Munich, Germany
- National Scientific Center for Highly Dangerous Infections, Almaty, Kazakhstan
| | | | | | | | - Zhanna Shapiyeva
- Scientific Practical Center of Sanitary Epidemiological Expertise and Monitoring, Almaty, Kazakhstan
| | - Talgat Nurmakhanov
- National Scientific Center for Highly Dangerous Infections, Almaty, Kazakhstan
| | - Yerlan Sansyzbayev
- National Scientific Center for Highly Dangerous Infections, Almaty, Kazakhstan
| | - Guenter Froeschl
- Center for International Health, Ludwig-Maximilians-Universität, Munich, Germany
- Division of Infectious Diseases and Tropical Medicine, University Hospital, LMU Munich, Munich, Germany
| | - Michael Hoelscher
- Division of Infectious Diseases and Tropical Medicine, University Hospital, LMU Munich, Munich, Germany
| | | | | | - Stefan Frey
- Institute of Microbiology, Munich, Germany
- present Address: Bundeswehr Research Institute for Protective Technologies and CBRN Protection, Munster, Germany
| |
Collapse
|
4
|
Rubel F, Walter M, Vogelgesang JR, Brugger K. Tick-borne encephalitis (TBE) cases are not random: explaining trend, low- and high-frequency oscillations based on the Austrian TBE time series. BMC Infect Dis 2020; 20:448. [PMID: 32586360 PMCID: PMC7316636 DOI: 10.1186/s12879-020-05156-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 06/12/2020] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Why human tick-borne encephalitis (TBE) cases differ from year to year, in some years more 100%, has not been clarified, yet. The cause of the increasing or decreasing trends is also controversial. Austria is the only country in Europe where a 40-year TBE time series and an official vaccine coverage time series are available to investigate these open questions. METHODS A series of generalized linear models (GLMs) has been developed to identify demographic and environmental factors associated with the trend and the oscillations of the TBE time series. Both the observed and the predicted TBE time series were subjected to spectral analysis. The resulting power spectra indicate which predictors are responsible for the trend, the high-frequency and the low-frequency oscillations, and with which explained variance they contribute to the TBE oscillations. RESULTS The increasing trend can be associated with the demography of the increasing human population. The responsible GLM explains 12% of the variance of the TBE time series. The low-frequency oscillations (10 years) are associated with the decadal changes of the large-scale climate in Central Europe. These are well described by the so-called Scandinavian index. This 10-year oscillation cycle is reinforced by the socio-economic predictor net migration. Considering the net migration and the Scandinavian index increases the explained variance of the GLM to 44%. The high-frequency oscillations (2-3 years) are associated with fluctuations of the natural TBE transmission cycle between small mammals and ticks, which are driven by beech fructification. Considering also fructification 2 years prior explains 64% of the variance of the TBE time series. Additionally, annual sunshine duration as predictor for the human outdoor activity increases the explained variance to 70%. CONCLUSIONS The GLMs presented here provide the basis for annual TBE forecasts, which were mainly determined by beech fructification. A total of 3 of the 5 years with full fructification, resulting in high TBE case numbers 2 years later, occurred after 2010. The effects of climate change are therefore not visible through a direct correlation of the TBE cases with rising temperatures, but indirectly via the increased frequency of mast seeding.
Collapse
Affiliation(s)
- Franz Rubel
- Unit for Veterinary Public Health and Epidemiology, University of Veterinary Medicine Vienna, Austria, Veterinaerplatz 1, Vienna, 1210, Austria.
| | - Melanie Walter
- Unit for Veterinary Public Health and Epidemiology, University of Veterinary Medicine Vienna, Austria, Veterinaerplatz 1, Vienna, 1210, Austria
| | - Janna R Vogelgesang
- Unit for Veterinary Public Health and Epidemiology, University of Veterinary Medicine Vienna, Austria, Veterinaerplatz 1, Vienna, 1210, Austria
| | - Katharina Brugger
- Unit for Veterinary Public Health and Epidemiology, University of Veterinary Medicine Vienna, Austria, Veterinaerplatz 1, Vienna, 1210, Austria
| |
Collapse
|
5
|
Divé I, Veje M, Dobler G, Bergström T, Buxmann H, Paul B, Louwen F, Berger A, Jahnke K, Strzelczyk A, Studahl M, Hentz E, Nürnberger L. Tick-borne encephalitis virus (TBEV) infection in pregnancy: Absence of virus transmission to the fetuses despite severe maternal disease - A case study. Ticks Tick Borne Dis 2020; 11:101491. [PMID: 32723645 DOI: 10.1016/j.ttbdis.2020.101491] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 06/07/2020] [Indexed: 12/29/2022]
Abstract
Tick-borne encephalitis (TBE) is an emerging infectious disease in large parts of Europe and Asia. Whereas other members of the Flaviviridae family can harm fetal development, there are only very few reports on TBE virus (TBEV) infections during pregnancy. Thus, the implications for fetal health remain largely unknown. In this study, we present detailed pre- and postnatal health assessment of three children in the context of severe maternal TBEV infection during pregnancy. Following acute TBEV infection of the mothers, intrauterine growth and development of all children were assessed by repetitive prenatal ultrasound. Postnatal examinations included clinical and virological analyses over a follow-up period of 18 months. Prenatally, no signs of intrauterine growth restrictions were observed. All neonates were delivered at term. Umbilical cord blood of the newborns tested negative for TBEV RNA. Virus-specific IgG antibodies were positive at birth but negative at 9 and 11 months of age. Importantly, IgM antibodies remained negative throughout the period of observation. Taken together, these clinical and virological data strongly suggest that fetal TBEV infection did not occur, despite severe manifestations in the mothers.
Collapse
Affiliation(s)
- Iris Divé
- Department of Neurology, University Hospital, Goethe University Frankfurt, Schleusenweg 2-16, 60528 Frankfurt am Main, Germany.
| | - Malin Veje
- Region Västra Götaland, Sahlgrenska University Hospital, Department of Infectious Diseases, Guldhedsgatan 10 A-B, 41346 Gothenburg, Sweden; Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, Guldhedsgatan 10 A-B, 41346 Gothenburg, Sweden.
| | - Gerhard Dobler
- Bundeswehr Institute of Microbiology, German Center of Infection Research (DZIF), Neuherbergstraße 11, 80937 Munich, Germany.
| | - Tomas Bergström
- Region Västra Götaland, Sahlgrenska University Hospital, Department of Infectious Diseases, Guldhedsgatan 10 A-B, 41346 Gothenburg, Sweden; Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, Guldhedsgatan 10 A-B, 41346 Gothenburg, Sweden.
| | - Horst Buxmann
- Department of Pediatric and Adolescent Medicine, Division for Neonatology, University Hospital, Goethe University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany.
| | - Bettina Paul
- Department of Obstetrics and Prenatal Medicine, University Hospital, Goethe University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany.
| | - Frank Louwen
- Department of Obstetrics and Prenatal Medicine, University Hospital, Goethe University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany.
| | - Annemarie Berger
- Institute of Clinical Virology, University Hospital, Goethe University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany.
| | - Kolja Jahnke
- Department of Neurology, University Hospital, Goethe University Frankfurt, Schleusenweg 2-16, 60528 Frankfurt am Main, Germany.
| | - Adam Strzelczyk
- Department of Neurology, University Hospital, Goethe University Frankfurt, Schleusenweg 2-16, 60528 Frankfurt am Main, Germany.
| | - Marie Studahl
- Department of Infectious Diseases, Institute of Biomedicine, Sahlgrenska Academy, Guldhedsgatan 10 A-B, 41346 Gothenburg, Sweden.
| | - Elisabet Hentz
- Division of Neonatology, Queen Silvia Children´s Hospital, Sahlgrenska University Hospital, Rondvägen 10, 41650 Gothenburg, Sweden.
| | - Lucas Nürnberger
- Department of Neurology, University Hospital, Goethe University Frankfurt, Schleusenweg 2-16, 60528 Frankfurt am Main, Germany.
| |
Collapse
|
6
|
Akello JO, Leib SL, Engler O, Beuret C. Evaluation of Viral RNA Recovery Methods in Vectors by Metagenomic Sequencing. Viruses 2020; 12:v12050562. [PMID: 32438629 PMCID: PMC7290855 DOI: 10.3390/v12050562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 05/17/2020] [Accepted: 05/18/2020] [Indexed: 11/16/2022] Open
Abstract
Identification and characterization of viral genomes in vectors including ticks and mosquitoes positive for pathogens of great public health concern using metagenomic next generation sequencing (mNGS) has challenges. One such challenge is the ability to efficiently recover viral RNA which is typically dependent on sample processing. We evaluated the quantitative effect of six different extraction methods in recovering viral RNA in vectors using negative tick homogenates spiked with serial dilutions of tick-borne encephalitis virus (TBEV) and surrogate Langat virus (LGTV). Evaluation was performed using qPCR and mNGS. Sensitivity and proof of concept of optimal method was tested using naturally positive TBEV tick homogenates and positive dengue, chikungunya, and Zika virus mosquito homogenates. The amount of observed viral genome copies, percentage of mapped reads, and genome coverage varied among different extractions methods. The developed Method 5 gave a 120.8-, 46-, 2.5-, 22.4-, and 9.9-fold increase in the number of viral reads mapping to the expected pathogen in comparison to Method 1, 2, 3, 4, and 6, respectively. Our developed Method 5 termed ROVIV (Recovery of Viruses in Vectors) greatly improved viral RNA recovery and identification in vectors using mNGS. Therefore, it may be a more sensitive method for use in arbovirus surveillance.
