Virus

Arbovirus

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Arbovirus, Arthropod-borne Virus, Arbovirus Infection

  • See Also
  1. Arthropod Bite
  2. Vector Borne Disease
  3. Fever in the Returning Traveler
  4. Flaviviridae
  5. Bunyaviridae
  6. Togaviridae
  7. Reoviridae
  • Definitions
  1. Arthropod-borne Virus (or Ar-Bo-Virus)
    1. Viral Infections borne by Insects (Mosquitos, ticks, fleas, biting flies)
    2. Arbovirus is a non-taxonomic grouping of viruses with shared mode of transmission via arthropods
  • Pathophysiology
  1. Arboviruses are single-stranded RNA Viruses EXCEPT Reovirus
  2. Message Sense RNA Arboviruses (Positive Stranded, +ssRNA)
    1. Background
      1. Message sense RNA (+ssRNA) are identical to Messenger RNA (mRNA)
      2. Like mRNA, +ssRNA may be immediately translated by host ribosomes into Protein
    2. Enveloped, Icosahedral +ssRNA Viruses
      1. Togaviridae
      2. Flaviviridae
  3. Anti-Message Sense RNA Arboviruses (Negative Stranded, -ssRNA)
    1. Background
      1. Anti-Message sense RNA (-ssRNA) need to first be transcribed into +ssRNA
      2. RNA dependent RNA Polymerase (RNA replicase, RdRp)
        1. RdRp is an enzyme carried by the -ssRNA virus within its capsid
        2. RdRp transcribes -ssRNA into +ssRNA within the host cell
      3. Translation follows +ssRNA transcription from -ssRNA (by RdRp)
        1. As with mRNA, +ssRNA translated by host ribosomes into Protein
    2. Enveloped, Helical -ssRNA Viruses
      1. Bunyaviridae
  4. Double Stranded RNA Arboviruses (dsRNA)
    1. Reovirus or Reoviridae
      1. Reoviridae are the only dsRNA viruses known to be a human pathogen
      2. Icosahedral, non-enveloped (naked) virus
  • Types
  1. Family Bunyaviridae (Bunyavirus)
    1. Genus Nairovirus (Crimean–Congo hemorrhagic fever virus)
    2. Genus Orthobunyavirus (Bunyamwera virus, California Encephalitis virus, La Crosse Encephalitis virus)
    3. Genus Phlebovirus (Rift Valley Fever virus, Toscana virus, Heartland virus)
    4. Hantavirus was previously included in Bunyaviridae
      1. Reclassified in the Family Hantaviridae (and the genus Orthohantavirus) as of 2018
      2. Hantavirus is also not Arthopod borne
  2. Family Flaviviridae (Flavivirus)
    1. Genus Flavivirus (Tick-borne Encephalitis virus, Dengue, Japanese Encephalitis Virus, St. Louis Encephalitis virus, West Nile Virus, Yellow Fever)
  3. Family Reoviridae (Reovirus)
    1. Genus Orbivirus (African horse sickness virus, Bluetongue disease virus, Equine encephalosis virus)
    2. Genus Seadornavirus (Banna virus)
    3. Genus Coltivirus (Colorado Tick Fever virus)
    4. Rotavirus is also included in the Reoviridae family, but is an enteric virus, not arthropod borne
  4. Family Togaviridae (Togavirus)
    1. Genus Alphavirus (Eastern Equine Encephalitis virus, Ross River virus, Venezuelan equine Encephalitis virus, Western equine Encephalitis virus)
    2. Genus Rubivirus (Rubella)
      1. Rubella is not arthropod borne, despite being in the family Togaviridae
  5. References
    1. Wikipedia: Arboviruses
      1. http://en.wikipedia.org/wiki/Arbovirus
  • Presentations
  1. Acute febrile illness (fever, myalgias, Arthralgias, Headache, rash)
    1. Dengue
    2. Yellow Fever
  2. Meningitis, Encephalitis or Acute Flaccid Paralysis
    1. Viral Encephalitis
    2. Tick-borne fever
  3. Acute hemorrhagic fever
    1. Dengue
    2. Yellow Fever
  4. Acute polyarthropathy
    1. Chikungunya
    2. Mayaro virus
  • References
  1. Anderson (2014) Crit Dec Emerg Med 28(7): 11-9