LB 13 Terminating Two Clonal Outbreaks of Panresistant Acinetobacter baumanii in a Tertiary Intensive Care Unit

Sunday, March 21, 2010
Grand Hall (Hyatt Regency Atlanta)
Angela V. Michelin , National Institutes of Health, Bethesda, MD
Tara Palmore, MD , National Institute of Health Clinical Center, Bethesda, MD
Sarah E. Turkel , National Institutes of Health, Bethesda, MD
MaryAnn Bordner , National Institutes of Health, Bethesda, MD
Frida Stock , National Institutes of Health, Bethesda, MD
David K Henderson , National Institutes of Health, Bethesda, MD
Background:  The NIH Clinical Center (CC), a research hospital with a largely immunosuppressed patient population, experienced an ICU-based outbreak of multidrug-resistant Acinetobacter baumanii (MDRAB) in 2007. The outbreak persisted despite escalating infection control interventions; termination was associated with posting of monitors outside MDRAB patient rooms. After 9 months of inactivity, MDRAB activity recurred. Two historical strains reemerged in sporadic cases; in 8/09, a new, imported strain led to a second outbreak. We describe successful termination of 2 MDRAB outbreaks 2 years apart; in both instances outbreak termination was temporally associated with the use of dedicated adherence monitors.

Objective:  To describe the use of monitors in terminating MDRAB outbreaks.

Methods:  Measures implemented early in the outbreak included: 1) placing all ICU patients on strict contact isolation; 2) geographic and 3) nurse cohorting of MDRAB-infected and colonized patients; 4) active surveillance; 5) culturing and enhanced cleaning of the environment; and 6) daily chlorhexidine baths for all ICU patients. Because of continued transmission, in 11/09, contract nurses were hired as 24/7 infection control adherence monitors. Candidates were screened for interest in infection control and for assertiveness. Monitors were trained to observe and intervene to assure adherence to hand hygiene (HH), use of personal protective equipment (PPE), disinfection of equipment, and other precautions. Monitors were stationed at MDRAB cohorted areas and recorded details of each observation and intervention. Names of scofflaws were reported to supervisors.

Results:  During the 2009 outbreak, 34 patients (25 infected, 9 colonized) acquired a single strain of MDRAB. Among 11 who died, MDRAB contributed to at least 4 deaths. Monitors were employed for 10 weeks and recorded nearly 5000 observations. Analysis of the first 2382 observations shows that most staff (96%) independently complied with precautions. Few (1%) required reminders for adherence. Physicians were responsible for the majority of violations. Among 22 staff who failed to use HH, 12 were physicians, 5 were visitors, and 3 were housekeepers. Among 28 staff who failed to don proper PPE, 22 were physicians. Situations involving large groups (e.g., interdisciplinary rounds) resulted in low adherence to HH and PPE.

Conclusions:  Our experiences in two large clonal outbreaks suggest that use of short-term infection control adherence monitors was particularly effective in eradicating MDRAB. Data collected by monitors identified a small number of staff (primarily physicians) who were non-compliant; such noncompliance could permit continued spread of MDRAB. Eradicating MDRAB is laborious and expensive; however, the expense is justified in preventing the striking morbidity and mortality associated with this resistant and tenacious organism.