Collapse
Affiliation(s)
- Joyce Odeke Akello
- Biology Division, Spiez Laboratory, Swiss Federal Office for Civil Protection, Austrasse, CH-3700 Spiez, Switzerland;
- Institute for Infectious Diseases, University of Bern, Friedbühlstrasse 51, 3001 Bern, Switzerland;
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Hochschulstrasse 4, 3012 Bern, Switzerland
- Correspondence: (J.O.A.); (C.B.); Tel.: +41-316328646 (J.O.A.); +41-584681664 (C.B.)
| | - Stephen L. Leib
- Institute for Infectious Diseases, University of Bern, Friedbühlstrasse 51, 3001 Bern, Switzerland;
| | - Olivier Engler
- Biology Division, Spiez Laboratory, Swiss Federal Office for Civil Protection, Austrasse, CH-3700 Spiez, Switzerland;
| | - Christian Beuret
- Biology Division, Spiez Laboratory, Swiss Federal Office for Civil Protection, Austrasse, CH-3700 Spiez, Switzerland;
- Correspondence: (J.O.A.); (C.B.); Tel.: +41-316328646 (J.O.A.); +41-584681664 (C.B.)
| |
Collapse
|
7
|
Deviatkin AA, Kholodilov IS, Vakulenko YA, Karganova GG, Lukashev AN. Tick-Borne Encephalitis Virus: An Emerging Ancient Zoonosis? Viruses 2020; 12:v12020247. [PMID: 32102228 PMCID: PMC7077300 DOI: 10.3390/v12020247] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 02/10/2020] [Accepted: 02/19/2020] [Indexed: 12/19/2022] Open
Abstract
Tick-borne encephalitis (TBE) is one of the most important viral zoonosis transmitted by the bite of infected ticks. In this study, all tick-borne encephalitis virus (TBEV) E gene sequences available in GenBank as of June 2019 with known date of isolation (n = 551) were analyzed. Simulation studies showed that a sample bias could significantly affect earlier studies, because small TBEV datasets (n = 50) produced non-overlapping intervals for evolutionary rate estimates. An apparent lack of a temporal signal in TBEV, in general, was found, precluding molecular clock analysis of all TBEV subtypes in one dataset. Within all subtypes and most of the smaller groups in these subtypes, there was evidence of many medium- and long-distance virus transfers. These multiple random events may play a key role in the virus spreading. For some groups, virus diversity within one territory was similar to diversity over the whole geographic range. This is best exemplified by the virus diversity observed in Switzerland or Czech Republic. These two countries yielded most of the known European subtype Eu3 subgroup sequences, and the diversity of viruses found within each of these small countries is comparable to that of the whole Eu3 subgroup, which is prevalent all over Central and Eastern Europe. Most of the deep tree nodes within all three established TBEV subtypes dated less than 300 years back. This could be explained by the recent emergence of most of the known TBEV diversity. Results of bioinformatics analysis presented here, together with multiple field findings, suggest that TBEV may be regarded as an emerging disease.
Collapse
Affiliation(s)
- Andrei A. Deviatkin
- Laboratory of Molecular Biology and Biochemistry, Institute of Molecular Medicine, Sechenov First Moscow State Medical University, 119048 Moscow, Russia;
- Laboratory of Postgenomic Technologies, Izmerov Research Institute of Occupational Health, 105275 Moscow, Russia
- Correspondence: ; Tel.: +7-906-739-0860
| | - Ivan S. Kholodilov
- Laboratory of Biology of Arboviruses, Chumakov Institute of Poliomyelitis and Viral Encephalitides (FSBSI “Chumakov FSC R&D IBP RAS), 108819 Moscow, Russia; (I.S.K.); (G.G.K.)
| | - 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
| | - Galina G. Karganova
- Laboratory of Biology of Arboviruses, Chumakov Institute of Poliomyelitis and Viral Encephalitides (FSBSI “Chumakov FSC R&D IBP RAS), 108819 Moscow, Russia; (I.S.K.); (G.G.K.)
- Department of Organization and Technology of Immunobiological Preparations, Institute for Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University, 119991 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;
| |
Collapse
|
8
|
Holding M, Dowall SD, Medlock JM, Carter DP, Pullan ST, Lewis J, Vipond R, Rocchi MS, Baylis M, Hewson R. Tick-Borne Encephalitis Virus, United Kingdom. Emerg Infect Dis 2020; 26:90-96. [PMID: 31661056 PMCID: PMC6924911 DOI: 10.3201/eid2601.191085] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
During February 2018–January 2019, we conducted large-scale surveillance for the presence and prevalence of tick-borne encephalitis virus (TBEV) and louping ill virus (LIV) in sentinel animals and ticks in the United Kingdom. Serum was collected from 1,309 deer culled across England and Scotland. Overall, 4% of samples were ELISA-positive for the TBEV serocomplex. A focus in the Thetford Forest area had the highest proportion (47.7%) of seropositive samples. Ticks collected from culled deer within seropositive regions were tested for viral RNA; 5 of 2,041 ticks tested positive by LIV/TBEV real-time reverse transcription PCR, all from within the Thetford Forest area. From 1 tick, we identified a full-length genomic sequence of TBEV. Thus, using deer as sentinels revealed a potential TBEV focus in the United Kingdom. This detection of TBEV genomic sequence in UK ticks has important public health implications, especially for undiagnosed encephalitis.
Collapse
|
9
|
Nah K, Bede-Fazekas Á, Trájer AJ, Wu J. The potential impact of climate change on the transmission risk of tick-borne encephalitis in Hungary. BMC Infect Dis 2020; 20:34. [PMID: 31931734 PMCID: PMC6958747 DOI: 10.1186/s12879-019-4734-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 12/24/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Impact of climate change on tick-borne encephalitis (TBE) prevalence in the tick-host enzootic cycle in a given region depends on how the region-specific climate change patterns influence tick population development processes and tick-borne encephalitis virus (TBEV) transmission dynamics involving both systemic and co-feeding transmission routes. Predicting the transmission risk of TBEV in the enzootic cycle with projected climate conditions is essential for planning public health interventions including vaccination programs to mitigate the TBE incidence in the inhabitants and travelers. We have previously developed and validated a mathematical model for retroactive analysis of weather fluctuation on TBE prevalence in Hungary, and we aim to show in this research that this model provides an effective tool for projecting TBEV transmission risk in the enzootic cycle. METHODS Using the established model of TBEV transmission and the climate predictions of the Vas county in western Hungary in 2021-2050 and 2071-2100, we quantify the risk of TBEV transmission using a series of summative indices - the basic reproduction number, the duration of infestation, the stage-specific tick densities, and the accumulated (tick) infections due to co-feeding transmission. We also measure the significance of co-feeding transmission by observing the cumulative number of new transmissions through the non-systemic transmission route. RESULTS The transmission potential and the risk in the study site are expected to increase along with the increase of the temperature in 2021-2050 and 2071-2100. This increase will be facilitated by the expected extension of the tick questing season and the increase of the numbers of susceptible ticks (larval and nymphal) and the number of infected nymphal ticks co-feeding on the same hosts, leading to compounded increase of infections through the non-systemic transmission. CONCLUSIONS The developed mathematical model provides an effective tool for predicting TBE prevalence in the tick-host enzootic cycle, by integrating climate projection with emerging knowledge about the region-specific tick ecological and pathogen enzootic processes (through model parametrization fitting to historical data). Model projects increasing co-feeding transmission and prevalence of TBEV in a recognized TBE endemic region, so human risk of TBEV infection is likely increasing unless public health interventions are enhanced.
Collapse
Affiliation(s)
- Kyeongah Nah
- Laboratory for Industrial and Applied Mathematics, Department of Mathematics and Statistics, York University, 4700 Keele St., Toronto, M3J 1P3 Canada
| | - Ákos Bede-Fazekas
- MTA Centre for Ecological Research, Institute of Ecology and Botany, Alkomány u. 2-4., Vácrátót, H-2163 Hungary
- MTA Centre for Ecological Research, GINOP Sustainable Ecosystems Group, Klebelsberg Kuno u. 3., Tihany, H-8237 Hungary
| | - Attila János Trájer
- Institute of Environmental Engineering, University of Pannonia, Egyetem u. 10., Veszprém, H-8200 Hungary
- Department of Limnology, University of Pannonia, Egyetem u. 10., Veszprém, H-8200 Hungary
| | - Jianhong Wu
- Laboratory for Industrial and Applied Mathematics, Department of Mathematics and Statistics, York University, 4700 Keele St., Toronto, M3J 1P3 Canada
| |
Collapse
|
10
|
Michelitsch A, Wernike K, Klaus C, Dobler G, Beer M. Exploring the Reservoir Hosts of Tick-Borne Encephalitis Virus. Viruses 2019; 11:v11070669. [PMID: 31336624 PMCID: PMC6669706 DOI: 10.3390/v11070669] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 07/17/2019] [Accepted: 07/19/2019] [Indexed: 12/20/2022] Open
Abstract
Tick-borne encephalitis virus (TBEV) is an important arbovirus, which is found across large parts of Eurasia and is considered to be a major health risk for humans. Like any other arbovirus, TBEV relies on complex interactions between vectors, reservoir hosts, and the environment for successful virus circulation. Hard ticks are the vectors for TBEV, transmitting the virus to a variety of animals. The importance of these animals in the lifecycle of TBEV is still up for debate. Large woodland animals seem to have a positive influence on virus circulation by providing a food source for adult ticks; birds are suspected to play a role in virus distribution. Bank voles and yellow-necked mice are often referred to as classical virus reservoirs, but this statement lacks strong evidence supporting their highlighted role. Other small mammals (e.g., insectivores) may also play a crucial role in virus transmission, not to mention the absence of any suspected reservoir host for non-European endemic regions. Theories highlighting the importance of the co-feeding transmission route go as far as naming ticks themselves as the true reservoir for TBEV, and mammalian hosts as a mere bridge for transmission. A deeper insight into the virus reservoir could lead to a better understanding of the development of endemic regions. The spatial distribution of TBEV is constricted to certain areas, forming natural foci that can be restricted to sizes of merely 500 square meters. The limiting factors for their occurrence are largely unknown, but a possible influence of reservoir hosts on the distribution pattern of TBE is discussed. This review aims to give an overview of the multiple factors influencing the TBEV transmission cycle, focusing on the role of virus reservoirs, and highlights the questions that are waiting to be further explored.
Collapse
Affiliation(s)
- Anna Michelitsch
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Südufer 10, 17493 Greifswald-Insel Riems, Germany
| | - Kerstin Wernike
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Südufer 10, 17493 Greifswald-Insel Riems, Germany
| | - Christine Klaus
- Institute for Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, Naumburger Str. 96a, 07743 Jena, Germany
| | - Gerhard Dobler
- Bundeswehr Institute of Microbiology, German Center of Infection Research (DZIF) partner site Munich, Neuherbergstraße 11, 80937 München, Germany
| | - Martin Beer
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Südufer 10, 17493 Greifswald-Insel Riems, Germany.
| |
Collapse
|
11
|
Hockicková I, Sekula J, Hudáčková D, Paraličová Z. [Tick-borne encephalitis in a pregnant patient]. Klin Mikrobiol Infekc Lek 2019; 25:16-19. [PMID: 31266089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
There is a lack of information in the literature about the course and risk of vertical transmission of tick-borne encephalitis (TBE) during pregnancy. Presented is a case report of a female patient in the 37th week of pregnancy infected by foodborne transmission. She developed meningitis with no neurological damage. Three weeks after the first symptoms, she gave birth to a healthy child who, at the age of 30 months, had a negative result of anti-TBE antibodies in both IgM and IgG classes. In the child, no signs of neurological injury or impaired psychomotor development were observed throughout the follow-up period.
