TRANSMISSION OF THE RABIES VIRUS - IMPORT ANCE OF THE SPECIES BARRIER

The authors describe experimental inoculations of different animal spe cies with either the wild-type rabies virus or the modified one throug h in vivo or in vitro passages. With these experiments it was possible to determine the 50% lethal dose of these viruses for these species, and to thus quantify the importance of the species barrier that oppose s, in particular; the transmission of vulpine rabies to cats and dogs (respectively 10(5) and 10(6) times more resistant than foxes). Studie s were also undertaken on the influence of the inoculation route and t hat of serial passages of the virus in vivo or in vitro on the importa nce of resistance to rabies. The epidemiological consequences of the e xistence of a species barrier, its nature and variability, are discuss ed.