Rabies - Overview

Clinical Signs
Treatment, Control,
  and Prevention
Human Health Risk

Knowledge of “Mad Dogs” has existed for centuries in human cultures.  The word is derived from an ancient Sanskrit word meaning "to do violence"  The ancient mesopotamian city-state of Eshnunna included a section in its laws (~ 2500 years ago) dealing with rabid dogs. 

"If a dog is mad and the authorities have brought the fact to the knowledge of its owners; if he does not keep it in, it bites a man and caused his death, then the owner shall pay two thirds of a mina (40 shekels) in silver.  If it bites a slave and causes his death he shall pay fifteen shekels of silver."

Myths of rabies have also been around for centuries, and it is widely believed that parts of the myths about vampires and werewolves may arise from outbreaks of rabies both in people as well as dogs, wolves, and bats.  Many of the supposed characteristics of  vampires can be related to the affects of rabies on the limbic system - lesions here cause an increase in aggression and violence, increased libido, hyperesthesia (hence aversion to light and rapid movements of shiny crosses, etc.), disruption in normal sleeping patterns (becoming nocturnal), loss of normal appetite and paralysis of facial muscles (inability to eat).  The animal associations are of course the common carriers of rabies. 

        Eshnunna tablets    Dog bite

Rabies is caused by a lyssa virus in the Rhabdoviridae family or negative stranded RNA viruses.  It is related to several other bat lyssa viruses which are limited to bats.  The virion is an enveloped cylinder with helical symmetry, approximately 75 x 180 nm. 

Longitudinal Section of Rabies Virion          Cross Section of Rabies Virion

Rabies viruses are generally named based on their normal host in region, and by the species they are affecting.  In any region where rabies is endemic there is usually only one primary host, though it may infect a variety of other species.  Thus if a dog is infected with a strain of rabies that came from a skunk it would be called "skunk rabies in a dog".  The source of the rabies can be determined by using monoclonal antibody studies.