Collapse
Affiliation(s)
- Ivana Hockicková
- Department of Infectology and Travel Medicine, Faculty of Medicine P. J. Šafarik University and L. Pasteur University Hospital, Košice,Slovak Republik, e-mail:
| | | | | | | |
Collapse
|
12
|
Abstract
Little is known about the occurrence of tick-borne encephalitis in Romania. Sheep are an infection source for humans and are useful sentinels for risk analysis. We demonstrate high antibody prevalence (15.02%) among sheep used as sentinels for this disease in 80% of the tested localities in 5 counties of northwestern Romania.
Collapse
|
13
|
Abstract
During early 2017, we conducted a seroepidemiologic investigation for tickborne encephalitis virus among 291 Japan Self-Defense Forces members in Hokkaido. Two (0.7%) tested positive. Neither had clinically apparent symptoms after removing ticks.
Collapse
|
14
|
Eisen L. Pathogen transmission in relation to duration of attachment by Ixodes scapularis ticks. Ticks Tick Borne Dis 2018; 9:535-542. [PMID: 29398603 PMCID: PMC5857464 DOI: 10.1016/j.ttbdis.2018.01.002] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 01/05/2018] [Accepted: 01/12/2018] [Indexed: 11/22/2022]
Abstract
The blacklegged tick, Ixodes scapularis, is the primary vector to humans in the eastern United States of the deer tick virus lineage of Powassan virus (Powassan virus disease); the protozoan parasite Babesia microti (babesiosis); and multiple bacterial disease agents including Anaplasma phagocytophilum (anaplasmosis), Borrelia burgdorferi and Borrelia mayonii (Lyme disease), Borrelia miyamotoi (relapsing fever-like illness, named Borrelia miyamotoi disease), and Ehrlichia muris eauclairensis (a minor causative agent of ehrlichiosis). With the notable exception of Powassan virus, which can be transmitted within minutes after attachment by an infected tick, there is no doubt that the risk of transmission of other I. scapularis-borne pathogens, including Lyme disease spirochetes, increases with the length of time (number of days) infected ticks are allowed to remain attached. This review summarizes data from experimental transmission studies to reinforce the important disease-prevention message that regular (at least daily) tick checks and prompt tick removal has strong potential to reduce the risk of transmission of I. scapularis-borne bacterial and parasitic pathogens from infected attached ticks. The most likely scenario for human exposure to an I. scapularis-borne pathogen is the bite by a single infected tick. However, recent reviews have failed to make a clear distinction between data based on transmission studies where experimental hosts were fed upon by a single versus multiple infected ticks. A summary of data from experimental studies on transmission of Lyme disease spirochetes (Bo. burgdorferi and Bo. mayonii) by I. scapularis nymphs indicates that the probability of transmission resulting in host infection, at time points from 24 to 72 h after nymphal attachment, is higher when multiple infected ticks feed together as compared to feeding by a single infected tick. In the specific context of risk for human infection, the most relevant experimental studies therefore are those where the probability of pathogen transmission at a given point in time after attachment was determined using a single infected tick. The minimum duration of attachment by single infected I. scapularis nymphs required for transmission to result in host infection is poorly defined for most pathogens, but experimental studies have shown that Powassan virus can be transmitted within 15 min of tick attachment and both A. phagocytophilum and Bo. miyamotoi within the first 24 h of attachment. There is no experimental evidence for transmission of Lyme disease spirochetes by single infected I. scapularis nymphs to result in host infection when ticks are attached for only 24 h (despite exposure of nearly 90 experimental rodent hosts across multiple studies) but the probability of transmission resulting in host infection appears to increase to approximately 10% by 48 h and reach 70% by 72 h for Bo. burgdorferi. Caveats to the results from experimental transmission studies, including specific circumstances (such as re-attachment of previously partially fed infected ticks) that may lead to more rapid transmission are discussed.
Collapse
Affiliation(s)
- Lars Eisen
- Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, 3156, Rampart Road, Fort Collins, CO 80521, United States.
| |
Collapse
|
15
|
Jahfari S, de Vries A, Rijks JM, Van Gucht S, Vennema H, Sprong H, Rockx B. Tick-Borne Encephalitis Virus in Ticks and Roe Deer, the Netherlands. Emerg Infect Dis 2018; 23:1028-1030. [PMID: 28518024 PMCID: PMC5443429 DOI: 10.3201/eid2306.161247] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
We report the presence of tick-borne encephalitis virus (TBEV) in the Netherlands. Serologic screening of roe deer found TBEV-neutralizing antibodies with a seroprevalence of 2%, and TBEV RNA was detected in 2 ticks from the same location. Enhanced surveillance and awareness among medical professionals has led to the identification of autochthonous cases.
Collapse
|
16
|
Zhou W, Woodson M, Neupane B, Bai F, Sherman MB, Choi KH, Neelakanta G, Sultana H. Exosomes serve as novel modes of tick-borne flavivirus transmission from arthropod to human cells and facilitates dissemination of viral RNA and proteins to the vertebrate neuronal cells. PLoS Pathog 2018; 14:e1006764. [PMID: 29300779 PMCID: PMC5754134 DOI: 10.1371/journal.ppat.1006764] [Citation(s) in RCA: 104] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 11/20/2017] [Indexed: 11/18/2022] Open
Abstract
Molecular determinants and mechanisms of arthropod-borne flavivirus transmission to the vertebrate host are poorly understood. In this study, we show for the first time that a cell line from medically important arthropods, such as ticks, secretes extracellular vesicles (EVs) including exosomes that mediate transmission of flavivirus RNA and proteins to the human cells. Our study shows that tick-borne Langat virus (LGTV), a model pathogen closely related to tick-borne encephalitis virus (TBEV), profusely uses arthropod exosomes for transmission of viral RNA and proteins to the human- skin keratinocytes and blood endothelial cells. Cryo-electron microscopy showed the presence of purified arthropod/neuronal exosomes with the size range of 30 to 200 nm in diameter. Both positive and negative strands of LGTV RNA and viral envelope-protein were detected inside exosomes derived from arthropod, murine and human cells. Detection of Nonstructural 1 (NS1) protein in arthropod and neuronal exosomes further suggested that exosomes contain viral proteins. Viral RNA and proteins in exosomes derived from tick and mammalian cells were secured, highly infectious and replicative in all tested evaluations. Treatment with GW4869, a selective inhibitor that blocks exosome release affected LGTV loads in both arthropod and mammalian cell-derived exosomes. Transwell-migration assays showed that exosomes derived from infected-brain-microvascular endothelial cells (that constitute the blood-brain barrier) facilitated LGTV RNA and protein transmission, crossing of the barriers and infection of neuronal cells. Neuronal infection showed abundant loads of both tick-borne LGTV and mosquito-borne West Nile virus RNA in exosomes. Our data also suggest that exosome-mediated LGTV viral transmission is clathrin-dependent. Collectively, our results suggest that flaviviruses uses arthropod-derived exosomes as a novel means for viral RNA and protein transmission from the vector, and the vertebrate exosomes for dissemination within the host that may subsequently allow neuroinvasion and neuropathogenesis.
Collapse
MESH Headings
- Animals
- Arthropod Vectors/cytology
- Arthropod Vectors/ultrastructure
- Arthropod Vectors/virology
- Cell Line
- Cells, Cultured
- Cerebral Cortex/cytology
- Cerebral Cortex/pathology
- Cerebral Cortex/ultrastructure
- Cerebral Cortex/virology
- Chlorocebus aethiops
- Coculture Techniques
- Cryoelectron Microscopy
- Embryo, Mammalian/cytology
- Encephalitis Viruses, Tick-Borne/pathogenicity
- Encephalitis Viruses, Tick-Borne/physiology
- Encephalitis Viruses, Tick-Borne/ultrastructure
- Encephalitis, Tick-Borne/pathology
- Encephalitis, Tick-Borne/transmission
- Encephalitis, Tick-Borne/virology
- Endothelium, Vascular/cytology
- Endothelium, Vascular/pathology
- Endothelium, Vascular/ultrastructure
- Endothelium, Vascular/virology
- Exosomes/ultrastructure
- Exosomes/virology
- Host-Parasite Interactions
- Host-Pathogen Interactions
- Humans
- Ixodes/cytology
- Ixodes/ultrastructure
- Ixodes/virology
- Keratinocytes/cytology
- Keratinocytes/pathology
- Keratinocytes/ultrastructure
- Keratinocytes/virology
- Mice
- Mice, Inbred C57BL
- Models, Biological
- Neurons/cytology
- Neurons/pathology
- Neurons/ultrastructure
- Neurons/virology
- RNA, Viral/metabolism
- Viral Proteins/metabolism
Collapse
Affiliation(s)
- Wenshuo Zhou
- Department of Biological Sciences, Old Dominion University, Norfolk, VA, United States of America
| | - Michael Woodson
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, United States of America
| | - Biswas Neupane
- Department of Biological Sciences, The University of Southern Mississippi, Hattiesburg, MS, United States of America
| | - Fengwei Bai
- Department of Biological Sciences, The University of Southern Mississippi, Hattiesburg, MS, United States of America
| | - Michael B. Sherman
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, United States of America
- Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, United States of America
| | - Kyung H. Choi
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, United States of America
| | - Girish Neelakanta
- Department of Biological Sciences, Old Dominion University, Norfolk, VA, United States of America
- Center for Molecular Medicine, Old Dominion University, Norfolk, VA, United States of America
| | - Hameeda Sultana
- Department of Biological Sciences, Old Dominion University, Norfolk, VA, United States of America
- Center for Molecular Medicine, Old Dominion University, Norfolk, VA, United States of America
- Department of Medicine, Division of Infectious Diseases and International Health, University of Virginia School of Medicine, Charlottesville, VA, United States of America
- * E-mail:
| |
Collapse
|
17
|
Kříž B, Fialová A, Šebestová H, Daniel M, Malý M. Comparison of the epidemiological patterns of Lyme borreliosis and tick-borne encephalitis in the Czech Republic in 2007-2016. Epidemiol Mikrobiol Imunol 2018; 67:134-140. [PMID: 30602281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
BACKGROUND Lyme borreliosis (LB) and tick-borne encephalitis (TBE) are two vector-borne diseases transmitted by ticks. Both diseases are endemic and have been reported in all regions of the Czech Republic including urban agglomerations, but in varying proportions. Because of the natural conditions in the border areas, the risk of infection is also high for travelers from the neighboring countries such as Austria, Germany, Poland, and Slovakia. MATERIALS AND METHODS To gain more information on the epidemiology of LB and TBE in the last decade, we analyzed national surveillance data from 2007 to 2016. RESULTS Incidence of LB in the Czech Republic was 37.3/100,000 population and year (27.6 - 46.1/100,000). Incidence of TBE incidence was 5.7/100,000 (3.4-8.2/100,000) and declined although the trend was not significant (p = 0.155). Difference between the incidences of LB and TBE was increasing in time. Overall male-to-female ratio was 0.84 and 1.51 for LB and TBE, respectively. The age-specific incidences of both infections have a typical two-peak shape, with the first peak in the age group 5-9 years for LB and 15-19 years for TBE. The second peak for both LB and TBE is in the age group 55-64 years. TBE poses a considerable risk to children < 15 years. Among 39,074 cases of LB, the most common clinical manifestations were erythema migrants 62.1% and Lyme neuroborreliosis 25.1%. All 5969 TBE cases manifested itself by affecting nervous system, namely meningo-encephalitis 47.9%, meningoencephalomyelitis 21.8% and meningitis 19.8%. CONCLUSIONS The data evidence the high chance risk of infection with LB and TBE in the Czech Republic. The incidence of both infections shows a bimodal distribution during the year. LB cases are five to six times as frequent as TBE cases. Over the last years, the incidence of LB has remained roughly stable while TBE has shown a downward trend. The present study is unique in allowing the comparison of the incidence rates of LB and TBE over time and space.
