Influenza- and respiratory syncytial virus-associated adult mortality in Soweto

S Afr Med J. 2009 Oct;99(10):750-4.

Abstract

Background: Influenza and respiratory syncytial virus (RSV) infections cause seasonal excess mortality and hospitalisation in adults (particularly the elderly) in high-income countries. Little information exists on the impact of these infections on adults in Africa.

Objectives: To estimate influenza- and RSV-related adult mortality, stratified by age and hospitalisation in Soweto.

Study design: A retrospective hospital-based study in Soweto from 1997 to 1999 to estimate influenza- and RSV-related excess all-cause deaths and hospitalisation using a rate-difference method. The study was based on influenza seasons of varying severity, provided by surveillance data.

Results: Influenza seasons were significantly associated with excess mortality in adults across all 3 years, except for 18 - 64-year-olds in 1998. Excess mortality was highest in those > or = 65 years of age: 82.8/100 000 population in the mild 1997 season and 220.9/100 000 in the severe 1998 season. Influenza significantly increased adult medical hospitalisation in the severe 1998 season alone. RSV did not significantly affect mortality or hospitalisation.

Conclusion: Influenza-related mortality was substantial and disproportionately affected the elderly. Influenza vaccination for the elderly warrants consideration. The RSV-related burden was not significantly increased but merits observation over a longer period.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Comorbidity
  • Female
  • Hospitalization / statistics & numerical data
  • Humans
  • Influenza, Human / mortality*
  • Male
  • Middle Aged
  • Respiratory Syncytial Virus Infections / mortality*
  • South Africa / epidemiology