Reduction of periprosthetic Staphylococcus aureus infection by preoperative screening and decolonization of nasal carriers undergoing total knee arthroplasty

Objective The aim of this study was to evaluate whether the establishment of a preoperative screening and decolonization protocol for Staphylococcus aureus carriers undergoing total knee arthroplasty (TKA) could decrease the incidence of periprosthetic joint infection (PJI) caused by this microorganism. Methods We conducted a retrospective study comparing a control group comprising 400 patients (134 men, and 266 women; mean age: 72.2 ± 6.8 years) who went through surgery between January 2009 and December 2013, with a second intervention group of 403 patients (125 men, and 278 women; mean age: 72.4 ± 6.9 years) in which the protocol of screening and decolonization of S. aureus nasal carriers was applied between January 2014 and December 2016. During this latter period patients were preoperatively screened and, if positive, treated with mupirocin nasal ointment and chlorhexidine soap, for 5 days prior to surgery. Results In the control group, 17 of 400 patients (4.2%) had a SSI, 8 (2%) of them caused by S. aureus and 9 (2.2%) by other microorganisms. In the intervention group 20.6% of patients had a positive S. aureus nasal swab and were treated according to the protocol. 5 of 403 patients (1.2%) in this group had a SSI, 1 (0.2%) due to S. aureus and 4 (1%) to other microorganisms. When comparing surgical-site infection (SSI) rates between the two groups, we found a statistically significant reduction in both global SSI (p = 0.009) and specifically S. aureus SSI (p = 0.02), in the intervention group. No decolonized S. aureus nasal carrier presented a SSI. Discussion In patients undergoing TKA a preoperative screening and decolonization protocol for S. aureus nasal carriers, using mupirocin nasal ointment and chlorhexidine soap, is an effective measure to reduce the rate of SSI caused by this microorganism. Level of Evidence Level III; Therapeutic Study.