1133. Effectiveness of Screening and Decolonization of S. aureus in Surgery Outpatients
Session: Poster Abstract Session: MRSA/VRE Epidemiology
Friday, October 9, 2015
Room: Poster Hall

Background:

The primary study goal is to establish, for ambulatory adult surgery patients, the effectiveness of a novel preoperative decolonization bundle (nasal mupirocin, chlorhexidine gluconate [CHG] bathing, CHG mouthwash X 5 days) in eradicating Staphylococcus aureus (SA) from all 4 screened body sites, compared to the current standard of care (SOC), i.e., 2 preoperative showers with antiseptic soap.  Findings from the study will inform the design, sample size, and feasibility of a future trial of the novel decolonization bundle on surgical site infections.

Methods:

Patients are recruited in surgery clinics and randomized to the decolonization bundle versus SOC. Nasal, throat, axillary, and perianal swabs are cultured for SA before and after the intervention. SA isolates are tested for oxacillin and mupirocin susceptibility and for USA type (by PFGE).  

Results:

To date we have recruited 233 patients (80 SA carriers), of a planned 400 (goal: 128 SA carriers).

Table 1. Baseline SA screening results for 233 preoperative patients.

Positive SA cultures

No. of patients

As % of all screened

(n = 233)

As % of SA carriers

(n = 80)

SA carrier (any site)

80

34%

100%

   MSSA carrier (any site)

74

32%

93%

   MRSA carrier (any site)

6

3%

8%

Nasal SA carrier

65

28%

81%

Throat SA carrier

26

11%

33%

     “Throat only” SA carrier

3

1.3%

4%

Perianal SA carrier

14

6%

18%

Axillary SA carrier

9

4%

11%

 

 

 

 

 

 

 

 

 

 

 

 

 

 Adherence to study medications:  Decolonization arm: nasal mupirocin 93%, CHG body soap 96%, CHG mouthwash 97%. SOC arm:  antiseptic soap 100%.

PFGE profiles: Diverse, especially among MSSA isolates, for which the frequency of USA types was as follows: 100 (7), 200 (15), 400 (5), 600 (13), 800 (1), 900 (12), 1000 (1), and 1200 (5), plus 61 isolates (51%) that did not fit a defined USA type. For MRSA, 2 patients were colonized with USA 300 at multiple sites, 1 patient each had MRSA USA 800 and 1000, and 2 isolates (40%) did not fit a defined USA type.

Mupirocin resistance: None was detected in MSSA; 1 MRSA USA 300 strain was mupirocin-resistant.

Conclusion:

In this ambulatory preoperative adult population, 34% of patients carried SA, mostly MSSA (32%, vs. 3% for MRSA), with a gradient by site (nares > throat > perianal > axilla). Colonizing SA strains, especially MSSA, represented diverse USA types or, for 51% of isolates, no defined USA type but still diversity in the PFGE patterns. Recruitment is ongoing.

Susan Kline, MD, MPH, FSHEA, Medicine/Infectious Diseases, University of Minnesota Medical School and University of Minnesota Medical Center and Unviersity of Minnesota Masonic Children's Hospital, Minneapolis, MN, Patricia Ferrieri, MD, FIDSA, Department of Laboratory Medicine and Pathology, University of Minnesota Medical Center, Fairview, Minneapolis, MN, Ruth Lynfield, MD, FIDSA, Minnesota Department of Health, St. Paul, MN, James Neaton, PhD, Biostatistics, University of Minnesota, Minneapolis, MN, Anita Glennen, MT(ASCP), Minnesota Dept of Health, Minneapolis, MN, Selina Jawahir, BS, Public Health Laboratory, Minnesota Department of Health, St. Paul, MN and James R. Johnson, MD, FIDSA, FACP, FRCPE, Department of Medicine, Division of Infectious Diseases and International Medicine, University of Minnesota, Minneapolis, MN

Disclosures:

S. Kline, None

P. Ferrieri, None

R. Lynfield, None

J. Neaton, None

A. Glennen, None

S. Jawahir, None

J. R. Johnson, None

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