Extranasal methicillin-resistant Staphylococcus aureus colonization at admission to an acute care Veterans Affairs hospital.
OBJECTIVE
To evaluate the prevalence of and risk factors for extranasal methicillin-resistant Staphylococcus aureus (MRSA) colonization and its relationship to nasal colonization among veterans hospitalized for acute care.


METHODS
Prospective observational study.


METHODS
Veterans Affairs (VA) acute care hospital in Boston, Massachusetts.


METHODS
Convenience sample of 150 patients hospitalized within the previous 36 hours and screened for nasal MRSA who were not known to have an active MRSA infection or MRSA isolates recovered from a wound during the past 12 months.


METHODS
Potential risk factors for MRSA colonization were assessed, and oropharynx, axilla, hand, perirectal, wound, and catheter insertion site samples were obtained for culture. MRSA was identified in chromogenic agar and confirmed by use of routine culture techniques. Nasal MRSA colonization was detected by means of polymerase chain reaction (PCR).


RESULTS
Nasal swab samples analyzed by use of PCR yielded results positive for MRSA in 16 (11%) of 150 patients. Extranasal cultures yielded positive results for 3 (2%) of 134 patients who tested negative for nasal MRSA colonization and for 9 (56%) of 16 patients who tested positive for nasal MRSA colonization (odds ratio [OR], 56.1 [95% confidence interval {CI}, 12.4-254.6]; p < .001). The oropharynx was the most commonly colonized extranasal site (10 patients [7%]). Independent risk factors for extranasal MRSA colonization included nasal MRSA colonization (OR, 66.9 [95% CI, 11.8-379.7]; P < .001) and end-stage hepatic disease (OR, 98.5 [95% CI, 3.1-3,112.4]; P = .01).


CONCLUSIONS
Extranasal MRSA colonization is infrequent among veterans admitted for acute care to VA Boston Healthcare System. Extranasal MRSA colonization was strongly associated with nasal MRSA colonization, which suggests that the VA MRSA Prevention Initiative is not missing a large number of MRSA-colonized patients by focusing on nasal-only screening.
Baker
Stacey E
SE
Veterans Affairs Boston Health Care System, Boston, Massachusetts 02130, USA.
Brecher
Stephen M
SM
Robillard
Ernest
E
Strymish
Judith
J
Lawler
Elizabeth
E
Gupta
Kalpana
K
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001900:Boston / Q000453:epidemiology; D002353:Carrier State / Q000453:epidemiology / Q000382:microbiology; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology; D005260:Female; D006225:Hand / Q000382:microbiology; D006787:Hospitals, Veterans / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D008875:Middle Aged; D009666:Nose / Q000382:microbiology; D009960:Oropharynx / Q000382:microbiology; D010343:Patient Admission / Q000706:statistics & numerical data; D016133:Polymerase Chain Reaction / Q000379:methods; D015995:Prevalence; D012007:Rectum / Q000382:microbiology; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology; D014947:Wounds and Injuries / Q000382:microbiology; D055815:Young Adult