Pseudo-Outbreak of Ventriculitis in a Neurosurgical ICU

BACKGROUND: Infection is a potentially life-threatening complication of ventriculostomy placement. Placement of ventricular catheters frequently occurs outside the setting of the operating room. We typically detect <10 nosocomial central nervous system infections per year in our neurosurgical ICU. Over a 4–month period (May–August 2003), 19 positive cerebrospinal (CSF) cultures were noted in 10 patients. Organisms included coagulase-negative staphylococci (CNS, 16 cultures in 7 patients), Pseudomonas aeruginosa (4 cultures in 2 patients), and Acinetobacter lwoffi (1 culture in 1 patient). METHODS: An outbreak investigation was performed, including review of the patientsʹ clinical course, laboratory data, ventriculostomy catheter insertion, site care, CSF specimen collection practices, and interviews with all involved staff. RESULTS: Investigation revealed ventriculostomy CSF specimens were collected by a single neurosurgical resident each month. Five (50%) of the patients were determined to have infection. CNS was found in all (10) contaminated cultures. Of 66 cultures obtained in August, 17 (26%) were culture positive, and 9 (14%) of these were contaminated. One resident obtained all cultures in August. Meetings were held between epidemiology department, neurosurgery faculty, and nursing staff. Practice changes were implemented to emphasize hand hygiene, aseptic collection techniques, and exit site care. Inservices were held for nursing staff and neurosurgery residents. Subsequent review of CSF cultures has revealed no further contamination. CONCLUSIONS: Continuing education of medical and nursing staff is required to prevent poor collection technique to prevent contamination of CSF obtained from ventriculostomy catheters. When investigating a potential outbreak, it is important to review all laboratory and clinical data to ensure that positive culture results represent true infection.