Investigation of an outbreak of multi-drug resistant Acinetobacter baumannii in an intensive care burns unit

Over a three month period there was an outbreak of infection, due to a multi-drug resistant Acinetobacter baumannii in the intensive care burns unit with spread of infection to other patients, both within the unit and elsewhere in the hospital. Microbiological sampling of the environment and of the healthcare workers' (HCWs) hands were carried out. Strain relatedness of the isolates was confirmed by pulsed field gel electrophoresis. Fifteen patients were involved in the outbreak, whose infections were all hospital-acquired. The burns room environment was contaminated with the A. baumannii, as was the door handle of the door leading from the ante-chamber between both rooms. This allowed the hands of HCWs to be contaminated by A. baumannii despite appropriate handwashing procedures prior to leaving the rooms. Two staff members were colonized with A. baumannii. One HCW who was directly involved in patient care was found to be 'heavily' colonized, the other, with less patient contact, was only 'lightly' colonized. Review of handwashing practices revealed that chlorhexidine/alcohol hand wash solution was not used by the HCW whose hands were heavily colonized. A combination of a review of handwashing practice, education about the spread of bacteria via hands and contaminated environment, and the revision of infection control procedures in the unit contributed to a prompt termination of the outbreak. (C) 2001 The Hospital Infection Society.