Waldvogel A S, Anderson G A, Phillips D L, Osburn B I
Department of Pathology, School of Veterinary Medicine, University of California, Davis 95616.
J Comp Pathol. 1992 May;106(4):333-40. doi: 10.1016/0021-9975(92)90019-q.
Two strains of bluetongue virus serotype 11 (BTV 11), UC-2 avirulent and UC-8 neurovirulent in newborn mice, were inoculated into late-term bovine fetuses to investigate whether infection with these two BTV strains in late gestation would produce congenital infection and pathological changes. Fetuses were inoculated by intramuscular injection through the uterine wall at 243 days gestation and recovered after spontaneous delivery. In calves inoculated with UC-8, births occurred 15 to 27 days before expected parturition, resulting in small, weak calves. These calves had a mild encephalitis and were unthrifty at birth. Calves inoculated with UC-2 appeared healthy when born 7 to 11 days prior to expected parturition. No lesions were found in these calves at necropsy. All calves seroconverted by the time of birth. Viraemia was present in the calves inoculated with UC-8 and in one calf inoculated with UC-2. Plasma cortisol concentrations were prematurely elevated, particularly in the calves inoculated with UC-8, indicating that they were stressed by the infection. The elevated cortisol, associated with an active congenital infection caused by bluetongue virus serotype 11 strain UC-8, is capable of causing premature delivery of low birth-weight, weak calves.
将两株蓝舌病病毒血清型11（BTV 11），即对新生小鼠无毒的UC - 2株和具有神经毒性的UC - 8株，接种到妊娠晚期的牛胎儿中，以研究妊娠晚期感染这两种BTV毒株是否会导致先天性感染和病理变化。在妊娠243天时，通过子宫壁肌肉注射对胎儿进行接种，并在自然分娩后回收。接种UC - 8的犊牛在预期分娩前15至27天出生，导致犊牛体型小且虚弱。这些犊牛患有轻度脑炎，出生时发育不良。接种UC - 2的犊牛在预期分娩前7至11天出生时看起来健康。尸检时在这些犊牛中未发现病变。所有犊牛在出生时都发生了血清转化。接种UC - 8的犊牛和一头接种UC - 2的犊牛出现病毒血症。血浆皮质醇浓度过早升高，特别是在接种UC - 8的犊牛中，表明它们受到感染的应激。与蓝舌病病毒血清型11毒株UC - 8引起的活跃先天性感染相关的皮质醇升高，能够导致低体重、虚弱的犊牛早产。
