Community-acquired methicillin-resistant Staphylococcus aureus in a rural American Indian community.
BACKGROUND
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.


OBJECTIVE
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.


METHODS
Retrospective cohort study with medical record review.


METHODS
Indian Health Service facility in a rural midwestern American Indian community.


METHODS
Patients whose medical records indicated laboratory-confirmed S aureus infection diagnosed during 1997.


METHODS
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.
Groom
A V
AV
Indian Health Service National Epidemiology Program, 5300 Homestead Rd NE, Albuquerque, NM 87110, USA.
Wolsey
D H
DH
Naimi
T S
TS
Smith
K
K
Johnson
S
S
Boxrud
D
D
Moore
K A
KA
Cheek
J E
JE
D017714:Community-Acquired Infections / Q000453:epidemiology; D016521:Electrophoresis, Gel, Pulsed-Field; D006801:Humans; D007198:Indians, North American; D016106:Methicillin Resistance; D015146:Midwestern United States / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D012424:Rural Population; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000235:genetics