Encephalopathy in suckling mice infected with Kasba (Chuzan) virus

Kasba (Chuzan) virus (an orbivirus), strain K-47, produced encephalopathy w ith severe necrosis in suckling mice inoculated intracerebrally. On day 3 a fter inoculation with 10(3) TCID50, the mice showed severe focal en cephalo malacia and meningitis. On day 4, necrosis had spread to the midbrain, cere bellum and spinal cord. From one day after inoculation, virus was recovered from the brain and the titre rose over the next 3 days. Immunohistochemica l examination demonstrated viral antigens in the cytoplasm of both degenera te and intact neurons, and ependymal cells in or around necrotic lesions. T he study indicated that the virus has an affinity for immature nerve cells in the brains of suckling mice and causes primary encephalomalacia. Since t he lesions resembled those of the hydranencephaly-cerebellar hypoplasia syn drome in calves (Chuzan disease), the system described should prove useful in studies on pathogenesis. (C) 1999 W.B. Saunders Company Limited.