Control of Drug-Resistant Pathogens in Endemic Settings: Contact Precautions, Controversies, and a Proposal for a Less Restrictive Alternative

Increasing trend of healthcare-associated infections due to vancomycin-resistant Enterococcus faecium (VRE-fm) paralleling escalating community-acquired VRE-fm infections in a medical center implementing strict contact precautions: An epidemiologic and pathogenic genotype analysis and its implications

OBJECTIVE

To clarify whether there were clandestine intra-hospital spreads of vancomycin-resistant Enterococcus faecium (VRE-fm) isolates that led to specific strain of VRE lingering in the hospital and/or developing outbreaks that rendered a progressively increasing trend of healthcare-associated infections due to VRE-fm (VRE-fm-HAIs).

SETTING

Despite implementing strict contact precautions for hospitalized patients with VRE-fm-infection/colonization, number of VRE-fm-HAIs in a medical centre in southern Taiwan were escalating in 2009-2019, paralleling an increasing trend of community-acquired VRE-fm- infections.

METHODS

We analyzed epidemiologic data and genotypes of non-duplicate VRE-fm isolates each grown from a normally sterile site of 89 patients between December 2016 and October 2018; multilocus sequence typing (MLST) and pulse-field gel electrophoresis (PFGE) typing were performed.

RESULTS

Totally 13 sequence types (STs) were found, and the 3 leading STs were ST17 (44％), ST78 (37％), and ST18 (6％); 66 pulsotypes were generated by PFGE. Four VRE-fm isolates grouped as ST17/pulsotype S, 2 as ST17/pulsotype AS, 2 as ST17/pulsotype AU, and 3 as ST78/pulsotype V grew from clinical specimens sampled less than one week apart from patients staying at different wards/departments and/or on different floors of the hospital.

CONCLUSIONS

Despite possible small transitory clusters of intra-hospital VRE-fm spreads, there was no specific VRE-fm strain lingering in the hospital leading to increasing trend of VRE-fm-HAIs during the study period. Strict contact precautions were able to curb intra-hospital VRE-fm spreads, but unable to curb the increasing trend of VRE-fm-HAIs with the backdrop of progressively increasing VRE-fm-infections/colorizations in the community.

Infant isolation and cohorting for preventing or reducing transmission of healthcare-associated infections in neonatal units

BACKGROUND

Neonatal healthcare-associated infections (HAIs) result in increased morbidity and mortality, as well as increased healthcare costs. Patient isolation measures, i.e. single-room isolation or the cohorting of patients with similar infections, remain a recommended and commonly used practice for preventing horizontal spread of infections in the neonatal intensive care unit (NICU).  OBJECTIVES: Our primary objective was to assess the effect of single-room isolation or cohorting, or both for preventing transmission of HAIs or colonization with HAI-causing pathogens in newborn infants less than six months of age admitted to the neonatal intensive care unit (NICU). Our secondary objective was to assess the effect of single-room isolation or cohorting, or both on neonatal mortality and perceived or documented adverse effects in newborn infants admitted to the NICU.  SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, CINAHL, the WHO ICTRP and ClinicalTrials.gov trials registries. There were no restrictions to date, language or publication type. We also checked the reference lists of studies identified for full-text review.  SELECTION CRITERIA: Types of studies: cluster-randomized or quasi-randomized trials at the level of the cluster (where clusters may be defined by NICU, hospital, ward, or other subunits of the hospital). We also included cross-over trials with a washout period of more than four months (arbitrarily defined).

TYPES OF PARTICIPANTS

newborn infants less than six months of age in neonatal units that implemented patient isolation or cohorting as infection control measures to prevent HAIs. Types of interventions: patient isolation measures (single-room isolation or cohorting, or both of infants with similar colonization or infections) compared to routine isolation measures.

TYPES OF OUTCOME MEASURES

the primary outcome was the rate of transmission of HAIs as estimated by the infection and colonization rates in the NICU. Secondary outcomes included all-cause mortality during hospital stay at 28 days of age, length of hospital stay, as well as potential adverse effects of isolation or cohorting measures, or both.

DATA COLLECTION AND ANALYSIS

The standard methods of Cochrane Neonatal were used to identify studies and assess the methodological quality of eligible cluster-randomized trials. The certainty of the evidence was to be assessed by the GRADE method as evidence of high, moderate, low, or very low certainty. Infection and colonization rates were to be expressed as rate ratios for each trial and if appropriate for meta-analysis, the generic inverse variance method in RevMan was to be used.

MAIN RESULTS

We did not identify any published or ongoing trials to include in the review.

