Rabies is an acute, typically fatal, progressive disease of the nervous system of humans and other mammals, caused by infection with virus species in the Lyssavirus genus of the Rhabdoviridae family. The genus Lyssavirus includes rabies virus (RABV) and the so-called rabies-related viruses. The disease is most commonly caused by infection with RABV. Bats are the principal reservoir hosts for the majority of lyssaviruses, but circulation of RABV outside of the Americas is maintained in terrestrial carnivores, and the vast majority of human cases of rabies result from contact with infected domestic dogs. Virus present in saliva late in infection is generally transmitted to susceptible hosts by the bite of diseased animals.