Community-associated methicillin-resistant Staphylococcus aureus: review of an emerging public health concern.

Methicillin-resistant Staphylococcus aureus (MRSA) traditionally has been recognized as a virulent pathogen affiliated with health care institutions. However, community-associated strains of MRSA (CA-MRSA) have emerged over the past several years in young, healthy patients without significant health care contact. These isolates carry a distinct molecular makeup and lack the multidrug resistance pattern harbored by health care strains. CA-MRSA predominantly induces skin and soft tissue infections, though the presence of unique virulence factors may cause potentially lethal necrotizing pneumonia and other invasive infections. In response to this growing public health concern, clinicians must learn to identify risk factors for CA-MRSA, treat infections with judicious use of antimicrobial agents, and facilitate prevention strategies to limit transmission.