Strategies to prevent methicillin-resistant Staphylococcus aureus transmission and infection in acute care hospitals: 2014 update

Hygiene requirements for cleaning and disinfection of surfaces: recommendation of the Commission for Hospital Hygiene and Infection Prevention (KRINKO) at the Robert Koch Institute

This recommendation of the Commission for Hospital Hygiene and Infection Prevention (KRINKO) addresses not only hospitals, but also outpatient health care facilities and compiles current evidence. The following criteria are the basis for the indications for cleaning and disinfection: Infectious bioburden and tenacity of potential pathogens on surfaces and their transmission routes, influence of disinfecting surface cleaning on the rate of nosocomial infections, interruption of cross infections due to multidrug-resistant organisms, and outbreak control by disinfecting cleaning within bundles. The criteria for the selection of disinfectants are determined by the requirements for effectiveness, the efficacy spectrum, the compatibility for humans and the environment, as well as the risk potential for the development of tolerance and resistance. Detailed instructions on the organization and implementation of cleaning and disinfection measures, including structural and equipment requirements, serve as the basis for their implementation. Since the agents for surface disinfection and disinfecting surface cleaning have been classified as biocides in Europe since 2013, the regulatory consequences are explained. As possible addition to surface disinfection, probiotic cleaning, is pointed out. In an informative appendix (only in German), the pathogen characteristics for their acquisition of surfaces, such as tenacity, infectious dose and biofilm formation, and the toxicological and ecotoxicological characteristics of microbicidal agents as the basis for their selection are explained, and methods for the evaluation of the resulting quality of cleaning or disinfecting surface cleaning are presented.

Antimicrobial Resistance in Organ Transplant Recipients

The overall burden of the main clinically relevant bacterial multidrug-resistant organisms (MDROs) (eg, methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, extended-spectrum β-lactamase producing or extended-spectrum cephalosporin-resistant Enterobacterales, carbapenem-resistant or carbapenemase-producing Enterobacterales, MDR Pseudomonas aeruginosa, and carbapenem-resistant Acinetobacter baumannii) in solid organ transplant (SOT) populations is summarized showing prevalence/incidence, risk factors, and impact on graft/patient outcome according to the type of SOT. The role of such bacteria in donor-derived infections is also reviewed. As for the management, the main prevention strategies and treatment options are discussed. Finally, nonantibiotic-based strategies are considered as future directions for the management of MDRO in SOT setting.

SHEA/IDSA/APIC Practice Recommendation: Strategies to prevent methicillin-resistant Staphylococcus aureus transmission and infection in acute-care hospitals: 2022 Update

Previously published guidelines have provided comprehensive recommendations for detecting and preventing healthcare-associated infections (HAIs). The intent of this document is to highlight practical recommendations in a concise format designed to assist acute-care hospitals in implementing and prioritizing efforts to prevent methicillin-resistant Staphylococcus aureus (MRSA) transmission and infection. This document updates the "Strategies to Prevent Methicillin-Resistant Staphylococcus aureus Transmission and Infection in Acute Care Hospitals" published in 2014.1 This expert guidance document is sponsored by the Society for Healthcare Epidemiology of America (SHEA). It is the product of a collaborative effort led by SHEA, the Infectious Diseases Society of America (IDSA), the Association for Professionals in Infection Control and Epidemiology (APIC), the American Hospital Association (AHA), and The Joint Commission, with major contributions from representatives of a number of organizations and societies with content expertise.

Burden of severe infections due to carbapenem-resistant pathogens in intensive care unit

Intensive care units (ICU) for various reasons, including the increasing age of admitted patients, comorbidities, and increasingly complex surgical procedures (e.g., transplants), have become "the epicenter" of nosocomial infections, these are characterized by the presence of multidrug-resistant organisms (MDROs) as the cause of infection. Therefore, the perfect match of fragile patients and MDROs, as the cause of infection, makes ICU mortality very high. Furthermore, carbapenems were considered for years as last-resort antibiotics for the treatment of infections caused by MDROs; unfortunately, nowadays carbapenem resistance, mainly among Gram-negative pathogens, is a matter of the highest concern for worldwide public health. This comprehensive review aims to outline the problem from the intensivist's perspective, focusing on the new definition and epidemiology of the most common carbapenem-resistant MDROs (Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacterales) to emphasize the importance of the problem that must be permeating clinicians dealing with these diseases.

Prevention of device-related infections in patients with cancer: Current practice and future horizons

Over the past several years, multifaceted advances in the management of cancer have led to a significant improvement in survival rates. Throughout patients' oncological journeys, they will likely receive one or more implantable devices for the administration of fluids and medications as well as management of various comorbidities and complications related to cancer therapy. Infections associated with these devices are frequent and complex, often necessitating device removal, increasing health care costs, negatively affecting quality of life, and complicating oncological care, usually leading to delays in further life-saving cancer therapy. Herein, the authors comprehensively review multiple evidence-based recommendations along with best practices, expert opinions, and novel approaches for the prevention of diverse device-related infections. The authors present many general principles for the prevention of these infections followed by specific device-related recommendations in a systematic manner. The continuous involvement and meaningful cooperation between regulatory entities, industry, specialty medical societies, hospitals, and infection control-targeted interventions, along with primary care and consulting health care providers, are all vital for the sustained reduction in the incidence of these preventable infections.

Discontinuing MRSA and VRE contact precautions: Defining hospital characteristics and infection prevention practices predicting safe de-escalation

OBJECTIVE

To define conditions in which contact precautions can be safely discontinued for methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE).

DESIGN

Interrupted time series.

SETTING

15 acute-care hospitals.

