Susceptibility of mice to acute and persistent measles infection.

Intracerebral inoculation of neonatal mice with the Edmonston strain of measles virus produced an acute, lethal encephalitis and thymic dysplasia in susceptible mice. There was an age-related development of resistance to infection. This resistance was strain-dependent and appeared to be associated with the extent of virus growth in the brain. Studies on the genetic basis for susceptibility, using hybrid and backcross mice, revealed that the principal determinant of host resistance to acute infection was a dominant gene or genes which segregated independently of the H-2 complex. A small number of survivors of the acute infection showed persistence of measles virus antigens in the cerebellum and spleen for up to 2 months after inoculation. However, the low frequency of this persistence indicated that, at this time, intracerebral inoculation of neonatal mice with the Edmonston strain of measles virus constitutes a difficult model for the study of persistant measles infection.