Laboratory Transmission of Fibromas (Shope) in Cottontail Rabbits by Means of Fleas and Mosquitoes

Abstract

The fibroma virus used for transmission expts. was from 2 cottontails inoculated intracutaneously 48-63 days previously with the virus which had been recovered from a wild cottontail. Fleas and mosquitoes were fed first on the fibromas then, after suitable intervals, on the clipped sides of fresh rabbits. Fibroma virus may be transmitted from cottontail to cottontail by means of pin pricks, fleas found on cottontails, and by the mosquito Aedes aegypti, A. aegypti transmits fibroma virus under favorable circumstances, in as high a proportion of bites at 2 weeks following an infective feeding as at 24 hrs. Virus-carrying mosquitoes induced fibromas on the eyelid and close to the eye of 1 cottontail when given the opportunity to feed at will. Possible mechanisms involved in mosquito transmission are discussed.