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Simkute E, Pautienius A, Grigas J, Sidorenko M, Radzijevskaja J, Paulauskas A, Stankevicius A. The Prevalence of Tick-Borne Encephalitis Virus in Wild Rodents Captured in Tick-Borne Encephalitis Foci in Highly Endemic Lithuania. Viruses 2024; 16:444. [PMID: 38543809 PMCID: PMC10974453 DOI: 10.3390/v16030444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 03/10/2024] [Accepted: 03/11/2024] [Indexed: 05/23/2024] Open
Abstract
Wild rodents are considered to be one of the most important TBEV-amplifying reservoir hosts; therefore, they may be suitable for foci detection studies. To investigate the effectiveness of viral RNA detection in wild rodents for suspected TBEV foci confirmation, we trapped small rodents (n = 139) in various locations in Lithuania where TBEV was previously detected in questing ticks. Murine neuroblastoma Neuro-2a cells were inoculated with each rodent sample to maximize the chances of detecting viral RNA in rodent samples. TBEV RNA was detected in 74.8% (CI 95% 66.7-81.1) of the brain and/or internal organ mix suspensions, and the prevalence rate increased significantly following sample cultivation in Neuro-2a cells. Moreover, a strong correlation (r = 0.88; p < 0.05) was found between the average monthly air temperature of rodent trapping and the TBEV RNA prevalence rate in cell culture isolates of rodent suspensions, which were PCR-negative before cultivation in cell culture. This study shows that wild rodents are suitable sentinel animals to confirm TBEV foci. In addition, the study results demonstrate that sample cultivation in cell culture is a highly efficient method for increasing TBEV viral load to detectable quantities.
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Affiliation(s)
- Evelina Simkute
- Laboratory of Immunology, Department of Anatomy and Physiology, Lithuanian University of Health Sciences, Tilzes Str. 18, LT-47181 Kaunas, Lithuania; (A.P.); (J.G.); (A.S.)
| | - Arnoldas Pautienius
- Laboratory of Immunology, Department of Anatomy and Physiology, Lithuanian University of Health Sciences, Tilzes Str. 18, LT-47181 Kaunas, Lithuania; (A.P.); (J.G.); (A.S.)
- Institute of Microbiology and Virology, Lithuanian University of Health Sciences, Tilzes Str. 18, LT-47181 Kaunas, Lithuania
| | - Juozas Grigas
- Laboratory of Immunology, Department of Anatomy and Physiology, Lithuanian University of Health Sciences, Tilzes Str. 18, LT-47181 Kaunas, Lithuania; (A.P.); (J.G.); (A.S.)
- Institute of Microbiology and Virology, Lithuanian University of Health Sciences, Tilzes Str. 18, LT-47181 Kaunas, Lithuania
| | - Marina Sidorenko
- Department of Biology, Faculty of Natural Sciences, Vytautas Magnus University, K. Donelaicio Str. 58, LT-44248 Kaunas, Lithuania; (M.S.); (J.R.); (A.P.)
| | - Jana Radzijevskaja
- Department of Biology, Faculty of Natural Sciences, Vytautas Magnus University, K. Donelaicio Str. 58, LT-44248 Kaunas, Lithuania; (M.S.); (J.R.); (A.P.)
| | - Algimantas Paulauskas
- Department of Biology, Faculty of Natural Sciences, Vytautas Magnus University, K. Donelaicio Str. 58, LT-44248 Kaunas, Lithuania; (M.S.); (J.R.); (A.P.)
| | - Arunas Stankevicius
- Laboratory of Immunology, Department of Anatomy and Physiology, Lithuanian University of Health Sciences, Tilzes Str. 18, LT-47181 Kaunas, Lithuania; (A.P.); (J.G.); (A.S.)
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Vilibic-Cavlek T, Krcmar S, Bogdanic M, Tomljenovic M, Barbic L, Roncevic D, Sabadi D, Vucelja M, Santini M, Hunjak B, Stevanovic V, Boljfetic M, Bjedov L, Masovic V, Potocnik-Hunjadi T, Lakoseljac D, Al-Mufleh M, Savic V. An Overview of Tick-Borne Encephalitis Epidemiology in Endemic Regions of Continental Croatia, 2017-2023. Microorganisms 2024; 12:386. [PMID: 38399790 PMCID: PMC10891638 DOI: 10.3390/microorganisms12020386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Revised: 02/08/2024] [Accepted: 02/10/2024] [Indexed: 02/25/2024] Open
Abstract
Tick-borne encephalitis (TBE) represents an important public health problem in Europe. We analyzed the epidemiology of TBE based on data from humans, animals, and Ixodes ricinus ticks in endemic regions of continental Croatia. In the period from 2017 to 2023, cerebrospinal fluid (CSF) and serum samples of 684 patients with neuroinvasive diseases, 2240 horse serum samples, and 300 sheep serum samples were tested for TBEV. In addition, 8751 I. ricinus ticks were collected. CSF samples were tested using RT-PCR. Serological tests (serum, CSF) were performed using commercial ELISA, with confirmation of cross-reactive samples by a virus neutralization test. Eighty-four autochthonous human TBEV cases were confirmed. The majority of patients were in the age group of 40-69 years (58.3%) with a male predominance (70.2%). TBE showed a bimodal seasonality with a large peak in April-August and a small one in October-November. In addition to humans, TBEV IgG antibodies were found in 12.2% of horses and 9.7% of sheep. Seasonal tick abundance corresponds to the reported number of human infections. Continental Croatia is still an active natural focus of TBE. Continuous monitoring of infections in humans, sentinel animals, and ticks is needed for the implementation of preventive measures.
