Outbreak of Acinetobacter baumannii in an intensive care unit associated with tracheostomy

A case-control study was conducted to determine risk factors for acquisitio n of an epidemic strain of Acinetobacter baumannii in an intensive care uni t. The epidemic strain was identified by pulsed-field gel electrophoresis a nd was isolated from tracheal secretions in 13 (87%) of 15 patients. In a l ogistic regression analysis, presence of a tracheostomy was, an independent risk for Acinetobacter sp acquisition (odds ratio, 421; 95% confidence int end, 13.9-12925; P = .001) and the strength of the association was inversel y related to the duration of mechanical ventilation. The outbreak coincided with the introduction of a policy of early percutaneous tracheostomy in th e intensive care unit and probably resulted from inadequate infection contr ol practices during respiratory care. No environmental reservoir was found. Institution of contact precautions, enhanced handwashing and staff educati on was associated with resolution of the outbreak.