Experimental Virus Infections in Chinese Hamster. I. Susceptibility to Fixed Rabies Virus

The characteristics of most viruses are best demonstrable by their effects on hosts. It is therefore desirable to determine the pathogenicity of a given virus for as many species of animals as possible. It seems to us of both practical and academic interest to find out the effect of various viruses upon the Chinese hamster, a species of rodent readily obtainable. In the present communication, the susceptibility of the Chinese hamster to fixed rabies virus is recorded.

A strain of fixed rabies virus after 137 rabbit passages from a local street virus, was used. The brain virus preserved in 50% glycerin was thoroughly ground in a sterile mortar and suspended in saline solution. Normal Chinese hamsters weighing 20–30 gm. were divided into several groups and each group was separately inoculated with various dilutions of the rabbit brain virus through different routes. In intracerebral inoculation, the hamsters were anesthetized and 0.05 cc. of the ground virus suspension was injected through an opening in the skull posterior to the eye and lateral to the mid-dorsal line. In intraperitoneal, intratesticular, intramuscular and subcutaneous injections, 0.5 cc. of virus suspension was introduced each time. The latter 2 routes of injection were always made over the right thigh. Animals, after injection, were kept separately in cages and observed for over one month.

After intracerebral inoculations, the infected animals began to show general weakness and tremor of different parts of the body in 5 to 8 days. This was followed by progressive unsteadiness of gait accompanied by weakness of the hind-legs, leading in 24 hours to definite paralysis. The upper limbs were found to be involved later. At the terminal stage all limbs became paralyzed, respiratory movements feeble and the skeletal muscles flabby.