Medicine & USMLE


Viruses - RNA Viruses
  1. HIV: Microbiology and Characteristics
  2. HIV: Clinical Course
  3. Reovirus
  4. Picornavirus Overview
  5. Poliovirus
  6. Echovirus
  7. Rhinovirus
  8. Coxsackievirus
  9. Hepatitis A Virus (HAV)
  10. Hepevirus (Hepatitis E Virus)
  11. Calicivirus
  12. Flavivirus
  13. Hepatitis C Virus (HCV)
  14. Yellow Fever Virus
  15. Dengue Virus
  16. St. Louis Encephalitis and West Nile Virus
  17. Zika Virus
  18. Togavirus
  19. Rubella
  20. Retrovirus
  21. Coronavirus
  22. Orthomyxovirus
  23. Paramyxovirus
  24. Respiratory Syncytial Virus (RSV)
  25. Parainfluenza Virus (Croup)
  26. Measles
  27. Mumps
  28. Rhabdovirus
  29. Filovirus
  30. Arenavirus
  31. Bunyavirus
  32. Deltavirus


Rhabdoviruses are a class of RNA viruses that contain negative-sense RNA. They utilize a helical capsid, and are further surrounded by a viral envelope.

The most common rhabdovirus is rabies, which is a bullet shaped virus that is transmitted through bats and other wild animals like racoons. Rabies binds to neuronal nicotinic acetylcholine receptors in the peripheral nervous system, and travel in a retrograde fashion back to reach the brain or central nervous system. A rabies infection that reaches the brain causes encephalitis, which manifests clinically as hypersalivation, photophobia, and hydrophobia. To diagnose a rabies infection, clinicians do a brain biopsy and then search brain tissue for intracellular inclusions called Negri bodies. It is crucial that a patient who may be exposed to a rabid animal receive a killed rabies vaccine and rabies immunoglobulin as soon as possible to prevent the spread of the virus to the brain.

Key Points

  • Rhabdoviruses
    • Characteristics
      • RNA viruses
        • replicate in the cytoplasm of cells
        • Single-stranded
        • - sense
          • Must be translated into +RNA for translation and replication
        • Linear genome
      • Enveloped
      • Helical capsid
    • Presentation
      • Rabies virus
        • Characteristics
          • Bullet-shaped virus
        • Transmission
          • bat, raccoon, and skunk bites
            • More common than dog bites in US
          • Aerosol transmission (bat caves) also possible
        • Pathophysiology and Presentation: Rabies
          • Long incubation period (weeks to months) before symptom onset
          • Binds to ACh receptors
            • Travels to CNS by migrating in retrograde fashion (via dynein motors) up nerve axons
          • Prodrome (Fever, malaise, pharyngitis, pain around bite site)
          • Encephalitis
            • hypersalivation
            • photophobia
            • hydrophobia
            • paralysis
            • agitation, coma, focal neurological deficits, death
        • Diagnosis
          • Brain Biopsy
            • Usually diagnosed post-mortem
            • Negri bodies
              • Round eosinophilic cytoplasmic inclusions found in
                • Purkinje cells of cerebellum
                • pyramidal hippocampal neurons
          • RT-PCR can also be used
        • Post-exposure Prophylaxis
          • Wound cleaning
          • Killed (inactivated) vaccine
            • Active immunization
          • Rabies immunoglobulin
            • Passive immunization
        • Treatment
          • Supportive