Moran GJ, Krishnadasan A, Gorwitz RJ, Fosheim GE, McDougal LK, et al.
Methicillin-Resistant S. Aureus infections among patients in the emergency department
The New England Journal of Medicine
Methicillin-resistant Staphylococcus aureus (MRSA) emerged in the 1960s as a cause of infection among patients exposed to the bacteria in health care settings.1 More recently, MRSA infections have been reported among persons without such exposure (community-associated MRSA).2,3 Community-associated outbreaks of MRSA infection have occurred among prisoners, intravenous-drug users, athletes, military trainees, and men who have sex with men.4-6 Community-associated MRSA has primarily been described as a cause of skin and soft-tissue infections, but it has also been associated with sepsis and necrotizing pneumonia.7-9 As compared with health care–associated MRSA isolates, community-associated MRSA isolates tend to be resistant to fewer antibiotics, to produce different toxins,10 and to have different types of the gene complex known as staphylococcal cassette chromosome mec (SCCmec); this complex contains the mecA gene that confers methicillin resistance.10 Pulsed-field gel electrophoresis (PFGE) and other methods have identified a small number of molecular types that have accounted for most community-associated MRSA isolates characterized in the United States.11
Some institutions have a high prevalence of MRSA isolated from patients with sporadic skin and soft-tissue infections that are not associated with an outbreak.12,13 However, data are limited regarding the prevalence of MRSA as a cause of skin and soft-tissue infections among patients in several communities throughout the United States and the S. aureus isolates associated with these infections. Therefore, we determined the prevalence of MRSA as a cause of skin infections among adult patients presenting to emergency departments in several geographically diverse, metropolitan areas in the United States. We also determined the bacteriologic characteristics of S. aureus isolated from skin and soft-tissue infections and evaluated factors potentially associated with MRSA infections of skin and soft tissue.