Collapse
|
18
|
Brugger K, Walter M, Chitimia-Dobler L, Dobler G, Rubel F. Seasonal cycles of the TBE and Lyme borreliosis vector Ixodes ricinus modelled with time-lagged and interval-averaged predictors. Exp Appl Acarol 2017; 73:439-450. [PMID: 29181672 PMCID: PMC5727152 DOI: 10.1007/s10493-017-0197-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 11/17/2017] [Indexed: 05/15/2023]
Abstract
Ticks of the species Ixodes ricinus (L.) are the major vectors for tick-borne diseases in Europe. The aim of this study was to quantify the influence of environmental variables on the seasonal cycle of questing I. ricinus. Therefore, an 8-year time series of nymphal I. ricinus flagged at monthly intervals in Haselmühl (Germany) was compiled. For the first time, cross correlation maps were applied to identify optimal associations between observed nymphal I. ricinus densities and time-lagged as well as temporal averaged explanatory variables. To prove the explanatory power of these associations, two Poisson regression models were generated. The first model simulates the ticks of the entire time series flagged per 100 m[Formula: see text], the second model the mean seasonal cycle. Explanatory variables comprise the temperature of the flagging month, the relative humidity averaged from the flagging month and 1 month prior to flagging, the temperature averaged over 4-6 months prior to the flagging event and the hunting statistics of the European hare from the preceding year. The first model explains 65% of the monthly tick variance and results in a root mean square error (RMSE) of 17 ticks per 100 m[Formula: see text]. The second model explains 96% of the tick variance. Again, the accuracy is expressed by the RMSE, which is 5 ticks per 100 m[Formula: see text]. As a major result, this study demonstrates that tick densities are higher correlated with time-lagged and temporal averaged variables than with contemporaneous explanatory variables, resulting in a better model performance.
Collapse
Affiliation(s)
- Katharina Brugger
- Institute for Veterinary Public Health, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210, Vienna, Austria.
| | - Melanie Walter
- Institute for Veterinary Public Health, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210, Vienna, Austria
| | - Lidia Chitimia-Dobler
- Bundeswehr Institute of Microbiology, Neuherbergstraße 11, 80937, Munich, Germany
- German Center of Infection Research (DZIF) Partner Site Munich, Munich, Germany
| | - Gerhard Dobler
- Bundeswehr Institute of Microbiology, Neuherbergstraße 11, 80937, Munich, Germany
- German Center of Infection Research (DZIF) Partner Site Munich, Munich, Germany
- Parasitology Unit, University of Hohenheim, Emil-Wolff-Straße 34, 70593, Stuttgart, Germany
| | - Franz Rubel
- Institute for Veterinary Public Health, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210, Vienna, Austria
| |
Collapse
|
19
|
Abstract
BACKGROUND Illegal waste disposal impacts public health and causes aesthetic and environmental pollution. Waste disposed in places without permitted and controlled facilities can provide a ready source of nutrition and shelter for rodents and thus promote the spread of their ecto- and endoparasites. The presence of two distinct zoonotic viruses, lymphocytic choriomeningitis virus (LCMV) and tick-borne encephalitis virus (TBEV), was searched at illegal waste sites. The aim of this study was to determine the prevalence of infection with both viruses in rodents and to discuss the virus-rodent relations in such environments. METHODS Rodents sampled between October 2011 and April 2013 at 7 locations in the Istrian peninsula, were identified morphologically and genetically to minimize misidentification. Serological and molecular techniques were used to determine seroprevalence of infection in rodents and to detect viral RNAs. Serological testing was performed by immune fluorescence assay for detection of LCMV and TBEV specific antibodies. Real-time RT PCR was used for the detection of LCMV nucleoprotein gene and TBEV 3' non-coding region. Data were statistically analysed using SPSS statistic v2.0. RESULTS Out of 82 rodent sera tested, the presence of LCMV antibodies was demonstrated in 24.93%. The highest prevalence of LCMV infection was found in commensal Mus musculus (47.37%), followed by 11.53%, 19.04% and 25% prevalence of infection in A. agrarius, A. flavicolis and A. sylvaticus, respectively. The highest prevalence of infection in rodents (53.33%) was found in locations with large waste sites and high anthropogenic influence. LCMV seroprevalence was significantly lower in rodents sampled from natural habitats. Viral nucleic acids were screened in 46 samples but yielded no amplicons of LCMV or TBEV. In addition, TBEV specific antibodies were not detected. CONCLUSIONS Illegal waste sites have considerable impact on the area where they are located. Results have shown that the transmission of human pathogens can be significantly increased by the presence of waste sites. However, the pathogen must be endemic in the environment where the waste site is located. The introduction of a human pathogen as a consequence of the waste site in the area of interest could not be proven.
Collapse
Affiliation(s)
- Darja Duh
- Department for Medical Microbiology Maribor, Centre for Medical Microbiology, National Laboratory of Health, Environment and Food, Prvomajska 1, 2000 Maribor, Slovenia
| | - Sandra Hasic
- Department of Biodiversity, Faculty of Mathematics, Natural Sciences and Information Technologies, University of Primorska, Glagoljaška 8, 6000 Koper, Slovenia
| | - Elena Buzan
- Department of Biodiversity, Faculty of Mathematics, Natural Sciences and Information Technologies, University of Primorska, Glagoljaška 8, 6000 Koper, Slovenia
- Institute for Biodiversity Studies, Science and Research Centre, University of Primorska, Garibaldijeva 1, 6000 Koper, Slovenia
| |
Collapse
|
20
|
Talactac MR, Yoshii K, Hernandez EP, Kusakisako K, Galay RL, Fujisaki K, Mochizuki M, Tanaka T. Synchronous Langat Virus Infection of Haemaphysalis longicornis Using Anal Pore Microinjection. Viruses 2017; 9:v9070189. [PMID: 28714929 PMCID: PMC5537681 DOI: 10.3390/v9070189] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 07/06/2017] [Accepted: 07/06/2017] [Indexed: 11/16/2022] Open
Abstract
The tick-borne encephalitis virus (TBEV) serocomplex of flaviviruses consists of arboviruses that cause important diseases in animals and humans. The transmission of this group of viruses is commonly associated with tick species such as Ixodes spp., Dermacentor spp., and Hyalomma spp. In the case of Haemaphysalis longicornis, the detection and isolation of flaviviruses have been previously reported. However, studies showing survival dynamics of any tick-borne flavivirus in H. longicornis are still lacking. In this study, an anal pore microinjection method was used to infect adult H. longicornis with Langat virus (LGTV), a naturally attenuated member of the TBEV serocomplex. LGTV detection in ticks was done by real-time PCR, virus isolation, and indirect immunofluorescent antibody test. The maximum viral titer was recorded at 28 days post-inoculation, and midgut cells were shown to be the primary replication site. The tick can also harbor the virus for at least 120 days and can successfully transmit LGTV to susceptible mice as confirmed by detection of LGTV antibodies. However, no transovarial transmission was observed from the egg and larval samples. Taken together, our results highly suggest that anal pore microinjection can be an effective method in infecting adult H. longicornis, which can greatly assist in our efforts to study tick and virus interactions.
Collapse
Affiliation(s)
- Melbourne Rio Talactac
- Laboratory of Infectious Diseases, Joint Faculty of Veterinary Medicine, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065, Japan.
- Department of Pathological and Preventive Veterinary Science, The United Graduate School of Veterinary Science, Yamaguchi University, Yoshida, Yamaguchi 753-8515, Japan.
- Department of Clinical and Population Health, College of Veterinary Medicine and Biomedical Sciences, Cavite State University, Cavite 4122, Philippines.
| | - Kentaro Yoshii
- Laboratory of Public Health, Faculty of Veterinary Medicine, Hokkaido University, Kita-ku Kita-18 Nishi-9, Sapporo, Hokkaido 060-0818, Japan.
| | - Emmanuel Pacia Hernandez
- Laboratory of Infectious Diseases, Joint Faculty of Veterinary Medicine, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065, Japan.
- Department of Pathological and Preventive Veterinary Science, The United Graduate School of Veterinary Science, Yamaguchi University, Yoshida, Yamaguchi 753-8515, Japan.
| | - Kodai Kusakisako
- Laboratory of Infectious Diseases, Joint Faculty of Veterinary Medicine, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065, Japan.
- Department of Pathological and Preventive Veterinary Science, The United Graduate School of Veterinary Science, Yamaguchi University, Yoshida, Yamaguchi 753-8515, Japan.
| | - Remil Linggatong Galay
- Department of Veterinary Paraclinical Sciences, College of Veterinary Medicine, University of the Philippines Los Baños, Los Baños, Laguna 4031, Philippines.
| | - Kozo Fujisaki
- National Agriculture and Food Research Organization, 3-1-5 Kannondai, Tsukuba, Ibaraki 305-0856, Japan.
| | - Masami Mochizuki
- Laboratory of Infectious Diseases, Joint Faculty of Veterinary Medicine, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065, Japan.
- Department of Pathological and Preventive Veterinary Science, The United Graduate School of Veterinary Science, Yamaguchi University, Yoshida, Yamaguchi 753-8515, Japan.
| | - Tetsuya Tanaka
- Laboratory of Infectious Diseases, Joint Faculty of Veterinary Medicine, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065, Japan.
- Department of Pathological and Preventive Veterinary Science, The United Graduate School of Veterinary Science, Yamaguchi University, Yoshida, Yamaguchi 753-8515, Japan.
| |
Collapse
|
21
|
Abstract
During 2006–2014, four tick-borne encephalitis (TBE) cases occurred among Israeli travelers. We calculated TBE incidence at 321.0, 45.0, 13.2, and 7.5 cases/100,000 travelers/year of travel to Sweden, Switzerland, Austria, and Germany, respectively. TBE incidence among travelers to these destinations appears to justify TBE vaccination in accordance with World Health Organization recommendations.
