Latent Measles Virus Infection of the Hamster Central Nervous System

Abstract

Human measles virus adapted to the hamster brain replicated to high titers and initiated neural signs of encephalitis when incoulated intracerebrally into unprotected newborn hamsters. However, the presence of high levels of maternally acquired measles neutralizing antibody blocked the onset of acute encephalitis without interrupting intracellular virus replication. the measles infection remained latent until cyclophosphamide was introduced. A large percentage of the immunosuppressed hamsters developed chronic persistent myoclonic tremors of various muscular areas. Virus was isolated from these animals as long as 90 days post-infection. Thus, the newborn hamster is a useful model for the study of latent central nervous system infection by measles virus.