776. Methicillin-Resistant Staphylococcus aureus screening and isolation: is this an effective infection control strategy?
Session: Oral Abstract Session: Staph aureus: Screening and Prevention
Friday, October 21, 2011: 4:00 PM
Room: 157ABC

Methicillin resistant Staphylococcus aureus (MRSA) hospital acquired infections (HAIs) are responsible for escalating healthcare costs. “MRSA bundle” introduced across the Veterans Healthcare Administration in 2007 has shown reduction in MRSA HAI’s. To eliminate the remaining MRSA HAIs, other strategies may need to be implemented to include decolonization, but evidence has been lacking. To further investigate the source of the MRSA HAIs, the genotypes of nasal and clinical MRSA isolates were analyzed to see if these HAI are secondary to exogenous MRSA acquisition or endogenous MRSA with which the patients are colonized.


Retrospective analysis of all MRSA HAIs during June 2008 - January 2011 at Central Texas Veterans Health Care System at Temple, TX was conducted. Patients with MRSA nasal screen within 24 hours of admission were included in the analysis. Repeat HAIs and patients with incomplete data were excluded. The genotypes were analyzed using the Diversilab® system (BioMérieux, Hazelwood, MO). Patients with different genotypes or negative nares screen were classified as having acquired MRSA HAI secondary to exogenous flora and patients with similar genotypes were classified as having infections secondary to endogenous flora.


Total of 57 HAIs were identified by infection control department. Thirty-four were included in the final analysis. Seven patients had pneumonia, 4 patients had lower respiratory tract infection, other than pneumonia, 3 had blood stream infections, 12 had skin and soft tissue infections, 1 had urinary tract infection, 5 had surgical site infections, and 2 had systemic infections when National Health and Safety Network criteria were applied. MRSA nares screen was positive in 6/34 (18%) patients. HAIs due to exogenous MRSA were found in 28/34 (82%) patients and 6/34 (18%) patients had infections due to endogenous MRSA.


Significant numbers of HAIs are caused by endogenous MRSA which are not going to be effectively prevented by isolation alone. Decolonization with pre-operative Vancomycin or other innovative approaches may have a significant role in further reducing MRSA HAIs in patients with positive MRSA nares. Prospective studies are being planned to investigate this issue further.

Subject Category: N. Hospital-acquired and surgical infections, infection control, and health outcomes including general public health and health services research

Sarla Patil, MD, Infectious diseases Division, Scott and White and Central Texas Veterans Health Care System, Temple , TX, Thomas Huber, Ph.D, Microbiology, Central Texas Veterans Health Care System, Temple, TX, Zehra Hussain, B.S., Epidemiology, University of Texas School of Public Health, Houston, TX, Laurel Copeland, PhD, Center for Applied Health Research, Central Texas Veterans Health Care System / Scott & White, Temple, TX and Chetan Jinadatha, MD, MPH, Infectious Disease Division, Central Texas Veterans Health Care System, Temple, TX; Infectious Diseases, Texas A&M Health Science Center College of Medicine/Scott & White Infectious Disease Fellowship Program , Temple, TX


S. Patil, None

T. Huber, None

Z. Hussain, None

L. Copeland, None

C. Jinadatha, None

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