Studies on the pathogenesis of rabies.

In experiments on the pathogenesis of rabies, mice were challenged intracerebrally and intramuscularly with rabies virus and groups of the animals were sacrificed immediately and at various intervals after challenge and the virus content of several organs estimated. The influence of the site of injection on the duration of incubation and the effect of antirabies serum on the virus in the brain and in the skeletal muscle were also investigated.The results of these experiments indicate that shortly after intracerebral injection the rabies virus combines with susceptible cells in the central nervous system to form a non-neutralizable complex and later the virus penetrates into the cells and undergoes an eclipse. In muscular tissue, on the other hand, the greater part of the virus has no opportunity to combine with and penetrate into susceptible cells and the virus does not multiply there. It was found that the shorter the distance between the site of injection and the central nervous system, the shorter the duration of incubation. For maximum effectiveness, antirabies serum must be administered within 10 minutes of an intracerebral challenge and 20 minutes of an intramuscular challenge.From the experimental observations it can be concluded that the rabies virus travels along or in the nerves from the periphery to the central nervous system and vice versa.