Trends in Community Versus Health Care-Acquired Methicillin-Resistant Staphylococcus aureus Infections.

Since the first clinical isolate of methicillin-resistant Staphylococcus aureus was described in 1961, this pathogen has established itself as a leading cause of health care-associated infections. More recently, MRSA has become a relatively common cause of infection among persons without typical health care-associated risk factors and is now the most common cause of community-onset purulent skin and soft-tissue infections in many regions of the USA. The appearance of "community-associated" MRSA is not due to the expansion of health care-associated MRSA into the community but rather the result of the independent emergence of a novel clone of MRSA. There are some encouraging data to suggest that the incidence of MRSA infection, particularly invasive infections, is decreasing in the USA, but this pathogen remains a common cause of infection associated with substantial morbidity and mortality. Thus, there is ongoing need for effective and safe prevention, diagnosis, and treatment strategies.