OBSERVATIONS ON THE PATHOGENESIS OF RABIES: EXPERIMENTAL INFECTION WITH A VIRUS OF COYOTE ORIGIN

¹ From the Department of Epidemiology and Preventive Medicine, School of Veterinary Medicine, University of California, Davis, California 95616, U.S.A.
² Berkeley Dog and Cat Hospital, 2126 Haste Street, Berkeley, California 94707

The location and progress of rabies virus isolated from a coyote (Canis latrans) was studied in experimentally infected mice. Fluorescent antibody (FA) techniques were used, and nerve tissues from infected mice, selected at timed intervals post-infection, were passaged further in mice.

Rabies virus from inoculation in the left hind foot pad was detected by FA as fine particles in the sciatic nerve at 6 hours, but not until 5 days were fluorescent particles present in moderate concentrations. Virus particles were detected by FA in the spinal nerve at 72 hours, and in the brain at 8 days. Isolations of virus by mouse inoculation indicated that infectious doses were present in the sciatic nerve by 6 hours, the spinal cord at 24 hours, and in the brain by 72 hours.

A mouse brain suspension of rabies virus inoculated into the peritoneal cavity of rats was acted upon by leukocytes which cleared the cavity of FA-detectable rabies virus within 4 hours. Virus particles were seen in the spleen by FA at 2 hours indicating that a certain amount of virus can be carried through the body by other than neural pathways.