AETIOLOGY
Rabies viruses (RABV) belong to the Mononegavirales order, Rhabdoviridae family and Lyssavirus genus. Lyssaviruses have a non- segmented RNA genome of negative polarity encoding five viral proteins (3' to 5z): nucleoprotein N, phosphoprotein P, matrix protein M, glycoprotein G and polymerase L.
The virion has a bullet-shaped form, 100—300 nm in length and 75 nm in diameter. Rhabdovi- rus infections have been detected in insects, mammals and plants. The lyssaviruses, which comprise rabies viruses, are adapted to replicate in the mammalian central nervous system. Historically, one viral species was believed to cause rabies; however, serological, antigenic and genetic methods have now demonstrated that there are at least 11 different viral species or genotypes. Bat lyssaviruses are probably the evolutionary ancestors of all the currently described lyssaviruses.Only three genotypes are enzootic in Europe: the dog, fox and raccoon dog virus strains, which are closely related (genotype 1), and two groups of bat viruses, one isolated mainly from the serotine bat (Eptesicus serotinus) and identified as EBLV1 (European bat lyssavirus, genotype 5), and one from Myotis bats (M. dasycneme and M. daubentonit), named EBLV2 (genotype 6). Occasionally, other genotypes may be found in Europe following importation of animals from other regions of the world. Recently, a new lyssavirus (Bokeloh bat lyssavirus (BBLV)) was discovered from a Natterers bat (M. natteren) in Germany.