Discontinuation of reflex testing of stool samples for vancomycin-resistant enterococci resulted in increased prevalence

Vancomycin-resistant enterococci (VRE) screening and isolation in the general medicine ward: a cost-effectiveness analysis

Background

Vancomycin-resistant enterococci (VRE) are a serious antimicrobial resistant threat in the healthcare setting. We assessed the cost-effectiveness of VRE screening and isolation for patients at high-risk for colonisation on a general medicine ward compared to no VRE screening and isolation from the healthcare payer perspective.

Methods

We developed a microsimulation model using local data and VRE literature, to simulate a 20-bed general medicine ward at a tertiary-care hospital with up to 1000 admissions, approximating 1 year. Primary outcomes were accrued over the patient's lifetime, discounted at 1.5%, and included expected health outcomes (VRE colonisations, VRE infections, VRE-related bacteremia, and deaths subsequent to VRE infection), quality-adjusted life years (QALYs), healthcare costs, and incremental cost-effectiveness ratio (ICER). Probabilistic sensitivity analysis (PSA) and scenario analyses were conducted to assess parameter uncertainty.

Results

In our base-case analysis, VRE screening and isolation prevented six healthcare-associated VRE colonisations per 1000 admissions (6/1000), 0.6/1000 VRE-related infections, 0.2/1000 VRE-related bacteremia, and 0.1/1000 deaths subsequent to VRE infection. VRE screening and isolation accrued 0.0142 incremental QALYs at an incremental cost of $112, affording an ICER of $7850 per QALY. VRE screening and isolation practice was more likely to be cost-effective (> 50%) at a cost-effectiveness threshold of $50,000/QALY. Stochasticity (randomness) had a significant impact on the cost-effectiveness.

Conclusion

VRE screening and isolation can be cost-effective in majority of model simulations at commonly used cost-effectiveness thresholds, and is likely economically attractive in general medicine settings. Our findings strengthen the understanding of VRE prevention strategies and are of importance to hospital program planners and infection prevention and control.

Defining the Role of the Environment in the Emergence and Persistence of vanA Vancomycin-Resistant Enterococcus (VRE) in an Intensive Care Unit: A Molecular Epidemiological Study

OBJECTIVETo describe the transmission dynamics of the emergence and persistence of vanA vancomycin-resistant enterococcus (VRE) in an intensive care unit (ICU) using whole-genome sequencing of patient and environmental isolates.DESIGNRetrospective cohort study.SETTINGICU in a tertiary referral center.PARTICIPANTSPatients admitted to the ICU over an 11-month period.METHODS VanA VRE isolated from patients (n=31) were sequenced using the Illumina MiSeq platform. Environmental samples from bed spaces, equipment, and waste rooms were collected. All vanA VRE-positive environmental samples (n=14) were also sequenced. Data were collected regarding patient ward and bed movements.RESULTSThe 31 patient vanA VRE isolates were from screening (n=19), urine (n=4), bloodstream (n=3), skin/wound (n=3), and intra-abdominal (n=2) sources. The phylogeny from sequencing data confirmed several VRE clusters, with 1 group accounting for 38 of 45 isolates (84%). Within this cluster, cross-transmission was extensive and complex across the ICU. Directionality indicated that colonized patients contaminated environmental sites. Similarly, environmental sources not only led to patient colonization but also to infection. Notably, shared equipment acted as a conduit for transmission between different ICU areas. Infected patients, however, were not linked to further VRE transmission.CONCLUSIONSGenomic sequencing confirmed a predominantly clonal outbreak of VRE with complex transmission dynamics. The environmental reservoir, particularly from shared equipment, played a key role in ongoing VRE spread. This study provides evidence to support the use of multifaceted strategies, with an emphasis on measures to reduce bacterial burden in the environment, for successful VRE control.Infect Control Hosp Epidemiol 2018;39:668-675.

Reinstatement of Reflex Testing of Stool Samples for Vancomycin-Resistant Enterococci (VRE) Resulted in Decreased Incidence of Hospital-Associated VRE

Re-institution of reflex testing of stool submitted for Clostridium difficile testing for vancomycin-resistant enterococci (VRE) reduced the incidence of healthcare-associated VRE bacteremia and bacteriuria compared to when testing was not in place (1.9 versus 3.3 cases per 10,000 patient days when testing was not in use).

Resistance Mechanisms, Epidemiology, and Approaches to Screening for Vancomycin-Resistant Enterococcus in the Health Care Setting

Infections attributable to vancomycin-resistant Enterococcus (VRE) strains have become increasingly prevalent over the past decade. Prompt identification of colonized patients combined with effective multifaceted infection control practices can reduce the transmission of VRE and aid in the prevention of hospital-acquired infections (HAIs). Increasingly, the clinical microbiology laboratory is being asked to support infection control efforts through the early identification of potential patient or environmental reservoirs. This review discusses the factors that contribute to the rise of VRE as an important health care-associated pathogen, the utility of laboratory screening and various infection control strategies, and the available laboratory methods to identify VRE in clinical specimens.