Rates of pneumonia during influenza epidemics in Seattle, 1964 to 1975

JAMA. 1979 Jan 19;241(3):253-8.


Influenza A epidemics were associated with a doubling to tripling of pneumonia rates among adult members of a prepaid medical care group studied between 1963 and 1975. Rates of influenza A associated with pneumonia increased with age. Influenza B epidemics did not have a similar effect. Overall pneumonia rates were highest in children younger than 5 years, but in this age group, other respiratory viruses dominated as causative agents. Influenza A and B epidemics were not always synchronized with those reported for the United States, and rates of influenza A infection varied between urban and suburban areas in sequential epidemics. In 1974, a year practically free from influenza A, a prolonged Mycoplasma pneumoniae epidemic kept rates of pneumonia high, especially during the summer.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Age Factors
  • Aged
  • Child
  • Child, Preschool
  • Disease Outbreaks / epidemiology*
  • Humans
  • Infant
  • Influenza, Human / epidemiology*
  • Middle Aged
  • Mycoplasma Infections / epidemiology
  • Pneumonia / epidemiology*
  • Pneumonia / mortality
  • Seasons
  • Washington