1813. Residential Proximity to Large Swine CAFOs is Associated with Increased Risk of Methicillin-Resistant Staphylococcus aureus Colonization at Time of Hospital Admission in Rural Iowa Veterans
Session: Oral Abstract Session: Addressing Healthcare-Associated MRSA Outside of the Inpatient Setting
Saturday, October 5, 2013: 2:00 PM
Room: The Moscone Center: 200-212
Background: Methicillin-resistant S. aureus (MRSA) colonization has been documented in livestock, livestock workers and individuals living in areas of high livestock density in the US and Europe. Recently, the US Veterans Administration (VA) implemented procedures that screened all patients at time of admission for MRSA colonization via nasal swabs.  We aimed to determine whether residential proximity to swine Confined Animal Feeding Operations (CAFOs) was associated with increased MRSA colonization in patients admitted to the Iowa City VA Medical Center (IC-VAMC).

Methods: Nasal swabs were taken from 2996 patients on admission to the IC-VAMC from 12/1/2009 -12/31/2011 and MRSA status was assessed.  Patient addresses were geocoded and assigned to rural or urban residential status based on Census designations.  The number of swine within 1 mile of the patient household was calculated using data provided by the Iowa Department of Natural Resources.  Relative risk was estimated for rural residents based upon residential proximity to any swine or to large numbers of swine.  Generalized estimating equations were used to determine the impact of residential proximity to any or large numbers of swine, controlling for age and number of prior admissions to the IC-VAMC.

Results: Overall MRSA colonization among rural IC-VAMC patients was 7%.  Residential proximity within 1 mile of large swine populations was independently associated with double the risk of MRSA colonization at time of admission (relative risk= 2.1, 95% CI=1.296, 3.434).  After adjusting for number of prior hospital admissions, age was positively associated with MRSA colonization (p=0.0021), while residential proximity to smaller numbers of swine was significantly protective against MRSA colonization (p=0.0013).  The relationship between MRSA and no residential proximity to swine was not significant (p=0.0866).

Conclusion: Residential proximity to large swine CAFO populations in rural Iowans was associated with increased risk of MRSA colonization at time of hospital admission, while proximity to smaller swine populations was not associated with MRSA colonization.  Healthcare facilities serving rural populations need to respond to increased risk MRSA introduction into healthcare settings.

Margaret Carrel, Ph.D., Geography, University of Iowa, Iowa City, IA, Marin Schweizer, PhD, Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, Tara Smith, PhD, College of Public Health, University of Iowa, Iowa City, IA and Eli Perencevich, MD, MS, FIDSA, FSHEA, Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA


M. Carrel, None

M. Schweizer, None

T. Smith, None

E. Perencevich, None

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