PARTICIPANTS

Inpatients.

INTERVENTION

Contact precautions for endemic MRSA and VRE were discontinued in 12 intervention hospitals and continued at 3 nonintervention hospitals. Rates of MRSA and VRE healthcare-associated infections (HAIs) were collected for 12 months before and after. Trends in HAI rates were analyzed using Poisson regression. To predict conditions when contact precautions may be safely discontinued, selected baseline hospital characteristics and infection prevention practices were correlated with HAI rate changes, stratified by hospital.

RESULTS

Aggregated HAI rates from intervention hospitals before and after discontinuation of contact precautions were 0.14 and 0.15 MRSA HAI per 1,000 patient days (P = .74), 0.05 and 0.05 VRE HAI per 1,000 patient days (P = .96), and 0.04 and 0.04 MRSA laboratory-identified (LabID) events per 100 admissions (P = .57). No statistically significant rate changes occurred between intervention and non-intervention hospitals. All successful hospitals had low baseline MRSA and VRE HAI rates and high hand hygiene adherence. We observed no correlations between rate changes after discontinuation and the assessed hospital characteristics and infection prevention factors, but the rate improved with higher proportion of semiprivate rooms (P = .04).

CONCLUSIONS

Discontinuing contact precautions for MRSA/VRE did not result in increased HAI rates, suggesting that contact precautions can be safely removed from diverse hospitals, including community hospitals and those with lower proportions of private rooms. Good hand hygiene and low baseline HAI rates may be conditions permissive of safe removal of contact precautions.

High Levels of Methicillin-Resistant Staphylococcus aureus Carriage Among Healthcare Workers at a Teaching Hospital in Addis Ababa Ethiopia: First Evidence Using mecA Detection

Background

Staphylococcus aureus is a major human pathogen and causes healthcare and community-acquired infection. Data on the extent of MRSA colonization among health-care workers (HCWs) in sub-Saharan Africa are limited. Hence, we determined the burden of MRSA colonisation among HCWs and administrative staff in Tikur Anbessa Specialised Hospital (TASH), College of Health Sciences (CHS), Addis Ababa University, Ethiopia.

Methods

Using a cross-sectional study design, participants were screened for MRSA colonisation between June 2018 and August 2019 using nasal swabs. The swabs were analysed using standard laboratory methods including antibiotic resistance gene, mecA. Anonymised sociodemographic data were collected by pretested questionnaires to evaluate HCWs factors associated with MRSA carriage.

Results

A total of 588 HCWs and 468 administrative staff were screened for MRSA. Women were over-represented. Overall, 49.1% (289/588) of HCWs were nurses and 25% (117/468) of the administrative staff were cleaners or laundry workers. Overall, 138 S. aureus isolates were retrieved from the nasal swabs of both groups (16.3%, 96/588 from HCWs). The burden of MRSA colonisation was 4.8% (28/580, 95% CI: 3.1–6.5%) among HCWs compared to 0.2% (1/468, 95% CI: 0.18–0.6%) of administrative staff (p value <0.05). The majority of S. aureus and all MRSA isolates were resistant to penicillin. Isolates from HCWs were more resistant to tested antibiotics than administrative staff (P-value <0.05).

Conclusion

This is the first report in Ethiopia on MRSA colonization using mecA and revealed that; (i) overall carriage rates of MRSA in HCWs are comparable with observations reported in some other countries and (ii) HCWs exhibit a higher burden of MRSA carriage than administrative staff. Our data support strategic screening of MRSA and antimicrobial stewardship for better intervention measures.

Risk factors for bloodstream infection by multidrug-resistant organisms in critically ill patients in a reference trauma hospital

BACKGROUND

Bloodstream infections (BSI) by multidrug-resistant (MDR) organisms are responsible for significant mortality in critically ill trauma patients. Our objective is to identify the risk factors for BSI by MDR agents and their resistance mechanisms in a trauma reference hospital.

METHODS

During 18 months, all patients admitted in our Intensive Care Unit (ICU) were enrolled in this prospective cohort. We included the first episode of BSI by carbapenem-resistant Gram-negative bacteria, methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin resistant enterococcus. Demographic and clinical data were compared among patients with and without BSI and variables with P < .05 were tested in a multivariate analysis. We performed PCR for identification of carbapenemase and SCC mec genes and Pulsed-field gel electrophoresis for clonality.

RESULTS

Out of 1,528 patients, 302 (19.8%) were trauma and 66 (4.3%) had a MDR-BSI (19.5% were trauma). The multivariate analysis showed that mechanical ventilation (OR3.16; 95% CI 1-8; P = .02), hemodialysis (OR3.16; 95% CI 1-5; P = .0003) and surgery (OR1.76; 95% CI 1-3; P = .04) were independent risk factors for MDR-BSI. The most frequent MDR were Klebsiella pneumoniae (n = 26) and MRSA (n = 27). Regarding K pneumoniae strains (n = 24), 20 (83.8%) harbored bla KPC gene and 1 bla NDM. The majority of KPC isolates belonged to a predominant clone; while the MRSA were polyclonal and SCC mec type II.

CONCLUSIONS

Mechanical ventilation, surgery and hemodialysis were independent risk factors for MDR-BSI in our cohort, but trauma was not. KPC was the main mechanism of resistance among carbapenem-resistant K pneumoniae that belonged to a predominant clone which could indicate cross-transmission.

A Multicenter Analysis of Changes in Pediatric Antibiotic Susceptibilities Among Staphylococcus aureus and Pseudomonas aeruginosa Isolates: 2014–2018

OBJECTIVE

To describe antibiotic susceptibilities for Staphylococcus aureus and Pseudomonas aeruginosa among pediatric institutions in 2018. To assess correlations between antibiotic utilization and susceptibilities.

