Sustained Reduction in Methicillin-Resistant Staphylococcus aureus Wound Infections After Cardiothoracic Surgery

Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) wound infections after cardiac surgery have increased in recent years and carry significant morbidity and mortality. In our hospital, MRSA accounted for 56% of postoperative infections. Postoperative wound infection rates were compared for the 3 years before (baseline period) and after (intervention period) introduction of a comprehensive MRSA intervention program. The intervention included preoperative screening for MRSA colonization, administration of intravenous vancomycin prophylaxis for identified carriers, administration of intranasal mupirocin calcium ointment to all patients regardless of colonization status for 5 days beginning the day before surgery, and application of mupirocin to chest tube sites at the time of removal. Postoperative MRSA wound infections decreased by 93% (32 infections per 2767 cases in the baseline period vs 2 infections per 2496 cases in the intervention period; relative risk, 0.069; P < .001). Overall wound infection rates decreased from 2.1% to 0.8% (59 infections per 2769 cases vs 20 infections per 2496 cases; P < .001). During the intervention period, there was no change in the number of MRSA infections after noncardiac surgery. This MRSA intervention program, in which all patients receive intranasal mupirocin and patients colonized with MRSA receive vancomycin prophylaxis, has resulted in a near-complete and sustained elimination of MRSA wound infections after cardiac surgery.