Abstract
Experimental transmission of the spontaneous rabbit-pox discussed in the preceding communication 1 was attempted early in the course of the pandemic. Since the result of bacteriological examinations together with the clinical picture of the condition made it appear unlikely that we were dealing with any of the usual bacterial agents, the initial experiments were carried out with Berkefeld “V” filtrates of various organs and tissues from rabbits showing well marked symptoms of the disease. In other experiments, unfiltered suspensions were used. The organs employed included: testicle, liver, spleen, lung, popliteal lymph nodes, brain, spinal cord, blood, and skin. Injections were made into the testicles of rabbits procured from outside sources.
The results of the first experiments were positive in that an orchitis and scrotal edema were pronounced within 48 hours, fever developed (105°-107°), the animals appeared ill, frequently a diarrhea was present, and death occurred in from 4 to 8 days. This condition has been produced successively from rabbit to rabbit by means of filtered material (usually testicle) and the agent is now in the fifteenth serial passage. Other routes of inoculation have also been successfully employed, namely, intracutaneous, subcutaneous, intravenous, intraperitoneal, intramuscular, intracerebral, and nasal and conjunctival instillation. By using small doses and certain routes of inoculation, it has been possible to reproduce all the clinical and pathological features of the spontaneous disease including the characteristic pock eruption of the skin and mucous membranes. In addition, complete recovery has occurred in these circumstances.
The agent is active in tissue stored in 50% glycerol at ice box temperature for at least 94 days. Unfiltered material is much more potent than that filtered through a Berkefeld “V” candle but an “N” filtrate is also active.
Get full access to this article
View all access options for this article.