Mortality Associated With Influenza and Respiratory Syncytial Virus in the US, 1999-2018

Respiratory syncytial virus (RSV) mortality estimates have not been updated since 2009, and no study has assessed changes in influenza mortality after the 2009 pandemic. Updated burden estimates are needed to characterize long-term changes in the epidemiology of these viruses.

To evaluate excess mortality from RSV and influenza in the US from 1999 to 2018. DESIGN, SETTING, AND PARTICIPANTS: This cross-sectional study used data from 50.3 million US death certificates from 1999 to 2018 to create age-specific linear regression models and assess weekly mortality fluctuations above a seasonal baseline associated with RSV and influenza. Statistical analysis was performed for 1043 weeks from January 3, 1999, to December 29, 2018. MAIN OUTCOMES AND MEASURES: Excess mortality associated with RSV and influenza estimated from the difference between observed and expected underlying respiratory mortality each season.