299. Risk Factors for Recurrent Methicillin-Resistant Staphylococcus aureus (MRSA) Infection
Session: Poster Abstract Session: HAI: MSSA, MRSA, and other Gram-Positives
Thursday, October 27, 2016
Room: Poster Hall
Background: MRSA commonly causes invasive and noninvasive infections and recurrences are frequent. Risk factors (RFs) for recurrences have not been well studied.

Methods: In February 2012-August 2013, 111 people with a first known MRSA infection were enrolled at University of Chicago and followed for 2 years to determine RFs for recurrence. Participants were surveyed and screened for S. aureus colonization of the nose, throat and peri-rectum at enrollment. Genotyping of all S. aureus isolates was performed. Enrollees were called every 3 months to assess recurrent MRSA infection. Medical record reviews were performed for demographics, comorbidities, and characteristics and management of index and culture-proven recurrences; and to distinguish recurrent from ongoing infections.

Results: Among 111 subjects, there were 45 recurrent infections in 2 years of follow up, 20 culture-proven and 25 self-reported recurrences. 21 (46.7%) of the recurrences occurred within the first 90 days after index infection. Subjects with a recurrence, compared with those with no recurrence, did not differ in univariate analysis by race, age, gender, work in healthcare, number of people in the household or number sharing a bedroom, a child in daycare, pets, drug use, contact with someone with a skin infection, or using a gym or spa. Diabetes mellitus; immunosuppressed state; lung, heart, peripheral vascular or skin disease; having an artificial device; antibiotic use in the year prior to index infection; and colonization with S. aureus at baseline were not significant RFs. Participation in contact sports (p = 0.052), community-associated MRSA infection (p = 0.08) and public insurance (p = 0.1) trended toward significance. BMI in adults (p = 0.04), skin and soft tissue as the site of index infection (p = 0.045) and having a USA300 index infection isolate (p = 0.008) were significant RFs for recurrence. In multivariate regression analysis, only a USA300 index infection isolate was a significant predictor of recurrence (OR = 3.1, 95% CI [1.26,7.51], p = 0.01).

Conclusion: Among 111 subjects followed for 2 years after an index MRSA infection, a USA300 index infection isolate was predictive of recurrent infection.

Moira C. Mcnulty, MD, Section of Infectious Diseases and Global Health, University of Chicago Medicine, Chicago, IL, Zachary Yin, BA, Pediatrics, University of Chicago Medicine, Chicago, IL and Michael Z David, MD PhD, Section of Infectious Diseases and Global Health, Dept of Medicine, University of Chicago Medicine, Chicago, IL


M. C. Mcnulty, None

Z. Yin, None

M. Z. David, None

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