Rabbit Pox I. Clinical Manifestations and Course of Disease by Harry

In December, 1932, a disease presenting many of the characteristic features of small pox in man appeared in a colony of rabbits maintained for the study of problems of constitution and quickly assumed epidemic proportions with a high mortality in certain classes of animals. The nature of the disease and the origin of the outbreak were obscure, but the picture presented indicated that the disease was due to a virus and not to a bacterial infection. This impression was supported by observations made in the spring of 1930 when there was a small epidemic of a disease presenting the same clinical and pathological picture. While it is known that infection with vaccine virus may be transmitted from one rabbit to another by contact or to other animals in the same room, the prevailing impression is that these infections usually are mild or asymptomatic. However, a number of severe epidemic infections have been attributed to neurovaccine virus. In the present instance, work with a number of viruses was being carried on in several laboratories, but at the time very little information could be obtained concerning the use of vaccine virus. It was subsequently learned, however, that prior to the outbreak of the epidemic in question , at least three laboratories had inoculated rabbits with vaccine virus and that in two of these neurovaccine had been used. Some of the inoculated animals were on a lower floor of a building in which a small section of the breeding colony was kept, while others were on the same floor of the building in which the main colony was housed and there were connecting links by means of which a highly contagious infection might be transported from one group of animals to another,