Levanov Lev, Vera Cristina Pérez, Vapalahti Olli
Department of Virology, University of Helsinki, Helsinki, Finland.
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.
Ticks Tick Borne Dis. 2016 Jul;7(5):979-982. doi: 10.1016/j.ttbdis.2016.05.002. Epub 2016 May 6.
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.
蜱传脑炎（TBE）是欧洲和亚洲北部发生的最危险的人类神经感染之一，有数千病例，数百万人接种了针对它的疫苗。TBE的风险可通过分析从野生动物或与人类密切接触的动物采集的样本进行评估。狗已被证明是这些研究的良好哨兵物种。用于诊断狗TBE的血清学检测主要基于纯化和灭活的TBEV抗原。在此，我们描述了一种新型的狗抗TBEV IgG单克隆抗体（MAb）捕获检测方法，该方法基于在来自Semliki森林病毒（SFV）复制子的哺乳动物细胞中表达的TBEV prME亚病毒颗粒，以及基于用相同SFV复制子转染的Vero E6细胞的IgG免疫荧光检测（IFA）。我们进一步展示了它们在芬兰不同地区的狗的小规模TBEV血清流行率研究中的应用。总共，通过新型检测方法对148份狗血清样本进行了检测，并将结果与使用商业IgG酶免疫测定（EIA）、血凝抑制试验和用TBEV感染细胞的IgG IFA获得的结果进行了比较。与参考检测相比，所开发检测方法的敏感性为90 - 100%，两种检测方法的特异性均为100%。对狗血清样本的分析显示，奥兰群岛的血清流行率为40%，芬兰西南群岛为6%。总之，开发了用于检测犬血清中IgG抗体的特异性和灵敏的EIA和IFA。基于这些检测方法，评估了芬兰不同地区狗中IgG抗体的血清流行率，结果显示与已知的人类疾病负担情况相似，特别是西南群岛和奥兰群岛的狗TBEV抗体流行率相当高，代表了人类TBE高风险地区。
