Eradication of Methicillin-Resistant Staphylococcus aureus Carriage: A Systematic Review

A systematic review was performed to determine the effectiveness of different approaches for eradicating methicillin-resistant Staphylococcus aureus carriage. Twenty-three clinical trials were selected that evaluated oral antibiotics (7 trials), topically applied antibiotics (12 trials), or both (4 trials). Because of clinical heterogeneity, quantitative analysis of all studies was deemed to be inappropriate, and exploratory subgroup analyses were performed for studies with similar study populations, methods, and targeted bacteria. The estimated pooled relative risk of treatment failure 1 week after short-term nasal mupirocin treatment, compared with placebo, was 0.10 (range, 0.07–0.14). There was low heterogeneity between study outcomes, and effects were similar for patients and healthy subjects, as well as in studies that included only methicillin-susceptible S. aureus carriers or both methicillin-susceptible S. aureus and methicillin-resistant S. aureus carriers. The development of drug resistance during treatment was reported in 1% and 9% of patients receiving mupirocin and oral antibiotics, respectively. Short-term nasal application of mupirocin is the most effective treatment for eradicating methicillin-resistant S. aureus carriage, with an estimated success of rate of 90% 1 week after treatment and ∼60% after a longer follow-up period. Colonization is an important step in the pathogenesis of Staphylococcus aureus infection and is instrumental in the nosocomial epidemiology of these bacteria. Approximately 20% of the general population is persistently colonized with S. aureus, most frequently in the anterior nares, although other body sites, such as the perineum and throat, may also be colonized. Another 30% of the general population is intermittently colonized, and the remaining 50% appear not to be susceptible, for unknown reasons, to S. aureus carriage [1]. Methicillin-resistant S. aureus (MRSA) has become endemic in health care institutions worldwide, with up to 70% of invasive S. aureus infections having resistance [2–5], and most patients who develop drug-resistant S. aureus infection will have been colonized prior to infection. The half-life of MRSA carriage has been reported to be as long as 40 months in individuals who do not receive treatment [6].