Expanding the Universe of Methicillin-Resistant Staphylococcus aureus Prevention

Staphylococcus aureus is one of the most common causes of infection in both the community and the health care setting. First described in 1961 (1), methicillin-resistant S. aureus (MRSA) has increased dramatically and now constitutes more than 50% of S. aureus isolates that cause infections in the hospital setting (2–4). Furthermore, MRSA infections are associated with poor clinical and economic outcomes (5).

Asymptomatic colonization with MRSA often precedes clinical MRSA infection (6). Patients with MRSA colonization are typically identified only as a result of a positive clinical culture (that is, a culture obtained because of a suspected infection). However, the number of hospital patients asymptomatically colonized with MRSA far exceeds the number of patients identified through clinical cultures (7). Patients asymptomatically colonized with MRSA are a substantial reservoir for person-to-person spread in the hospital.

Due in large part to a lack of rigorous scientific evidence, there remains no consensus on how best to limit transmission of this organism. Use of active surveillance cultures to identify and isolate patients asymptomatically colonized with MRSA has been recommended as one strategy (8, 9). However, exactly when and how these interventions should be implemented remains controversial (10). Past studies that evaluated the impact of active surveillance strategies were small, focused on only select hospital units or specific patient populations, or were limited to outbreaks.

In light of the importance of MRSA and despite the uncertainty about how to contain it, external pressure for action increases. Legislation in several states mandates uniform surveillance for MRSA in health care settings. This one-size-fits-all legislative approach ignores the inherent differences in MRSA epidemiology among hospitals. These perhaps-precipitate actions seem to reflect the public's impatience with the health care professions' failure to act.

The article by Robicsek and colleagues (11) in …