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Affiliation(s)
- Tatjana Vilibic-Cavlek
- Department of Virology, Croatian Institute of Public Health, 10000 Zagreb, Croatia;
- School of Medicine, University of Zagreb, 10000 Zagreb, Croatia;
| | - Stjepan Krcmar
- Department of Biology, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia;
| | - Maja Bogdanic
- Department of Virology, Croatian Institute of Public Health, 10000 Zagreb, Croatia;
| | - Morana Tomljenovic
- Department of Epidemiology, Teaching Institute of Public Health of the Primorje-Gorski Kotar County, 51000 Rijeka, Croatia; (M.T.); (D.R.); (D.L.)
- Department of Social Medicine and Epidemiology, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia
| | - Ljubo Barbic
- Department of Microbiology and Infectious Diseases with Clinic, Faculty of Veterinary Medicine, University of Zagreb, 10000 Zagreb, Croatia; (L.B.); (V.S.); (V.M.)
| | - Dobrica Roncevic
- Department of Epidemiology, Teaching Institute of Public Health of the Primorje-Gorski Kotar County, 51000 Rijeka, Croatia; (M.T.); (D.R.); (D.L.)
- Department of Public Health, Faculty of Health Studies, University of Rijeka, 51000 Rijeka, Croatia
| | - Dario Sabadi
- Department of Infectious Diseases, Clinical Hospital Center Osijek, 31000 Osijek, Croatia;
- Medical Faculty, University of Osijek, 31000 Osijek, Croatia
| | - Marko Vucelja
- Department of Forest Protection and Wildlife Management, Faculty of Forestry and Wood Technology, University of Zagreb, 10000 Zagreb, Croatia; (M.V.); (M.B.); (L.B.)
| | - Marija Santini
- School of Medicine, University of Zagreb, 10000 Zagreb, Croatia;
- University Hospital for Infectious Diseases “Dr. Fran Mihaljevic”, 10000 Zagreb, Croatia
| | - Blazenka Hunjak
- Department of Bacteriology, Croatian Institute of Public Health, 10000 Zagreb, Croatia;
- Department of Microbiology, University of Applied Health Sciences, 10000 Zagreb, Croatia
| | - Vladimir Stevanovic
- Department of Microbiology and Infectious Diseases with Clinic, Faculty of Veterinary Medicine, University of Zagreb, 10000 Zagreb, Croatia; (L.B.); (V.S.); (V.M.)
| | - Marko Boljfetic
- Department of Forest Protection and Wildlife Management, Faculty of Forestry and Wood Technology, University of Zagreb, 10000 Zagreb, Croatia; (M.V.); (M.B.); (L.B.)
| | - Linda Bjedov
- Department of Forest Protection and Wildlife Management, Faculty of Forestry and Wood Technology, University of Zagreb, 10000 Zagreb, Croatia; (M.V.); (M.B.); (L.B.)
| | - Viktor Masovic
- Department of Microbiology and Infectious Diseases with Clinic, Faculty of Veterinary Medicine, University of Zagreb, 10000 Zagreb, Croatia; (L.B.); (V.S.); (V.M.)
| | | | - Danijela Lakoseljac
- Department of Epidemiology, Teaching Institute of Public Health of the Primorje-Gorski Kotar County, 51000 Rijeka, Croatia; (M.T.); (D.R.); (D.L.)
- Department of Public Health, Faculty of Health Studies, University of Rijeka, 51000 Rijeka, Croatia
| | - Mahmoud Al-Mufleh
- Department of Infectious Diseases, County Hospital Cakovec, 40000 Cakovec, Croatia;
| | - Vladimir Savic
- Poultry Center, Croatian Veterinary Institute, 10000 Zagreb, Croatia
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Sidorenko M, Radzijevskaja J, Mickevičius S, Bratchikov M, Mardosaitė-Busaitienė D, Sakalauskas P, Paulauskas A. Phylogenetic characterisation of tick-borne encephalitis virus from Lithuania. PLoS One 2024; 19:e0296472. [PMID: 38324618 PMCID: PMC10849421 DOI: 10.1371/journal.pone.0296472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 12/13/2023] [Indexed: 02/09/2024] Open
Abstract
The Baltic states are the region in Europe where tick-borne encephalitis (TBE) is most endemic. The highest notification rate of TBE cases is reported in Lithuania, where the incidence of TBE has significantly increased since 1992. A recent study reported 0.4% prevalence of TBE virus (TBEV) in the two most common tick species distributed in Lithuania, Ixodes ricinus and Dermacentor reticulatus, with the existence of endemic foci confirmed in seven out of Lithuania's ten counties. However, until now, no comprehensive data on molecular characterisation and phylogenetic analysis have been available for the circulating TBEV strains. The aim of this study was to analyse TBEV strains derived from I. ricinus and D. reticulatus ticks collected from Lithuania and provide a genotypic characterisation of viruses based on sequence analysis of partial E protein and NS3 genes. The 54 nucleotide sequences obtained were compared with 81 TBEV strains selected from the NCBI database. Phylogenetic analysis of the partial E and NS3 gene sequences derived from 34 Lithuanian TBEV isolates revealed that these were specific to Lithuania, and all belonged to the European subtype, with a maximum identity to the Neudoerfl reference strain (GenBank accession no. U27495) of 98.7% and 97.4%, respectively. The TBEV strains showed significant regional genetic diversity. The detected TBEV genotypes were not specific to the tick species. However, genetic differences were observed between strains from different locations, while strains from the same location showed a high similarity.
