title: [Risk factors for methicillin-resistant Staphylococcus aureus bacteremia: A multicenter matched case-control study].
abstract: BACKGROUND
  Methicillin-resistant Staphylococcus aureus is a frequent pathogen at critical care services. Its presence leads to increased hospital stays and mortality risk in patients with bacteremia. However, the etiology of this resistance marker has not been fully studied.
  
  
  OBJECTIVE
  To identify risk factors associated with the emergence of methicillin-resistant S. aureus bacteremia in critically ill patients treated at intensive care units in Bogotá, Colombia.
  
  
  METHODS
  We conducted a retrospective paired case-control study, nested in a cohort of patients diagnosed with S. aureus bacteremia and treated at intensive care units between 2006 and 2008 in Bogotá. Cases were patients with positive blood culture to methicillin resistance, matched in a 1:1 ratio with methicillin-sensitive controls isolated from the same institution and hospitalization year. We used conditional logistic regression to analyze the risk factors associated with the presence of resistance, with emphasis on prior antibiotic therapy.
  
  
  RESULTS
  We included 372 patients with S. aureus bacteremia. Factors such as the use of pre-hospital devices: vascular (OR=1.986, 95% CI 1.038 to 3.801) and urinary (OR=2.559, 95% CI: 1.170 to 5.596), along with the number of previously used antibiotics, were associated with the emergence of resistance. The number of antibiotics used previously was determined to have a gradient effect, particularly carbapenems.
  
  
  CONCLUSIONS
  The rational use of antibiotics and surveillance of exposure to surgical procedures or use of invasive devices are interventions that could diminish the emergence of methicillin-resistant S. aureus bacteremia causes.
authors.affiliation: Maestría en Epidemiología, Universidad el Bosque, Bogotá, D.C., Colombia. paomariana.ariaso@gmail.com.
authors.forename: Paola Mariana
authors.initials: PM
authors.lastname: Arias-Ortiz
authors.forename: Libia Del Pilar
authors.initials: LD
authors.lastname: Calderón
authors.forename: Juan Sebastián
authors.initials: JS
authors.lastname: Castillo
authors.forename: José
authors.initials: J
authors.lastname: Moreno
authors.forename: Aura Lucía
authors.initials: AL
authors.lastname: Leal
authors.forename: Jorge Alberto
authors.initials: JA
authors.lastname: Cortés
authors.forename: Carlos Arturo
authors.initials: CA
authors.lastname: Álvarez
authors.forename: Grupo
authors.initials: G
authors.lastname: Grebo
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D016470:Bacteremia / Q000453:epidemiology* / Q000382:microbiology; D016022:Case-Control Studies; D003105:Colombia / Q000453:epidemiology; D015897:Comorbidity; D016638:Critical Illness; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D005260:Female; D006760:Hospitalization; D006779:Hospitals, Public; D006801:Humans; D016867:Immunocompromised Host; D007362:Intensive Care Units; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000302:isolation & purification* / Q000502:physiology; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology / Q000382:microbiology; D012307:Risk Factors; D012737:Sex Factors; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D062606:Tertiary Care Centers
chemical_list: D000900:Anti-Bacterial Agents
keywords: Methicillin-resistant Staphylococcus aureus; case-control studies; drug resistance, microbial; intensive care units; risk factors