1999 Volume 52 Issue 9 Pages 565-569
During a period of September and October 1997, 44 cases of abnormal delivery, mainly abortion and stillbirth, occurred in Fukuoka Prefecture. Neutralizing antibody to Ibaraki virus (IBAV) was detected from 81.8% of the affected maternal cows, and 14 virus strains were isolated from maternal blood samples, placentas and fetal brains using HmLu-1 cell culture. During the same period 7 cases with dysphagia were shown to have neutralizing antibody to IBAV, and 2 virus strains were isolated from blood cells and identified physicochemically and serologically as IBAV. Blood samples collected from 100 sentinel calves spending the first summer season at 50 farms in 1997 showed seroconversion; 5 cases in September, 38 cases in October and 13 cases in November. These findings suggested that IBAV might have been concerned in the multiple cases of abortion and stillbirth.
