Molecular Pathogenesis of Sindbis Virus Encephalitis in Experimental Animals

The alphavirus group of arthropod-borne viruses includes a number of agents, such as Eastern equine, Western equine, and Venezuelan equine encephalitis viruses that cause acute encephalitis. The group also includes viruses, such as Ross River, Chikungunya, O'nyongnyong, and Ockelbo viruses, that cause primarily rashes and acute arthritis in humans. These alphavirus-induced diseases vary in their severity from benign febrile illnesses to illnesses associated with severe morbidity and mortality. Several alphaviruses with varying degrees of virulence also infect and cause disease in laboratory animals and are therefore particularly amenable to experimental investigation. The availability of animal models of disease combined with the relatively simple structure of alphaviruses and an extensive base of knowledge of the fundamentals of replication and genomic sequence of this virus group provide unique opportunities for the study of virulence. Sindbis virus is the type species of alphaviruses, and infection with this virus has proved to be a fruitful area for both molecular and pathogenetic studies.