METHODS

Institutional antibiograms from 2018 were compiled among 13 institutions via a survey. Resistant pathogens and antibiotic days of therapy/1000 patient days (PD) were collected from 6 institutions over 5 years. Correlations were assessed as pooled data among all institutions and relative changes within individual institutions.

RESULTS

All 8552 S aureus isolates in 2018 were vancomycin susceptible and 40.1% were methicillin resistant (MRSA). Among MRSA, 96.3% and 78.8% were susceptible to trimethoprim/sulfamethoxazole and clindamycin, respectively. Pooled yearly MRSA/1000 PD decreased from 2014–2018 and correlated with pooled yearly decreases in vancomycin utilization (R = 0.983, p = 0.003). Institutional relative decreases in vancomycin utilization from 2014–2018 did not correlate with institutional relative decreases in MRSA susceptibility (R = −0.659, p = 0.16). Susceptibility to meropenem was 90.9% among 2315 P aeruginosa isolates in 2018. Antipseudomonal beta-lactam susceptibility ranged from 89.4% to 92.3%. Pooled yearly meropenem-resistant P aeruginosa/1000 PD and meropenem utilization did not significantly decrease over time or correlate (both p &gt; 0.6). Institutional relative change in meropenem utilization from 2013–2017 correlated with the institutional relative change in P aeruginosa susceptibility to meropenem from 2014–2018 (Rs = −0.89, p = 0.019).

CONCLUSIONS

Among included institutions, the burden of MRSA decreased over time. Institutional MRSA prevalence did not consistently correlate with institutional vancomycin utilization. Institutional changes in meropenem utilization correlated with P aeruginosa susceptibility the following year. Pooled analyses did not illustrate this correlation, likely owing to variability in utilization between institutions.

Evaluation of Patients' Adverse Events During Contact Isolation for Vancomycin-Resistant Enterococci Using a Matched Cohort Study With Propensity Score

IMPORTANCE

Although contact isolation has been widely recommended for multidrug-resistant organisms, contact isolation has raised some concerns that it may bring unintended patient harms.

OBJECTIVE

To compare adverse events between a contact isolation group with vancomycin-resistant Enterococcus (VRE) and a matched comparison group using a relatively large data set from full electronic medical records (EMR) and propensity score-matching methods.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective, matched cohort study was conducted at Seoul National University Bundang Hospital (SNUBH) in Korea, a tertiary, university-affiliated hospital that has 1337 inpatient beds. Participants included a total of 98 529 hospitalized adult patients (aged ≥18 years) during 2015 to 2017.

EXPOSURES

Contact isolation in a single or shared double room.

MAIN OUTCOMES AND MEASURES

As adverse contact isolation-related outcomes, falls and pressure ulcers were included. All relevant EMR data were extracted from the SNUBH clinical data warehouse. Risk factors for adverse events were included in the propensity score model based on literature reviews, such as Braden scale score and Hendrich II fall risk score. A fine stratification and weighting (FSW) and a 1:10 nearest neighbor (NN) propensity score matching as a sensitivity analysis were adopted to compare adverse events between the 2 groups for the observation period from the study entry date and the exit date. Time-to-event analyses with a Cox proportional hazard model were conducted in December 2021.

RESULTS

For comparison of outcomes in wards, 177 patients (mean [SD] age, 67.38 [14.12] years; 98 [55.4%] female) with VRE and 93 022 patients (mean [SD] age, 56.44 [16.88] years; 49 462 [53.2%] female) without VRE were included and no difference was found in basic characteristics from the FSW (VRE contact isolation [n = 172] vs comparison [n = 69 434]) as well as from the 1:10 NN (VRE contact isolation [n = 168] vs comparison [n = 1650]). Among 177 patients with VRE contact isolation, 8 pressure ulcers and 3 falls occurred during their hospital stays; incidence rates of adverse events were 2.5 and 0.9 per 1000 patient-days, respectively (pressure ulcer incidence rate from the FSW: 2.53 per 1000 patient-days [95% CI, 1.09-4.99 per 1000 patient-days]; pressure ulcer incidence rate from the 1:10 NN: 2.54 per 1000 patient-days [95% CI, 1.10-5.01 per 1000 patient-days]; fall incidence rate from the FSW: 0.87 per 1000 patient-days [95% CI, 0.18-2.54 per 1000 patient-days]; fall incidence rate from the 1:10 NN: 0.87 per 1000 patient-days [95% CI, 0.18-2.55 per 1000 patient-days]). The hazard ratios for adverse events showed no statistically significant differences for both groups: 1.42 (95% CI, 0.67-2.99) for pressure ulcer and 0.66 (95% CI, 0.20-2.13) for fall from the FSW.

CONCLUSIONS AND RELEVANCE

In this cohort study, no association was found between the likelihood of adverse events and contact isolation using propensity score-matching methods and closely related covariates for adverse events.

Recurrent Bacterial Infections in Cutaneous T-cell Lymphoma

Cutaneous T-cell lymphoma (CTCL) is a dermatologically manifesting immune cell disorder. We present a case of a 76-year-old female with a past medical history of CTCL, presenting with cellulitis of the left foot. After diagnosis of CTCL, the patient was admitted multiple times for treatment of cutaneous and soft-tissue infections with methicillin-resistant Staphylococcus aureus. Her recurrent infection with S. aureus had led to treatment for sepsis and a below-knee amputation on the right during prior hospitalizations. On this admission, the patient was treated with intravenous vancomycin and cefepime as in-patient and oral linezolid as out-patient. Recent articles show that patients with CTCL have an increased tendency to harbor S. aureus, which leads to recurrent infections. Additionally, evidence suggests that S. aureus toxins aid the progression of CTCL by helping the cancer to escape immune regulation. Our patient demonstrates this unique relationship between CTCL and S. aureus, and moreover, we make a case that S. aureus infection in CTCL, as compared to that in other dermatitis, should be better managed to not exacerbate the disease. 