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Affiliation(s)
- Marina Sidorenko
- Department of Biology, Faculty of Natural Sciences, Vytautas Magnus University, Kaunas, Lithuania
| | - Jana Radzijevskaja
- Department of Biology, Faculty of Natural Sciences, Vytautas Magnus University, Kaunas, Lithuania
| | - Saulius Mickevičius
- Department of Biology, Faculty of Natural Sciences, Vytautas Magnus University, Kaunas, Lithuania
| | - Maksim Bratchikov
- Department of Physiology, Biochemistry, Microbiology and Laboratory Medicine, Institute of Biomedical Sciences, Faculty of Medicine, Vilnius University, Vilnius, Lithuania
| | | | - Povilas Sakalauskas
- Department of Biology, Faculty of Natural Sciences, Vytautas Magnus University, Kaunas, Lithuania
| | - Algimantas Paulauskas
- Department of Biology, Faculty of Natural Sciences, Vytautas Magnus University, Kaunas, Lithuania
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Simkute E, Pautienius A, Grigas J, Urbute P, Stankevicius A. The Prevalence, Seroprevalence, and Risk Factors of Tick-Borne Encephalitis Virus in Dogs in Lithuania, a Highly Endemic State. Viruses 2023; 15:2265. [PMID: 38005941 PMCID: PMC10674385 DOI: 10.3390/v15112265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 11/03/2023] [Accepted: 11/14/2023] [Indexed: 11/26/2023] Open
Abstract
The rising awareness and increasing number of case reports of tick-borne encephalitis (TBE) in dogs indicate that the virus might be an important tick-borne pathogen in dogs, especially in endemic areas. Therefore, the aim of the present study was to investigate the prevalence rate of TBEV RNA and TBEV-specific antibodies in clinical samples of dogs living in a highly endemic region of Lithuania and to evaluate the main risk factors for severe disease course and death. The blood samples (n = 473) of dogs were collected in two veterinary clinics in central Lithuania. Tick-borne encephalitis virus (TBEV) RNA was detected in 18.6% (88/473; CI 95% 15.2-22.4) and TBEV-specific antibodies were found in 21.6% (102/473; CI 95% 17.9-25.6) of dog blood serum samples after confirmation with a virus neutralization test. The death/euthanasia rate was 18.2% (16/88; CI 95% 10.8-27.8) in PCR-positive dogs. Male dogs were more likely to develop neurological symptoms (p = 0.008). Older dogs (p = 0.003), dogs with the presence of neurological symptoms (p = 0.003), and dogs with the presence of TBEV-specific antibodies (p = 0.024) were more likely to experience worse outcomes of the disease. The results of the present study demonstrate that TBEV is a common and clinically important pathogen in dogs in such endemic countries as Lithuania.
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Affiliation(s)
- Evelina Simkute
- Laboratory of Immunology, Department of Anatomy and Physiology, Lithuanian University of Health Sciences, Tilzes Str. 18, LT-47181 Kaunas, (J.G.)
| | - Arnoldas Pautienius
- Laboratory of Immunology, Department of Anatomy and Physiology, Lithuanian University of Health Sciences, Tilzes Str. 18, LT-47181 Kaunas, (J.G.)
- Institute of Microbiology and Virology, Lithuanian University of Health Sciences, LT-47181 Kaunas, Lithuania
| | - Juozas Grigas
- Laboratory of Immunology, Department of Anatomy and Physiology, Lithuanian University of Health Sciences, Tilzes Str. 18, LT-47181 Kaunas, (J.G.)
- Institute of Microbiology and Virology, Lithuanian University of Health Sciences, LT-47181 Kaunas, Lithuania
| | - Paulina Urbute
- Laboratory of Immunology, Department of Anatomy and Physiology, Lithuanian University of Health Sciences, Tilzes Str. 18, LT-47181 Kaunas, (J.G.)
| | - Arunas Stankevicius
- Laboratory of Immunology, Department of Anatomy and Physiology, Lithuanian University of Health Sciences, Tilzes Str. 18, LT-47181 Kaunas, (J.G.)
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de Heus P, Bagó Z, Weidinger P, Lale D, Trachsel DS, Revilla-Fernández S, Matiasek K, Nowotny N. Severe Neurologic Disease in a Horse Caused by Tick-Borne Encephalitis Virus, Austria, 2021. Viruses 2023; 15:2022. [PMID: 37896799 PMCID: PMC10611255 DOI: 10.3390/v15102022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 09/27/2023] [Accepted: 09/27/2023] [Indexed: 10/29/2023] Open
Abstract
As evidenced by sero-epidemiological studies, infections of horses with the tick-borne encephalitis virus (TBEV) occur frequently in TBEV-endemic areas. However, there are only very few reports of clinical cases. A possible underreporting may be due to a variety of diagnostic challenges. In this study, ELISA and neutralization tests were applied to serum samples. Brain tissue samples were investigated for the presence of nucleic acids of TBEV, Equid alphaherpesvirus 1, Borna disease virus 1, West Nile and Usutu viruses, rustrela virus, as well as Eastern, Western, and Venezuelan equine encephalitis viruses with RT-qPCR, RT-PCR, and qPCR, respectively. TBEV-specific amplification products were subjected to Sanger sequencing. In addition, a direct fluorescent antibody test for rabies was performed. Clinical and patho-histological findings are reported. Using specific RT-qPCR and RT-PCR assays, TBEV nucleic acids were demonstrated in brain tissue samples. Sequencing revealed the Western (formerly Central) European subtype of TBEV as the etiological agent. A high titer of TBEV-specific neutralizing antibodies was found in the serum. RNAscope in situ hybridization revealed TBEV RNA confined to neuronal cell bodies and processes. No other pathogens or nucleic acids thereof could be detected. Diagnostic procedures need to be carried out early after the onset of neurological signs to allow for a final etiological diagnosis of acute TBEV infections in horses.
