title: Prevalence and acquisition of MRSA amongst patients admitted to a tertiary-care hospital in Brazil.
abstract: BACKGROUND
  There are few studies in Brazil that address baseline prevalence of MRSA colonization and associated risk factors at hospital admission, or the incidence of nosocomial colonization. We report a prospective study in a tertiary-care, university-affiliated hospital to implement a new MRSA control policy at the institution.
  
  
  METHODS
  A cohort of randomly selected patients admitted to emergency and clinical wards at our hospital was followed until discharge. Nasal swabs were taken for identification of MRSA-colonized patients and detection of SCCmecA in positive cultures, at admission and weekly thereafter. Multivariate analysis using a log-binomial analysis was used to identify risk factors for colonization.
  
  
  RESULTS
  After screening 297 adult patients and 176 pediatric patients, the prevalence of MRSA at admission was 6.1% (95%CI, 3.6% to 9.4%), in the adult population and 2.3% (95%CI, 0.6% to 5.7%), for children. From multivariate analysis, the risk factors associated with colonization in adults were: age above 60 years (P = 0.019) and hospitalization in the previous year (P = 0.022). Incidence analysis was performed in 276 MRSA-negative patients (175 adults and 101 children). Acquisition rate was 5.5/1,000 patient-days for adults (95%CI, 3.4 to 8.5/1,000 patients-days), and 1.1/1,000 patient-days for children (95%CI, 0.1 to 4.0/1,000 patients-days).
  
  
  CONCLUSIONS
  The identification of MRSA carriers is a step towards establishing a control policy for MRSA, and helps to identify measures needed to reduce colonization pressure and to decrease the high acquisition rate in hospitalized patients.
authors.affiliation: Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil. hbsantos@hcpa.ufrgs.br
authors.forename: Helena B
authors.initials: HB
authors.lastname: Santos
authors.forename: Denise P
authors.initials: DP
authors.lastname: Machado
authors.forename: Suzi A
authors.initials: SA
authors.lastname: Camey
authors.forename: Ricardo S
authors.initials: RS
authors.lastname: Kuchenbecker
authors.forename: Afonso L
authors.initials: AL
authors.lastname: Barth
authors.forename: Mário B
authors.initials: MB
authors.lastname: Wagner
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001938:Brazil / Q000453:epidemiology; D002353:Carrier State / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D003428:Cross Infection / Q000453:epidemiology*; D005260:Female; D006785:Hospitals, University / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000302:isolation & purification*; D008875:Middle Aged; D015999:Multivariate Analysis; D015995:Prevalence; D011446:Prospective Studies; D012044:Regression Analysis; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000453:epidemiology*