Lessons Learned in Controlling an Acinetobacter Outbreak

BACKGROUND/OBJECTIVES: Acinetobacter baumannii has been associated with many outbreaks in hospitals. Lessons learned by a community teaching hospital that experienced two outbreaks of A. baumannii are presented. METHODS: Advocate Illinois Masonic Medical Center is a 551 bed trauma center in Chicago. An outbreak of multidrug-resistant (MDR) A. baumannii was first identified in August 2004 in the adult surgical intensive care unit (SICU), primarily among trauma patients on ventilators. Infection Control (IC) immediately stressed strict Contact Precautions for patients with MDR strains, increased handwashing awareness, and emphasized oral care every 2 hours, discarding Yankauers at the end of every nursing shift, and proper handling of ventilator circuits. When new cases continued to develop and were transferred to other units, all patients with Acinetobacter, regardless of the antibiotic susceptibility profile and location, were placed on Contact Precautions. Surveillance cultures (patients, environment, equipment, especially previously reported reservoirs) were taken in the SICU. Supplies stocked in patient rooms were minimized. IC reviewed routine procedures (housekeeping, handling of blood gases, cleaning of rented specialty beds, etc.) to identify breaks in infection control techniques. Since the Trauma residents rotated throughout the city and other regional trauma centers were experiencing similar outbreaks, the investigation widened to the Emergency Department and Wound Care Center. IC presented education programs, wrote guidelines, and monitored personnel practices. RESULTS: Surveillance cultures did not identify a reservoir. Positive environmental cultures taken from supposedly cleaned surfaces revealed inadequate housekeeping. Pulse field gel electrophoresis performed at another trauma center found the isolates to be unrelated. After these measures were taken, only sporadic unrelated cases of A. baumannii developed in the SICU. No outbreaks in other areas of the hospital. About a year later, a new outbreak of antibiotic susceptible Acinetobacter occurred. Rapid implementation of aggressive infection control techniques used during the previous outbreak helped to quickly suppress this one. Since September 2005, only two unrelated cases have occurred. CONCLUSIONS: The key to controlling the organism is strict adherence to isolation procedures (gowning and gloving before entering the room, removing the gown and gloves before exiting), careful handwashing, and thorough cleaning and disinfection of environmental surfaces and equipment. With increasing MDR Acinetobacter cases, vigilant surveillance for cases, monitoring of personnel practices, and meticulous adherence to basic infection control techniques is critical.