Geographic information system localization of community-acquired MRSA soft tissue abscesses

Soft tissue infections with methicillin-resistant Staphylococcus aureus (MRSA) pose an ever-increasing risk to children in the community. Although historically these infections were limited to children with prolonged hospitalization, the authors have seen an increase in community-acquired infections in children without identifiable risk factors. The goal of this study is to determine the incidence of truly community-acquired MRSA soft tissue infections in our community and geographically map regions of increased risk. After obtaining the institutional review board's approval, a retrospective chart review was conducted on 195 patients records who underwent an incision and drainage of soft tissue infections from January 1, 2000, to December 31, 2003. Thirteen patients were excluded from the study because no cultures were taken at the time of incision and drainage. The most common organism isolated from wound culture was S aureus, 40% (73/182), of which 45% (33/73) were MRSA. Eighty-one percent (27/33) of MRSA infections were in Springfield, 1 of 18 towns represented in the patient population. Geographic information system analysis identified a significant MRSA cluster 1.96 km in diameter within the city of Springfield. Geography proved to be a significant risk factor for presenting with MRSA infection. Geographic maps of antibiotic resistance can be used to guide physician antibiotic selection before culture results are available. This has significant implications for the health care provider in proper antibiotic selection within the community.