Evaluation of Staphylococcus aureus eradication therapy in orthopaedic surgery

Introduction Carriers of Staphylococcus aureus, both methicillin sensitive (MSSA) and methicillin resistant (MRSA), have an increased risk for health-care associated infections. Despite WHO recommendations there is currently no national screening and eradication policy for the detection of MSSA in the UK or USA. This study aimed to evaluate the effectiveness of current standard MRSA eradication therapies in the context of S. aureus decolonisation prior to joint replacement surgery. Methods Pre-operative PCR nasal screening was performed in 273 Orthopaedic patients awaiting joint replacement surgery. In all 100 patients were positive for S. aureus and enrolled into the study. All enrolled patients received and were instructed to administer the decolonisation regimen for five days. Prior to commencement of the eradication therapy swabs of the anterior nares, throat, and perineum were taken for culture. Further culture swabs were taken at; 48–96 hours after completion of the five-day eradication regimen, at hospital admission for surgery, and at hospital discharge. Patients were followed up for six weeks post-surgery. Following completion of the five-day course patients were asked to provide feedback on their experience using Likert rating scales. The primary outcome of this study was S. aureus clearance 48–96 hours post-completion of eradication therapy. Results At 48–96 hours post-completion there was S. aureus clearance from: the anterior nares 93.8% (95% Confidence Interval (CI) 79.2–99.2%), throat 65.6% (95% CI 46.8–81.4%), and groin 87.5% (95%CI 71–96.5). Mean compliance with nasal mupirocin was 98.2% (standard deviation ±5.2). There was no statistically significant recolonisation effect between completion of eradication therapy and the day of surgery (P>0.05) at a median time of 9.5 days (Interquartile range 6–13 days) at all sites. Discussion and Conclusion Current MRSA decolonisation regimens are well-tolerated and effective for S. aureus decolonisation for the anterior nares and groin. The decolonisation effect is preserved for up to 10 days following completion.