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Updated: May 4, 2026
Subcutaneous Infection of Methicillin Resistant Staphylococcus Aureus MRSA
Published on: February 10, 2011
Community-acquired methicillin-resistant Staphylococcus aureus in a rural American Indian community
A V Groom1, D H Wolsey, T S Naimi
1Indian Health Service National Epidemiology Program, 5300 Homestead Rd NE, Albuquerque, NM 87110, USA.
Context:
Until recently, methicillin-resistant Staphylococcus aureus (MRSA) infections have been acquired primarily in nosocomial settings. Four recent deaths due to MRSA infection in previously healthy children in the Midwest suggest that serious MRSA infections can be acquired in the community in rural as well as urban locations.
Objectives:
To document the occurrence of community-acquired MRSA infections and evaluate risk factors for community-acquired MRSA infection compared with methicillin-susceptible S aureus (MSSA) infection.
Design:
Retrospective cohort study with medical record review.
Setting:
Indian Health Service facility in a rural midwestern American Indian community.
Patients:
Patients whose medical records indicated laboratory-confirmed S aureus infection diagnosed during 1997.
Main Outcome Measures:
Proportion of MRSA infections classified as community acquired based on standardized criteria; risk factors for community-acquired MRSA infection compared with those for community-acquired MSSA infection; and relatedness of MRSA strains, determined by pulsed-field gel electrophoresis (PFGE).
Results:
Of 112 S aureus isolates, 62 (55%) were MRSA and 50 (45%) were MSSA. Forty-six (74%) of the 62 MRSA infections were classified as community acquired. Risk factors for community-acquired MRSA infections were not significantly different from those for community-acquired MSSA. Pulsed-field gel electrophoresis subtyping indicated that 34 (89%) of 38 community-acquired MRSA isolates were clonally related and distinct from nosocomial MRSA isolates found in the region.
Conclusions:
Community-acquired MRSA may have replaced community-acquired MSSA as the dominant strain in this community. Antimicrobial susceptibility patterns and PFGE subtyping support the finding that MRSA is circulating beyond nosocomial settings in this and possibly other rural US communities.
Insights
Community-acquired methicillin-resistant Staphylococcus aureus (MRSA) infections are emerging in rural areas, potentially replacing methicillin-susceptible S aureus (MSSA). This study documents community MRSA occurrence and risk factors in a rural American Indian community.
Area of Science:
- Infectious Diseases
- Epidemiology
- Microbiology
Background:
- Methicillin-resistant Staphylococcus aureus (MRSA) was historically associated with healthcare settings.
- Recent severe MRSA infections in healthy children suggest community acquisition is increasing.
- This study investigates MRSA in a rural community setting.
Purpose of the Study:
- To document the incidence of community-acquired MRSA infections.
- To compare risk factors for community-acquired MRSA versus methicillin-susceptible S aureus (MSSA).
- To analyze the genetic relatedness of MRSA strains.
Main Methods:
- Retrospective cohort study utilizing medical record review.
- Study conducted at an Indian Health Service facility in a rural midwestern American Indian community.
- Analysis included MRSA classification, risk factor comparison, and pulsed-field gel electrophoresis (PFGE) for strain typing.
Main Results:
- Out of 112 Staphylococcus aureus isolates, 62% were MRSA and 45% were MSSA.
- A significant proportion (74%) of MRSA infections were community-acquired.
- No significant difference in risk factors was found between community-acquired MRSA and MSSA.
- PFGE revealed that most community-acquired MRSA strains were clonally related and distinct from nosocomial strains.
Conclusions:
- Community-acquired MRSA appears to be the dominant strain in this rural community, potentially supplanting MSSA.
- Findings suggest MRSA is circulating widely in rural US communities, extending beyond hospitals.
- Antimicrobial susceptibility and strain typing support the widespread presence of MRSA in non-nosocomial settings.
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