AUTHORS' CONCLUSIONS

The review found no evidence from randomized trials to either support or refute the use of patient isolation measures (single-room isolation or cohorting) in neonates with HAIs. Risks secondary to infection control measures need to be balanced against the benefits of decreasing horizontal transmission in the neonatal unit for optimal neonatal outcomes. There is an urgent need to research the effectiveness of patient isolation measures for preventing the transmission of HAIs in neonatal units. Well-designed trials randomizing clusters of units or hospitals to a type of patient isolation method intervention are warranted.

Biomineralized Cascade Enzyme-Encapsulated ZIF-8 Nanoparticles Combined with Antisense Oligonucleotides for Drug-Resistant Bacteria Treatment

The unrestrained use of antibiotics accelerates the development of drug-resistant bacteria and leads to an increasing threat to human health. Therefore, there is an urgent need to explore novel and effective strategies for the treatment of bacterial infections. Herein, zeolite imidazole framework-8 (ZIF-8) material was utilized to construct biomineralized nanomaterial (GOx&HRP@ZIF-8/ASO) by encapsulating biological cascade enzymes and combining with antisense oligonucleotides (ASOs), which achieved effective and synergistic antidrug-resistant bacteria therapy. Various in vitro assays confirmed that GOx&HRP@ZIF-8/ASO exhibited excellent antibacterial properties against Escherichia coli, Staphylococcus aureus, methicillin-resistant S. aureus (MRSA) during catalysis of glucose (Glu), especially the minimum inhibitory concentration (MIC) against MRSA was only 16 μg/mL. Compared with simple ZIF-8 (32.85%) and ftsZ ASO (58.65%), GOx&HRP@ZIF-8/ASO+Glu exhibited superb biofilm destruction ability, and the bacteria removal efficiency of the MRSA biofilm could be as high as 88.2%, indicating that the reactive oxygen species (ROS) produced by the cascade enzyme reaction imparted the main synergistic antibacterial capability, and simultaneously, ftsZ ASO significantly enhanced the antibacterial effect by inhibiting the expression of the ftsZ gene. In vivo anti-infection treatment experiments revealed that GOx&HRP@ZIF-8/ASO exhibited the best wound repairing performance and excellent biocompatibility in the presence of Glu. These findings suggested that GOx&HRP@ZIF-8/ASO has favorably realized high-efficiency treatment of MRSA infection and filled the gap in the antibacterial application of biological enzymes.

Stopping the routine use of contact precautions for management of MRSA and VRE at three academic medical centers: An interrupted time series analysis

BACKGROUND

Contact precautions (CP) are a widely adopted strategy to prevent cross-transmission of organisms, commonly methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE). Some hospitals have discontinued CP for patients with MRSA or VRE; however, the impact on hospital-acquired infection rates (HAI) has not been assessed systematically.

METHODS

Retrospective multicenter interrupted time series between 2002 and 2017 at three academic hospitals. Participating hospitals discontinued CP for patients with contained body fluids who were colonized or infected with MRSA or VRE. The primary intervention was stopping the use of CP. Secondary interventions were horizontal infection prevention strategies. The primary outcomes were rates of central line-associated bloodstream infections, catheter-associated urinary tract infections, mediastinal surgical site infection, and ventilator-associated pneumonia due to MRSA, VRE, or any organism using Centers for Disease Control and Prevention National Healthcare Safety Network surveillance definitions.

RESULTS

Central line-associated bloodstream infections, catheter-associated urinary tract infections, mediastinal surgical site infection, and ventilator-associated pneumonia rates trended down at each institution. There were no statistically significant increases in these infections associated with discontinuing CP. Individual horizontal infection prevention strategies variably impacted HAI outcomes.

CONCLUSIONS

Stopping the routine use of CP for patients with contained body fluids who are colonized or infected with MRSA or VRE did not result in increased HAIs. Bundled horizontal infection prevention strategies resulted in sustained HAI reductions.

The learning hospital: From theory to practice in a hospital infection prevention program

The learning hospital is distinguished by ceaseless evolution of erudition, enhancement, and implementation of clinical best practices. We describe a model for the learning hospital within the framework of a hospital infection prevention program and argue that a critical assessment of safety practices is possible without significant grant funding. We reviewed 121 peer-reviewed manuscripts published by the VCU Hospital Infection Prevention Program over 16 years. Publications included quasi-experimental studies, observational studies, surveys, interrupted time series analyses, and editorials. We summarized the articles based on their infection prevention focus, and we provide a brief summary of the findings. We also summarized the involvement of nonfaculty learners in these manuscripts as well as the contributions of grant funding. Despite the absence of significant grant funding, infection prevention programs can critically assess safety strategies under the learning hospital framework by leveraging a diverse collaboration of motivated nonfaculty learners. This model is a valuable adjunct to traditional grant-funded efforts in infection prevention science and is part of a successful horizontal infection control program.

