The Pathogenesis of Theiler’s GD VII Encephalomyelitis Virus Infection in Mice as Studied by Immunofluorescent Technique and Infectivity Titrations

Summary By means of infectivity titrations and immunofluorescent staining, the pathogenesis of Theiler’s GD VII virus infection in mice was studied. After intracerebral inoculation of virus, infection appeared to start at the site of inoculation and then spread along the ventral part of the brain and the hippocampus. Following intranasal inoculation, virus gained entrance to the central nervous system (CNS) through the olfactory bulbs and olfactory tracts to initiate infection in the brain. By feeding mice with GD VII virus, small amounts of the virus could be demonstrated in visceral organs by infectivity titrations while much larger amounts of virus were found in the CNS when encephalitis became apparent. Use of the immunofluorescence technique did not enable us to localize the primary sites of viral multiplication prior to invasion of the central nervous system in mice infected by gavage.