Decolonization of Methicillin-Resistant Staphylococcus aureus (MRSA) Carriers in a Surgical Intensive Care Unit (SICU): Success Rate and Risk Factors for Decolonization Failure
Methods: This study was conducted at a 14-bed SICU over a 23-month period. During a baseline period (January 2012, through November 2012), active surveillance cultures (ASC) for MRSA were performed on nasal swab samples from all SICU patients at admission. Isolation precautions were performed when MRSA was identified. ASC were processed using Chrom-Agar at admission and weekly from August 2012. During an intervention period (December 2012, through November 2013), MRSA decolonization was implemented and ASC were performed twice a week. The MRSA decolonization consisted of a 5-day regimen of nasal mupirocin ointment, chlorhexidine mouth rinse and whole body chlorhexidine bathing. To evaluate the risk factors for short-term decolonization failure, patients who were decolonized for ≥ 3 days were analyzed. Successful decolonization was defined as at least two consecutive negative sets of ASC after decolonization. Segmented regression analysis was used to assess the effect of intervention.
Results: After intervention, the incidence density of MRSA colonization or infection decreased by 27.1% (incidence density, 10.7 vs 7.8 cases per 1,000 patient-days; β, -2.15; 95% CI, -3.49 to -0.80; P < 0.01). Of 63 MRSA isolates which underwent susceptibility testing, all isolates remained susceptible to chlorhexidine (MIC90, 4 µg/mL), 11 (17%) were low-level mupirocin resistance (MuR), and no isolates was High-level MuR. Of 46 patients who underwent decolonization for ≥ 3 days, 36 (78%) had successful decolonization. Univariate analysis showed that hospital acquisition of MRSA (OR 12.4, 95% CI 1.77-85.50) and low-level MuR (OR 8.05, 95% CI, 0.92-70.33) were associated with decolonization failure.
Conclusion: Our data support that the use of intranasal mupirocin and chlorhexidine bathing to decrease rates of MRSA infection or colonization. Although high decolonization success rates could be achieved using antiseptic protocols, decolonization may be less successful in patients carrying a mupirocin-resistant MRSA.
O. H. Cho,
Y. M. Lee, None
E. H. Baek, None
M. H. Bak, None
I. G. Bae, None