Trends for influenza-related deaths during pandemic and epidemic seasons, Italy, 1969-2001

Emerg Infect Dis. 2007 May;13(5):694-9. doi: 10.3201/eid1305.061309.

Abstract

Age-specific patterns of death from influenza vary, depending on whether the influenza season is epidemic or pandemic. We assessed age patterns and geographic trends in monthly influenza-related deaths in Italy from 1969 through 2001, focusing on differences between epidemic and pandemic seasons. We evaluated age-standardized excess deaths from pneumonia and influenza and from all causes, using a modified version of a cyclical Serfling model. Excess deaths were highest for elderly persons in all seasons except the influenza A (H3N2) pandemic season (1969-70), when rates were greater for younger persons, confirming a shift toward death of younger persons during pandemic seasons. When comparing northern, central, and southern Italy, we found a high level of synchrony in the amplitude of peaks of influenza-related deaths.

MeSH terms

  • Age Distribution
  • Age Factors
  • Disease Outbreaks / statistics & numerical data*
  • Humans
  • Influenza A Virus, H1N1 Subtype / pathogenicity
  • Influenza A Virus, H3N2 Subtype / pathogenicity
  • Influenza B virus / pathogenicity
  • Influenza, Human / mortality*
  • Italy / epidemiology
  • Mortality / trends*
  • Population Surveillance
  • Seasons