515. Hospitalizations Associated with Influenza and Respiratory Syncytial Virus in the United States from the 1993 through 2008
Session: Poster Abstract Session: Influenza and other Respiratory Viral Infections Epidemiology Studies
Friday, October 21, 2011
Room: Poster Hall B1

Understanding the relative hospitalization burden of influenza and respiratory syncytial virus (RSV) viruses by age can inform prevention efforts. Previous studies have not simultaneously estimated the burden of these viruses using similar data sources over many seasons.


Annual hospitalization rates associated with the circulation of seasonal influenza and RSV viruses were estimated using State Inpatient Databases from the Healthcare Cost and Utilization Project for 13 states representing 40% of the US population from the 1993 through 2008. Data on laboratory-confirmed virus detection were obtained from World Health Organization collaborating laboratories for influenza and from the National Respiratory and Enteric Virus Surveillance system for RSV. For each state and age group, we estimated the contribution of influenza and RSV to respiratory and circulatory disease hospitalizations using negative binomial regression models that incorporated weekly viral surveillance data as covariates. National hospitalization rates were extrapolated from state-specific estimates.


The estimated average annual rate of influenza-associated hospitalizations in the United States was 62 per 100,000 (95% confidence interval [CI]: 40-215); the rate for RSV-associated hospitalizations was 57 per 100,000 (95% CI: 46-99). For influenza, persons aged 65 years or older had the highest hospitalization rates: 309 per 100,000 (95% CI: 186-1104). For RSV, children younger than 1 year had the highest hospitalization rates: 2,350 per 100,000 (95% CI: 2219-2525). While RSV causes 16 times more hospitalizations than influenza in children less than 1 year, influenza causes 8 times more hospitalization than RSV in people over 5 years.


Our results suggest that the burden of influenza and RSV is similar with respect to population-wide hospitalization rates in the US; however, age-specific burdens differ dramatically. Our estimates are consistent with past efforts focusing on either influenza or RSV, or specific age groups. Our national estimates allow robust comparisons of the health burden of these two respiratory pathogens by age group and over time.

Subject Category: N. Hospital-acquired and surgical infections, infection control, and health outcomes including general public health and health services research

Hong Zhou1, William Thompson1, Cecile Viboud2, Corinne Ringholz3, Claudia Steiner4, Po-Yung Cheng, PhD5, Glen Abedi, BS6, Larry Anderson, MD, FIDSA1, Lynnette Brammer, MPH5 and David Shay, MD, MPH1, (1)CDC, Atlanta, GA, (2)Fogarty International Center, National Institutes of Health, Bethesda, MD, (3)NIH, Bethesda, MD, (4)Agency for Healthcare Research and Quality, Rockville, MD, (5)Centers for Disease Control and Prevention, Atlanta, GA, (6)Division of Viral Diseases, Centers for Disease Control and Prevention, Atlanta, GA


H. Zhou, None

W. Thompson, None

C. Viboud, None

C. Ringholz, None

C. Steiner, None

P. Y. Cheng, None

G. Abedi, None

L. Anderson, None

L. Brammer, None

D. Shay, None

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