SECONDARY CARRIAGE WITH MULTIRESISTANT ACINETOBACTER-BAUMANNII AND KLEBSIELLA-PNEUMONIAE IN AN ADULT ICU POPULATION - RELATIONSHIP WITH NOSOCOMIAL INFECTIONS AND MORTALITY

A one year prospective, observational survey was performed to evaluate the abnormal carriage of multi-resistant Klebsiella pneumoniae and/or Acinetobacter baumannii, to determine associated risk factors for car riage, and to correlate the abnormal carriage with infectious morbidit y and mortality in the intensive care unit (ICU) of a University Hospi tal. Two hundred and ninety-eight patients who stayed in the ICU >48h, and were not neutropenic, were studied. Salivary and rectal samples w ere obtained on admission and weekly until discharge. Out of 265 evalu able patients, 88 (33%) developed oropharyngeal and/or rectal carriage within a median of nine days. Three factors were significantly associ ated with abnormal carriage: higher 'severity of illness score on admi ssion, a threefold increase in ICU stay, and the need for mechanical v entilation. K. pneumoniae or A. baumannii accounted for 57/158 (36%) o f all ICU-acquired infections (in 46 patients). They were considered a s secondary endogenous infections (SEI) in 42 patients who were previo usly colonized with the same strains, and developed infection within a median of three days (range 0-68 days). Prolonged stay in ICU was the only factor associated with SEI in the carrier population. Mortality was significantly greater in the carrier group (43 vs 25%, P=0.0006). Post hoc stratification suggested that abnormal carriage only influenc ed mortality in patients showing a low severity of illness score on ad mission to ICU. Abnormal carriage was found in the most severely ill p atients, predisposed to secondary nosocomial infections, and co influe nce mortality in the less severely ill.