Screening of MRSA colonization in patients undergoing total joint arthroplasty

Background: Periprosthetic infection is commonly caused by Staphylococcus aureus and, if resistant to methicillin (MRSA), is associated with increase in severity and costs to patient and healthcare systems. MRSA colonizes 1–5% of the population, therefore using a screening and decolonisation protocol the risk of periprosthetic infection could be reduced. The objective of our study is to report the results of a preoperative MRSA screening and management protocol utilised at our hospital. Methods: All patients undergoing a total joint arthroplasty at our hospital were preoperatively screened for MRSA colonization with swab samples of five different locations. Exposure to risk factors were investigated in colonised patients and they were treated for 5 days prior surgery with nasal mupirocin, chlorhexidine sponges and oral tablets. Results: During the 48 months of the study, MRSA colonisation was identified in 22 (1.01%) of 2188 patients operated. The culture was positive only in the nasal swab in 55 patients. In five patients the nasal culture was negative, but they had another positive swab culture (three in the groin and two perianal). None of the patients reported a history of recent antibiotic treatment or hospitalization. Conclusion: At our institution, the prevalence of MRSA colonisation is 1.01% in patients undergoing hip and knee arthroplasty. Interestingly, our screening protocol included samples from five different anatomic locations, and it is important to highlight that we found patients with negative nares culture and positive cultures in other locations. Therefore, the number of carriers may be underdiagnosed if only nasal samples are obtained. Level of evidence: IV