title: Swabbing Surgical Sites Does Not Improve the Detection of Staphylococcus aureus Carriage in High-Risk Surgical Patients.
abstract: BACKGROUND
  A major risk factor for the development of surgical site infections is Staphylococcus aureus carriage. Compared with non-carriers, S. aureus carriers have up to a 14-fold greater risk for post-surgical infections. Pre-operative screening for S. aureus carriage is controversial. Yet, targeted screening in high-risk patients or from clinically relevant sites may be beneficial. We aimed to determine whether S. aureus detection in high-risk surgical patients would be increased by culturing surgical sites, in addition to the nares, vs. nares-only culturing.
  
  
  METHODS
  Adults undergoing pre-operative evaluations in orthopedic and neurosurgical clinics were eligible for participation. For each subject, specimens were collected from the anterior nares and from the proposed surgical site. Samples were inoculated onto methicillin-resistant S. aureus-selective chromogenic agar plates and blood agar plates.
  
  
  RESULTS
  Of 150 subjects, 80 (53.3%) were women and 70 (46.7%) men. The mean age was 61 years and 77/150 (51.3%) had a BMI≥30. Culture results were available for 147/150 subjects. Of the 147 surgical site cultures, 54 (36.7%), 51 (34.7%), and 28 (19.0%) were collected from knee, hip, and lumbar sites, respectively; the remaining 14 (9.5%) were from cervical, thoracic, or infra-clavicular sites. Overall, 35/147 (23.8%) nasal cultures grew S. aureus; 29/147 (19.7%) grew methicillin-susceptible S. aureus (MSSA), and 6/147 (4.1%) grew methicillin-resistant S. aureus (MRSA). Only 2/147 (1.4%) surgical site cultures grew S. aureus; both grew MSSA and MSSA was cultured also from the nasal swabs of these subjects. Using nasal culture+surgical site culture as "true positive," the percentage of additional S. aureus carriers detected by the addition of surgical site screening was zero as compared to nasal screening alone.
  
  
  CONCLUSIONS
  The detection of S. aureus carriage in high-risk surgical patients is not improved by swabbing surgical sites in addition to the nares.
authors.affiliation: 1 Division of Infectious Diseases, Department of Internal Medicine, University of California , Davis Medical Center, Sacramento, California.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Brown
authors.affiliation: 2 Division of Biostatistics, Department of Public Health Sciences, School of Medicine, University of California , Davis, Sacramento, California.
authors.forename: Chin-Shang
authors.initials: CS
authors.lastname: Li
authors.affiliation: 3 Department of Orthopedic Surgery, University of California , Davis Medical Center, Sacramento, California.
authors.forename: Mauro
authors.initials: M
authors.lastname: Giordani
authors.affiliation: 4 Department of Neurological Surgery, University of California , Davis Medical Center, Sacramento, California.
authors.forename: Kiarash
authors.initials: K
authors.lastname: Shahlaie
authors.affiliation: 3 Department of Orthopedic Surgery, University of California , Davis Medical Center, Sacramento, California.
authors.forename: Eric O
authors.initials: EO
authors.lastname: Klineberg
authors.affiliation: 1 Division of Infectious Diseases, Department of Internal Medicine, University of California , Davis Medical Center, Sacramento, California.
authors.forename: Joanna R
authors.initials: JR
authors.lastname: Tripet-Diel
authors.affiliation: 1 Division of Infectious Diseases, Department of Internal Medicine, University of California , Davis Medical Center, Sacramento, California.
authors.forename: Marie S
authors.initials: MS
authors.lastname: Ihara
authors.affiliation: 1 Division of Infectious Diseases, Department of Internal Medicine, University of California , Davis Medical Center, Sacramento, California.
authors.forename: Stuart H
authors.initials: SH
authors.lastname: Cohen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002353:Carrier State / Q000175:diagnosis* / Q000382:microbiology; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D009666:Nose / Q000382:microbiology*; D011300:Preoperative Care / Q000379:methods; D011446:Prospective Studies; D018570:Risk Assessment; D012867:Skin / Q000382:microbiology*; D013048:Specimen Handling / Q000379:methods*; D013203:Staphylococcal Infections / Q000175:diagnosis* / Q000382:microbiology; D013211:Staphylococcus aureus / Q000302:isolation & purification*; D013530:Surgical Wound Infection / Q000517:prevention & control; D055815:Young Adult