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Affiliation(s)
- Phebe de Heus
- Clinical Unit of Equine Internal Medicine, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria; (P.d.H.); (D.L.); (D.S.T.)
| | - Zoltán Bagó
- Institute for Veterinary Disease Control Mödling, Austrian Agency for Health and Food Safety Ltd. (AGES), Robert Koch-Gasse 17, 2340 Mödling, Austria; (Z.B.); (S.R.-F.)
| | - Pia Weidinger
- Viral Zoonoses, Emerging and Vector-Borne Infections Group, Institute of Virology, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria;
| | - Dilara Lale
- Clinical Unit of Equine Internal Medicine, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria; (P.d.H.); (D.L.); (D.S.T.)
| | - Dagmar S. Trachsel
- Clinical Unit of Equine Internal Medicine, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria; (P.d.H.); (D.L.); (D.S.T.)
| | - Sandra Revilla-Fernández
- Institute for Veterinary Disease Control Mödling, Austrian Agency for Health and Food Safety Ltd. (AGES), Robert Koch-Gasse 17, 2340 Mödling, Austria; (Z.B.); (S.R.-F.)
| | - Kaspar Matiasek
- Section of Clinical & Comparative Neuropathology, Institute of Veterinary Pathology, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-Universität München, Feodor-Lynen Straße 23, 81377 Munich, Germany;
| | - Norbert Nowotny
- Viral Zoonoses, Emerging and Vector-Borne Infections Group, Institute of Virology, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria;
- Department of Basic Medical Sciences, College of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai Healthcare City, Building 14, Dubai P.O. Box 505055, United Arab Emirates
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Gothe LMR, Ganzenberg S, Ziegler U, Obiegala A, Lohmann KL, Sieg M, Vahlenkamp TW, Groschup MH, Hörügel U, Pfeffer M. Horses as Sentinels for the Circulation of Flaviviruses in Eastern-Central Germany. Viruses 2023; 15:v15051108. [PMID: 37243194 DOI: 10.3390/v15051108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 04/27/2023] [Accepted: 04/28/2023] [Indexed: 05/28/2023] Open
Abstract
Since 2018, autochthonous West Nile virus (WNV) infections have been regularly reported in eastern-central Germany. While clinically apparent infections in humans and horses are not frequent, seroprevalence studies in horses may allow the tracing of WNV and related flaviviruses transmission, such as tick-borne encephalitis virus (TBEV) and Usutu virus (USUV), and consequently help to estimate the risk of human infections. Hence, the aim of our study was to follow the seropositive ratio against these three viruses in horses in Saxony, Saxony Anhalt, and Brandenburg and to describe their geographic distribution for the year 2021. In early 2022, i.e., before the virus transmission season, sera from 1232 unvaccinated horses were tested using a competitive pan-flavivirus ELISA (cELISA). In order to estimate the true seropositive ratio of infection with WNV, TBEV, and USUV for 2021, positive and equivocal results were confirmed by a virus neutralization test (VNT). In addition, possible risk factors for seropositivity using questionnaires were analyzed using logistic regression based on questionnaires similar to our previous study from 2020. In total, 125 horse sera reacted positive in the cELISA. Based on the VNT, 40 sera showed neutralizing antibodies against WNV, 69 against TBEV, and 5 against USUV. Three sera showed antibodies against more than one virus, and eight were negative based on the VNT. The overall seropositive ratio was 3.3% (95% CI: 2.38-4.40) for WNV, 5.6% (95% CI: 4.44-7.04) for TBEV, and 0.4% (95% CI: 0.14-0.98) for USUV infections. While age and number of horses on the holding were factors predicting TBEV seropositivity, no risk factors were discovered for WNV seropositivity. We conclude that horses are useful sentinels to determine the flavivirus circulation in eastern-central Germany, as long as they are not vaccinated against WNV.
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Affiliation(s)
- Leonard M R Gothe
- Institute of Animal Hygiene and Veterinary Public Health, Faculty of Veterinary Medicine, Leipzig University, 04103 Leipzig, Germany
| | - Stefanie Ganzenberg
- Department for Horses, Faculty of Veterinary Medicine, Leipzig University, 04103 Leipzig, Germany
| | - Ute Ziegler
- Friedrich-Loeffler Institut (FLI), Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, 17493 Greifswald-Insel Riems, Germany
| | - Anna Obiegala
- Institute of Animal Hygiene and Veterinary Public Health, Faculty of Veterinary Medicine, Leipzig University, 04103 Leipzig, Germany
| | - Katharina L Lohmann
- Department for Horses, Faculty of Veterinary Medicine, Leipzig University, 04103 Leipzig, Germany
| | - Michael Sieg
- Institute of Virology, Faculty of Veterinary Medicine, Leipzig University, 04103 Leipzig, Germany
| | - Thomas W Vahlenkamp
- Institute of Virology, Faculty of Veterinary Medicine, Leipzig University, 04103 Leipzig, Germany
| | - Martin H Groschup
- Friedrich-Loeffler Institut (FLI), Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, 17493 Greifswald-Insel Riems, Germany
| | - Uwe Hörügel
- Animal Diseases Fund Saxony, Horse Health Service, 01099 Dresden, Germany
| | - Martin Pfeffer
- Institute of Animal Hygiene and Veterinary Public Health, Faculty of Veterinary Medicine, Leipzig University, 04103 Leipzig, Germany
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Fracasso G, Grillini M, Grassi L, Gradoni F, Rold GD, Bertola M. Effective Methods of Estimation of Pathogen Prevalence in Pooled Ticks. Pathogens 2023; 12:pathogens12040557. [PMID: 37111443 PMCID: PMC10146257 DOI: 10.3390/pathogens12040557] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 03/29/2023] [Accepted: 04/02/2023] [Indexed: 04/09/2023] Open
Abstract
Since tick-borne diseases (TBDs) incidence, both in human and animal populations, is increasing worldwide, there is the need to assess the presence, distribution and prevalence of tick-borne pathogens. Reliable estimates on tick-borne pathogens (TBPs) prevalence represent the public health foundation to create risk maps and take effective prevention and control actions against TBDs. Tick surveillance consists of collecting and testing (usually in pools) thousands of specimens. Construction and analysis of tick pools represent a challenge due to the complexity of tick-borne pathogens and tick-borne diseases ecology. The aim of this study is to provide a practical guideline on appropriate pooling strategies and statistical analysis of infection prevalence through: (i) reporting the different pooling strategies and statistical methodologies commonly used to calculate pathogen prevalence in tick populations and (ii) practical comparison between statistical methods utilising a real dataset of infection prevalence in ticks collected in Northern Italy. Reporting detailed information on tick pool composition and size is as important as the correct TBPs prevalence estimation. Among the prevalence indexes, we suggest using maximum-likelihood estimates of pooled prevalence instead of minimum infection rate or pool positivity rate given the merits of the method and availability of software.
