Prevalence, risk factors, and molecular epidemiology of methicillin-resistant Staphylococcus aureus among newly arrested men in Baltimore, Maryland.
BACKGROUND
Outbreaks of methicillin-resistant Staphylococcus aureus (MRSA) within prison populations seemingly attest to its spread within the corrections industry; however, the extent of MRSA colonization on arrest is unknown.


METHODS
This study determined the prevalence and risk factors of S aureus on arrest. Nasal swabs from 602 newly arrested men were evaluated. Risk factors were assessed through self-report. Molecular characterization of each isolate was completed.


RESULTS
The prevalence of S aureus nasal colonization was 40.4% (243/602). MRSA colonization was found in 15.8% (95/602) of the total population and in 39.1% (95/243) of the total S aureus isolates. Twenty-three skin infections were identified; of these, 11 (47.8%) were S aureus infections, with methicillin-susceptible S aureus (MSSA) in accounting for 3 cases (13.1%) and MRSA accounting for 8 cases (34.8%). In 2 cases (25%) of MRSA wound infection, the nasal colonizing strain was MSSA. By pulsed-field gel electrophoresis, 76 of 95 (80%) nasal isolates were found to be USA300 or related subtypes, with the other 19 (20%) being non-USA300 strains. The Panton-Valentine leukocidin gene was identified in 38 (97.4%) USA300 isolates and in 6 (31.6%) non-USA 300 isolates.


CONCLUSIONS
MRSA colonization is far greater in this sample than in the general public. USA300 subtypes are highly prevalent. History of previous arrest was not associated with increased MRSA prevalence. MRSA risk factors differed significantly between those with and without a history of previous arrest.
School of Nursing, Johns Hopkins University, Baltimore, MD, USA. jfarley@son.jhmi.edu.
Jason E
JE
Farley
Tracy
T
Ross
Paul
P
Stamper
Sharon
S
Baucom
Elaine
E
Larson
Karen C
KC
Carroll
D000328:Adult; D001426:Bacterial Proteins / Q000235:genetics; D001427:Bacterial Toxins / Q000235:genetics; D015373:Bacterial Typing Techniques; D015142:Baltimore / Q000453:epidemiology; D002353:Carrier State / Q000382:microbiology; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D005098:Exotoxins / Q000235:genetics; D005838:Genotype; D006801:Humans; D007956:Leukocidins / Q000235:genetics; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification* / Q000302:isolation & purification*; D008875:Middle Aged; D017720:Molecular Epidemiology; D009297:Nasal Mucosa / Q000382:microbiology; D015995:Prevalence; D011329:Prisoners; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology*; D013207:Staphylococcal Skin Infections / Q000453:epidemiology / Q000382:microbiology
D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004269:DNA, Bacterial; D005098:Exotoxins; D007956:Leukocidins; C078284:Panton-Valentine leukocidin