The persistence of Staphylococcus aureus decolonization after mupirocin and topical chlorhexidine: implications for patients requiring multiple or delayed procedures.

Preoperative screening and decolonization of methicillin-sensitive and methicillin-resistant Staphylococcus aureus (MSSA and MRSA, respectively) are advocated to reduce surgical site infections. We determined the rate and duration of decolonization in patients undergoing elective orthopedic surgery. Patients undergoing elective orthopedic surgery were seen in our preoperative testing program (PAT) and had their anterior nares cultured for MRSA and MSSA. All patients were treated with intranasal mupirocin and a topical chlorhexidine solution. A cohort of patients returned to PAT before a subsequent elective procedure and were recultured. All culture results and time between PAT visits were recorded, and the rates of successful initial and persistent decolonization were determined. Six hundred ten patients visited PAT 1290 times. Overall, 94 (70.1%) of 134 patients with initially MRSA- or MSSA-positive cultures remained decolonized at a mean time of 156 days (SD=140), whereas 40 patients (29.9%) were not decolonized by the time of repeat testing at a mean time of 213 days (SD=187). At repeat testing, there were 2 newly MRSA-positive and 35 newly MSSA-positive patients. Staphylococcus aureus decolonization with intranasal mupirocin and topical chlorhexidine was effective but not persistent in a significant proportion of patients. A small number of previously uncolonized patients became colonized. Staphylococcus aureus screening and decolonization protocols must be repeated before any readmission, regardless of prior colonization status.