Selective use of intranasal mupirocin and chlorhexidine bathing and the incidence of methicillin-resistant Staphylococcus aureus colonization and infection among intensive care unit patients

OBJECTIVE. To determine whether the use of chlorhexidine bathing and intranasal mupirocin therapy among patients colonized with methicillin-resistant Staphylococcus aureus ( MRSA) would decrease the incidence of MRSA colonization and infection among intensive care unit ( ICU) patients. METHODS. After a 9-month baseline period ( January 13, 2003, through October 12, 2003) during which all incident cases of MRSA colonization or infection were identified through the use of active-surveillance cultures in a combined medical-coronary ICU, all patients colonized with MRSA were treated with intranasal mupirocin and underwent daily chlorhexidine bathing. RESULTS. After the intervention, incident cases of MRSA colonization or infection decreased 52% ( incidence density, 8.45 vs 4.05 cases per 1,000 patient-days; P = .048). All MRSA isolates remained susceptible to chlorhexidine; the overall rate of mupirocin resistance was low ( 4.4%) among isolates identified by surveillance cultures and did not increase during the intervention period. CONCLUSIONS. We conclude that the selective use of intranasal mupirocin and daily chlorhexidine bathing for patients colonized with MRSA reduced the incidence of MRSA colonization and infection and contributed to reductions identified by active-surveillance cultures. This finding suggests that additional strategies to reduce the incidence of MRSA infection and colonization-beyond expanded surveillance may be needed.