Methicillin-Resistant Staphylococcus aureus: An Update on Prevention and Control in Acute Care Settings

Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of health-care-associated infections. Controversies regarding the effectiveness of various control strategies have contributed to varying approaches to MRSA control. However, new evidence from large-scale studies has emerged, particularly concerning screening and decolonization. Importantly, implementation and outcomes of control measures in practice are not only influenced by scientific evidence, but also economic, administrative, and political factors, as demonstrated by decreasing MRSA rates in a number of countries after concerted and coordinated efforts at a national level. Flexibility to adapt measures based on local epidemiology and resources is essential for successful MRSA control.

Strategies for Effective Infection Prevention Programs: Structures, Processes, and Funding

Successful Infection Prevention Programs (IPPs) consist of a multidisciplinary team led by a hospital epidemiologist and managed by infection preventionists. Knowledge of the economics of health care-associated infections (HAIs) and the ability to make a business plan is now essential to the success of programs. Prevention of HAIs is the core function of IPPs with impact on patient outcomes, quality of care, and cost savings for hospitals. This article discusses the structure and responsibilities of an IPP, the regulatory pressures and opportunities that these programs face, and how to build and manage a successful program.

Evaluation of the reliability of MRSA screens in patients undergoing universal decolonization

PURPOSE

Colonization of methicillin-resistant Staphylococcus aureus (MRSA) can be detected via nasal screens. Evidence indicates that negative MRSA nasal screens may be used to de-escalate anti-MRSA antibiotics in pulmonary infections. In the ICU, universal decolonization with intranasal mupirocin is implemented to reduce MRSA infection risk. This study aimed to determine whether mupirocin administration affects the reliability of MRSA PCR nasal screens.

METHODS

This retrospective study divided subjects based on timing of intranasal mupirocin administration-before and after MRSA screen. Subjects with confirmed pulmonary infection that received vancomycin, blood/respiratory cultures, and had MRSA PCR screen collected were included. Subjects with concurrent infection requiring vancomycin or MRSA infection in prior 30 days were excluded. Primary outcome of this non-inferiority study was the negative predictive value (NPV) of the screen. Secondary outcomes included the positive predictive value (PPV), sensitivity, and specificity of the screen and duration of vancomycin.

RESULTS

Ultimately, 125 subjects were included in each group. The NPV in the group receiving mupirocin before screen was 95.2%, whereas the NPV in the group receiving mupirocin after screen was 99%. The difference between groups was -3.8% (90% CI -7.8%-0.2%; p=0.31), which failed to meet non-inferiority criteria. The secondary outcomes of PPV, sensitivity and specificity of the screen were similar in both groups. The duration of vancomycin was significantly longer in subjects receiving mupirocin before screen (3 days vs. 2 days; p<0.05).

CONCLUSION

Intranasal mupirocin prior to the screen may reduce NPV in pulmonary infections. Approach de-escalation of vancomycin based on screen results with caution.

The cost-effectiveness of temporary single-patient rooms to reduce risks of healthcare-associated infection

BACKGROUND

The use of single rooms for patient isolation often forms part of a wider bundle to prevent certain healthcare-associated infections (HAIs) in hospitals. Demand for single rooms often exceeds what is available and the use of temporary isolation rooms may help resolve this. Changes to infection prevention practice should be supported by evidence showing that cost-effectiveness is plausible and likely.

AIM

To perform a cost-effectiveness evaluation of adopting temporary single rooms into UK National Health Service (NHS) hospitals.

METHODS

The cost-effectiveness of a decision to adopt a temporary, single-patient, isolation room to the current infection prevention efforts of an NHS hospital was modelled. Primary outcomes are the expected change to total costs and life-years from an NHS perspective.

FINDINGS

The mean expected incremental cost per life-year gained (LYG) is £5,829. The probability that adoption is cost-effective against a £20,000 threshold per additional LYG is 93%, and for a £13,000 threshold the probability is 87%. The conclusions are robust to scenarios for key model parameters. If a temporary single-patient isolation room reduces risks of HAI by 16.5% then an adoption decision is more likely to be cost-effective than not. Our estimate of the effectiveness reflects guidelines and reasonable assumptions and the theoretical rationale is strong.

CONCLUSION

Despite uncertainties about the effectiveness of temporary isolation rooms for reducing risks of HAI, there is some evidence that an adoption decision is likely to be cost-effective for the NHS setting. Prospective studies will be useful to reduce this source of uncertainty.

MRSA Transmission in Intensive Care Units: Genomic Analysis of Patients, Their Environments, and Healthcare Workers

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA)-and now USA300 MRSA-is a significant intensive care unit (ICU) pathogen; healthcare worker (HCW) contamination may lead to patient cross-transmission.

METHODS

From September 2015 to February 2016, to study the spread of MRSA, we enrolled HCWs in 4 adult ICUs caring for patients on MRSA contact precautions. Samples were collected from patient body sites and high-touch surfaces in patient rooms. HCW hands, gloves, and personal protective equipment were sampled pre/post-patient encounter. Whole genome sequencing (WGS) was used to compare isolates from patients, HCWs, and environment.

