In Reply: Dr David and colleagues highlight the difficulty in classifying persons with invasive infections with MRSA in terms of their exposures to established risk factors. We previously reported the frequency of strains of community origin among persons with health care risk factors, and of strains of health care origin among persons without health care risk factors,1 indicating that microbiologic characteristics are no longer accurate in classifying the source of acquisition of MRSA.
Klevens RM, Morrison MA, Fridkin SK. Determining Whether Methicillin-Resistant Staphylococcus aureus Is Associated With Health Care—Reply. JAMA. 2008;299(5):519-520. doi:10.1001/jama.299.5.519-b