Screening, Isolation, and Decolonization Strategies for Vancomycin-Resistant Enterococci or Extended Spectrum Beta-Lactamase Producing Organisms: A Systematic Review of the Clinical Evidence and Health Services Impact [Internet]

Excerpt

Bacterial resistance to antibiotics is an increasing problem in Canada and worldwide. Vancomycin-resistant enterococci (VRE) are strains of Enterococcus faecium or Enterococcus faecalis that contain genes conferring resistance to vancomycin. Escherichia coli (E. coli), Klebsiella pneumonia (K. pneumonia), and other gram-negative bacteria may produce the enzymes known as extended spectrum beta-lactamases (ESBL). These have the ability to inactivate beta lactam antibiotics such as penicillin, ampicillin, and the cephalosporins.

The presence and growth (colonization) of VRE and ESBL-producing micro-organisms in the gastrointestinal tract is usually of no consequence for the host, but under certain circumstances, such as immunosuppression, gastrointestinal surgery, or physical debilitation, they may serve as a source of infection for the carrier. These hosts may also serve as a reservoir for the transmission of VRE and ESBL-producing organisms to other persons. Results from the Canadian Nosocomial Infection Surveillance Program showed that from 1999 to 2005, the rate of VRE colonization and VRE infection increased from 0.37 to 1.32 cases, and from 0.02 to 0.05 cases respectively per 1,000 patients admitted to hospital. The laboratory-based Canadian Ward Surveillance Study in 2008 found that ESBL-producing E. coli were identified in all Canadian geographic regions, and that 4.9% of E. coli isolates were ESBL producers.

Specific prevention and control measures for antibiotic-resistant organisms (AROs) include screening (a process to identify persons colonized with AROs) and isolation of the carriers. Hospital infection prevention and control strategies have been developed in some Canadian jurisdictions, and these are compatible with other national and international documents. Non-specific strategies for controlling ARO transmission and infection include hand hygiene; environmental cleaning; antimicrobial stewardship; and bundled practices, such as those to prevent central line-associated blood stream infections.

Antibiotic-resistant organisms, such as VRE and ESBL-producers, lead to the increased use of hospital resources due to extended hospital stays, laboratory tests, physician consultations, costly medications if therapy for a VRE or ESBL-related infection were to arise, and the need to adhere to infection prevention and control measures to prevent the further spread of these pathogens. Some of the increased resource usage results from the morbidity caused by VRE or ESBL-producing organism infections, while some is a consequence of control strategies. For example, it may be harder to transfer a patient to a rehabilitation facility if they are currently in isolation, which will in and of itself, prolong the length of stay.

The objective of this systematic review is to evaluate the clinical evidence for the effectiveness of screening, isolation, and decolonization strategies for persons colonized or infected with VRE and ESBL-producing organisms in acute and long-term care facilities. The health services impact of these strategies will be discussed.