846. MRSA Carriage is Highly Persistent in an Inner-City Community-based Population
Session: Oral Abstract Session: MRSA - Epidemiological Trends
Saturday, October 22, 2011: 9:15 AM
Room: 157ABC
Background: In North America, methicillin-resistant Staphylococcus aureus (MRSA) carriage is prevalent in high-risk community settings. Little is known about the persistence of MRSA carriage in these communities.

Methods: We estimated the prevalence of MRSA carriage from nares and wounds among 4 high-risk single-room occupancy (SRO) hotel settings at 2 time periods: January 2006 – November 2006 and June 2007 – February 2008. We examined bivariate associations between demographic and socio-economic variables among those who were persistently positive or negative for MRSA.

Results: A total of 145 individuals were captured during both periods.  The median age was 46 years, 70% were male, and 83% had a history of injection drug use.  Among these, 30 (21%) and 44 (30%) individuals were positive for MSSA and MRSA respectively at baseline. Among those with MRSA carriage, 34 (77%) remained persistently positive, while only 10 (23%) lost MRSA carriage.  An additional 31 (21%) individuals gained S. aureus carriage during the study period, of which 23 (74%) was MRSA. Overall, 40 (28%) were persistently negative at both time periods. Those who were persistently positive for MRSA were significantly more likely to be female (41% vs. 20%, p=0.047), HIV positive (56% vs. 25%, p=0.001), had injected drugs in the past 6 months (79% vs. 48%, p=0.001), and had a skin infection in the last 6 months (62% vs. 23%, p=0.001) compared to those who were persistently negative. Those who had persistent MRSA carriage reported significantly greater emergency room visits (71% vs. 45%, p=0.027) in the preceding 12 months than those who were persistently negative.

Conclusion: Persistent MRSA carriage among an inner-city community-based population was extensive, with 77% of those initially found to carry MRSA remaining positive over a study period of 18 months. Persistent MRSA carriage is associated with a history of injection drug use, prior skin infections and HIV infection. Those with persistent MRSA carriage were also more likely to report emergency room use within the preceding 12 months. These findings have implications for healthcare utilization and infection control practice and policy for those requiring admission to acute care facilities. 

Subject Category: C. Clinical studies of bacterial infections and antibacterials including sexually transmitted diseases and mycobacterial infections (surveys, epidemiology, and clinical trials)

Mark Hull, MD1,2, Elisa Lloyd-Smith3, Hong Wang2, Daniel Hawkins3, Sylvie Champagne, MD1,4 and Marc G. Romney, MD1,4, (1)University of British Columbia, Vancouver, BC, Canada, (2)BC Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada, (3)Providence Health Care, Vancouver, BC, Canada, (4)Pathology and Laboratory Medicine, Providence Health Care, Vancouver, BC, Canada


M. Hull, Merck-Frosst: Scientific Advisor and Speaker's Bureau, Consulting fee and Speaker honorarium
Gilead: Speaker's Bureau, Speaker honorarium
Ortho-Janssen: Scientific Advisor, Consulting fee

E. Lloyd-Smith, None

H. Wang, None

D. Hawkins, None

S. Champagne, None

M. G. Romney, Wyeth Pharmaceuticals: Grant Investigator, Research grant
Pfizer: Grant Investigator, Research grant

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.