title: Risk factors for the acquisition of imipenem-resistant Acinetobacter baumannii in a burn unit: An appraisal of the effect of colonization pressure.
abstract: Imipenem-resistant Acinetobacter baumannii (IRAB) is a major threat for critically ill patients, including those admitted to burn units. Recent studies have suggested that colonization pressure (the proportion of patients or patient-days harbouring the pathogen of interest) is an important driver of the risk for acquisition of multidrug-resistant organisms. With that in mind, we conducted a cohort study, enrolling 208 patients admitted to a burn unit from November 2008 through December 2009. The outcome of interest was the acquisition of IRAB. In addition to the usual risk factors, we assessed the impact of colonization pressure. The number of wound excisions (odds ratio (OR) 12.06, 95% confidence interval (CI) 2.82-51.64) and the number of antimicrobials used (OR 22.82, 95% CI 5.15-101.19) were significant risk factors for the outcome of interest. On the other hand, colonization pressure (measured for whole time of exposure or up to the last 14, 7, or 3 days) was not associated with the risk for IRAB acquisition.
authors.affiliation: From the Departamento de Doenças Tropicais, Faculdade de Medicina de Botucatu, UNESP - Universidade Estadual Paulista , Botucatu, São Paulo State , Brazil.
authors.forename: Ricardo de Souza
authors.initials: Rde S
authors.lastname: Cavalcante
authors.forename: Priscila
authors.initials: P
authors.lastname: Canet
authors.forename: Carlos Magno Castelo Branco
authors.initials: CM
authors.lastname: Fortaleza
mesh_terms: D000151:Acinetobacter Infections / Q000453:epidemiology* / Q000382:microbiology; D040981:Acinetobacter baumannii / Q000187:drug effects / Q000302:isolation & purification*; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002053:Burn Units; D015331:Cohort Studies; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D005260:Female; D006801:Humans; D015378:Imipenem / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D018440:beta-Lactam Resistance
chemical_list: D000900:Anti-Bacterial Agents; D015378:Imipenem
keywords: Acinetobacter baumannii; burn unit; colonization pressure; resistance to imipenem