Clinical Unit of Equine Internal Medicine, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria.
Institute for Veterinary Disease Control Mödling, Austrian Agency for Health and Food Safety Ltd. (AGES), Robert Koch-Gasse 17, 2340 Mödling, Austria.
Viruses. 2023 Sep 29;15(10):2022. doi: 10.3390/v15102022.
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, , 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.
血清流行病学研究表明，在虫媒脑炎病毒（TBEV）流行地区，马经常感染 TBEV。然而，仅有极少数临床病例报告。可能存在漏报的原因是诊断存在多种挑战。在这项研究中，应用 ELISA 和中和试验对血清样本进行了检测。通过 RT-qPCR、RT-PCR 和 qPCR 分别对脑组织样本进行了 TBEV、博纳病病毒 1、西尼罗河病毒和乌苏图病毒、锈叶病毒以及东方、西方和委内瑞拉马脑炎病毒的核酸检测。对 TBEV 特异性扩增产物进行了 Sanger 测序。此外，还进行了狂犬病的直接荧光抗体检测。报告了临床和病理组织学发现。使用特定的 RT-qPCR 和 RT-PCR 检测方法，在脑组织样本中检测到了 TBEV 核酸。测序结果显示，引起感染的病原体为 TBEV 的西方（原称中欧）亚型。在血清中发现了高滴度的 TBEV 特异性中和抗体。RNAscope 原位杂交显示 TBEV RNA 局限于神经元胞体和突起。未检测到其他病原体或其核酸。需要在神经症状出现后尽早进行诊断程序，以便对马的急性 TBEV 感染进行最终的病因诊断。
