Protracted Outbreak of Multidrug-ResistantAcinetobacter baumanniiafter Intercontinental Transfer of Colonized Patients

Abstract

To describe the course and management of a protracted outbreak after intercontinental transfer of 2 patients colonized with multidrug-resistant Acinetobacter baumannii (MDRAB). An 18-month outbreak investigation. An 860-bed university hospital in France. Case patients (ie, carriers) were those colonized or infected with an MDRAB isolate. During the epidemic period, all intensive care unit (ICU) patients and contacts of carriers who were transferred to wards were screened for MDRAB carriage. Contact precautions, environmental screening, and auditing of healthcare worker (HCW) practices were implemented; rooms were cleaned with hydrogen peroxide mist disinfection. One ICU, in which most of the cases occurred, was closed on 4 occasions for thorough cleaning and disinfection. The 2 index case patients were identified as 2 patients who carried the same MDRAB strain and who were admitted to the hospital after repatriation from Tahiti 5 months apart. During an 18-month period, a total of 84 secondary cases occurred. Reintroduction of MDRAB into the ICUs occurred from patients previously colonized or from healthcare personnel. Termination of the outbreak was only achieved when all carriers from wards or the ICU were cohorted to an isolation unit with dedicated healthcare personnel. Intercontinental transfer of carriers of MDRAB can result in extensive outbreaks and serious disruption of the hospital's organization. Transmission from carriers most likely occurred via the hands of HCWs, poor cleaning protocols, airborne spread, and contaminated water from sink traps. This protracted outbreak was controlled only after implementation of an extensive control program and eventual cohorting of all carriers in an isolation unit with dedicated healthcare personnel.