title: Staphylococcus aureus Community-acquired Pneumonia: Prevalence, Clinical Characteristics, and Outcomes.
abstract: Prevalence of Staphylococcus aureus community-acquired pneumonia (CAP) and its clinical features remain incompletely understood, complicating empirical selection of antibiotics.
  
  
  
  Using a multicenter, prospective surveillance study of adults hospitalized with CAP, we calculated the prevalence of methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) among all CAP episodes. We compared the epidemiologic, radiographic, and clinical characteristics of S. aureus CAP (per respiratory or blood culture) with those of pneumococcal (per respiratory or blood culture or urine antigen) and all-cause non-S. aureus CAP using descriptive statistics.
  
  
  
  Among 2259 adults hospitalized for CAP, 37 (1.6%) had S. aureus identified, including 15 (0.7%) with MRSA and 22 (1.0%) with MSSA; 115 (5.1%) had Streptococcus pneumoniae Vancomycin or linezolid was administered to 674 (29.8%) patients within the first 3 days of hospitalization. Chronic hemodialysis use was more common among patients with MRSA (20.0%) than pneumococcal (2.6%) and all-cause non-S. aureus (3.7%) CAP. Otherwise, clinical features at admission were similar, including concurrent influenza infection, hemoptysis, multilobar infiltrates, and prehospital antibiotics. Patients with MRSA CAP had more severe clinical outcomes than those with pneumococcal CAP, including intensive care unit admission (86.7% vs 34.8%) and in-patient mortality (13.3% vs 4.4%).
  
  
  
  Despite very low prevalence of S. aureus and, specifically, MRSA, nearly one-third of adults hospitalized with CAP received anti-MRSA antibiotics. The clinical presentation of MRSA CAP overlapped substantially with pneumococcal CAP, highlighting the challenge of accurately targeting empirical anti-MRSA antibiotics with currently available clinical tools and the need for new diagnostic strategies.
authors.affiliation: Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: Wesley H
authors.initials: WH
authors.lastname: Self
authors.affiliation: Northwestern University Feinberg School of Medicine, Chicago, Illinois.
authors.forename: Richard G
authors.initials: RG
authors.lastname: Wunderink
authors.affiliation: Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Williams
authors.affiliation: Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: Yuwei
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Emory University Medical Center, Atlanta, Georgia.
authors.forename: Evan J
authors.initials: EJ
authors.lastname: Anderson
authors.affiliation: Rush University Medical Center.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Balk
authors.affiliation: John H. Stroger, Jr Hospital of Cook County, Chicago, Illinois.
authors.forename: Sherene S
authors.initials: SS
authors.lastname: Fakhran
authors.affiliation: Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: James D
authors.initials: JD
authors.lastname: Chappell
authors.affiliation: Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Casimir
authors.affiliation: Northwestern University Feinberg School of Medicine, Chicago, Illinois.
authors.forename: D Mark
authors.initials: DM
authors.lastname: Courtney
authors.affiliation: University of Tennessee Health Science Center/Saint Thomas Health, Nashville.
authors.forename: Christopher
authors.initials: C
authors.lastname: Trabue
authors.affiliation: Northwestern University Feinberg School of Medicine, Chicago, Illinois University of Western Australia, Perth.
authors.forename: Grant W
authors.initials: GW
authors.lastname: Waterer
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Anna
authors.initials: A
authors.lastname: Bramley
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Shelley
authors.initials: S
authors.lastname: Magill
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, Georgia.
authors.forename: Seema
authors.initials: S
authors.lastname: Jain
authors.affiliation: Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Edwards
authors.affiliation: Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: Carlos G
authors.initials: CG
authors.lastname: Grijalva
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D002487:Centers for Disease Control and Prevention, U.S.; D017714:Community-Acquired Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology; D062665:Epidemiological Monitoring; D005260:Female; D006801:Humans; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects; D008875:Middle Aged; D011023:Pneumonia, Staphylococcal / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology; D015995:Prevalence; D011446:Prospective Studies; D013211:Staphylococcus aureus / Q000187:drug effects*; D014481:United States / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents
keywords: Staphylococcus aureus; antibiotics; pneumonia