1817. Rate of Survival of MRSA Cleared Status over a 4 year period
Session: Oral Abstract Session: Addressing Healthcare-Associated MRSA Outside of the Inpatient Setting
Saturday, October 5, 2013: 3:00 PM
Room: The Moscone Center: 200-212
Background: Patients with MRSA colonization can subsequently be cleared of their MRSA  statususing passive or active strategies. The long term success of clearance of MRSA is not well studied. Patients have been screened on admission and discharge at our facility as part of the VA MRSA Program since 2008.  Patients have not been routinely decolonized.  Patients who have negative nasal screening for MRSA after a previous + MRSA culture or nasal swab are eligible to be cleared from precautions. We sought to determine the MRSA free survival time after patients met our clearance criteria.

Methods: We determined the rate of patients remaining free of MRSA after being cleared based on 2 negative nasal PCR screens at least 1 week apart or 1 negative PCR if the last positive was >1 year ago, without concurrent antibiotics. All nasal screening results (PCR and agar) and clinical cultures performed subsequent to the date of clearance were used to determine the time of reversion to MRSA+ or MRSA free survival time. Patients who remained MRSA free were censored at their last negative test date.

Results: Over 400 patients had been cleared of MRSA status. Review of 104 revealed that 80 (76.9%) patients remained MRSA-free and 24 reverted to MRSA positive over a total of 36,182  daysof follow-up. By 7 days from clearance, 4 persons failed and 9 were censored. The failure rate was 8% by day 30, 11% by day 90, 22% at 1 year, 32% at 2 years, and 53% at 4.5 years. The mean age of patients was 65.9 (range 30-100, SD 16), 101 (97%) were male, 84.2% of patients were white. Patients had a mean of 4.43 negative swabs (range 0-24) after clearance if they remained negative and 4.04 (range 0-17) swabs if they reverted to positive (p = NS). Death occurred in 20/80 (19%) of patients remaining MRSA free and 7/24 (29%) of patients reverting to MRSA. 

Conclusion: The survival rate of MRSA clearance was about 50% over 4.5 years among patients who were passively cleared of their MRSA status.  The number of repeat screens was not associated with failure of MRSA free status. Although clearance of MRSA status has potential benefits, re-screening for failure of cleared status on an intermittent basis should be considered.

Judith Strymish, MD1,2, Ernest Robillard, RN3, Martin Evans, MD4,5,6 and Kalpana Gupta, MD, MPH1,7, (1)VA Boston HCS, West Roxbury, MA, (2)Medicine, Harvard Medical School, Boston, MA, (3)Infection Prevention, VA Boston HCS, West Roxbury, MA, (4)Internal Medicine, University of Kentucky, Lexington, KY, (5)National Infectious Diseases Service, Department of Veterans Affairs Central Office, Washington, DC, (6)VHA MRSA/MDRO Program, Lexington, KY, (7)Boston University School of Medicine, Boston, MA


J. Strymish, None

E. Robillard, None

M. Evans, None

K. Gupta, None

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