Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Feb 1;5(2):e220527.
doi: 10.1001/jamanetworkopen.2022.0527.

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

Chelsea L Hansen  1   2 , Sandra S Chaves  3   4 , Clarisse Demont  5 , Cécile Viboud  1
Affiliations

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

Chelsea L Hansen et al. JAMA Netw Open. .

Abstract

Importance: 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.

Objective: 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.

Results: There were 50.3 million death certificates (50.1% women and 49.9% men; mean [SD] age at death, 72.7 [18.6] years) included in this analysis, 1.0% for children younger than 1 year and 73.4% for adults aged 65 years or older. A mean of 6549 (95% CI, 6140-6958) underlying respiratory deaths were associated with RSV annually, including 96 (95% CI, 92-99) deaths among children younger than 1 year. For influenza, there were 10 171 (95% CI, 9652-10 691) underlying respiratory deaths per year, with 23 deaths (95% CI, 19-27) among children younger than 1 year. The highest mean mortality rate per 100 000 population for both viruses was among adults aged 65 years or older at 14.7 (95% CI, 13.8-15.5) for RSV and 20.5 (95% CI, 19.4-21.5) for influenza. A lower proportion of influenza deaths occurred among those aged 65 years or older compared with earlier estimates (75.1% [95% CI, 67.4%-82.8%]). Influenza mortality was highest among those aged 65 years or older in seasons when A/H3N2 predominated (18 739 [95% CI, 16 616-21 336] deaths in 2017-2018) and among those aged 5 to 49 years when A/H1N1pdm2009 predominated (1683 [95% CI, 1583-1787] deaths in 2013-2014). Results were sensitive to the choice of mortality outcome and method, with the broadest outcome associated with annual means of 23 352 (95% CI, 21 814-24 891) excess deaths for RSV and 27 171 (95% CI, 25 142-29 199) for influenza.

Conclusions and relevance: This study suggests that RSV poses a greater risk than influenza to infants, while both are associated with substantial mortality among elderly individuals. Influenza has large interannual variability, affecting different age groups depending on the circulating virus. The emergence of the influenza A/H1N1pdm2009 pandemic virus in 2009 shifted mortality toward middle-aged adults, a trend still observed to date. This study's estimates provide a benchmark to evaluate the mortality benefits associated with interventions against respiratory viruses, including new or improved immunization strategies.

PubMed Disclaimer

Conflict of interest statement

Conflict of Interest Disclosures: Ms Hansen reported receiving personal contracting fees from Sanofi Pasteur during the conduct of the study and outside the submitted work. No other disclosures were reported.

Figures

Figure 1.
Figure 1.. Respiratory Syncytial Virus (RSV) Results by Test Type and Season and Influenza Results by Type, Subtype, and Season
A, RSV test results. Bars indicate the number of RSV tests conducted each season from 1999-2000 to 2017-2018, with bars above the horizontal line corresponding to the number of positive test results and bars below the line corresponding to the number of negative test results. Bar colors indicate the type of test used (antigen, culture, or polymerase chain reaction [PCR]), where those data are available beginning in 2010. B, Influenza test results. Bars indicate the number of influenza tests conducted each season from 1999-2000 to 2017-2018, with bars above the horizontal line corresponding to the number of positive test results and bars below the line corresponding to the number of negative test results. Bar colors above the horizontal line (positive test results) indicate the influenza type and subtype detected.
Figure 2.
Figure 2.. Weekly Time Series for Respiratory Syncytial Virus (RSV) and Influenza Surveillance Proxies and the Underlying Respiratory Mortality Rate per 100 000 Population in Children Younger Than 1 Year and Adults Aged 65 Years or Older
A, Weekly time series of the proportion of RSV tests with positive results. The different shades of color indicate the type of test used. B, Weekly time series of the proportion of influenza tests with positive results multiplied by weekly, weighted influenza-like illness (ILI) outpatient visits. The different shades of color indicate the dominant influenza A subtype circulating during each season. C, Weekly time series of the underlying respiratory mortality rate for children younger than 1 year (black line), the weekly underlying respiratory mortality rate for children younger than 1 year estimated by the model (blue line), the estimated weekly baseline mortality for children younger than 1 year (blue area), the weekly estimated excess mortality for children younger than 1 year associated by the model with influenza (brown area), and the weekly excess mortality for children younger than 1 year associated by the model with RSV (tan area). D, Same as panel C but for adults aged 65 years or older. PCR indicates polymerase chain reaction.
Figure 3.
Figure 3.. Estimated Excess Mortality Rate for 3 Underlying Causes of Death for Respiratory Syncytial Virus (RSV) and Influenza, by Season and by Age Group
Point estimates and 95% CIs for RSV and influenza-associated excess mortality rates per 100 000 population for each respiratory virus season (from 1999-2000 to 2017-2018), age group (<1, 1-4, 5-49, 50-64, and ≥65 years), and underlying cause of death (pneumonia and influenza, respiratory, and respiratory and circulatory). Yellow points indicate RSV mortality, dark gray points indicate influenza A/H1N1 mortality, light gray points indicate influenza A/H3N2 mortality, and open points indicate influenza A/H1N1pdm2009 mortality.
Figure 4.
Figure 4.. Estimated Mean Annual Excess Influenza and Respiratory Syncytial Virus (RSV) Mortality in Adults Aged 65 Years or Older for 3 Underlying Causes of Death, by US Department of Health and Human Services (HHS) Region and Pairwise Comparisons Between HHS Regions
A-C, Heat maps show estimated mean, annual excess underlying mortality rates associated with RSV for each HHS region, with lighter shades indicating lower RSV mortality rates and darker shades, higher RSV mortality rates. Numbers on color scale are minimum, median, and maximum RSV mortality rates. Numbers on map indicate HHS regions. Panels G-I show these data for mortality rates associated with influenza. D-F, Pairwise comparisons of mean annual excess underlying RSV mortality rates between HHS regions (1-10), with lighter shades indicating smaller absolute difference between mean values and darker shades, larger absolute difference between mean values. Numbers on color scale indicate minimum, median, and maximum difference in mean values. Black points in center of tiles indicate statistically significant differences, whereas triangles indicate differences that are not statistically significant. Panels J-L show these data for mortality rates associated with influenza. All rates are per 100 000.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Thompson WW, Shay DK, Weintraub E, et al. . Mortality associated with influenza and respiratory syncytial virus in the United States. JAMA. 2003;289(2):179-186. doi:10.1001/jama.289.2.179 - DOI - PubMed
    1. Matias G, Taylor R, Haguinet F, Schuck-Paim C, Lustig R, Shinde V. Estimates of mortality attributable to influenza and RSV in the United States during 1997-2009 by influenza type or subtype, age, cause of death, and risk status. Influenza Other Respir Viruses. 2014;8(5):507-515. doi:10.1111/irv.12258 - DOI - PMC - PubMed
    1. Woolf SH, Schoomaker H. Life expectancy and mortality rates in the United States, 1959-2017. JAMA. 2019;322(20):1996-2016. doi:10.1001/jama.2019.16932 - DOI - PMC - PubMed
    1. Stoll BJ, Hansen NI, Bell EF, et al. ; Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network. Trends in care practices, morbidity, and mortality of extremely preterm neonates, 1993-2012. JAMA. 2015;314(10):1039-1051. doi:10.1001/jama.2015.10244 - DOI - PMC - PubMed
    1. Bhatt CB, Beck-Sagué CM. Medicaid expansion and infant mortality in the United States. Am J Public Health. 2018;108(4):565-567. doi:10.2105/AJPH.2017.304218 - DOI - PMC - PubMed

Publication types