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Affiliation(s)
- Gerardo Fracasso
- Eco-Epidemiology Group, Department of Biomedical Sciences, Institute of Tropical Medicine, 2000 Antwerp, Belgium
- Evolutionary Ecology Group, Department of Biology, University of Antwerp, 2610 Wilrijk, Belgium
| | - Marika Grillini
- Department of Animal Medicine, Production and Health, University of Padua, 35020 Legnaro, Italy
| | - Laura Grassi
- Department of Animal Medicine, Production and Health, University of Padua, 35020 Legnaro, Italy
| | - Francesco Gradoni
- Istituto Zooprofilattico Sperimentale delle Venezie, 35020 Legnaro, Italy
| | - Graziana da Rold
- Istituto Zooprofilattico Sperimentale delle Venezie, 35020 Legnaro, Italy
| | - Michela Bertola
- Istituto Zooprofilattico Sperimentale delle Venezie, 35020 Legnaro, Italy
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8
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Trozzi G, Adjadj NR, Vervaeke M, Matthijs S, Sohier C, De Regge N. Comparison of Serological Methods for Tick-Borne Encephalitis Virus-Specific Antibody Detection in Wild Boar and Sheep: Impact of the Screening Approach on the Estimated Seroprevalence. Viruses 2023; 15:v15020459. [PMID: 36851673 PMCID: PMC9958861 DOI: 10.3390/v15020459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 01/27/2023] [Accepted: 02/02/2023] [Indexed: 02/10/2023] Open
Abstract
Tick-borne encephalitis virus (TBEV) is a flavivirus transmitted by ticks. Serological screenings in animals are performed to estimate the prevalence and distribution of TBEV. Most screenings consist of a primary screening by ELISA, followed by confirmation of positive samples by plaque reduction neutralization tests (PRNTs). In this study, 406 wild boar sera were tested with 2 regularly used commercial ELISAs for flavivirus screening in animals (Immunozym FSME (TBEV) IgG All Species (Progen) and ID Screen West Nile Competition (Innovative Diagnostics)) and PRNTs for TBEV and USUTU virus. The results showed that the Immunozym and IDScreen ELISAs had low relative sensitivities of 23% and 20%, respectively, compared to the PRNT results. The relative specificities were 88% and 84% due to cross reactions with USUTU virus-specific antibodies. The minimal TBEV prevalence in our sample set was 8.6% when determined by PRNT. When the screening approach of ELISA testing followed by PRNT confirmation was applied, a TBEV seroprevalence of only 2.0% and 1.7% was found. The suboptimal performance of the ELISAs was confirmed by testing sera collected from experimentally TBEV-infected sheep. While the PRNT detected TBEV specific antibodies in 94% of samples collected between 7 and 18 days post-infection, the ELISAs classified only 50% and 31% of the samples as positive. Both routinely used ELISAs for TBEV antibody screening in animal sera were shown to have a low sensitivity, potentially leading to an underestimation of the true prevalence, and furthermore cross-react with other flavivirus antibodies.
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Affiliation(s)
- Gabrielle Trozzi
- Unit of Exotic and Vector-Borne Diseases, Sciensano, Groeselenberg 99, 1180 Brussels, Belgium
- Correspondence:
| | - Nadjah Radia Adjadj
- Unit of Exotic and Vector-Borne Diseases, Sciensano, Groeselenberg 99, 1180 Brussels, Belgium
| | | | - Severine Matthijs
- Viral Reemerging, Enzootic and Bee Diseases, Sciensano, Groeselenberg 99, 1180 Brussels, Belgium
| | - Charlotte Sohier
- Unit of Exotic and Vector-Borne Diseases, Sciensano, Groeselenberg 99, 1180 Brussels, Belgium
| | - Nick De Regge
- Unit of Exotic and Vector-Borne Diseases, Sciensano, Groeselenberg 99, 1180 Brussels, Belgium
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Cavalleri JV, Korbacska‐Kutasi O, Leblond A, Paillot R, Pusterla N, Steinmann E, Tomlinson J. European College of Equine Internal Medicine consensus statement on equine flaviviridae infections in Europe. Vet Med (Auckl) 2022; 36:1858-1871. [DOI: 10.1111/jvim.16581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 10/19/2022] [Indexed: 11/13/2022]
Affiliation(s)
- Jessika‐M. V. Cavalleri
- Clinical Unit of Equine Internal Medicine, Department for Companion Animals and Horses University of Veterinary Medicine Vienna Vienna Austria
| | - Orsolya Korbacska‐Kutasi
- Clinical Unit of Equine Internal Medicine, Department for Companion Animals and Horses University of Veterinary Medicine Vienna Vienna Austria
- Department for Animal Breeding, Nutrition and Laboratory Animal Science University of Veterinary Medicine Budapest Hungary
- Hungarian Academy of Sciences—Szent Istvan University (MTA‐SZIE) Large Animal Clinical Research Group Üllő Dóra major Hungary
| | - Agnès Leblond
- EPIA, UMR 0346, Epidemiologie des maladies animales et zoonotiques, INRAE, VetAgro Sup University of Lyon Marcy l'Etoile France
| | - Romain Paillot
- School of Equine and Veterinary Physiotherapy Writtle University College Chelmsford UK
| | - Nicola Pusterla
- Department of Medicine and Epidemiology, School of Veterinary Medicine University of California Davis California USA
| | - Eike Steinmann
- Department of Molecular and Medical Virology, Faculty of Medicine Ruhr University Bochum Bochum Germany
| | - Joy Tomlinson
- Baker Institute for Animal Health Cornell University College of Veterinary Medicine Ithaca New York USA
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10
