title: National burden of invasive methicillin-resistant Staphylococcus aureus infections, United States, 2011.
abstract: OBJECTIVE
  Estimating the US burden of methicillin-resistant Staphylococcus aureus (MRSA) infections is important for planning and tracking success of prevention strategies.
  
  
  OBJECTIVE
  To describe updated national estimates and characteristics of health care- and community-associated invasive methicillin-resistant Staphylococcus aureus (MRSA) infections in 2011.
  
  
  METHODS
  Active laboratory-based case finding identified MRSA cultures in 9 US metropolitan areas from 2005 through 2011. Invasive infections (MRSA cultured from normally sterile body sites) were classified as health care-associated community-onset (HACO) infections (cultured ≤ 3 days after admission and/or prior year dialysis, hospitalization, surgery, long-term care residence, or central vascular catheter presence ≤ 2 days before culture); hospital-onset infections (cultured >3 days after admission); or community-associated infections if no other criteria were met. National estimates were adjusted using US census and US Renal Data System data.
  
  
  METHODS
  National estimates of invasive HACO, hospital-onset, and community-associated MRSA infections using US census and US Renal Data System data as the denominator.
  
  
  RESULTS
  An estimated 80,461 (95% CI, 69,515-93,914) invasive MRSA infections occurred nationally in 2011. Of these, 48,353 (95% CI, 40,195-58,642) were HACO infections; 14,156 (95% CI, 10,096-20,440) were hospital-onset infections; and 16,560 (95% CI, 12,806-21,811) were community-associated infections. Since 2005, adjusted national estimated incidence rates decreased among HACO infections by 27.7% and hospital-onset infections decreased by 54.2%; community-associated infections decreased by only 5.0%. Among recently hospitalized community-onset (nondialysis) infections, 64% occurred 3 months or less after discharge, and 32% of these were admitted from long-term care facilities.
  
  
  CONCLUSIONS
  An estimated 30,800 fewer invasive MRSA infections occurred in the United States in 2011 compared with 2005; in 2011 fewer infections occurred among patients during hospitalization than among persons in the community without recent health care exposures. Effective strategies for preventing infections outside acute care settings will have the greatest impact on further reducing invasive MRSA infections nationally.
authors.affiliation: Epidemic Intelligence Service, Scientific Education and Professional Development Program Office, Centers for Disease Control and Prevention, Atlanta, Georgia2Division of Healthcare Quality Promotion, Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Raymund
authors.initials: R
authors.lastname: Dantes
authors.forename: Yi
authors.initials: Y
authors.lastname: Mu
authors.forename: Ruth
authors.initials: R
authors.lastname: Belflower
authors.forename: Deborah
authors.initials: D
authors.lastname: Aragon
authors.forename: Ghinwa
authors.initials: G
authors.lastname: Dumyati
authors.forename: Lee H
authors.initials: LH
authors.lastname: Harrison
authors.forename: Fernanda C
authors.initials: FC
authors.lastname: Lessa
authors.forename: Ruth
authors.initials: R
authors.lastname: Lynfield
authors.forename: Joelle
authors.initials: J
authors.lastname: Nadle
authors.forename: Susan
authors.initials: S
authors.lastname: Petit
authors.forename: Susan M
authors.initials: SM
authors.lastname: Ray
authors.forename: William
authors.initials: W
authors.lastname: Schaffner
authors.forename: John
authors.initials: J
authors.lastname: Townes
authors.forename: Scott
authors.initials: S
authors.lastname: Fridkin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000382:microbiology; D017281:Cost of Illness; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology; D005260:Female; D006760:Hospitalization; D006801:Humans; D007223:Infant; D008134:Long-Term Care; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus; D008875:Middle Aged; D009735:Nursing Homes; D006435:Renal Dialysis; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology*; D014481:United States / Q000453:epidemiology
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