Vercauteren G, Miry C, Vandenbussche F, Ducatelle R, Van der Heyden S, Vandemeulebroucke E, De Leeuw I, Deprez P, Chiers K, De Clercq K
Pathology, Bacteriology and Poultry Diseases, Faculty of Veterinary Medicine, Ghent University, Belgium.
Transbound Emerg Dis. 2008 Sep;55(7):293-8. doi: 10.1111/j.1865-1682.2008.01034.x. Epub 2008 Jun 28.
Hydranencephaly, the almost complete absence of the cerebral parenchyma, induced by infection with modified live bluetongue virus (BTV) crossing the placenta has previously been reported in sheep and rarely in cattle in the USA and in South Africa. The current study describes 29 cases of hydranencephaly in bovine foetuses and 'dummy' calves up to 3 months of age in Belgium associated with natural BTV serotype 8 infection very early in gestation. Histological examination of the remaining cerebral parenchyma showed moderate to severe atrophy of the neural tissue. The lesions observed support the hypothesis of BTV-induced destruction of precursor cells. However, in several calves a slight infiltration of the walls of venules and arterioles with T lymphocytes (vasculitis) was observed as well, which seems to be responsible for at least some of the lesions. Bluetongue viral RNA was detected in 15 animals using a BTV-specific real-time RT-PCR with a much higher success rate in brain tissues compared with blood and spleen samples. Virus isolation in embryonated eggs was unsuccessful. In conclusion, hydranencephaly in calves can be associated with natural wild-type BTV-8 intra-uterine infection.
积水性无脑畸形是指脑实质几乎完全缺失，此前曾有报道称，经胎盘感染改良活蓝舌病毒（BTV）可导致绵羊出现积水性无脑畸形，在美国和南非，牛出现这种情况的案例则较为罕见。本研究描述了比利时29例牛胎儿和3月龄以下“假犊”出现积水性无脑畸形的病例，这些病例与妊娠早期自然感染BTV血清型8有关。对剩余脑实质进行组织学检查发现神经组织有中度至重度萎缩。观察到的病变支持BTV诱导前体细胞破坏的假说。然而，在几只犊牛中还观察到小静脉和小动脉壁有T淋巴细胞轻度浸润（血管炎），这似乎至少是部分病变的原因。使用BTV特异性实时逆转录聚合酶链反应（RT-PCR）在15只动物中检测到蓝舌病毒RNA，与血液和脾脏样本相比，在脑组织中的成功率要高得多。在鸡胚中进行病毒分离未成功。总之，犊牛积水性无脑畸形可能与自然野生型BTV-8宫内感染有关。
