A comparison of the tissue lesions produced in adult hamsters by two strains of avirulent Venezuelan equine encephalomyelitis virus.

Adult hamsters were infected with two avirulent strains of Venezuelan equine encephalomyelitis virus, TC-83 and the small plaque variant (SPV) of Fe 3-7c. Histologic examination showed that significant brain lesions were produced by both strains and affected primarily the olfactory bulbs, lateral olfactory tracts and the pyriform lobes of the cerebral cortex. The type of lesions produced by both strains were similar, but when the two groups were compared, more of the hamsters inoculated with SPV had lesions and they were of greater severity. Outstanding lesions observed were: vasculitis, lymphocytic perivascular cuffing and hemorrhage, demyelination of the lateral olfactory tracts and neuronal necrosis of the olfactory bulbs.