RESULTS

There were 413 MRSA isolates sequenced (38% USA300, 52% USA100) from 66 patient encounters. Six of 66 HCWs were contaminated with MRSA prior to room entry. Isolates from a single patient encounter were typically either USA100 or USA300; in 8 (12%) encounters both USA300 and USA100 were isolated. WGS demonstrated that isolates from patients, HCWs, and environment often were genetically similar, although there was substantial between-encounter diversity. Strikingly, there were 5 USA100 and 1 USA300 clusters that contained similar strains (<22 single-nucleotide variants [SNVs], with most <10 SNVs) within the cluster despite coming from different encounters, suggesting intra- and inter-ICU spread of strains, that is, 4 of these genomic clusters were from encounters in the same ICU; 5 of 6 clusters occurred within 1 week.

CONCLUSIONS

We demonstrated frequent spread of MRSA USA300 and USA100 strains among patients, environment, and HCWs. WGS identified possible spread within and even between ICUs. Future analysis with detailed contact tracing in conjunction with genomic data may further elucidate pathways of MRSA spread and points for intervention.

Decolonization of Staphylococcus aureus

Staphylococcus aureus infections are associated with increased morbidity, mortality, hospital stay, and health care costs. S aureus colonization has been shown to increase risk for invasive and noninvasive infections. Decolonization of S aureus has been evaluated in multiple patient settings as a possible strategy to decrease the risk of S aureus transmission and infection. In this article, we review the recent literature on S aureus decolonization in surgical patients, patients with recurrent skin and soft tissue infections, critically ill patients, hospitalized non-critically ill patients, dialysis patients, and nursing home residents to inform clinical practice.

Staphylococcus aureus Skin and Soft Tissue Infection Recurrence Rates in Outpatients: A Retrospective Database Study at 3 US Medical Centers

Background

Staphylococcusaureus skin and soft tissue infections (SA-SSTIs) are common in healthcare and community settings, and recurrences occur at variable frequency, even after successful initial treatment. Knowing the exact burden and timing of recurrent disease is critical to planning and evaluating interventions to prevent recurrent SSTIs.

Methods

In this retrospective study, SSTI cases in patients aged ≥18 years at 3 US medical centers (Columbia, Chicago, Vanderbilt) between 2006 and 2016 were analyzed according to a biennial cohort design. Index SSTIs (with or without key comorbidities), either microbiologically confirmed to be SA-SSTI or not microbiologically tested (NMT-SSTI), were recorded within 1 calendar year and followed up for 12 months for recurrent infections. The number of index cases, proportion of index cases with ≥1 recurrence(s), time to first recurrence, and number of recurrences were collected for both SA-SSTI and NMT-SSTI events.

Results

In the most recent cohorts, 4755 SSTI cases were reported at Columbia, 2873 at Chicago, and 6433 at Vanderbilt. Of these, 452, 153, and 354 cases were confirmed to be due to S. aureus. Most cases were reported in patients without key comorbidities. Across centers, 16.4%–19.0% (SA-SSTI) and 11.0%–19.2% (NMT-SSTI) of index cases had ≥1 recurrence(s). In patients without key comorbidities, more than 60% of index SSTIs with recurrences had only 1 recurrence, half of which occurred in the first 3 months following primary infection.

Conclusions

SA-SSTI recurrences are common among healthy adults and occur in at least 1 in 6 individuals during the 1 year following the primary event.

The effect of routine surveillance and decolonization on the rate of Staphylococcus aureus infections in a level IV neonatal intensive care unit

OBJECTIVE

To evaluate the impact of active surveillance cultures (ASC) for Staphylococcus aureus (SA) and decolonization on the rate of infection in neonates in a neonatal intensive care unit (NICU).

STUDY DESIGN

Using a quasi-experimental design with control groups, rates of SA infections before and after implementing weekly ASC and topical mupirocin decolonization in a level IV NICU were compared. Comparators were the rates of gram negative bloodstream infections (BSI) and of SA BSI at an affiliated NICU where the intervention was not implemented.

RESULT

There was a 77% (p < 0.010) reduction in rate of NICU-wide methicillin-susceptible SA (MSSA) BSI, but no significant change in rate of methicillin-resistant SA BSI, likely due to a prevalent mupirocin-resistant clone. Rates of gram negative BSI and SA BSI at an affiliated NICU did not change significantly.

CONCLUSION

Weekly ASC and decolonization were associated with a unit-wide reduction in MSSA infections in a NICU.

Chlorhexidine Bathing Strategies for Multidrug-Resistant Organisms: A Summary of Recent Evidence

Objective

The aim of the study was to summarize the latest evidence for patient bathing with a 2% to 4% chlorhexidine gluconate solution to reduce multidrug-resistant organism (MDRO) transmission and infection.

Methods

We searched 3 databases (CINAHL, MEDLINE, and Cochrane) for a combination of the key words “chlorhexidine bathing” and MeSH terms “cross-infection prevention,” “drug resistance, multiple, bacterial,” and “drug resistance, microbial.” Articles from January 1, 2008, to December 31, 2018, were included, as well as any key articles published after December 31.

Results

Our findings focused on health care–associated infections (HAIs) and 3 categories of MDROs: methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), and carbapenem-resistant Enterobacteriaceae (CRE). Chlorhexidine bathing reduces MRSA acquisition and carriage, but not all studies found significant reductions in MRSA infections. Several studies found that chlorhexidine bathing reduced VRE acquisition and carriage, and one study showed lower VRE infections in the bathing group. Two studies found that bathing reduced CRE carriage (no studies examined CRE infections). Two very large studies (more than 140,000 total patients) found bathing significantly reduced HAIs, but these reductions may be smaller when HAIs are already well controlled by other means.