Alternative doffing strategies of personal protective equipment to prevent self-contamination in the health care setting

BACKGROUND

Health care workers routinely contaminate skin and clothing when doffing personal protective equipment (PPE). Alternative doffing strategies, such as hand hygiene on gloved hands and double gloving, have been suggested but not validated by comparison against the standard Centers for Disease Control and Prevention procedures.

METHODS

Participants were assigned to doff PPE following 1 of 4 specific strategies. Prior to doffing, PPE was "contaminated" with Glo Germ and fluorescing Staphylococcus epidermidis at the recommended level of 1.5 × 10⁸ colony forming units/mL. After doffing, areas of self-contamination were detected using a black light. Cultures were taken from these areas using cotton swabs, inoculated onto blood agar plates, and incubated for 48hours. Each participant completed a survey regarding usability. The Fisher exact test and the Kruskal-Wallis test were used for data analysis with SAS 9.4.

RESULTS

There were 51 participants who completed the study. Breaches in PPE were observed in only 5 of 51 doffs (10%). However, 46 of 51 (90%) had areas of self-contamination that was apparent by transfer of Glo Germ to skin or clothing. A subset (16%) of these sites also grew fluorescing S epidermidis. Assigned doffing strategy was associated with bacterial contamination (P = .0151), but not usability (P = .2372).

CONCLUSIONS

Participants experienced self-contamination when doffing PPE with both a surrogate marker and live bacteria. Close attention to doffing technique is necessary for optimal results, and one-step procedures may be more effective.

Hospital Infection Prevention: How Much Can We Prevent and How Hard Should We Try?

PURPOSE OF REVIEW

To summarize the extent to which hospital-acquired infections (HAIs) are preventable and to assess expectations, challenges, and barriers to improve patient outcomes.

RECENT FINDINGS

HAIs cause significant morbidity and mortality. Getting to zero HAIs is a commonly stated goal yet leads to unrealistic expectations. The extent to which all HAIs can be prevented remains debatable and is subject to multiple considerations and barriers. Current infection prevention science is inexact and evolving. Evidence-based infection prevention practices are often incompletely implemented and at times controversial. Highly sensitive surveillance results in overdiagnosis, calling into question the real incidence of HAIs. Perceived reductions in HAIs by gaming the system lead to false conclusions about preventability and may cause harm. Successful HAI reduction programs require executive oversight yet keeping hospital leaders engaged in infection prevention is a challenge given competing priorities. Medicine is not a physical science with precisely defined laws; thus, infection prevention interventions are subject to variable outcomes. Perhaps up to 55-70% of HAIs are potentially preventable. This is subject to a law of diminishing returns as the preventable proportion of HAIs may reduce over time with improvements in patient safety. As the principle tenet of medicine is first do no harm, infection prevention programs should relentlessly pursue reliable, sustainable, and practical strategies for heightened patient safety.

Evaluation of contact precautions for methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus

BACKGROUND

There are limited controlled data demonstrating contact precautions (CPs) prevent methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) infections in endemic settings. We evaluated changes in hospital-acquired MRSA and VRE infections after discontinuing CPs for these organisms.

METHODS

This is a retrospective study done at an 800-bed teaching hospital in urban Detroit. CPs for MRSA and VRE were discontinued hospital-wide in 2013. Data on MRSA and VRE catheter-associated urinary tract infections (CAUTIs), ventilator-associated pneumonia (VAP), central line-associated bloodstream infections (CLABSIs), surgical site infections (SSIs), and hospital-acquired MRSA bacteremia (HA-MRSAB) rates were compared before and after CPs discontinuation.

RESULTS

There were 36,907 and 40,439 patients hospitalized during the two 12-month periods: CPs and no CPs. Infection rates in the CPs and no-CPs periods were as follows: (1) MRSA infections: VAP, 0.13 versus 0.11 (P = .84); CLABSI, 0.11 versus 0.19 (P = .45); SSI, 0 versus 0.14 (P = .50); and CAUTI, 0.025 versus 0.033 (P = .84); (2) VRE infections: CAUTI, 0.27 versus 0.13 (P = .19) and CLABSI, 0.29 versus 0.3 (P = .94); and (3) HA-MRSAB rates: 0.14 versus 0.11 (P = .55), respectively.

CONCLUSIONS

Discontinuation of CPs did not adversely impact endemic MRSA and VRE infection rates.

Universal versus targeted additional contact precautions for multidrug-resistant organism carriage for patients admitted to an intensive care unit

BACKGROUND

Although additional contact precautions (ACPs) are routinely used to reduce cross-transmission of multidrug-resistant organisms (MDROs), the relevance of isolation precautions remains debated. We hypothesized that the collection of recognized risk factors for MDRO carriage on intensive care unit (ICU) admission might be helpful to target ACPs without increasing MDRO acquisition during ICU stays, compared with universal ACPs.

