title: Infectious disease hospitalizations in the United States.
abstract: BACKGROUND
  Infectious diseases (IDs) cause widespread morbidity and mortality. We describe the epidemiology of ID hospitalizations in the United States with use of a nationally representative database.
  
  
  METHODS
  First-listed ID hospitalizations in the United States were analyzed using the Nationwide Inpatient Sample for 1998-2006. Hospitalization rates were calculated overall for IDs and for specific ID groups.
  
  
  RESULTS
  An estimated 40,085,978 (standard error, 255,418) hospitalizations with a first-listed ID occurred during 1998-2006, for an age-adjusted hospitalization rate of 154.4 (95% confidence interval, 153.3-155.5) hospitalizations per 10,000 persons. The rate increased slightly over the study period (152.5 [95% confidence interval, 149.6-155.4] in 1998 vs 162.2 [95% confidence interval, 158.7-165.5] in 2006); an increase was seen for both sexes, for older patients, and for Hispanic patients. Among those aged 5-39 years, female patients had a significantly higher hospitalization rate than did male patients; male patients had higher rates among the youngest children and adults aged > or = 40 years. Approximately 4.5 million hospital days and $865 billion in hospital charges were associated with primary ID hospitalizations over the study period. Lower respiratory tract infections were the most commonly listed ID (34.4%), followed by kidney, urinary tract, and bladder infections; cellulitis; and abdominal and rectal infections.
  
  
  CONCLUSIONS
  The ID hospitalization rate increased during 1998-2006, reflecting an increase in ID hospitalizations among adults aged > or = 30 years, particularly older adults. Differences in trends and patterns of ID hospitalizations were noted by sex, age group, and race. Lower respiratory tract infections accounted for the largest proportion of ID hospitalizations. Future efforts should focus on preventive measures and improving early interventions for IDs.
authors.affiliation: Division of Viral and Rickettsial Diseases, National Center for Zoonotic, Vector-Borne, and Enteric Diseases, Centers for Disease Control and Prevention, U.S. Department of Health and Human Services, Rockville, Maryland, USA. KYorita@cdc.gov
authors.forename: Krista L Yorita
authors.initials: KL
authors.lastname: Christensen
authors.forename: Robert C
authors.initials: RC
authors.lastname: Holman
authors.forename: Claudia A
authors.initials: CA
authors.lastname: Steiner
authors.forename: James J
authors.initials: JJ
authors.lastname: Sejvar
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Stoll
authors.forename: Lawrence B
authors.initials: LB
authors.lastname: Schonberger
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D003141:Communicable Diseases / Q000453:epidemiology*; D005006:Ethnicity; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data / Q000639:trends*; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D012737:Sex Factors; D014481:United States / Q000453:epidemiology; D055815:Young Adult