section_path: Prognosis
section_name: Prognosis
paragraph_text: Prognosis
  
  The mortality rate from variola minor is approximately 1%, while the mortality rate from variola major is approximately 30%.
  
  Ordinary type-confluent is fatal about 50–75% of the time, ordinary-type semi-confluent about 25–50% of the time, in cases where the rash is discrete the case-fatality rate is less than 10%. The overall fatality rate for children younger than 1 year of age is 40–50%. Hemorrhagic and flat types have the highest fatality rates. The fatality rate for flat or late hemorrhagic type smallpox is 90% or greater and nearly 100% is observed in cases of early hemorrhagic smallpox. The case-fatality rate for variola minor is 1% or less. There is no evidence of chronic or recurrent infection with variola virus. In cases of flat smallpox in vaccinated people, the condition was extremely rare but less lethal, with one case series showing a 67% death rate.
  
  In fatal cases of ordinary smallpox, death usually occurs between days 10–16 of the illness. The cause of death from smallpox is not clear, but the infection is now known to involve multiple organs. Circulating immune complexes, overwhelming viremia, or an uncontrolled immune response may be contributing factors. In early hemorrhagic smallpox, death occurs suddenly about six days after the fever develops. The cause of death in early hemorrhagic cases is commonly due to heart failure and pulmonary edema. In late hemorrhagic cases, high and sustained viremia, severe platelet loss and poor immune response were often cited as causes of death. In flat smallpox modes of death are similar to those in burns, with loss of fluid, protein and electrolytes, and fulminating sepsis.