Collapse
|
22
|
Pukhovskaya NM, Morozova OV, Belozerova NB, Bakhmetyeva SV, Vysochina NP, Zdanovskaya NI, Ivanov LI. Comparative analysis of genomes of tick-borne encephalitis virus strains isolated from mosquitoes and ticks. Vopr Virusol 2017; 62:30-35. [PMID: 29323844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The tick-borne encephalitis virus (TBEV) strain Lazo MP36 was isolated from the pool of mosquitoes Aedes vexans collected in Lazo region of Khabarovsk territory in August 2014. Phylogenetic analysis of the strain Lazo MP36 complete genome (GenBank accession number KT001073) revealed its correspondence to the TBEV Far Eastern subtype and differences from the following strains: 1) from ticks Ixodes persulcatus P. Schulze, 1930 [vaccine strain 205 (JX498939) and strains Khekhtzir 1230 (KF880805), Chichagovka (KP844724), Birobidzhan 1354 (KF880805) isolated in 2012-2013]; 2) from mosquitoes [strain Malyshevo (KJ744034) isolated in 1978 from Aedes vexans nipponii in Khabarovsk territory; strain Sakhalin 6-11 isolated from the pool of mosquitoes in 2011 (KF826916)]; 3) from human brain [vaccine strain Sofjin (JN229223), Glubinnoe/2004(DQ862460). Kavalerovo (DQ862460), Svetlogorie (DQ862460)]. The fusion peptide necessary for flavivirus entry to cells of the three TBEV strains isolated from mosquitoes (Lazo MP36, Malyshevo and Sakhalin 6-11) has the canonical structure 98-DRGWGNHCGLFGKGSI-113 for the tick-borne flaviviruses. Amino acid transition H104G typical for the mosquito-borne flaviviruses was not found. Structures of 5’- and 3’-untranslated (UTR) regions of the TBEV strains from mosquitoes were 85-98% homologous to the TBEV strains of all subtypes without recombination with mosquito-borne flaviviruses found in the Far East of Russia. Secondary structures of 5’- and 3'-UTR as well as cyclization sequences (CS) of types a and B are highly homologous for all TBEV isolates independently of the biological hosts and vectors. similarity of the genomes of the TBEV isolates from mosquitoes, ticks and patients as well as pathogenicity of the isolates for new-borne laboratory mice and tissue cultures might suggest a possible role of mosquitoes in the TBEV circulation in natural foci as an accidental or additional virus carrier.
Collapse
MESH Headings
- Aedes/virology
- Amino Acid Sequence
- Animals
- Animals, Newborn
- Disease Vectors
- Dogs
- Encephalitis Viruses, Tick-Borne/classification
- Encephalitis Viruses, Tick-Borne/genetics
- Encephalitis Viruses, Tick-Borne/isolation & purification
- Encephalitis, Tick-Borne/epidemiology
- Encephalitis, Tick-Borne/transmission
- Encephalitis, Tick-Borne/virology
- Asia, Eastern/epidemiology
- Genome, Viral
- Genotype
- Humans
- Ixodes/virology
- Mice
- Mice, Inbred ICR
- Nucleic Acid Conformation
- Phylogeny
- RNA, Viral/chemistry
- RNA, Viral/genetics
- RNA, Viral/isolation & purification
- Rodentia/virology
- Sequence Alignment
- Sequence Homology, Amino Acid
- Siberia/epidemiology
Collapse
|
23
|
Mlera L, Meade-White K, Saturday G, Scott D, Bloom ME. Modeling Powassan virus infection in Peromyscus leucopus, a natural host. PLoS Negl Trop Dis 2017; 11:e0005346. [PMID: 28141800 PMCID: PMC5302833 DOI: 10.1371/journal.pntd.0005346] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 02/10/2017] [Accepted: 01/22/2017] [Indexed: 02/07/2023] Open
Abstract
The tick-borne flavivirus, Powassan virus (POWV) causes life-threatening encephalitis in humans in North America and Europe. POWV is transmitted by ixodid tick vectors that feed on small to medium-sized mammals, such as Peromyscus leucopus mice, which may serve as either reservoir, bridge or amplification hosts. Intraperitoneal and intracranial inoculation of 4-week old Peromyscus leucopus mice with 103 PFU of POWV did not result in overt clinical signs of disease. However, following intracranial inoculation, infected mice seroconverted to POWV and histopathological examinations revealed that the mice uniformly developed mild lymphocytic perivascular cuffing and microgliosis in the brain and spinal cord from 5 to 15 days post infection (dpi), suggesting an early inflammatory response. In contrast, intracranial inoculation of 4-week old C57BL/6 and BALB/c mice was lethal by 5 dpi. Intraperitoneal inoculation was lethal in BALB/c mice, but 40% (2/5) of C57BL/6 mice survived. We concluded that Peromyscus leucopus mice infected i.c. with a lethal dose of POWV support a limited infection, restricted to the central nervous system and mount an antibody response to the virus. However, they fail to develop clinical signs of disease and are able to control the infection. These results suggest the involvement of restriction factors, and the mechanism by which Peromyscus leucopus mice restrict POWV infection remains under study.
Collapse
Affiliation(s)
- Luwanika Mlera
- Laboratory of Virology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rocky Mountain Laboratories, Hamilton, Montana, United States of America
| | - Kimberly Meade-White
- Rocky Mountain Veterinary Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rocky Mountain Laboratories, Hamilton, Montana, United States of America
| | - Greg Saturday
- Rocky Mountain Veterinary Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rocky Mountain Laboratories, Hamilton, Montana, United States of America
| | - Dana Scott
- Rocky Mountain Veterinary Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rocky Mountain Laboratories, Hamilton, Montana, United States of America
| | - Marshall E. Bloom
- Laboratory of Virology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rocky Mountain Laboratories, Hamilton, Montana, United States of America
| |
Collapse
|
24
|
Nikitin AY, Noskov AK, Balandina TP. [POPULATION MORBIDITY BY INFECTIONS TRANSMITIED VIA IXODES PER- SULCATUS IN THE NORTH AND SOUTH OF IRKUTSK REGION]. Zh Mikrobiol Epidemiol Immunobiol 2016:34-40. [PMID: 30695387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
AIM Evaluate the degree of epidemic risk of emergence of tick-borne encephalitis (TBE) and ixodes ticks' borreliosis (ITB) in municipalities (MPs) of Irkutsk region with various natural- climate conditions. MATERIALS AND METHODS Morbidity was compared for TBE and ITB during 2001 - 2015 in MPs of Irkutsk region located, to the north or south of the 55th parallel, i.e. in the con- ditions of different severity of sharply continental climate. 5-year average data were analyzed. RESULTS ITB morbidity was 2 - 3 times higher than TBE for all the 5-year periods in the north of the region, whereas in the south -differences were not present. Moreover, in MPs located to the north of the 55th parallel in 2001 - 2015 a decrease of TBE and ITB morbidity did not occur, as in the south of the region. CONCLUSION The lack of population morbidity reduction by TBE and ITB in the north and prevalence of the latter nosoform requires enhancement of a complex of prophylaxis measures in these MPs with an accent in development of non-specific means, includ- ing acaricidic treatment, enhancement of operations of centers of express diagnostics of transmissible infections, familiarizing of the population with the use of protective suits during periods of high activity of ticks.
Collapse
|
25
|
Brugger K, Boehnke D, Petney T, Dobler G, Pfeffer M, Silaghi C, Schaub GA, Pinior B, Dautel H, Kahl O, Pfister K, Süss J, Rubel F. A Density Map of the Tick-Borne Encephalitis and Lyme Borreliosis Vector Ixodes ricinus (Acari: Ixodidae) for Germany. J Med Entomol 2016; 53:1292-1302. [PMID: 27498885 DOI: 10.1093/jme/tjw116] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 06/27/2016] [Indexed: 05/27/2023]
Abstract
The castor bean tick Ixodes ricinus (L.) is the principal vector for a variety of viral, bacterial, and protozoan pathogens causing a growing public-health issue over the past decades. However, a national density map of I. ricinus is still missing. Here, I. ricinus nymphs in Germany were investigated by compiling a high-resolution map depicting the mean annually accumulated nymphal density, as observed by monthly flagging an area of 100 m2 Input data comprise ticks collected at 69 sampling sites. The model domain covers an area of about 357,000 km2 (regional scale). Two negative binomial regression models were fitted to the data to interpolate the tick densities to unsampled locations using bioclimatic variables and land cover, which were selected according to their significance by the Akaike information criterion (AIC). The default model was fitted to the complete dataset resulting in AIC = 842. An optimized model resulted in a significantly better value of AIC = 732. Tick densities are very low in urban (green) areas. Maximum annual densities up to 1,000 nymphs per 100 m2 are observed in broad-leaved forests. The tick maps were verified by leave-one-out cross-validation. Root mean square errors of RMSE = 137 and RMSE = 126 nymphs per 100 m2 were estimated for the two models, respectively. These errors are of the order of the interannual variation of the tick densities. The compilation of a high-resolution density map of unfed nymphal I. ricinus for Germany provides a novel, nationwide insight into the distribution of an important disease vector.
