A Report on the Secular Trends and Descriptive Epidemiology of Methicillin-Resistant Staphylococcus aureus (MRSA) from an Outpatient Clinic Population in Appalachian Ohio and West Virginia

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a common antibiotic resistant pathogen and a significant public health problem worldwide. Infections due to MRSA have historically involved nosocomial transmission, but over the past decade, reports of community transmission of MRSA have increased considerably. Despite this fact, reports describing the extent of MRSA in rural communities are limited.

Methods: Secular trends were analyzed for all methicillin-sensitive S. aureus (MSSA) and MRSA-positive cultures analyzed at a large outpatient clinic laboratory with clinic branches throughout Southeastern Ohio and Western West Virginia from January 1, 2000 to December 31, 2005. In addition, the descriptive epidemiology for all MRSA-positive specimens collected during the study period was summarized.

Results: Of 1,368 outpatient cultures with S. aureus identified from 2000 – 2005, 525 (38.4%) were determined to be MRSA. Overall, the proportion of all S. aureus cultures identified as MRSA increased significantly from 20.0% in 2000 to 64.0% in 2005 (p<0.01). Furthermore, the proportion of positive MRSA cultures in persons <20 years old (p<0.01) and from wound specimens (p<0.01) also increased significantly during the study period. Concurrent secular decreases were noted among the proportion of positive MRSA cultures in persons older than 60 years and from urine cultures.

Conclusion: This study identified dramatic increases in the proportion of MRSA-positive wound cultures in young persons seeking care at large outpatient clinics in rural Appalachian Ohio and West Virginia. The findings are consistent with recent studies conducted in other geographic regions that indicate large increases in community-associated MRSA infections.