MATERIALS AND METHODS

This is a sequential single-center observational study performed in consecutive patients admitted to a French medical and surgical ICU. During the first 6-month period, screening for MDRO carriage and ACPs were performed in all patients. During the second 6-month period, screening was maintained, but ACP use was guided by the presence of at least 1 defined risk factor for MDRO.

RESULTS

During both periods, 33 (10%) and 30 (10%) among 327 and 297 admissions were, respectively, associated with a positive admission MDRO carriage. During both periods, a second screening was performed in 147 (45%) and 127 (43%) patients. Altogether, the rate of acquired MDRO (positive screening or clinical specimen) was similar during both periods (10% [n = 15] and 11.8% [n = 15], respectively; P = .66).

CONCLUSIONS

The results of our study contribute to support the safety of an isolation-targeted screening policy on ICU admission compared with universal screening and isolation regarding the rate of ICU-acquired MDRO colonization or infection.

Vancomycin-Resistant Enterococci: Epidemiology, Infection Prevention, and Control

Vancomycin-resistant enterococci (VRE) infections have acquired prominence as a leading cause of health care-associated infections. Understanding VRE epidemiology, transmission modes in health care settings, risk factors for colonization, and infection is essential to prevention and control of VRE infections. Infection control strategies are pivotal in management of VRE infections and should be based on patient characteristics, hospital needs, and available resources. Hand hygiene is basic to decrease acquisition of VRE. The effectiveness of surveillance and contact precautions is variable and controversial in endemic settings, but important during VRE outbreak investigations and control. Environmental cleaning, chlorhexidine bathing, and antimicrobial stewardship are vital in VRE prevention and control.

Discontinuation of Systematic Surveillance and Contact Precautions for Vancomycin-Resistant Enterococcus (VRE) and Its Impact on the Incidence of VRE faecium Bacteremia in Patients with Hematologic Malignancies

OBJECTIVE To study the effect of discontinuation of systematic surveillance for vancomycin-resistant Enterococcus (VRE) and contact isolation of colonized patients on the incidence of VRE bacteremia SETTING A hematology-oncology unit with high prevalence of VRE colonization characterized by predominantly sporadic molecular epidemiology PARTICIPANTS Inpatients with hematologic malignancies and recipients of hematopoietic stem cell transplantation METHODS The incidence of VRE bacteremia was measured prospectively during 2 different 3-year time periods; the first during active VRE surveillance and contact precautions and the second after discontinuation of these policies. We assessed the collateral impact of this policy change on the incidence of bacteremia due to methicillin-resistant Staphylococcus aureus (MRSA) and Clostridium difficile infection even though we maintained contact precautions for these organisms. Incidence of infectious events was measured as number of events per 1,000 patients days per month. Time series analysis was used to evaluate trends. RESULTS The incidence of VRE bacteremia remained stable after discontinuation of VRE surveillance and contact precautions. The incidence of MRSA bacteremia and Clostridium difficile infection for which we continued contact precautions also remained stable. Aggregated antibiotic utilization and nursing hours per patient days were similar between the 2 study periods. CONCLUSION Active surveillance and contact precautions for VRE colonization did not appear to prevent VRE bacteremia in patients with hematologic malignancies and recipients of hematopoietic stem cell transplantation with high prevalence of VRE characterized by predominantly sporadic molecular epidemiology.

The Impact of Discontinuing Contact Precautions for VRE and MRSA on Device-Associated Infections

The impact of discontinuing contact precautions for patients with MRSA and VRE colonization/infection on device-associated hospital-acquired infection rates at an academic medical center was investigated in this before-and-after study. In the setting of a strong horizontal infection prevention platform, discontinuation of contact precautions had no impact on device-associated hospital-acquired infection rates.

Infect. Control Hosp. Epidemiol. 2015;36(8):978–980

Modern trends in infection control practices in intensive care units

Hospital-acquired infections (HAIs) are common in intensive care unit (ICU) patients and are associated with increased morbidity and mortality. There has been an increasing effort to prevent HAIs, and infection control practices are paramount in avoiding these complications. In the last several years, numerous developments have been seen in the infection prevention strategies in various health care settings. This article reviews the modern trends in infection control practices to prevent HAIs in ICUs with a focus on methods for monitoring hand hygiene, updates in isolation precautions, new methods for environmental cleaning, antimicrobial bathing, prevention of ventilator-associated pneumonia, central line-associated bloodstream infections, catheter-associated urinary tract infections, and Clostridium difficile infection.