Ikeda S, Yonaiyama K
Natl Inst Anim Health Q (Tokyo). 1978 Winter;18(3-4):89-96.
A material containing 10(3.0) approximately 10(5.0) TCID50 of Akabane virus was inoculated into 6-day-old chick embryos by the yolk sac route. Death of embryos did not increase in the course of embryonic development till 18 days of age, as compared with control groups. Later than 18 days of age, however, the numbers of dead and peeping but unhatched embryos increased, making the hatching rate significantly low. Deformities, such as arthrogryposis and hydranencephaly, appeared in almost all the dead and unhatched embryos. They were severe in dead embryos, considerably severe in peeping unhatched embryos, and comparatively mild, though highly frequent, in affected hatched chicks. Many of the hatched chicks manifested ataxia, abnormal gait, astasia, or tremor of body or legs separately or together. Virus growth was demonstrated in chick embryos inoculated at 7 days of age. The virus titer was the highest (10(3.25 approximately 10(3.75) TCID50/O.1g) in head, trunk, and muscle, and the second highest (10(2.0) approximately 10(2.5) in brain, heart, and other visceral organs. It was the highest (10(4.0) approximately 10(4.5)) in muscle and a mixture of cerebellum and brain stem in embryos inoculated at 8 days of age.
将含有约10(3.0)至10(5.0)半数组织培养感染剂量（TCID50）的赤羽病毒的材料，通过卵黄囊途径接种到6日龄鸡胚中。与对照组相比，直到18日龄胚胎发育过程中胚胎死亡数均未增加。然而，18日龄之后，死亡和啄壳但未孵出的胚胎数量增加，导致孵化率显著降低。几乎所有死亡和未孵出的胚胎都出现了诸如关节弯曲和积水性无脑等畸形。这些畸形在死亡胚胎中严重，在啄壳未孵出的胚胎中相当严重，而在受影响的孵出雏鸡中虽然频繁出现但相对较轻。许多孵出的雏鸡分别或同时表现出共济失调、步态异常、站立不稳或身体或腿部震颤。在7日龄接种的鸡胚中证明有病毒生长。病毒滴度在头部、躯干和肌肉中最高（10(3.25)至10(3.75) TCID50/0.1g），在脑、心脏和其他内脏器官中次之（10(2.0)至10(2.5)）。在8日龄接种的胚胎中，肌肉以及小脑和脑干的混合物中病毒滴度最高（10(4.0)至10(4.5)）。