Collapse
Affiliation(s)
- Katharina Brugger
- Institute for Veterinary Public Health, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria (; ; )
| | - Denise Boehnke
- Institute of Geography and Geoecology, Karlsruhe Institute of Technology, Reinhard-Baumeister-Platz 1, 76131 Karlsruhe, Germany
| | - Trevor Petney
- Institute of Zoology, Department of Ecology and Parasitology, Karlsruhe Institute of Technology, Kornblumen Straße 13, 76131 Karlsruhe, Germany
| | - Gerhard Dobler
- Bundeswehr Institute of Microbiology, Neuherbergstraße 11, 80937 Munich, Germany
| | - Martin Pfeffer
- Institute of Animal Hygiene and Veterinary Public Health, University of Leipzig, An den Tierkliniken 1, Leipzig, Germany
| | - Cornelia Silaghi
- Institute of Parasitology, National Center of Vector Entomology, University of Zurich, Winterthurerstraße 266a, 8057 Zurich, Switzerland
| | - Günter A Schaub
- Group Zoology/Parasitology, Ruhr-Universität Bochum, Universitätsstraße 150, 44801 Bochum, Germany
| | - Beate Pinior
- Institute for Veterinary Public Health, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria (; ; )
| | - Hans Dautel
- Tick-Radar GmbH, Haderslebener Straße 9, 12163 Berlin, Germany (; )
| | - Olaf Kahl
- Tick-Radar GmbH, Haderslebener Straße 9, 12163 Berlin, Germany (; )
| | - Kurt Pfister
- Comparative Tropical Medicine and Parasitology, Ludwig-Maximilians-Universität München, Leopoldstraße 5, 80752 Munich, Germany
| | - Jochen Süss
- Tick Information Center, Lindenstraße 35, 07646 Lippersdorf, Germany
| | - Franz Rubel
- Institute for Veterinary Public Health, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria (; ; )
| |
Collapse
|
26
|
[Carefully assessing benefits and risks. Also vaccinate young children against "ticks"?]. MMW Fortschr Med 2016; 158:16. [PMID: 27119133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
|
27
|
Gilbert L. Louping ill virus in the UK: a review of the hosts, transmission and ecological consequences of control. Exp Appl Acarol 2016; 68:363-374. [PMID: 26205612 DOI: 10.1007/s10493-015-9952-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 07/14/2015] [Indexed: 05/26/2023]
Abstract
Louping ill virus (LIV) is a tick-borne flavivirus that is part of the tick-borne encephalitis complex of viruses (TBEV) and has economic and welfare importance by causing illness and death in livestock, especially sheep, Ovies aries, and red grouse, Lagopus lagopus scoticus, an economically valuable gamebird. Unlike Western TBEV which is found primarily in woodlands and is reservoired by small rodents, LIV is not generally transmitted by small rodents but instead by sheep, red grouse and mountain hares and, therefore, is associated with upland heather moorland and rough grazing land. Red grouse are a particularly interesting transmission host because they may acquire most of their LIV infections through eating ticks rather than being bitten by ticks. Furthermore, the main incentive for the application of LIV control methods is not to protect sheep, but to protect red grouse, which is an economically important gamebird. The widespread intensive culling of mountain hares which has been adopted in several areas of Scotland to try to control ticks and LIV has become an important issue in Scotland in recent years. This review outlines the reservoir hosts and transmission cycles of LIV in the UK, then describes the various control methods that have been tried or modelled, with far-reaching implications for conservation and public opinion.
Collapse
Affiliation(s)
- Lucy Gilbert
- James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK.
| |
Collapse
|
28
|
Krotkova EN, Babaeva IV, Bogutskiy M, Tsyrkunov VM. Epidemiological and clinical features of tick-borne encephalitis in north-western region in Belarus. Przegl Epidemiol 2016; 70:436-443. [PMID: 27883379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
THE PURPOSE OF THE STUDY to present epidemiological features and clinical manifestations of TBE in patients residing in Grodno region. MATERIALS AND METHODS A retrospective analysis of 124 case histories of patients with TBE in “Grodno Regional Infectious Clinical Hospital” in 2010 – 2014. RESULTS Epidemiological features of tick-borne encephalitis are the prevalence of the transmission mechanism of contamination (57.3%), involvement of residents of Grodno and Grodno region (54.2%) of middle age (46.6±3.5 years) in the epidemic process. Clinical features of the illness in 124 patients were the prevalence of moderate forms of the illness (72%) in the form of meningeal (34.6%) and common infectious (29%) clinical cases. CONCLUSIONS Over the last 5 years in Grodno region an increased incidence of tick-borne encephalitis exceeding republican indices has been established. Among clinical cases there is an increase in severe forms of neuroinfections and mixed tick-borne.
Collapse
Affiliation(s)
| | | | - Michail Bogutskiy
- Educational Institution «Grodno State Medical University», Grodno, Belarus
| | | |
Collapse
|
29
|
Liu R, Zhang G, Liu X, Li Y, Zheng Z, Sun X, Yang Y. [Detection of the Siberian Tick-borne Encephalitis Virus in the Xinjiang Uygur Autonomous Region, northwestern China]. Bing Du Xue Bao 2016; 32:26-31. [PMID: 27295880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Until the recent emergence/re-emergence of human-pathogenic viruses in ticks, tick-borne viruses have been neglected as causative agents of human disease (particularly in China). To gain insight into the diversity of tick-borne viruses in Xinjiang Uygur Autonomous Region (northwestern China), we conducted illumina deep sequencing-based screening for virus-derived small RNAs in field-collected Ixodes persulcatus ticks. We found 32, 631 unique virus-matched reads. In particular, 77 reads mapped to the tick-borne group within the genus of Flavivirus, and covered 3.8%-2.4% viral genomes. In addition, 32 unique reads were specific to the Siberian subtype of tick-borne encephalitis viruses (TBEV-Sib) which have never been reported in Chinese TBE loci. We confirmed the potential existence of TBEV-Sib by amplification (using reverse transcription-polymerase chain reaction) of genomic fragments from the envelope gene or 3' genomic terminus from the pools of examined ticks. Both sequences demonstrated high homology to TBEV-Sib strains attached geographically to southern Siberia with nucleotide identity of 97.2%-95.5% and aminoacid identity of 99.4%-98.3%, respectively. In conclusion, we report, for the first time, detection of TBEV-Sib in the natural TBE loci of China. These novel data may provide genetic information for further isolation and epidemiologic investigation of TBEV-Sib.
Collapse
|
30
|
Daniel M, Rudenko N, Golovchenko M, Danielová V, Fialová A, Kříž B, Malý M. The occurrence of Ixodes ricinus ticks and important tick-borne pathogens in areas with high tick-borne encephalitis prevalence in different altitudinal levels of the Czech Republic Part II. Ixodes ricinus ticks and genospecies of Borrelia burgdorferi sensu lato complex. Epidemiol Mikrobiol Imunol 2016; 65:182-192. [PMID: 27690476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
STUDY OBJECTIVE Three years long research study (2011-2013) on population density of Ixodes ricinus and the infection rate of the pathogens that they transmit was conducted in four topographically distant areas in the Czech Republic. In the previous decade (2001-2010) thirteen loci with increased incidence of tick borne encephalitis cases were defined, suggesting the permanent interaction of human population with ticks and indicating the landmarks for study of the presence of other tick borne pathogens. The work program included the identification of existing spectrum of spirochetes from Borrelia burgdorferi sensu lato complex and the conditions of their occurrence and distribution. MATERIAL AND METHODS In the areas of the Ústí nad Labem Region, Olomouc Region, South Bohemian Region, and Highlands Region, 600 m2 plots were selected in the local optimal I. ricinus habitats where tick flagging was performed every year in the spring-summer and autumn seasons of the tick questing activity. Collected adult ticks (1369 males and 1404 females) were individually screened for B. burgdorferi s. l. spirochets. RESULTS Spirochetes from B. burgdorferi s.l. complex were detected in all 13 studies sites in all altitudes from 280 to 1030 meters a. s. l. The total rate of infection was determined as 11.4% (males 10.4%, females 12.4%) with range limits from 1.4% (Ústí nad Labem in 2011) to 19.7% (South Bohemian Region, 2012).Genospecies were detected in various proportions and in different combinations: Borrelia afzelii, B. garinii, B. burgdorferi s. s., B. bavariensis, B. bissettii, B. valaisiana, B. spielmanii and B. lusitaniae. The three-year observation justifies the assumption that the regional differences in infectivity of I. ricinus are based on the character of the local biocenosis of the respective region. The dynamics of its seasonal changes, conditioned by climatic factors, determines the annual differences. CONCLUSION Three of the medically most important Borrelia species formed a core group among all detected genospecies. B. afzelii was a dominated one (115 detections), followed by B. garinii (100) and by B. burgdorferi s.s. (19). Other genospecies were detected sporadically. However, the detection of B. bissettii should be emphasized due to the recently proven pathogenic effects of this genospecies and yet little-known sporadic expansion in the Czech Republic. The medical importance and distribution of other sporadically occurred genospecies is also discussed.Key words: Ixodes ricinus - Borrelia afzelii - B. garinii - B. burgdorferi s. s. - B. bavariensis - B. valaisiana - B. spielmanii - B. lusitaniae - B. bissettii - distribution - altitude - season - medical importance.
Collapse
|
31
|
Mel'nikova OV, Adel'shin RV, Korzun VM, Trushina YN, Andaev EI. Tick-borne encephalitis virus isolates from natural foci of the Irkutsk region: clarification of the genotype landscape. Vopr Virusol 2016; 61:229-234. [PMID: 29323856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The Irkutsk region is the unique territory where all known subtypes of tick-borne encephalitis virus (TBEV) circulate. In the last years, the phenomenon of changes in TBEV subtypes (substitution of the Far-Eastern subtype by the Siberian one) was noted in some regions of the Russian Federation. The results of individual investigation of 11522 Ixodes persulcatus ticks and brain specimens from 81 small mammals collected in natural foci of the Irkutsk region during 2006-2014 are presented in the article. More than 60 TBEV strains have been isolated and studied by virological methods; E gene fragments (1193 b.p.) of 68 isolates have been typed. The majority of the strains (irrespective of subtype) were of high virulence for laboratory mice (LM) in case of both intracerebral and subcutaneous inoculation of virus. All isolates from warm-blooded small mammals and humans were of high virulence for LM, but placed in the same clusters of the phylogenetic tree with ticks collected in the same area. Tick-borne strains of different virulence also did not form separate clusters on the tree. Phylogenetic analysis showed that modern TBEV genotypic landscape of the studied territory is changing toward absolute predominance of the Siberian subtype (94.1%). This subtype is represented by two groups with prototype strains “Zausaev” and “Vasilchenko”. The “Vasilchenko” group of strains is spread on the whole territory under study; the strains of “Zausaev” group were isolated previously in the Irkutsk suburbs. The European subtype of TBEV circulates in natural foci of Pribaikalie permanently (at least 5% of the random sampling); the strains are of high virulence for LM. The Far-Eastern TBEV subtype was not found within the group of isolates collected in 20062014. The phylogenetic relationship of the strains under study had a higher correlation with the place of isolation than with the year or source.
Collapse
|
32
|
Kovalev SY, Mukhacheva TA. [UNIFICATION OF THE MOLECULAR EPIDEMIOLOGICAL RESEARCH OF THE TICK-BORNE ENCEPHALITIS]. Vopr Virusol 2016; 61:89-95. [PMID: 27451502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Molecular genetic techniques and approaches in epidemiological studies were breakthrough in the understanding of the laws, ways, and mechanisms of the spread of the pathogens. However, lack of standard methods makes it difficult to compare results obtained by different scientific groups. In this work we propose to choose one fragment of the TBEV genome as a genetic marker whose sequencing would be both obligatory and sufficient for the molecular epidemiological studies. The best candidate for this purpose may be a fragment of the gene E of 454 nucleotides in length. The deduced amino acid sequence of this fragment was a basis for a new approach for the TBEV differentiation with clusteron being a structural unit (Kovalev and Mukhacheva, 2013). The clusteron approach was proved to be informative for studying the genetic structure of the TBEV-Sib population in the Middle Urals. TBE foci were shown to be unique in both quantitative and qualitative composition of the clusterons. The greatest clusteron diversity in the south of the Middle Urals, through the Trans-Siberian way, may reflect the history of the colonization, closely associated with the roads between Siberia and the European part of Russia. The age of three clusterons did not exceed 50 years, which may indicate an ongoing evolutionary process taking place in the TBEV-Sib populations. In turn, their spatial distribution indicates the crucial role of human factors in the spread of the TBEV (Kovalev & Mukhacheva, 2014). The clusteron approach provides formalization of ideas about the structure of the viral populations and could be used not only by researchers but also by epidemiological surveillance services. Unification of the studies of the TBEV on the basis of a standard genetic marker would consolidate the efforts of researchers from different regions of Russia and other countries.