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Magouras I, Schoster A, Fouché N, Gerber V, Groschup MH, Ziegler U, Fricker R, Griot C, Vögtlin A. Neurological disease suspected to be caused by tick-borne encephalitis virus infection in 6 horses in Switzerland. J Vet Intern Med 2022; 36:2254-2262. [PMID: 36093849 DOI: 10.1111/jvim.16533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 08/22/2022] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Reports on acute tick-borne encephalitis virus (TBEV) infections with signs of neurologic disease in horses are limited. OBJECTIVES To describe the epidemiological, clinical, and laboratory findings of suspected acute TBEV infections in 6 horses. ANIMALS Six horses originating from TBEV endemic regions of Switzerland were presented to equine hospitals with acute onset of neurologic disease between 2011 and 2019. METHODS Retrospective case series. Horses with acute onset of signs of neurologic disease that were subjected to clinical and microbiological examinations to rule out infectious diseases affecting the central nervous system. RESULTS All horses exhibited acute signs of neurologic disease including ataxia and proprioceptive deficits. Horses tested positive for TBEV using virus neutralization test and samples were further tested for TBEV-specific IgM. The presence of TBEV-specific IgM antibodies was confirmed in 5 horses (cases 1-5, Laboratory Unit [LU] values ranging from 30 to 56). One horse (case no. 6) with an LU value just below the test threshold (LU = 22.3) was also included under the hypothesis that the horse was transitioning from acute to chronic infection. All horses originated from areas where humans with confirmed tick-borne encephalitis reported to have been bitten by ticks. CONCLUSIONS AND CLINICAL IMPORTANCE Acute TBEV infection should be a differential diagnosis in horses with signs of neurologic disease and originating from TBEV endemic areas. The establishment of harmonized diagnostic criteria would help to overcome the diagnostic challenges associated with TBEV and other Flavivirus infections in horses.
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Affiliation(s)
- Ioannis Magouras
- Veterinary Public Health Institute, Department of Clinical Research and Veterinary Public Health, University of Bern, Bern, Switzerland.,Centre for Applied One Health Research and Policy Advice, Department of Infectious Diseases and Public Health, City University of Hong Kong, Hong Kong, China
| | - Angelika Schoster
- Clinic for Equine Internal Medicine, Equine Department, University of Zurich, Zurich, Switzerland
| | - Nathalie Fouché
- Swiss Institute of Equine Medicine, University of Bern, Bern, Switzerland
| | - Vinzenz Gerber
- Swiss Institute of Equine Medicine, University of Bern, Bern, Switzerland
| | - Martin H Groschup
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Greifswald, Insel Riems, Germany
| | - Ute Ziegler
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Greifswald, Insel Riems, Germany
| | - Raffael Fricker
- Institute for Virology and Immunology IVI, Department of Infectious Diseases and Pathobiology, University of Bern, Mittelhäusern and Bern, Switzerland
| | - Christian Griot
- Institute for Virology and Immunology IVI, Department of Infectious Diseases and Pathobiology, University of Bern, Mittelhäusern and Bern, Switzerland
| | - Andrea Vögtlin
- Institute for Virology and Immunology IVI, Department of Infectious Diseases and Pathobiology, University of Bern, Mittelhäusern and Bern, Switzerland
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11
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Ganzenberg S, Sieg M, Ziegler U, Pfeffer M, Vahlenkamp TW, Hörügel U, Groschup MH, Lohmann KL. Seroprevalence and Risk Factors for Equine West Nile Virus Infections in Eastern Germany, 2020. Viruses 2022; 14:v14061191. [PMID: 35746662 PMCID: PMC9229339 DOI: 10.3390/v14061191] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 05/23/2022] [Accepted: 05/25/2022] [Indexed: 11/16/2022] Open
Abstract
West Nile virus (WNV) infections were first detected in Germany in 2018, but information about WNV seroprevalence in horses is limited. The study’s overall goal was to gather information that would help veterinarians, horse owners, and veterinary-, and public health- authorities understand the spread of WNV in Germany and direct protective measures. For this purpose, WNV seroprevalence was determined in counties with and without previously registered WNV infections in horses, and risk factors for seropositivity were estimated. The cohort consisted of privately owned horses from nine counties in Eastern Germany. A total of 940 serum samples was tested by competitive panflavivirus ELISA (cELISA), and reactive samples were further tested by WNV IgM capture ELISA and confirmed by virus neutralization test (VNT). Information about potential risk factors was recorded by questionnaire and analyzed by logistic regression. A total of 106 serum samples showed antibodies against flaviviruses by cELISA, of which six tested positive for WNV IgM. The VNT verified a WNV infection for 54 samples (50.9%), while 35 sera neutralized tick-borne encephalitis virus (33.0%), and eight sera neutralized Usutu virus (7.5%). Hence, seroprevalence for WNV infection was 5.8% on average and was significantly higher in counties with previously registered infections (p = 0.005). The risk factor analysis showed breed type (pony), housing in counties with previously registered infections, housing type (24 h turn-out), and presence of outdoor shelter as the main significant risk factors for seropositivity. In conclusion, we estimated the extent of WNV infection in the resident horse population in Eastern Germany and showed that seroprevalence was higher in counties with previously registered equine WNV infections.