Conclusions

There is a high level of evidence supporting chlorhexidine bathing to reduce MDRO acquisition; less evidence is available on reducing infections. Chlorhexidine bathing is low cost to implement, and adverse events are rare and resolve when chlorhexidine use is stopped. There is evidence of chlorhexidine resistance, but not at concentrations in typical use. Further research is needed on chlorhexidine bathing’s impact on outcomes, such as mortality and length of stay.

Burden of perianal Staphylococcus aureus colonization in nursing home residents increases transmission to healthcare worker gowns and gloves

OBJECTIVE

To evaluate the effect of the burden of Staphylococcus aureus colonization of nursing home residents on the risk of S. aureus transmission to healthcare worker (HCW) gowns and gloves.

DESIGN

Multicenter prospective cohort study.

SETTING AND PARTICIPANTS

Residents and HCWs from 13 community-based nursing homes in Maryland and Michigan.

METHODS

Residents were cultured for S. aureus at the anterior nares and perianal skin. The S. aureus burden was estimated by quantitative polymerase chain reaction detecting the nuc gene. HCWs wore gowns and gloves during usual care activities; gowns and gloves were swabbed and then cultured for the presence of S. aureus.

RESULTS

In total, 403 residents were enrolled; 169 were colonized with methicillin-resistant S. aureus (MRSA) or methicillin-sensitive S. aureus (MSSA) and comprised the study population; 232 were not colonized and thus were excluded from this analysis; and 2 were withdrawn prior to being swabbed. After multivariable analysis, perianal colonization with S. aureus conferred the greatest odds for transmission to HCW gowns and gloves, and the odds increased with increasing burden of colonization: adjusted odds ratio (aOR), 2.1 (95% CI, 1.3-3.5) for low-level colonization and aOR 5.2 (95% CI, 3.1-8.7) for high level colonization.

CONCLUSIONS

Among nursing home patients colonized with S. aureus, the risk of transmission to HCW gowns and gloves was greater from those colonized with greater quantities of S. aureus on the perianal skin. Our findings inform future infection control practices for both MRSA and MSSA in nursing homes.

Effects of subinhibitory concentrations of chlorhexidine and mupirocin on biofilm formation in clinical meticillin-resistant Staphylococcus aureus

BACKGROUND

The effects of subinhibitory concentrations (sub-MICs) of antibacterial agents on the biofilm-forming ability of Staphylococcus aureus require further study.

AIM

To investigate the effects of sub-MICs of chlorhexidine and mupirocin on biofilm formation in clinical meticillin-resistant Staphylococcus aureus (MRSA) isolates.

METHODS

MRSA isolates were collected from patients with bloodstream infections at a tertiary care hospital. The basal level of biofilm formation and biofilm induction by sub-MICs of chlorhexidine and mupirocin were evaluated by measuring biofilm mass stained with Crystal Violet.

FINDINGS

Of the 112 MRSA isolates tested, 63 (56.3%) and 44 (39.3%) belonged to sequence type (ST)5 and ST72 lineages, respectively, which are the predominant healthcare- and community-associated clones in South Korea. ST5 isolates were more likely to have chlorhexidine MIC ≥4 (73.0% vs 29.5%), resistance to mupirocin (23.8% vs 0%), agr dysfunction (73.0% vs 9.1%), and qacA/B gene (58.7% vs 2.3%) compared to ST72 isolates. The basal level of biofilm formation ability was frequently stronger in ST72 isolates compared to ST5 isolates (77.3% vs 12.7%). Sub-MICs of chlorhexidine and mupirocin promoted biofilm formation in 56.3% and 53.6%, respectively, of all isolates. Biofilm induction was more prevalent in ST5 isolates (85.7% for chlorhexidine, 69.8% for mupirocin) than in ST72 isolates (15.9% for chlorhexidine, 27.3% for mupirocin).

CONCLUSION

Sub-MICs of chlorhexidine and mupirocin promoted biofilm formation in half of the clinical MRSA isolates. Our results suggest that ST5 MRSA biofilm can be induced together with some other bacterial virulent factors following exposure to chlorhexidine, which might confer a survival advantage to this clone in the healthcare environment.

Catheter-Associated Urinary Tract Infection, Clostridioides difficile Colitis, Central Line-Associated Bloodstream Infection, and Methicillin-Resistant Staphylococcus aureus

Hospital-acquired infections increase cost, morbidity, and mortality for patients across the United States and the world. Principal among these infections are central line-associated bloodstream infection, catheter-associated urinary tract infection, Clostridioides difficile, and methicillin-resistant Staphylococcus aureus colonization and infections. This article provides succinct summaries of the background, epidemiology, diagnosis, and treatment of these conditions. In addition, novel prevention strategies, including those related to recent national interventions, are reviewed.

Screening the nose, throat and the naso-pharynx for methicillin-resistant Staphylococcus aureus: a pilot study

Patients who carry nasal methicillin-resistant Staphylococcus aureus (MRSA) may also harbour MRSA in the oro-pharyngeal cavity. However, the naso-oro-pharyngeal co-carriage is infrequently assessed. The incidence of concurrent MRSA carriage of the naso-oro-pharynx was ascertained, and the sensitivity of two methods, a throat swab and a phosphate buffered saline (PBS) oral rinse, for MRSA detection was investigated. Among nasal MRSA carriers, 80% harboured MRSA in the oro-pharynx. Among these patients, 15% had MRSA detected in the oro-pharynx and not in the throat. Oro-pharyngeal colonisation represents a significant reservoir to persistence as well as nasal recolonisation. Decolonisation methods effective in reducing oro-pharyngeal MRSA in addition to nasal carriage should be investigated.

