Monkeypox…The Basics

Background: Monkeypox is a poxviridae virus closely related to smallpox (variola).  It was first described in humans in 1970 and has since become endemic in parts of Africa.  In recent weeks, clusters of cases have been described in several countries prompting us to revisit this topic as it is not one we typically deal with in the ED.

The Virus:

  • Family: Poxviridae
  • Subfamily: Chordopoxvirinae
  • Genus: Orthopoxvirus
  • Species: Monkeypox virus
  • Brick-shaped virus , surrounded by a lipoprotein envelope with linear double-stranded DNA genome
  • Genetically distinct from other viruses of the Poxviridae family (i.e. variola, vaccinia, ectromelia, camelpox, and cowpox)
  • There are two distinct clades of monkeypox virus [3]
    • West African: More favorable prognosis with case fatality rate <1%
    • Central Basin: more lethal, with a case fatality rate of up to 11% in unvaccinated children

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