Collapse
|
33
|
Daniel M, Danielová V, Kříž B, Růžek D, Fialová A, Malý M, Materna J, Pejčoch M, Erhart J. The occurrence of Ixodes ricinus ticks and important tick-borne pathogens in areas with high tick-borne encephalitis prevalence in different altitudinal levels of the Czech Republic Part I. Ixodes ricinus ticks and tick-borne encephalitis virus. Epidemiol Mikrobiol Imunol 2016; 65:118-128. [PMID: 27467329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
STUDY OBJECTIVE The aim of the three-year study (2011-2013) was to monitor population density of Ixodes ricinus ticks and its infection rate with the tick-borne encephalitis virus in areas with a high incidence of tick-borne encephalitis as reported in the previous decade 2001-2010. Such a comprehensive and long-term study based on existing epidemiolo-gical findings has not previously been conducted in Europe. MATERIAL AND METHODS In the areas of the Ústí nad Labem Region, Olomouc Region, South Bohemian Region, and Highlands Region, 600 m2 plots were selected in the local optimal I. ricinus habitats where tick flagging was performed every year in the spring-summer and autumn seasons of the questing activity. In total, 18,721 I. ricinus ticks (1448 females, 1425 males, and 15,848 nymphs) were collected and investigated. RESULTS AND CONCLUSION The results have shown that the differences in the infection rate of I. ricinus observed between regions are driven by variation in the density of the local I. ricinus populations which is influenced by the characteris-tics of the whole local biocenosis. The overall prevalence estimate of TBE virus in Ixodes ricinus ticks at the altitudes below 600 m a.s.l. was 0.096 % (95% CI 0.055-0.156) for nymphs, and 0.477 % (95% CI 0.272-0.773) for adults. The dynamics of the seasonal variation in I. ricinus populations, depending primarily on the climatic factors, are behind the interyear differences in the infection rate of ticks and, consequently, in the epidemiological situation of tick-borne encephalitis. The nymph to adult ratio was 5.5 on average but showed great interregional variability (from 10.3 in the Ústí nad Labem Region to 1.8 in the Highlands Region). It might be used in the future as one of the indicators of the composition of the local I. ricinus population and of the level of the circulation of tick-borne pathogens in zoonotic sphere and also for use in the health risk assessment in a given area. Despite the permanent expansion of ticks and tick-borne pathogens in higher altitudes the high risk limit for human infection with tick-borne encephalitis is 600 m a.s.l. in the Czech Republic.
Collapse
|
34
|
Ponomareva EP, Mikryukova TP, Gori AV, Kartashov MY, Protopopova EV, Chausov EV, Konovalova SN, Tupota NL, Gheorghita SD, Burlacu VI, Ternovoi VA, Loktev VB. Detection of Far-Eastern subtype of tick-borne encephalitis viral RNA in ticks collected in the Republic of Moldova. J Vector Borne Dis 2015; 52:334-336. [PMID: 26714515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023] Open
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Valery B Loktev
- State Research Center of Virology and Biotechnology "Vector", Department of Molecular Virology for Flaviviruses and Viral Hepatitis, Koltsovo, Novosibirsk Region; Tomsk State University, Tomsk; Novosibirsk State University, Novosibirsk; Institute of Cytology and Genetics, Novosibirsk, Russia
| |
Collapse
|
35
|
|
36
|
Deutsches Grünes Kreuz e. V. [Ticks lurk in the garden]. Kinderkrankenschwester 2015; 34:237. [PMID: 26309999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
|
37
|
Zöldi V, Papp T, Rigó K, Farkas J, Egyed L. A 4-year study of a natural tick-borne encephalitis virus focus in Hungary, 2010-2013. Ecohealth 2015; 12:174-182. [PMID: 25227182 DOI: 10.1007/s10393-014-0969-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 08/11/2014] [Accepted: 08/14/2014] [Indexed: 06/03/2023]
Abstract
A tick-borne encephalitis virus focus was identified in a former goat pasture that had been associated with a milk-borne encephalitis outbreak in 2007. Ticks and rodents were sampled monthly from April 2010 to October 2013 on two separate 0.5 ha sampling sites. At site 1, three tick-borne encephalitis virus strains were isolated from a total of 7,247 sampled ticks; 28 of the 539 tested sera (5.19%) were seropositive. At site 2, from the 2,369 sampled ticks, virus was not isolated, tests of 284 rodent sera resulted in 14 positives (4.93%). For survival, the virus needs a territory with continuously dense rodent and tick population, although observed TBEV prevalence was low both in ticks and in rodents. Sampling points of positive ticks and rodents did not coincided exactly, at a certain time only some m(2) territory is dangerous, these hot spots change unpredictably as positive ticks die or move on with their hosts.
Collapse
Affiliation(s)
- Viktor Zöldi
- Department of Vector and Public Health Pest Control, National Center for Epidemiology, Albert Flórián út 2-6, 1097, Budapest, Hungary,
| | | | | | | | | |
Collapse
|
38
|
Malkhazova SM, Mironova VA, Orlov DS, Shartova NV. [The "natural focal diseases" medical and geographical atlas of Russia as a tool to analyze their incidence in the population]. Med Parazitol (Mosk) 2014:3-7. [PMID: 25812399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The Faculty of Geography, M.V. Lomonosov Moscow State University, is creating a "Natural Focal Diseases" medical and geographical atlas of Russia. The paper considers the possibilities of the atlas to monitor and assess the epidemiological situation of a number of diseases. The atlas allows one to define a spectrum of the most epidemically significant natural focal diseases in Russia, to quantitatively characterize their incidence in the population, and to visualize it in a series of maps, to make a medical geographical analysis of the prevalence of the nosological entities of natural focal diseases in both individual subjects of the Russian Federation and in Russia as a whole. By using tick-borne encephalitis as an example, the authors consider approaches to analyzing the incidence of natural focal infections, by using different types of the maps given in the atlas.
Collapse
|
39
|
Slovák M, Kazimírová M, Siebenstichová M, Ustaníková K, Klempa B, Gritsun T, Gould EA, Nuttall PA. Survival dynamics of tick-borne encephalitis virus in Ixodes ricinus ticks. Ticks Tick Borne Dis 2014; 5:962-9. [PMID: 25131151 DOI: 10.1016/j.ttbdis.2014.07.019] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 07/18/2014] [Accepted: 07/22/2014] [Indexed: 12/12/2022]
Abstract
Biotic factors contributing to the survival of tick-borne viruses in nature are poorly understood. Using tick-borne encephalitis virus (TBEV) and its principal European vector, Ixodes ricinus, we examined the relative roles of salivary gland infection, co-feeding transmission, and moulting in virus survival. Virus titres in the salivary glands increased after blood-feeding in a time- and dose-dependent manner. This was observed in ticks infected by inoculation but not in ticks infected by the natural route of co-feeding. Amplification of infection prevalence occurred via co-feeding. However, when larvae or nymphs subsequently moulted, the infection prevalence dramatically declined although this was not observed when ticks were infected by inoculation. Trans-stadial survival is a hitherto overlooked parameter that may contribute to the low incidence of TBEV infection in field-collected I. ricinus ticks.
Collapse
Affiliation(s)
- Mirko Slovák
- Institute of Zoology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Mária Kazimírová
- Institute of Zoology, Slovak Academy of Sciences, Bratislava, Slovakia
| | | | | | - Boris Klempa
- Institute of Virology, Slovak Academy of Sciences, Bratislava, Slovakia; Institute of Virology, Charité Medical School, Berlin, Germany
| | - Tamara Gritsun
- School of Biological Sciences, University of Reading, Reading, United Kingdom
| | - Ernest A Gould
- Unité des Virus Emergents, Faculté de Médecine de Marseille, Aix-Marseille Universite, France; NERC Centre for Ecology & Hydrology, Wallingford, Oxfordshire, United Kingdom
| | - Patricia A Nuttall
- NERC Centre for Ecology & Hydrology, Wallingford, Oxfordshire, United Kingdom; Department of Zoology, University of Oxford, United Kingdom.
| |
Collapse
|
40
|
Lindblom P, Wilhelmsson P, Fryland L, Matussek A, Haglund M, Sjöwall J, Vene S, Nyman D, Forsberg P, Lindgren PE. Factors determining immunological response to vaccination against tick-borne encephalitis virus in older individuals. PLoS One 2014; 9:e100860. [PMID: 24967619 PMCID: PMC4072701 DOI: 10.1371/journal.pone.0100860] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2014] [Accepted: 05/30/2014] [Indexed: 12/30/2022] Open
Abstract
We performed a cross-sectional study including 533 individuals (median age 61) from the highly TBE endemic Åland Islands in the archipelago between Sweden and Finland. Blood samples, questionnaires and vaccination records were obtained from all study participants. The aim was to investigate if there was any association between TBEV antibody titer and 12 health-related factors. Measurement of TBEV IgG antibodies was performed using two commercial ELISA assays (Enzygnost and Immunozym), and a third in-house rapid fluorescent focus inhibition test was used to measure TBEV neutralizing antibodies. The age of the individual and the number of vaccine doses were the two most important factors determining the immunological response to vaccination. The response to each vaccine dose declined linearly with increased age. A 35 year age difference corresponds to a vaccine dose increment from 3 to 4 to achieve the same immunological response. Participants previously vaccinated against other flaviviruses had lower odds of being seropositive for neutralizing TBEV antibodies on average, while participants with self-reported asthma had higher odds of being seropositive. By comparing the 3 serological assays we show that the Enzygnost and Immunozym assay differ due to choice of cutoffs, but not in overall accuracy.
