905. Trends in Hospitalizations for Pneumonia in the United States, 2002-2010
Session: Poster Abstract Session: Respiratory Infections
Friday, October 4, 2013
Room: The Moscone Center: Poster Hall C
  • Pneumonia_Poster_round_10.png (1.3 MB)
  • Background: Pneumonia is the leading cause of infectious-related mortality in the United States and has serious complications such as respiratory failure, empyema and sepsis.  Our study was conducted to examine the epidemiology of the etiological agents responsible for cases of pneumonia.

    Methods: This was a retrospective cohort study reviewing the Nationwide Inpatient Sample (NIS) database.  The database was queried from 2002-2010 and the etiology of pneumonia was determined by all-listed ICD-9-CM diagnosis coding.  The etiologies were divided into six categories: Staphyloccocus aureus, Streptococcus pneumoniae, other Streptococcal species, gram-negative bacteria (Klebsiella, Pseudomonas, H. influenza and E. coli), atypical bacteria (Legionella, Chlamydia and Mycoplasma) and viral (Influenza, Parainfluenza, CMV, RSV and Adenovirus).

    Results: From over 350 million weighted hospitalizations in the NIS, we found 23 million cases of pneumonia from 2002-2010 in the U.S.  The annual hospitalization rate of pneumonia increased 15% from 765/100 000 to 876/100 000 population with the greatest increase in atypical bacteria at 75%.  Hospitalization rates by etiology, per 100 000 population, were S. aureus (35.7), gram-negatives (35.2), S. pneumoniae (18.5), viral (12), other Streptococcal species (5.1) and atypical (4.5).  The overall case fatality rate decreased 16% from 9.1% to 7.6% and changed as follows: S. aureus (20 to 13%), gram-negatives (13.6 to 12.2%), other Streptococcal species (9.2 to 7.3%), S. pneumoniae (7.7 to 5.9%), atypical (3 to 2.8%) and viral (3.3 to 4.6%).  The mean length of stay and total charges were the following, respectively: gram-negatives (16 days, $106,930), S. aureus (16 days, $99,783), other Streptococcal species (11 days, $71,070), S. pneumoniae (8 days, $44,325), viral (7 days, $38,880) and atypical (7 days, $37,993).

    Conclusion: From 2002-2010, the annual hospitalization rate of pneumonia increased while the case fatality rate decreased.  The predominance of the hospitalization rate of S. aureus and its elevated fatality rate are consistent with its pathogenicity and the outbreak in the first decade of the millennium.  The outbreaks of new strains of influenza over the same time period, including the 2009 H1N1 pandemic, likely attributed to the significant increase (39.4%) in the viral pneumonia case fatality rate.

    Brandon Wuerth, BS, Division of Infectious Diseases, University of Louisville Department of Medicine, Louisville, KY, John Bonnewell, BA, Division of Infectious Disease, University of Louisville Department of Medicine, Louisville, KY and Forest Arnold, DO, Division of Infectious Diseases, University of Louisville, Louisville, KY


    B. Wuerth, None

    J. Bonnewell, None

    F. Arnold, None

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