INVESTIGATION OF A MULTIYEAR MULTIPLE CRITICAL CARE UNIT OUTBREAK DUETO RELATIVELY DRUG-SENSITIVE ACINETOBACTER-BAUMANNII - RISK-FACTORS AND ATTRIBUTABLE MORTALITY

From 1990 to 1993, an outbreak of respiratory Acinetobacter baumannii infection occurred in five intensive care units (ICUs) of a tertiary c are center. A. baumannii was subsequently isolated from disinfected te mperature probes and ventilator circuits, Pulsed-field gel electrophor esis suggested that a single strain accounted for 93% of patient isola tes and 88% of environmental isolates, Univariate risk factors for A. baumannii acquisition were tracheostomy (P < .01), ventilation >3 days (P < .01), dialysis (P = .03), Stenotrophomonas maltophilia respirato ry colonization (P = .02), parenteral nutrition (P = .05), and enteric feeding (P < .01). Logistic regression analysis showed duration of ve ntilation and enteric feeding to be independent risk factors, The outb reak strain was relatively antibiotic-susceptible, but the mortality a ttributable to respiratory A, baumannii acquisition was 23%, Only the APACHE II score was independently associated with increased mortality, Multifaceted control measures, including gas sterilization of tempera ture probes, terminated the outbreak.