Barton A J, Prow N A, Hall R A, Kidd L, Bielefeldt-Ohmann H
School of Veterinary Science, The University of Queensland, Gatton, Queensland, 4343, Australia.
Aust Vet J. 2015 Mar;93(3):53-7. doi: 10.1111/avj.12294.
This report summarises the findings from a case of naturally-occurring Murray Valley encephalitis in a 2-year-old filly presenting with acute onset of depression and weakness. Serum samples tested at the onset of clinical signs were negative for Hendra and Kunjin virus antibodies, but positive for Murray Valley encephalitis virus (MVEV) using IgM-capture ELISA (1 : 300 dilution). A virus neutralisation assay performed 4 weeks later confirmed a titre of 1 : 160. Sera collected in the weeks preceding neurological signs returned a negative titre for MVEV 2 weeks prior followed by a titre of 1:80 in the week prior to illness. Serological surveillance conducted on 67 co-located horses returned a positive titre of 1 : 20 in one in-contact horse. There was no history of clinical disease in that horse. At 3 months after the onset of clinical signs in the index case, the filly continued to show mild facial paresis and hypermetria; the owners elected euthanasia and gave permission for necropsy. Histopathological analysis of the brain showed a mild meningoencephalitis.
The progression of a naturally-occurring MVEV infection in a horse has been documented in this case.
本报告总结了一匹2岁小雌马自然发生墨累谷脑炎的病例结果，该马表现为急性抑郁和虚弱。临床症状出现时检测的血清样本对亨德拉病毒和库京病毒抗体呈阴性，但使用IgM捕获ELISA（1:300稀释）检测墨累谷脑炎病毒（MVEV）呈阳性。4周后进行的病毒中和试验证实滴度为1:160。在出现神经症状前几周采集的血清，在发病前2周MVEV滴度为阴性，发病前一周滴度为1:80。对67匹同厩马匹进行的血清学监测显示，一匹接触马的滴度为1:20呈阳性。该匹马无临床疾病史。在首例病例出现临床症状3个月后，这匹小雌马仍表现出轻度面瘫和辨距不良；主人选择实施安乐死并同意进行尸检。对大脑的组织病理学分析显示为轻度脑膜脑炎。
本病例记录了马自然发生MVEV感染的病程。