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Affiliation(s)
- Stefanie Ganzenberg
- Department for Horses, Faculty of Veterinary Medicine, Leipzig University, 04103 Leipzig, Germany;
| | - Michael Sieg
- Institute of Virology, Faculty of Veterinary Medicine, Leipzig University, 04103 Leipzig, Germany; (M.S.); (T.W.V.)
| | - Ute Ziegler
- Friedrich-Loeffler Institut (FLI), Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, 17493 Greifswald-Insel Riems, Germany; (U.Z.); (M.H.G.)
| | - Martin Pfeffer
- Institute of Animal Hygiene and Veterinary Public Health, Faculty of Veterinary Medicine, Leipzig University, 04103 Leipzig, Germany;
| | - Thomas W. Vahlenkamp
- Institute of Virology, Faculty of Veterinary Medicine, Leipzig University, 04103 Leipzig, Germany; (M.S.); (T.W.V.)
| | - Uwe Hörügel
- Animal Diseases Fund Saxony, Pferdegesundheitsdienst, 01099 Dresden, Germany;
| | - Martin H. Groschup
- Friedrich-Loeffler Institut (FLI), Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, 17493 Greifswald-Insel Riems, Germany; (U.Z.); (M.H.G.)
| | - Katharina L. Lohmann
- Department for Horses, Faculty of Veterinary Medicine, Leipzig University, 04103 Leipzig, Germany;
- Correspondence: ; Tel.: +49-341-97-38224
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12
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Da Rold G, Obber F, Monne I, Milani A, Ravagnan S, Toniolo F, Sgubin S, Zamperin G, Foiani G, Vascellari M, Drzewniokova P, Castellan M, De Benedictis P, Citterio CV. Clinical Tick-Borne Encephalitis in a Roe Deer (Capreolus capreolus L.). Viruses 2022; 14:v14020300. [PMID: 35215891 PMCID: PMC8875940 DOI: 10.3390/v14020300] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/26/2022] [Accepted: 01/28/2022] [Indexed: 11/16/2022] Open
Abstract
Tick-borne encephalitis virus (TBEV) is the causative agent of tick-borne encephalitis (TBE), a severe zoonosis occurring in the Palearctic region mainly transmitted through Ixodes ticks. In Italy, TBEV is restricted to the north-eastern part of the country. This report describes for the first time a case of clinical TBE in a roe deer (Capreolus capreolus L.). The case occurred in the Belluno province, Veneto region, an area endemic for TBEV. The affected roe deer showed ataxia, staggering movements, muscle tremors, wide-base stance of the front limbs, repetitive movements of the head, persistent teeth grinding, hypersalivation and prolonged recumbency. An autopsy revealed no significant lesions to explain the neurological signs. TBEV RNA was detected in the brain by real-time RT-PCR, and the nearly complete viral genome (10,897 nucleotides) was sequenced. Phylogenetic analysis of the gene encoding the envelope protein revealed a close relationship to TBEV of the European subtype, and 100% similarity with a partial sequence (520 nucleotides) of a TBEV found in ticks in the bordering Trento province. The histological examination of the midbrain revealed lymphohistiocytic encephalitis, satellitosis and microgliosis, consistent with a viral etiology. Other viral etiologies were ruled out by metagenomic analysis of the brain. This report underlines, for the first time, the occurrence of clinical encephalitic manifestations due to TBEV in a roe deer, suggesting that this pathogen should be included in the frame of differential diagnoses in roe deer with neurologic disease.
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Affiliation(s)
- Graziana Da Rold
- U.O. Ecopathology SCT2-Belluno, Istituto Zoprofilattico Sperimentale delle Venezie (IZSVe), Via Cappellari 44/A, 32100 Belluno, Italy; (F.O.); (C.V.C.)
- OIE Collaborating Centre for Diseases at the Animal/Human Interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy; (I.M.); (A.M.); (S.R.); (F.T.); (S.S.); (G.Z.); (G.F.); (M.V.); (P.D.); (M.C.); (P.D.B.)
- Correspondence:
| | - Federica Obber
- U.O. Ecopathology SCT2-Belluno, Istituto Zoprofilattico Sperimentale delle Venezie (IZSVe), Via Cappellari 44/A, 32100 Belluno, Italy; (F.O.); (C.V.C.)
- OIE Collaborating Centre for Diseases at the Animal/Human Interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy; (I.M.); (A.M.); (S.R.); (F.T.); (S.S.); (G.Z.); (G.F.); (M.V.); (P.D.); (M.C.); (P.D.B.)
| | - Isabella Monne
- OIE Collaborating Centre for Diseases at the Animal/Human Interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy; (I.M.); (A.M.); (S.R.); (F.T.); (S.S.); (G.Z.); (G.F.); (M.V.); (P.D.); (M.C.); (P.D.B.)
- Laboratory for Viral Genomics and Trascriptomics, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy
| | - Adelaide Milani
- OIE Collaborating Centre for Diseases at the Animal/Human Interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy; (I.M.); (A.M.); (S.R.); (F.T.); (S.S.); (G.Z.); (G.F.); (M.V.); (P.D.); (M.C.); (P.D.B.)
- Laboratory for Viral Genomics and Trascriptomics, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy
| | - Silvia Ravagnan
- OIE Collaborating Centre for Diseases at the Animal/Human Interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy; (I.M.); (A.M.); (S.R.); (F.T.); (S.S.); (G.Z.); (G.F.); (M.V.); (P.D.); (M.C.); (P.D.B.)
- Laboratory of Parasitology Micology and Sanitary Enthomology, Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell’Università 10, 35020 Legnaro, Italy
| | - Federica Toniolo
- OIE Collaborating Centre for Diseases at the Animal/Human Interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy; (I.M.); (A.M.); (S.R.); (F.T.); (S.S.); (G.Z.); (G.F.); (M.V.); (P.D.); (M.C.); (P.D.B.)
- Laboratory of Parasitology Micology and Sanitary Enthomology, Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell’Università 10, 35020 Legnaro, Italy
| | - Sofia Sgubin
- OIE Collaborating Centre for Diseases at the Animal/Human Interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy; (I.M.); (A.M.); (S.R.); (F.T.); (S.S.); (G.Z.); (G.F.); (M.V.); (P.D.); (M.C.); (P.D.B.)
- Laboratory of Parasitology Micology and Sanitary Enthomology, Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell’Università 10, 35020 Legnaro, Italy
| | - Gianpiero Zamperin
- OIE Collaborating Centre for Diseases at the Animal/Human Interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy; (I.M.); (A.M.); (S.R.); (F.T.); (S.S.); (G.Z.); (G.F.); (M.V.); (P.D.); (M.C.); (P.D.B.)
