Canine distemper virus infection of weanling mice. Pathogenesis of CNS disease

Intracerebral inoculation of canine distemper virus (CDV) into weanling BALB/c, ICR an SJL mice produced acute encephalitis 2 - 3 weeks later. All animals that became ill exhibited lethargy an hind-limb paralysis followed by death. BALB/c mice were more susceptible to CDV than ICR or SJL mice. Pathologic changes were characterized primarily by meningitis and focal areas of parenchymal inflammation, necrosis and microglial hypertrophy. CDV was readily isolated from infected mouse brain 10 - 23 days after infection, and peak virus titers occurred at the height of neurologic disease 14 - 17 days after infection. CDV antigen was selected by immunofluorescence throughout grey and white matter of the brain and brain stem. CDV was rescued from explanted mouse brain tissue after it could not be isolated from brain homogenates. BALB/c mice which were inoculated intracerebrally with CDV one month after initial virus injection developed meningitis and a non-inflammatory degeneration of white matter.