Mupirocin-based decolonization of Staphylococcus aureus carriers in residents of 2 long-term care facilities: a randomized, double-blind, placebo-controlled trial

Abstract

Mupirocin has been used in nursing homes to prevent the spread of methicillin-resistant Staphylococcus aureus (MRSA), despite the lack of controlled trials. In this double-blind, randomized study, the efficacy of intranasal mupirocin ointment versus that of placebo in reducing colonization and preventing infection was assessed among persistent carriers of S. aureus. Twice-daily treatment was given for 2 weeks, with a follow-up period of 6 months. Staphylococcal colonization rates were similar between residents at the Ann Arbor Veterans Affairs (VA) Extended Care Center, Michigan (33%), and residents at a community-based long-term care facility in Ann Arbor (36%), although those at the VA Center carried MRSA more often (58% vs. 35%; P=.017). After treatment, mupirocin had eradicated colonization in 93% of residents, whereas 85% of residents who received placebo remained colonized (P<.001). At day 90 after study entry, 61% of the residents in the mupirocin group remained decolonized. Four patients did not respond to mupirocin therapy; 3 of the 4 had mupirocin-resistant S. aureus strains. Thirteen (86%) of 14 residents who became recolonized had the same pretherapy strain; no strain recovered during relapse was resistant to mupirocin. A trend toward reduction in infections was seen with mupirocin treatment.

Figures

Figure 1

Number of study participants evaluated for Staphylococcus aureus decolonization, by time point.

Figure 2

Proportion of long-term care residents free of colonization with Staphylococcus aureus after receiving mupirocin therapy (unshaded regions) or placebo (shaded regions) for 14 days. The number of patients remaining in the study at each time point is indicated above each bar.

Figure 3

Study participants (n = 14) who were recolonized with Staphylococcus aureus at various time points after initial decolonization. Patients either relapsed with the same pretherapy strain (shaded regions) or acquired a new strain (unshaded regions), as defined by PFGE.