- Laboratory for Viral Genomics and Trascriptomics, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy
| | - Greta Foiani
- OIE Collaborating Centre for Diseases at the Animal/Human Interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy; (I.M.); (A.M.); (S.R.); (F.T.); (S.S.); (G.Z.); (G.F.); (M.V.); (P.D.); (M.C.); (P.D.B.)
- Histopathology Laboratory, Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell’Universita 10, 35020 Legnaro, Italy
| | - Marta Vascellari
- OIE Collaborating Centre for Diseases at the Animal/Human Interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy; (I.M.); (A.M.); (S.R.); (F.T.); (S.S.); (G.Z.); (G.F.); (M.V.); (P.D.); (M.C.); (P.D.B.)
- Histopathology Laboratory, Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell’Universita 10, 35020 Legnaro, Italy
| | - Petra Drzewniokova
- OIE Collaborating Centre for Diseases at the Animal/Human Interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy; (I.M.); (A.M.); (S.R.); (F.T.); (S.S.); (G.Z.); (G.F.); (M.V.); (P.D.); (M.C.); (P.D.B.)
- Laboratory for Viral Emerging Zoonoses, Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell’Università 10, 35020 Legnaro, Italy
| | - Martina Castellan
- OIE Collaborating Centre for Diseases at the Animal/Human Interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy; (I.M.); (A.M.); (S.R.); (F.T.); (S.S.); (G.Z.); (G.F.); (M.V.); (P.D.); (M.C.); (P.D.B.)
- Laboratory for Viral Emerging Zoonoses, Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell’Università 10, 35020 Legnaro, Italy
| | - Paola De Benedictis
- OIE Collaborating Centre for Diseases at the Animal/Human Interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy; (I.M.); (A.M.); (S.R.); (F.T.); (S.S.); (G.Z.); (G.F.); (M.V.); (P.D.); (M.C.); (P.D.B.)
- Laboratory for Viral Emerging Zoonoses, Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell’Università 10, 35020 Legnaro, Italy
| | - Carlo Vittorio Citterio
- U.O. Ecopathology SCT2-Belluno, Istituto Zoprofilattico Sperimentale delle Venezie (IZSVe), Via Cappellari 44/A, 32100 Belluno, Italy; (F.O.); (C.V.C.)
- OIE Collaborating Centre for Diseases at the Animal/Human Interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Viale dell’Università 10, 35020 Legnaro, Italy; (I.M.); (A.M.); (S.R.); (F.T.); (S.S.); (G.Z.); (G.F.); (M.V.); (P.D.); (M.C.); (P.D.B.)
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13
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Bulk Milk Tank Samples Are Suitable to Assess Circulation of Tick-Borne Encephalitis Virus in High Endemic Areas. Viruses 2021; 13:v13091772. [PMID: 34578353 PMCID: PMC8472847 DOI: 10.3390/v13091772] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 09/01/2021] [Accepted: 09/02/2021] [Indexed: 11/17/2022] Open
Abstract
A reliable surveillance strategy of tick-borne encephalitis virus (TBEV) is necessary to ensure adequate disease control measures. However, current approaches assessing geographical TBEV circulation are ineffective or have significant limitations. In this study we investigated a total of 1363 goat and 312 sheep bulk tank milk samples for the presence of TBEV. Samples were collected from systematically selected farms in Lithuania every 4–5 days from April to November in 2018 and 2019. To validate results, we additionally tested 2685 questing ticks collected in the vicinity of milk collection sites. We found 4.25% (95% CI 3.25–5.47) and 4.48% (95% CI 2.47–7.41) goat and sheep milk samples to be positive for TBEV, respectively. Furthermore, geographical distribution of TBEV in milk samples coincided with the known TBE endemic zone and was correlated with incidence of TBE in humans in 2019. When sampling time coincides, TBEV detection in milk samples is as good a method as via flagged ticks, however bulk milk samples can be easier to obtain more frequently and regularly than tick samples. The minimal infectious rate (MIR) in ticks was 0.34% (CI 95% 0.15–0.64). Therefore, our results confirm that testing milk serves as a valuable tool to investigate the spatial distribution of TBEV at higher resolution and lower cost.
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14
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Clinical Presentation and Laboratory Diagnostic Work-Up of a Horse with Tick-Borne Encephalitis in Switzerland. Viruses 2021; 13:v13081474. [PMID: 34452340 PMCID: PMC8402657 DOI: 10.3390/v13081474] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 07/16/2021] [Accepted: 07/20/2021] [Indexed: 12/30/2022] Open
Abstract
Tick-borne encephalitis is an important viral tick-borne zoonosis in Europe and Asia. The disease is induced by tick-borne encephalitis virus (TBEV). This report describes a 16-year-old Warmblood gelding presenting with sudden onset of lethargy, ataxia, and muscle fasciculations on the nostrils, the lips, and the eye lids as the most important clinical findings. The horse further had a mild facial nerve paralysis with drooping of the right upper and lower lip. Diagnosis was based on paired serum samples using TBEV-ELISAs revealing high serum IgM in the first sample with normal IgM in the second sample and an increase in serum IgG and neutralizing antibodies, indicating acute and recent infection. TBEV was confirmed by a virus-neutralization test, revealing a fivefold increase in antibodies 32 days after of the onset of clinical signs. Although the specific PCR on cerebrospinal fluid (CSF) was negative, TBEV-specific IgG and IgM were identified in the CSF of the horse. Treatment consisted of anti-inflammatory and anti-oxidative treatment and the horse recovered with a mild drooping of the right nostril as the only remaining clinical sign. TBEV infection is a potential differential diagnosis of neurological disease in horses living in endemic areas and this is the first report to describe the diagnostic criteria in a horse as recommended in humans with suspected TBEV infection.
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