MICROBIOLOGY

• Rabies is caused by an enveloped, single-stranded, negative-sense RNA virus in the genus Lyssavirus (family Rhabdoviridae), nearly always fatal encephalitis in humans and other mammals.
  • Classic rabies virus is the predominant human pathogen globally, but other Lyssavirus species (e.g., European bat lyssaviruses) can rarely cause rabies-like disease.
  • The virus is highly neurotropic, entering peripheral nerves at the site of inoculation and spreading centripetally to the CNS via retrograde axonal transport.
    • Infectious material is limited to saliva and neural tissue; blood, urine, and feces are not considered infectious.
• The domestic dog is the main reservoir worldwide.
  • Wildlife species predominate in the U.S.
    • Major reservoirs include raccoons (eastern regions), skunks (central), foxes (southwest), and bats nationwide.
• Transmission usually occurs via inoculation of virus-laden saliva through a bite; viral replication in salivary glands facilitates transmission.