CONTRIBUTIONS TO THE PATHOLOGY OF EXPERIMENTAL VIRUS ENCEPHALITIS

Abstract

A strain of virus designated H. F. II was compared with strain H. F. I, previously studied. Both were obtained from vesicles in a case subject to frequent common colds with attendant labial herpes. Four years elapsed between dates of isolation. The H. F. I strain was found to be notably neurotropic; the H. F. II strain, slightly neurotropic and strongly dermotropic for rabbits. It appears that 2 strains of virus are involved, although the attacks of herpes provoked appeared to be alike. This conclusion is drawn in spite of the fact that the neurotropic property of the H. F. II virus was increased by cerebral passage through 4 rabbits, and that successive corneal inoculations through a series of 8 rabbits led to a reduction in its pathogenicity. Dermal inoculation of the H. F. II strain led to myelitis, with extension of virus to the brain. Two other strains from labial vesicles in cases of recurrent herpes were studied. Strain T proved to be highly neurotropic; strain F was of low neurotropic and moderate dermotropic activity. Strain F penetrated to the nervous system far more readily and certainly from the skin than from corneal surfaces. Immunity tests showed that in rabbits previously inoculated into the cornea, the opposite cornea is only partially, while the brain is wholly, protected against reinoculation effects.