Decreasing Cross-Transmission of Carbapenemase-Producing Enterobacteriaceae

By Elaine Chen, MD

Assistant Professor, Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, Section of Palliative Medicine, Rush University Medical Center, Chicago, IL

Dr. Chen reports no financial relationships relevant to this field of study.

SYNOPSIS: A bundled infection control intervention was shown to decrease cross-colonization, prevalence, and bloodstream infection of Klebsiella pneumonia carbapenemase-producing enterobacteriaceae in long-term acute care hospitals, which may have far-reaching effects into the ICU.

SOURCE: Hayden MK, et al. Prevention of colonization and infection by Klebsiella pneumonia carbapenemase-producing enterobacteriaceae in long term acute care hospitals. Clin Infect Dis 2015;60:1153-1161.

Carbapenem-resistant enterobacteriaceae (CRE) are highly resistant to multiple classes of antibiotics and pose a serious threat to our ability to control infections. Klebsiella pneumonia carbapenemase-producing enterobacteriaceae (KPC) are the most common in this group. Colonization usually precedes infection, and colonization is frequently acquired by cross-contamination in healthcare settings, particularly high-prevalence areas. Because prevalence is higher in long-term acute care hospitals (LTACHs) than elsewhere, this study was undertaken to try to decrease incidence of prevalence of KPC in LTACHs.

This quality improvement project was implemented in 4 LTACHs in a single metropolitan area. Baseline prevalence of KPC was measured before the intervention was initiated. The KPC intervention bundle included rectal swabs for KPC for all patients on admission and every 2 weeks thereafter during their hospitalization, contact isolation, geographic separation of KPC-positive patients, chlorhexidine (CHG) baths, and healthcare worker hand hygiene education and monitoring. All healthcare workers underwent a series of mandatory educational sessions. Adherence to all measures but one, including collection of admission and periodic surveillance swabs, geographic isolation of KPC-positive patients, hand hygiene at room exit, and donning gloves and gown before room entry, was greater than 70% during the intervention; adherence to hand hygiene at room entrance was low at 24%.

In the pre-intervention period, average KPC prevalence was 45.8% (95% confidence interval [CI], 42.1-49.5%). In the post-intervention period, following an initial decline, prevalence plateaued at 34.3% (95% CI, 32.4-36.2%; P < 0.001 for exponential decline). Admission prevalence remained stable at 20.6%, but incidence rate of KPC colonization decreased from four to two acquisitions per 100 patient-weeks (P = 0.004 for linear decline). Rates of KPC in any clinical culture, KPC bloodstream infection, bloodstream infection due to any pathogen, and contaminated blood cultures all decreased significantly during the intervention period.

Overall, this study showed that the implementation of a bundled infection control intervention was able to significantly decrease cross-transmission of a multi-drug-resistant pathogen and decrease healthcare-associated infections in an LTACH population.

COMMENTARY

Drug-resistant organisms have been increasing morbidity and mortality in healthcare settings. They are more common in LTACHs than in short-term acute care hospitals, and the chronically critically ill population is particularly at risk due to their high frequency of transfer among healthcare facilities. CRE (including KPC) colonization and infection are an increasing concern in ICUs, and have been associated with significantly longer ICU length of stay and higher mortality.¹ By decreasing KPC cross-transmission and infection in high-prevalence settings, there may be potential to decrease length of stay as well as mortality in both long-term and short-term care units.

This study presents a comprehensive infection control bundle, which was shown to decrease colonization and infection by KPC. Due to the bundled nature of the intervention, individual components of the bundle leading to improvement could not be identified. The authors speculate that the CHG baths were the intervention most responsible for the decrease in bloodstream infection, and that the bundled intervention is necessary to control cross-colonization. This bundle, as applied in LTACHs, has the potential to slow the regional spread of KPC and to decrease morbidity and mortality in both lower-acuity settings (such as skilled nursing) and higher-acuity settings (such as short-term ICUs). Potential drawbacks to the technique include high cost/benefit ratio and selection of further resistance with CHG baths. The authors propose further testing, including simulation modeling and molecular epidemiologic methods, to evaluate long-term and regional effects of the intervention.

REFERENCE

1. Dautzenberg MJD, et al. The association between colonization with carbapenemase-producing enterobacteriaceae and overall ICU mortality: An observational cohort study. Crit Care Med 2015. Apr 16 [Epub ahead of print].