Collapse
Affiliation(s)
- Pontus Lindblom
- Division of Medical Microbiology, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
- * E-mail:
| | - Peter Wilhelmsson
- Division of Medical Microbiology, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Linda Fryland
- Division of Infectious Diseases, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Andreas Matussek
- Division of Medical Services, Department of Microbiology, County Hospital Ryhov, Jönköping, Sweden
| | - Mats Haglund
- Department of Infectious Diseases, County Hospital Kalmar, Kalmar, Sweden
| | - Johanna Sjöwall
- Clinic of Infectious Diseases, Linköping University Hospital, Linköping, Sweden
| | - Sirkka Vene
- Public Health Agency of Sweden, Stockholm, Sweden
| | - Dag Nyman
- Åland Central Hospital, Mariehamn, Åland, Finland
| | - Pia Forsberg
- Division of Infectious Diseases, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
- Clinic of Infectious Diseases, Linköping University Hospital, Linköping, Sweden
| | - Per-Eric Lindgren
- Division of Medical Microbiology, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
- Division of Medical Services, Department of Microbiology, County Hospital Ryhov, Jönköping, Sweden
| |
Collapse
|
41
|
Kaiser R. [After-care in general practice after tick-borne encephalitis]. MMW Fortschr Med 2014; 156:49-54. [PMID: 24938066 DOI: 10.1007/s15006-014-0003-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
|
42
|
Shchuchinova. [Human granulocytic anaplasmosis and its concurrence with other tick-borne infections in the Republic of Altai]. Med Parazitol (Mosk) 2013;:20-3. [PMID: 25924278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Human granulocytic anaplasmosis (HGA) cases occur everywhere in the Republic of Altai. Anaplasma phagocytophilum is transmitted to humans by at least three genera of ticks: Ixodes, Dermacentor, and Haemaphysalis. The risk of the infection is higher in the northern part of the republic. Most patients with HGA show serologic evidence of coinfection with North Asian tick typhus and other tick-borne diseases. The high probability of HGA concurrent with other tick-borne infections requires an integrated approach to preventing these diseases in the Republic of Altai.
Collapse
|
43
|
Zhang GL, Liu R, Sun X, Zheng Y, Liu XM, Zhao Y, Dang RL, Liu SK, Xia J, Zheng Z, Yang YH. [Investigation on the endemic foci of new emerged tick-borne encephalitis in Charles Hilary, Xinjiang]. Zhonghua Liu Xing Bing Xue Za Zhi 2013; 34:438-442. [PMID: 24016430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
OBJECTIVE To investigate the recent emerged endemic region of tick-borne encephalitis (TBE) regarding its natural reserves, in Charles Hilary, northern Xinjiang and to isolate and characterize the viral geographic strain. METHODS Using indirect fluorescent assay to detect tick-borne encephalitis virus (TBEV) specific IgG antibodies from serum of local residents including 2 unconfirmed viral encephalitis patients in 2011 spring-summer. Viruses were isolated from tick samples by inoculating BALB/c mice and BHK-21 cells. For phylogenetic analysis. TBEV NS1 gene fragments were detected by RT-PCR and then subjected to sequence alignment. RESULTS 1760 ticks were captured from the fields to have found that Ixodes persulcatus were dominated among the tick population. Two viral encephalitis patients were diagnosed as TBEV infection. In addition, 35.4% (23/65) local residents were detected positive for presence of TBEV specific-IgG antibodies in serum. After inoculation, morbidity and mortality of BALB/c mice were 72.9% (70/96) and 55.7% (44/79), respectively. TBEV specific-fragments were amplified from brain tissue of dead mice and cells culture supernatant. NS1 sequence alignment showed that the viral isolates were clustered into TBEV far-eastern sub-type, phylogenetically, and were mostly close to the isolates from northeastern China (99%) and Russian strain (98%). CONCLUSION In this study, a new endemic loci of TBE was firstly described in Charles Hilary natural reserve, northern Xinjiang. TBEV geographic isolates belonged to TBEV far-eastern subtype while Ixodes persulcatus and Dermacentor silvarum played crucial roles for disease transition.
Collapse
Affiliation(s)
- Gui-lin Zhang
- Center for Disease Control and Prevention of Xinjiang Military Command Region, Urumuqi, China.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Bugmyrin SV, Nazarova LE, Bespiatova LA, Ieshko EP. [Concerning the problem of the northern limit of Ixodes persulcatus (Acari: Ixodidae) distribution in Karelia]. Izv Akad Nauk Ser Biol 2013:240-244. [PMID: 23789430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The influence of changes in climate conditions on the abundance and formation of the northern limit of Ixodes persulcatus distribution in Karelia has been studied. It has been demonstrated that the territory in which the heat provision is sufficient for the development of ixodid ticks significantly increased during 2000-2007. Thus, it favored an increase in the abundance and enhanced distribution of I. persulcatus.
Collapse
|
45
|
Abstract
Ixodes species ticks are competent vectors of tick-borne viruses including tick-borne encephalitis and Powassan encephalitis. Tick saliva has been shown to facilitate and enhance viral infection. This likely occurs by saliva-mediated modulation of host responses into patterns favorable for viral infection and dissemination. Because of the rapid kinetics of tick-borne viral transmission, this modulation must occur as early as tick attachment and initiation of feeding. In this study, cutaneous bite-site lesions were analyzed using Affymetrix mouse genome 430A 2.0 arrays and histopathology at 1, 3, 6, and 12 hours after uninfected Ixodes scapularis nymphal tick attachment. At 1 and 3 hrs after attachment, the gene expression profile is markedly different than at later time points. Upregulated gene ontology term clusters enriched at 1 and 3 hrs were related to post-translational modification. At 6 and 12 hrs, cytoskeletal rearrangements, DNA replication/cell division, inflammation, and chemotaxis were prominent clusters. At 6 and 12 hrs, extracellular matrix, signaling, and DNA binding clusters were downregulated. Histopathological analysis shows minimal inflammation at 1 and 3 hrs but an appreciable neutrophil infiltrate at 6 and 12 hrs. In addition, putative hyperemia, localized necrosis, and increased ECM deposition were identified. Putting the gene expression and histopathology analysis together suggests early tick feeding is characterized by modulation of host responses in resident cells that merges into a nascent, neutrophil-driven immune response by 12 hrs post-attachment.
Collapse
Affiliation(s)
- Dar M. Heinze
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - J. Russ Carmical
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Judith F. Aronson
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Saravanan Thangamani
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
| |
Collapse
|
46
|
Mel'nikova OV, Korzun VM, Verzhutskaia IA, Vershinin EA. [Ratio of the numbers of Ixodes persulcatus imagoes in the near-Baikal area with the use of different recording methods]. Med Parazitol (Mosk) 2012:39-42. [PMID: 23088149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The data of estimating the number of Ixodes perculcatus by two methods (the number of ticks per flag-hour and that per flag-kilometer) in the near-Baikal area were analyzed. According to these values, the abundance of taiga ticks in individual calculations ranged from 0 to 394. The association between the time of passage and the number of collected ticks was positive and high significant. The correction factors were calculated to obtain the abundance values expressed in per flag-kilometer units from the abundance values per flag-hour and conversely. The value of these factors depended on the number of ticks.
Collapse
|
47
|
Dobler G. [Ticks survive 40 degree C wash effortlessly. Masters of adaptation (interview by Dr. Christine Starostzik)]. MMW Fortschr Med 2012; O 154 Suppl 2:10. [PMID: 22916417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
|
48
|
Aslan Başbulut E, Gözalan A, Sönmez C, Cöplü N, Körhasan B, Esen B, Akın L, Ertek M. [Seroprevalence of Borrelia burgdorferi and tick-borne encephalitis virus in a rural area of Samsun, Turkey]. MIKROBIYOL BUL 2012; 46:247-256. [PMID: 22639313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Lyme disease or lyme borreliosis is a zoonosis caused by Borrelia burgdorferi transmitted by ticks, especially Ixodes species. Lyme borreliosis is a multi-systemic disease that invades the skin, musculoskeletal, cardiovascular and central nervous systems. Tick-borne encephalitis (TBE) is an important arboviral infection caused by tick-borne encephalitis virus (TBEV). The central nervous system is affected and the disease most often manifests as meningitis, encephalitis or meningoencephalitis. Previous studies have shown that B.burgdorferi and TBEV can be transmitted by the same tick species (Ixodes ricinus). Although the geographic location and climate is similar to some south-eastern European countries where lyme borreliosis and TBE have been reported, the incidence and prevalence of these diseases in Turkey still remain unclear. The aim of this study was to determine the seroprevelance of B.burgdorferi and TBEV in healthy population in Tekkeköy (41° 8-13' North; 36° 24-31' East), a district of Samsun province, Turkey with evidence of tick-borne disease and to explore the possible correlations of life styles of healthy individuals and prevelance. The cross-sectional study population included 419 people selected using a random proportional sampling method. All participants were asked at interview to complete a questionnaire and peripheral blood samples were collected. From the blood samples, B.burgdorferi IgG and IgM antibodies were evaluated using commercial ELISA (Euroimmun, Germany) and confirmed with Western blot (WB, Euroimmun, Germany). ELISA method was also used to asses IgM and IgG antibodies against TBEV, and neutralization test was used for confirmation. Of the 419 samples, 17 (4%) were positive for B.burgdorferi IgG by ELISA, however 14 (14/419; 3.3%) of them were confirmed by WB. B.burgdorferi seropositivity was higher among people living in rural areas, at an altitude of ≥ 400 meters and in locations ecologically suitable for wild boar and rabbits; seropositivity was also seen to be higher among dog owners (p= 0.001, p= 0.001, p= 0.001, p= 0.001, p= 0.018, respectively). For TBEV, two samples yielded IgG positive, and one IgM positive results by ELISA, however none of them were confirmed by neutralization assay. Nevertheless, one of those three TBEV ELISA positive samples, was found positive for West Nile virus specific antibodies with neutralization test. The results of this study emphasized the presence of tick-borne diseases in that specific region, and in this regard the need for public health interventions has been demonstrated.
Collapse
Affiliation(s)
- Eşe Aslan Başbulut
- Refik Saydam National Public Health Agency, Department of Communicable Diseases Research, Ankara, Turkey
| | | | | | | | | | | | | | | |
Collapse
|
49
|
Caini S, Szomor K, Ferenczi E, Szekelyne Gaspar A, Csohan A, Krisztalovics K, Molnar Z, Horvath J. Tick-borne encephalitis transmitted by unpasteurised cow milk in western Hungary, September to October 2011. Euro Surveill 2012; 17:20128. [PMID: 22490310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023] Open
Abstract
In October 2011, a cluster of four tick-borne encephalitis (TBE) cases was identified in Hungary. Initial investigations revealed a possible link with consumption of unpasteurised cow milk sold by a farmer without authorisation. We performed a cohort study including all regular customers of the farmer. Overall, eleven cases (seven confirmed and four suspected) were identified. Customers who had consumed the farmer’s unpasteurised cow milk had more than a two-fold increased risk for being a TBE case, although not at statistically significant level.
Collapse
Affiliation(s)
- S Caini
- European Programme for Intervention Epidemiology Training (EPIET), European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden
| | | | | | | | | | | | | | | |
Collapse
|
50
|
van der Most M, van der Burg S, Lipman L. [What a practicing veterinarian should know about the "louping ill" virus]. Tijdschr Diergeneeskd 2012; 137:183-184. [PMID: 22512066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
|