Risk Factors for Methicillin-Resistant Staphylococcal aureus Skin and Soft Tissue Infections Presenting in Primary Care: A South Texas Ambulatory Research Network (STARNet) Study

Purpose: To examine skin and soft tissue infections presenting at 4 primary care clinics and assess if historical risk factors and examination findings were associated with a positive methicillin-resistant Staphylococcus aureus (MRSA) culture. Methods: During the 10-month observational study (April 2007 through January 2008), physicians in 5 practices across South Texas collected history, physical examination findings, culture results, and antibiotic( s) prescribed for all patients presenting with a skin or soft tissue infection. Analyses were conducted to determine the relationship between historical indicators, location of lesions, and examination findings with a positive MRSA culture. Results: Across 4 practices, 164 cases of skin and soft tissue infections were collected during 10 months. Of the 94 with a culture, 63 (67%) were MRSA positive. Patients working in or exposed to a health care setting were more likely to have a culture positive for MRSA, as were those presenting with an abscess. MRSA-positive lesions were also significantly smaller in size. Conclusions: Because of the high prevalence of MRSA skin and soft tissue infections among patients presenting to family physicians, presumptive treatment for MRSA may be indicated. However, increasing levels of resistance to current antibiotics is concerning and warrants development of alternative management strategies. (J Am Board Fam Med 2009;22:375-9.)