• Smallpox is caused by the variola major virus

Image courtesy of CDC

• This is in the Orthopox genus which also includes the vaccinia and monkeypox species
• This virus replicates in the cytoplasm by producing eosinophilic antibodies

Transmission

• Direct prolonged face-to-face contact
• Direct contact with infected bodily fluids or contaminated objects such as bedding or clothing
• Rarely spread by aerosol in enclosed spaces

Incubation

7 - 17 days following exposure

Effects

• Initial effects
  • High fever
  • Head and body aches
  • Possible vomiting
• Early rash
  • Day 1 - Small red spots on tongue and mouth
  • Day 2 - Rash spreads to all parts of the body and the fever reduces.
  • Day 3 - Rash becomes raised bumps
  • Day 4 - Bumps become filled with thick, opaque liquid and the fever rises again



Image courtesy of CDC

• Pustule Rash

• Bumps become pustules (sharply raised, usually round, and firm to the touch)



Image courtesy of CDC

• Pustules and Scabs

• Pustules form a crust and then a scab
• Resoving scabs
  • Scabs fall off leaving scars on the skin
• Scabs resolves
  • All scabs have fallen off
  • Person is no longer contagious

Mortality

~30% overall

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