title: Epidemiology of methicillin-resistant Staphylococcus aureus pneumonia in community hospitals.
abstract: OBJECTIVE
  Describe the epidemiology of healthcare-related (ie, healthcare-associated and hospital-acquired) pneumonia due to methicillin-resistant Staphylococcus aureus (MRSA) among hospitalized patients in community hospitals.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Twenty-four community hospitals in the southeastern United States affiliated with the Duke Infection Control Outreach Network (median size, 211 beds; range, 103-658 beds).
  
  
  METHODS
  Adult patients with healthcare-related MRSA pneumonia admitted to study hospitals from January 1, 2008, to December 31, 2012, were identified using surveillance data. Seasonal and annual incidence rates (cases per 100,000 patient-days) were estimated using generalized estimating equation models. Characteristics of community-onset and hospital-onset cases were compared.
  
  
  RESULTS
  A total of 1,048 cases of healthcare-related pneumonia due to MRSA were observed during 5,863,941 patient-days. The annual incidence rate of healthcare-related MRSA pneumonia increased from 11.3 cases per 100,000 patient-days (95% confidence interval [CI], 6.8-18.7) in 2008 to 15.5 cases per 100,000 patient-days (95% CI, 8.4-28.5) in 2012 (P = .055). The incidence rate was highest in winter months and lowest in summer months (15.4 vs 11.1 cases per 100,000 patient-days; incidence rate ratio, 1.39 [95% CI, 1.06-1.82]; P = .016). A total of 814 cases (77.7%) were community-onset healthcare-associated pneumonia cases; only 49 cases (4.7%) were ventilator-associated cases. Of 811 patients whose disposition was known, 240 (29.6%) died during hospitalization or were discharged to hospice.
  
  
  CONCLUSIONS
  From 2008 through 2012, the incidence of healthcare-related MRSA pneumonia among patients who were admitted to a large network of community hospitals increased, despite the decreasing incidence of invasive MRSA infections nationwide. Additional study is warranted to evaluate trends in this important and potentially modifiable public health problem.
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Duke University Medical Center, Durham, North Carolina.
authors.forename: Sarah S
authors.initials: SS
authors.lastname: Lewis
authors.forename: Vanessa J
authors.initials: VJ
authors.lastname: Walker
authors.forename: Mi Suk
authors.initials: MS
authors.lastname: Lee
authors.forename: Luke
authors.initials: L
authors.lastname: Chen
authors.forename: Rebekah W
authors.initials: RW
authors.lastname: Moehring
authors.forename: Christopher E
authors.initials: CE
authors.lastname: Cox
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Sexton
authors.forename: Deverick J
authors.initials: DJ
authors.lastname: Anderson
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D017714:Community-Acquired Infections / Q000453:epidemiology*; D003428:Cross Infection / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology; D005260:Female; D006764:Hospitals, Community / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D017053:Infection Control / Q000706:statistics & numerical data; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000302:isolation & purification*; D008875:Middle Aged; D011023:Pneumonia, Staphylococcal / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology; D012189:Retrospective Studies; D012307:Risk Factors; D012621:Seasons; D015144:Southeastern United States / Q000453:epidemiology