Inapparent rabies virus infection of the central nervous system
Fischman, H.R.; Strandberg, J.D.
Journal of the American Veterinary Medical Association 163(9): 1050-1055
1973
ISSN/ISBN: 0003-1488 PMID: 4583866 Document Number: 68738
Abortive or inapparent infection of the CNS with fixed and attenuated strains of rabies virus was produced by intracerebral (i/c) use of high egg passage (HEP) virus in weanling mice, with all infected mice surviving. Development of virus in the brain was monitored via fluorescent-antibody (FA) examination of frozen tissue sections, with the greatest number of foci of fluorescence at days 3 and 4 after inoculation. Histological examination revealed striking meningeal involvement by day 7, accompanied by some neuronal necrosis and gliosis. Lesions were less striking by day 14; by day 60, infected brains could not be distinguished from brains of control mice. The mice were immune to i/c challenge at 3 days. The use of immunosuppression caused 75 to 100% mortality in the mice given HEP virus i/c but some reversal of this effect could be demonstrated when rabies antibody was introduced at various intervals after infection. Though HEP virus given i/v did not protect mice against i/c challenge at 3 days, it did afford protection against foot pad challenge. By 14 days, mice were immune regardless of route of challenge. Virus was not recovered from the brains of mice given HEP virus i/v, and immunosuppression did not precipitate disease.