Novel strategies for rapid identification and susceptibility testing of MRSA

INTRODUCTION

Methicillin-resistant Staphylococcus aureus (MRSA) is associated with adverse clinical outcomes and increased morbidity, mortality, length of hospital stay, and health-care costs. Rapid diagnosis of MRSA infections has been associated with positive impact on clinical outcomes.

AREAS COVERED

We searched relevant papers in PubMed for the last 10 years. In major papers, we scanned the bibliographies to ensure that important articles were included. This review describes screening and diagnostic test methods for MRSA and their analytical performances with a focus on rapid molecular-based assays including those that are on the horizon. Future novel technologies will allow more rapid detection of phenotypic resistance. In the case of whole-genome sequencing, detection of mutations may predict resistance, transmission, and virulence.

EXPERT OPINION

Currently there are many diagnostic options for the detection of MRSA in surveillance and clinical samples. In general, these are highly accurate and have resulted in improvements in targeted management and reduction in hospital or intensive care unit length of stay for both MSSA and MRSA. Impact on mortality has been variable. Promising novel technologies will not only accurately identify pathogens and detect their resistance markers but will allow discovery of virulence determinants that might further affect patient management.

Correlation Between Biofilm Formation and Antibiotic Resistance in MRSA and MSSA Isolated from Clinical Samples in Iran: A Systematic Review and Meta-Analysis

Objectives: This study aimed at reviewing the correlation between biofilm formation and antibiotic resistance in methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) isolates. Materials and Methods: This review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocols. The literature search was conducted in PubMed, Web of Science (ISI), and Scopus databases. Combinations of Mesh terms such as "biofilms" OR "biofilm formation," AND "Drug Resistance" OR "Antimicrobial Drug Resistance" OR "Antibiotic Resistance" AND "Staphylococcus aureus" OR "Methicillin-resistant Staphylococcus aureus" or "MRSA" AND "Methicillin-sensitive Staphylococcus aureus" OR "MSSA" AND "biofilm-related genes" AND "Prevalence" AND "Iran" were searched. Two reviewers independently searched the databases. Analyses were performed in Comprehensive Meta-Analysis software. The random-effects model was used to obtain the combined prevalence with a 95% confidence interval (CI). Results: The combined prevalence of MRSA retrieved from Iranian clinical samples was 48.3% (95% CI: 40.8-55.9). The pooled rate of biofilm formation in MRSA strains was reported as 80.9% (95% CI: 67.8-89.4). Overall, 52.9%, 45.3%, and 22.5% of MRSA isolates were strong, moderate, and weak biofilm producers, respectively. The highest frequency of biofilm-related genes was observed for icaD gene (67.7%) followed by clfA gene with a frequency of 64.7%. Among seven studies that addressed the relationship between biofilm formation and antibiotic resistance, six reported positive associations. Conclusions: Regarding the MRSA strains, they had a significantly higher ability of biofilm formation than MSSA strains; therefore, preventive measures against infections caused by them are required.

The oral cavity revealed as a significant reservoir of Staphylococcus aureus in an acute hospital by extensive patient, healthcare worker and environmental sampling

BACKGROUND

Methicillin-susceptible Staphylococcus aureus (MSSA) bloodstream infection rates have risen steadily in recent years, with a marked decline in the corresponding rates due to methicillin-resistant S. aureus (MRSA). Screening for MSSA carriage is not routinely undertaken and MRSA screening is not universal, so the extent of S. aureus colonisation pressure in nosocomial settings is unknown.

METHODS

We conducted a prospective, observational study of patients and healthcare workers (HCWs) across nine inpatient wards in a tertiary referral hospital over a two-year period. Participants were screened for MSSA and MRSA using nasal swabs and oral rinses. Environmental surfaces and air were also tested for S. aureus using contact plates and active air sampling.

FINDINGS

We enrolled 388 patients and 326 HCWs; and took 758 contact plate samples from surfaces and 428 air samples. MSSA was recovered from 24% of patients, 31.3% of HCWs, 16% of air samples and 7.9% of surface samples. MRSA was recovered from 6.4% of patients, 3.7% of HCWs, 2.5% of air samples and 2.2% of surface samples. Inclusion of the oral cavity in addition to the anterior nares in the sampling regimen identified 30 patients and 36 HCWs who exhibited exclusive oral colonisation.

CONCLUSIONS

The oral cavity comprises a significant nosocomial reservoir for S. aureus that is currently under-appreciated. Oral screening should be considered both in terms of the colonisation pressure in a healthcare facility, and on an individual patient level, especially in patients where decolonisation attempts have repeatedly failed and those undergoing high risk procedures.

The Rising Problem of Multidrug-Resistant Organisms in Intensive Care Units

Because of antimicrobial overuse and misuse, the issue of multidrug-resistant organisms has been increasingly significant. Multidrug-resistant organism infection is of extreme concern in critical care patients. Infections with these organisms are difficult to treat because of the elevated rate of antimicrobial therapy failure. Such infections are linked to high mortality, poor prognosis, prolonged hospital stays, and increased medical expenses. Nineteen percent of patients with intensive care unit stays of greater than 24 hours acquire infections. Critically ill patients have risk factors that make them susceptible to infections. Critical care nurses must implement infection prevention interventions. Infection control strategies can be categorized as vertical or horizontal. Vertical approaches target a single pathogen; horizontal approaches are nonspecific. Infection control practice compliance is vital to prevent transmission of multidrug-resistant organisms through cross-contamination. This article discusses the severity of multidrug-resistant organism infection, risk factors, and infection prevention strategies in critical care settings.

