Demonstration of Akabane virus antigen using immunohistochemistry in naturally infected newborn calves

Eight newborn calves showing ataxia were necropsied and examined histologic ally. Six of seven cerebrospinal fluid samples collected from these animals had neutralizing antibody for Akabane virus (AKV). All examined calves had nonsuppurative encephalomyelitis, localized mainly in the midbrain and spi nal cord. Corresponding to the encephalitic lesion, AKV antigen was demonst rated in neuroglial cells in the brain stem and neuronal cells in the ventr al horn of the spinal cord. This is the first study to demonstrate AKV anti gen by immunohistochemistry in naturally infected newborn calves.