title: Colonization pressure as a risk factor for colonization by multiresistant Acinetobacter spp and carbapenem-resistant Pseudomonas aeruginosa in an intensive care unit.
abstract: OBJECTIVE
  To determine factors associated with colonization by carbapenem-resistant Pseudomonas aeruginosa and multiresistant Acinetobacter spp.
  
  
  METHODS
  Surveillance cultures were collected from patients admitted to the intensive care unit at admission, on the third day after admission and weekly until discharge. The outcome was colonization by these pathogens. Two interventions were implemented: education and the introduction of alcohol rubs. Compliance with hand hygiene, colonization pressure, colonization at admission and risk factors for colonization were evaluated.
  
  
  RESULTS
  The probability of becoming colonized increased during the study. The incidence density of colonization by carbapenem-resistant P. aeruginosa and multiresistant Acinetobacter spp. and colonization pressure were different between periods, increasing gradually throughout the study. The increase in colonization pressure was due to patients already colonized at admission. The APACHE II score, colonization pressure in the week before the outcome and male gender were independent risk factors for colonization. Every 1% increase in colonization pressure led to a 2% increase in the risk of being colonized.
  
  
  CONCLUSIONS
  Colonization pressure is a risk factor for carbapenem-resistant P. aeruginosa and multiresistant Acinetobacter spp. colonization. When this pressure reaches critical levels, efforts primarily aimed at hand hygiene may not be sufficient to prevent transmission.
authors.affiliation: Faculdade de Medicina da Universidade de São Paulo, Department of Infectious Diseases and LIM 54, São Paulo/SPSP, Brazil.
authors.forename: Mirian Freitas
authors.initials: MF
authors.lastname: DalBen
authors.forename: Mariusa
authors.initials: M
authors.lastname: Basso
authors.forename: Cilmara Polido
authors.initials: CP
authors.lastname: Garcia
authors.forename: Silvia Figueiredo
authors.initials: SF
authors.lastname: Costa
authors.forename: Cristiana Maria
authors.initials: CM
authors.lastname: Toscano
authors.forename: William Robert
authors.initials: WR
authors.lastname: Jarvis
authors.forename: Renata Desordi
authors.initials: RD
authors.lastname: Lobo
authors.forename: Maura Salaroli
authors.initials: MS
authors.lastname: Oliveira
authors.forename: Anna Sara
authors.initials: AS
authors.lastname: Levin
mesh_terms: D018806:APACHE; D000150:Acinetobacter / Q000187:drug effects; D000151:Acinetobacter Infections / Q000453:epidemiology* / Q000382:microbiology / Q000517:prevention & control; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D058491:Bacterial Load; D001938:Brazil / Q000453:epidemiology; D015780:Carbapenems; D002648:Child; D002675:Child, Preschool; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology / Q000517:prevention & control; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D006760:Hospitalization; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D011552:Pseudomonas Infections / Q000453:epidemiology* / Q000382:microbiology / Q000517:prevention & control; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D012307:Risk Factors; D013997:Time Factors; D055815:Young Adult; D018440:beta-Lactam Resistance
chemical_list: D015780:Carbapenems
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