Endemic occurrence of Acinetobacter calcoaceticus biovar anitratus in an intensive care unit

One strain of Acinetobacter calcoaceticus biovar anitratus caused colonization of 111 patients admitted to an intensive care unit (ICU) during a 2-year period. All patients were intubated and had received antibiotic therapy prior to colonization. Morbidity due to the organism was about 1%. The colonization rate showed a decreasing trend during the study period, but no seasonal variation. The strain was found in the air in a low concentration and on the hands of 8-13% of the members of the staff. No chronic carriers were found.