Respiratory Syncytial Virus vs Influenza Virus Infection: Mortality and Morbidity Comparison Over 7 Epidemic Seasons in an Elderly Population

J Infect Dis. 2024 Nov 15;230(5):1130-1138. doi: 10.1093/infdis/jiae171.

Abstract

Background: Respiratory syncytial virus (RSV) infection is gaining interest due to the recent development of vaccines but is still misdiagnosed in the elderly. The primary objective was to compare all-cause mortality at day 30. Secondary objectives were to compare clinical presentation and rates of consolidative pneumonia, hospitalization, and intensive care unit (ICU) admission.

Methods: A single-center retrospective study was conducted in a French university hospital during 7 epidemic seasons including 558 patients aged ≥75 years: 125 with RSV and 433 with influenza (median age, 84.8 years).

Results: Patients with RSV had more respiratory symptoms (wheezing, dyspnea) whereas patients with influenza had more general symptoms (fever, asthenia, myalgia). The following were higher in the RSV group: consolidative pneumonia (28.8% vs 17.2%, P = .004), hospitalization (83.2% vs 70%, P = .003), ICU admission (7.2% vs 3.0%, P = .034), and length of stay (median [IQR], 9 days [2-16] vs 5 days [0-12]; P = .002). Mortality rates at day 30 were comparable (9.6% vs 9.7%, P = .973).

Conclusions: This study included the largest cohort of patients infected with RSV aged >75 years documented in-depth thus far. RSV shares a comparable mortality rate with influenza but is associated with higher rates of consolidative pneumonia, hospitalization, ICU admissions, and extended hospital stays.

Keywords: elderly; influenza virus; lower tract respiratory infection; mortality; respiratory syncytial virus.

Publication types

  • Comparative Study

MeSH terms

  • Aged
  • Aged, 80 and over
  • Epidemics
  • Female
  • France / epidemiology
  • Hospitalization* / statistics & numerical data
  • Humans
  • Influenza, Human* / epidemiology
  • Influenza, Human* / mortality
  • Intensive Care Units* / statistics & numerical data
  • Length of Stay / statistics & numerical data
  • Male
  • Respiratory Syncytial Virus Infections* / epidemiology
  • Respiratory Syncytial Virus Infections* / mortality
  • Retrospective Studies
  • Seasons