Introduction to Picornaviruses

Introduction

• Picornaviruses are broken into 3 groups
  • enteroviruses
    • acid-stable
    • most common in children
    • fecal-oral transmission
    • can cause aseptic (viral) meningitis
      • the most common cause of aseptic meningitis in the U.S.
    • can cause acute flaccid paralysis, acute disseminated myelitis, and acute transverse myelitis 
    • includes
      • poliovirus
      • coxsackievirus
      • echovirus
  • rhinoviruses
    • not acid-stable
    • grows at 33°C
    • includes
      • rhinovirus
  • hepatovirus
    • hepatitis A virus
• Characteristics
  • small (“pico-RNA-virus”)
  • naked capsid (non-enveloped)
    • resistant to alcohol and detergents
  • highest incidence in summer and fall seasons
  • RNA
    • single-stranded
    • positive-sense
    • linear
  • icosahedral
• Translation process is unique
  • RNA translated into 1 large polypeptide
  • polypeptide then cleaved to form functional viral proteins