title: Prevalence estimation of tick-borne encephalitis virus (TBEV) antibodies in dogs from Finland using novel dog anti-TBEV IgG MAb-capture and IgG immunofluorescence assays based on recombinant TBEV subviral particles.
abstract: Tick-borne encephalitis (TBE) is one of the most dangerous human neurological infections occurring in Europe and Northern parts of Asia with thousands of cases and millions vaccinated against it. The risk of TBE might be assessed through analyses of the samples taken from wildlife or from animals which are in close contact with humans. Dogs have been shown to be a good sentinel species for these studies. Serological assays for diagnosis of TBE in dogs are mainly based on purified and inactivated TBEV antigens. Here we describe novel dog anti-TBEV IgG monoclonal antibody (MAb)-capture assay which is based on TBEV prME subviral particles expressed in mammalian cells from Semliki Forest virus (SFV) replicon as well as IgG immunofluorescence assay (IFA) which is based on Vero E6 cells transfected with the same SFV replicon. We further demonstrate their use in a small-scale TBEV seroprevalence study of dogs representing different regions of Finland. Altogether, 148 dog serum samples were tested by novel assays and results were compared to those obtained with a commercial IgG enzyme immunoassay (EIA), hemagglutination inhibition test and IgG IFA with TBEV infected cells. Compared to reference tests, the sensitivities of the developed assays were 90-100% and the specificities of the two assays were 100%. Analysis of the dog serum samples showed a seroprevalence of 40% on Åland Islands and 6% on Southwestern archipelago of Finland. In conclusion, a specific and sensitive EIA and IFA for the detection of IgG antibodies in canine sera were developed. Based on these assays the seroprevalence of IgG antibodies in dogs from different regions of Finland was assessed and was shown to parallel the known human disease burden as the Southwestern archipelago and Åland Islands in particular had considerable dog TBEV antibody prevalence and represent areas with high risk of TBE for humans.
authors.affiliation: Department of Virology, University of Helsinki, Helsinki, Finland. Electronic address: lev.levanov@helsinki.fi.
authors.forename: Lev
authors.initials: L
authors.lastname: Levanov
authors.affiliation: Department of Virology, University of Helsinki, Helsinki, Finland; Department of Equine and Small Animal Medicine, University of Helsinki, Helsinki, Finland; Department of Clinical Veterinary Studies, Vetsuisse Faculty, University of Bern, Bern, Switzerland. Electronic address: cristina.perezvera@helsinki.fi.
authors.forename: Cristina Pérez
authors.initials: CP
authors.lastname: Vera
authors.affiliation: Department of Virology, University of Helsinki, Helsinki, Finland; Department of Virology and Immunology, Helsinki University Hospital, Helsinki, Finland; Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland. Electronic address: olli.vapalahti@helsinki.fi.
authors.forename: Olli
authors.initials: O
authors.lastname: Vapalahti
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D002522:Chlorocebus aethiops; D004283:Dog Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000276:immunology; D004285:Dogs; D004669:Encephalitis Viruses, Tick-Borne / Q000235:genetics / Q000276:immunology*; D004675:Encephalitis, Tick-Borne / Q000175:diagnosis / Q000453:epidemiology / Q000276:immunology* / Q000662:veterinary*; D005387:Finland; D005455:Fluorescent Antibody Technique / Q000379:methods; D006801:Humans; D007118:Immunoassay / Q000379:methods; D007074:Immunoglobulin G / Q000097:blood*; D012680:Sensitivity and Specificity; D016036:Seroepidemiologic Studies; D014709:Vero Cells
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G
keywords: Dogs; IgG enzyme immunoassay; IgG immunofluorescence assay; Seroprevalence; Tick-borne encephalitis