Experimental infection of pregnant goats with Akabane virus

Abstract

Ten pregnant goats were inoculated intravenously with a newly isolated strain of Akabane virus. As a result, vertical infection and experimental reproduction of congenital morphological abnormality were accomplished. Fetuses were removed from two of them 10 days after inoculation and used for recovery of the virus. Clinically, the goats were free from any abnormal sign. Mild viremia was demonstrated in one of them inoculated with the virus at 30 days of pregnancy, but the fetus removed from this goat was negative for virus recovery. No viremia was demonstrated in the other one inoculated with the virus at 55 days of pregnancy, but two fetuses removed from it were positive for virus recovery. No abnormal clinical signs were observed in eight goats inoculated with the virus at 40 approximately 115 days of pregnancy, but leukopenia was noticed in five of these goats. Viremia was demonstrated in all the goats. It persisted for 2 to approximately 4 days. Seven goats were held under observation up to the time of spontaneous parturition. Ten neonatal kids were obtained. All of them were normal, except three which were particularly weak and one which was mummified fetus. When precolostral serum was examined, it contained neutralizing antibody against Akabane virus in five of eight neonatal kids. Two fetuses (120 days of intrauterine life) were removed from the remaining one pregnant goat 80 days after inoculation. Congenital morphological anomaly was reproduced in one of them. The other was a normal fetus. Serum collected from the umbilical cord was positive for neutralizing antibody against Akabane virus in both fetuses.