title: Risk factors for the development of active methicillin-resistant Staphylococcus aureus (MRSA) infection in patients colonized with MRSA at hospital admission.
abstract: Patients who present to Veterans Affairs hospitals are screened for methicillin-resistant Staphylococcus aureus (MRSA) colonization. Those who test positive are isolated during their hospital stay. However, it is unknown which of these patients are most likely to subsequently develop active MRSA infections.
  
  
  
  This retrospective case-control study characterized risk factors for active MRSA infection among patients colonized with MRSA at hospital admission. Potential demographic and clinical risk factors were identified using electronic queries and manual chart abstraction; data were compared by standard statistical tests, and variables with P ≤ .05 in bivariable analysis were entered into a multivariable logistic regression model.
  
  
  
  There were 71 cases and 213 controls. Risk factors associated with MRSA infection included diabetes mellitus with or without end organ damage (26% vs 14%, P = .02), hemiplegia (9% vs 2%, P = .01), chronic kidney disease (33% vs 20%, P = .03), postcolonization inpatient admission within 90 days (44% vs 29%, P = .03), surgery (41% vs 9%, P < .01), and dialysis (10% vs 3%, P = .02). On multivariable analysis, surgery during follow-up, dialysis during follow-up, and hemiplegia remained significant.
  
  
  
  Among patients with MRSA colonization, surgery or dialysis during follow-up and history of hemiplegia were associated with subsequent MRSA infection. Knowledge of these risk factors may allow for future targeted interventions to prevent MRSA infections among colonized patients.
authors.affiliation: The South Texas Veterans Healthcare System, San Antonio, TX; University of Texas Health Science Center at San Antonio, San Antonio, TX.
authors.forename: Jose
authors.initials: J
authors.lastname: Cadena
authors.affiliation: University of Texas Health Science Center at San Antonio, San Antonio, TX.
authors.forename: Josephine
authors.initials: J
authors.lastname: Thinwa
authors.affiliation: The South Texas Veterans Healthcare System, San Antonio, TX; University of Texas Health Science Center at San Antonio, San Antonio, TX. Electronic address: waltere@uthscsa.edu.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Walter
authors.affiliation: The South Texas Veterans Healthcare System, San Antonio, TX; University of Texas Health Science Center at San Antonio, San Antonio, TX; The University of Texas at Austin, Austin, TX.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Frei
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002353:Carrier State / Q000453:epidemiology* / Q000382:microbiology; D016022:Case-Control Studies; D003956:Dialysis / Q000009:adverse effects; D005260:Female; D006429:Hemiplegia / Q000150:complications; D006761:Hospitals; D006801:Humans; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000302:isolation & purification*; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D013514:Surgical Procedures, Operative / Q000009:adverse effects
keywords: Active surveillance; MRSA; dialysis; hemiplegia