Randomized, Placebo-Controlled, Double-Blind Trial To Evaluate the Efficacy of Mupirocin for Eradicating Carriage of Methicillin-Resistant Staphylococcus aureus

Abstract

Mupirocin has been widely used for the clearance of nasal methicillin-resistant Staphylococcus aureus (MRSA) carriage during outbreaks, but no placebo-controlled trial has evaluated its value for eradicating MRSA carriage at multiple body sites in settings where MRSA is not epidemic. In a 1,500-bed teaching hospital with endemic MRSA, 102 patients colonized with MRSA were randomized into a double-blind, placebo-controlled trial and treated with either mupirocin (group M) or placebo (group P) applied to the anterior nares for 5 days; both groups used chlorhexidine soap for body washing. Follow-up screening, susceptibility testing, and genotyping were performed to evaluate treatment success, mupirocin or chlorhexidine resistance, and exogenous recolonization. At baseline, MRSA carriage was 60% in the nares, 38% in the groin, and 62% in other sites (skin lesions, urine). The MRSA eradication rate (all body sites) was 25% in group M (12 of 48 patients), compared to 18% in group P (9 of 50 patients; relative risk [RR], 0.72; 95% confidence interval [CI95], 0.33 to 1.55). At the end of follow-up, 44% of patients (19 of 43) were free of nasal MRSA in group M, compared to 23% (11 of 44) in group P (RR, 0.57; CI95, 0.31 to 1.04). Ten patients developed MRSA infections (three in group M and seven in group P). One mupirocin treatment failure was due to exogenous MRSA recolonization. No MRSA isolate showed chlorhexidine resistance or high-level mupirocin resistance; however, we observed an association (P = 0.003) between low-level mupirocin resistance at study entry (prevalence, 23%) and subsequent treatment failure in both study arms. These results suggest that nasal mupirocin is only marginally effective in the eradication of multisite MRSA carriage in a setting where MRSA is endemic.

Success of MRSA Eradication in Hospital Routine: Depends on Compliance

“…Our results are in contrast to the prospective studies of Sloot et al [7] and Rohr et al [8], who achieved eradication in 75% (28 patients, washing once daily for 5 days) and 64%, respectively (32 patients, washing once daily for 5 days), of patients with whole body washing with octenidine and mupirocin nasal ointment. In an earlier study [6], 14 persons (100%) were cleared of MRSA by washing with triclosan three times a day with eradication after an average of 22 days. Wenisch et al [11] demonstrated MRSA eradication in 100% of evaluable patients with pneumonia caused by MRSA by a holistic approach comprising of intravenous linezolid and rifampicin plus intratracheal vancomycin plus intranasal mupirocin plus skin and oropharyngeal washings with chlorhexidine plus wound treatment with polyvidone-iodide.…”

“…Harbarth et al [6] found that mupirocin was only marginally effective in the eradication of multisite MRSA carriage in a setting where MRSA was not epidemic. In their study MRSA was eradicated by antiseptic washings with chlorhexidine and mupirocin nasal ointment in 25% of patients only.…”

“…Thus different antiseptic preparations (for example triclosan or octenidine) are used for whole body washings of MRSA patients by different hospitals. Activity of antiseptic preparations as Triclosan, Chlorhexidine and Octenidine is proved, partly in combination with mupirocin nasal ointment, only in a limited number of studies on a small number of patients [4][5][6][7][8]. There are few studies reporting success of eradication under clinical routine conditions and their results are inconsistent [6,[8][9][10].…”

Community-associated methicillin-resistant Staphylococcus aureus: Incidence, clinical presentation, and treatment decisions

“…Mupirocin 2% nasal ointment administered for 5 days has been shown to be an effective agent for the elimination of S. aureus carriage [50]. In a randomized controlled trial, treatment with topical mupirocin, chlorhexidine gluconate washes, oral rifampin, and doxycycline for 7 days was safe and effective in eradicating MRSA colonization in hospitalized patients for at least 3 months [51].…”

Treatment of community-associated methicillin-resistant Staphylococcus aureus

“…MRSA colonization at two or more body sites has been associated with persistent colonization [9]. A study examining the efficacy of mupirocin for eliminating MRSA colonization among hospitalized patients in Switzerland found that at study enrollment, 58% of participants had nasal colonization, 46% had skin colonization (pressure sores or skin lacerations), 38% had groin colonization, 20% had urine colonization, and 70% of patients were colonized at more than one body site [10]. In another study, when stool specimens submitted for Clostridium difficile toxin analysis were examined, 9.8% of hospitalized patients were found to have MRSA in their stool [11].…”