Prevalence and risk factors for methicillin-resistant Staphylococcus aureus colonization in a diabetic outpatient population: A prospective cohort study

Abstract

Background: Diabetes mellitus is a risk factor for methicillin-resistant Staphylococcus aureus (MRSA) colonization and infection. We attempted to determine the prevalence and risk factors for MRSA colonization in a population of outpatients with diabetes. Methods: This prospective cohort study enrolled patients with diabetes. Anterior nares cultures were obtained from patients with diabetes admitted to outpatient endocrinology and metabolism clinics, and risk factors for MRSA colonization were analyzed. Results: Out of the 304 patients evaluated, 127 (41.9%) were colonized with S aureus and 30 (9.9%) were colonized with MRSA. Overall, 23.6% of all S aureus isolates were MRSA. In multivariate analysis, factors independently associated with an increased risk of MRSA colonization included the presence of connective tissue disease (odds ratio, 7.075; 95% confidence interval, 2.157-23.209; P =.001) and insulin therapy (odds ratio, 3.910; 95% confidence interval, 1.652-9.251; P =.002). Conclusions: The prevalence of MRSA colonization in our sample of diabetic outpatients was 9.9%. Independent risk factors for MRSA colonization were the presence of connective tissue disease and insulin use. A better understanding of the epidemiology and risk factors for nasal MRSA colonization in the persons with diabetes may have significant implications for the treatment and prevention of MRSA infections. © 2012 by the Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.