Pandemic Versus Epidemic Influenza Mortality: A Pattern of Changing Age Distribution

J Infect Dis. 1998 Jul;178(1):53-60. doi: 10.1086/515616.

Abstract

Almost all deaths related to current influenza epidemics occur among the elderly. However, mortality was greatest among the young during the 1918-1919 pandemic. This study compared the age distribution of influenza-related deaths in the United States during this century's three influenza A pandemics with that of the following epidemics. Half of influenza-related deaths during the 1968-1969 influenza A (H3N2) pandemic and large proportions of influenza-related deaths during the 1957-1958 influenza A (H2N2) and the 1918-1919 influenza A (H1N1) pandemics occurred among persons <65 years old. However, this group accounted for decrementally smaller proportions of deaths during the first decade following each pandemic. A model suggested that this mortality pattern may be explained by selective acquisition of protection against fatal illness among younger persons. The large proportion of influenza-related deaths during each pandemic and the following decade among persons <65 years old should be considered in planning for pandemics.

MeSH terms

  • Adolescent
  • Adult
  • Age Distribution
  • Aged
  • Child
  • Child, Preschool
  • Computer Simulation
  • Disease Outbreaks*
  • Humans
  • Infant
  • Influenza A virus*
  • Influenza, Human / epidemiology
  • Influenza, Human / mortality*
  • Middle Aged
  • Models, Biological
  • Seasons
  • United States / epidemiology