Increased multidrug resistant isolates: new clinical burdens for 66 hospitals in Shanghai, 2015 to 2017

Background

To investigate the etiology of urinary tract and respiratory infections and the rate of drug resistant bacteria in Shanghai from 2015 to 2017, provide the support to the promotion of the correct clinical etiological specimens detection.

Methods

The retrospective questionnaire survey was conducted to obtain the antibiotic prescription rate, pathogen detection rate, and isolation rate of drug-resistant bacteria of the inpatients in 66 hospitals of Shanghai in 2015 and 2017.

Results

Although the detection rate of multidrug-resistant bacteria in sputum specimens has decreased, the clinical pathogen detection still relied mainly on sputum specimens in 2017. Among the sputum specis, the detection rates of extended-spectrum β-lactamase-producing Escherichia (ESBL-ESC), extended-spectrum β-lactamase Klebsiella pneumoniae (ESBL-KP), carbapenem-resistant Acinetobacter baumannii (CRAB), carbapenem-resistant Pseudomonas aeruginosa (CRPA) and methicillin-resistant Staphylococcus aureus (MRSA) in 2017 were 66.67%, 32.46%, 61.74%, 32.01% and 58.55% respectively. The detection rates of ESBL-ESC, ESBL-KP, CRAB, CRPA in 2017 were increased while the MRSA was decreased than 2015 (P<0.001). Among the blood samples, the detection rates of ESBL-ESC, ESBL-KP, CRAB, CRPA, MRSA and vancomycin-resistant Enterococcus sp (VRE) in 2017 were 53.71%, 31.43%, 50.80%, 19.43%, 43.87% and 0.55% respectively. The detection rates of ESBL-KP, CRAB, CRPA and MRSA increased while the rates of ESBL-ESC and VRE decreased compared with 2015 (P<0.005). The pathogens of multi-drug resistant bacteria were mainly detected from sputum specimens in 2017, which were all higher than detected from the blood specimens (P<0.001).

Conclusions

Most of the multi-drug resistant bacteria in Shanghai, especially in Acinetobacter baumannii or Pseudomonas aeruginosa are mainly detected from sputum specimens, indicating that the actual drug resistance may be overestimated.

Effect of Treating Parents Colonized With Staphylococcus aureus on Transmission to Neonates in the Intensive Care Unit: A Randomized Clinical Trial

IMPORTANCE

Staphylococcus aureus is a leading cause of health care-associated infections in the neonatal intensive care unit (NICU). Parents may expose neonates to S aureus colonization, a well-established predisposing factor to invasive S aureus disease.

OBJECTIVE

To test whether treating parents with intranasal mupirocin and topical chlorhexidine compared with placebo would reduce transmission of S aureus from parents to neonates.

DESIGN, SETTING, AND PARTICIPANTS

Double-blinded randomized clinical trial in 2 tertiary NICUs in Baltimore, Maryland. Neonates (n = 236) with S aureus-colonized parent(s) were enrolled. The study period was November 7, 2014, through December 13, 2018.

INTERVENTIONS

Parents were assigned to intranasal mupirocin and 2% chlorhexidine-impregnated cloths (active treatment, n = 117) or petrolatum intranasal ointment and nonmedicated soap cloths (placebo, n = 119) for 5 days.

MAIN OUTCOMES AND MEASURES

The primary end point was concordant S aureus colonization by 90 days, defined as neonatal acquisition of an S aureus strain that was the same strain as a parental strain at time of screening. Secondary outcomes included neonatal acquisition of any S aureus strain and neonatal S aureus infections.

RESULTS

Among 236 randomized neonates, 208 were included in the analytic sample (55% male; 76% singleton births; mean birth weight, 1985 g [SD, 958 g]; 76% vaginal birth; mean parent age, 31 [SD, 7] years), of whom 18 were lost to follow-up. Among 190 neonates included in the analysis, 74 (38.9%) acquired S aureus colonization by 90 days, of which 42 (56.8%) had a strain concordant with a parental baseline strain. In the intervention and placebo groups, 13 of 89 neonates (14.6%) and 29 of 101 neonates (28.7%), respectively, acquired concordant S aureus colonization (risk difference, -14.1% [95% CI, -30.8% to -3.9%]; hazard ratio [HR], 0.43 [95.2% CI, 0.16 to 0.79]). A total of 28 of 89 neonates (31.4%) in the intervention group and 46 of 101 (45.5%) in the control group acquired any S aureus strain (HR, 0.57 [95% CI, 0.31 to 0.88]), and 1 neonate (1.1%) in the intervention group and 1 neonate (1.0%) in the control group developed an S aureus infection before colonization. Skin reactions in parents were common (4.8% intervention, 6.2% placebo).

CONCLUSIONS AND RELEVANCE

In this preliminary trial of parents colonized with S aureus, treatment with intranasal mupirocin and chlorhexidine-impregnated cloths compared with placebo significantly reduced neonatal colonization with an S aureus strain concordant with a parental baseline strain. However, further research is needed to replicate these findings and to assess their generalizability.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02223520.

Effects of the proportion of high-risk patients and control strategies on the prevalence of methicillin-resistant Staphylococcus aureus in an intensive care unit

Background

The presence of nosocomial pathogens in many intensive care units poses a threat to patients and public health worldwide. Methicillin-resistant Staphylococcus aureus (MRSA) is an important pathogen endemic in many hospital settings. Patients who are colonized with MRSA may develop an infection that can complicate their prior illness.

Methods

A mathematical model to describe transmission dynamics of MRSA among high-risk and low-risk patients in an intensive care unit (ICU) via hands of health care workers is developed. We aim to explore the effects of the proportion of high-risk patients, the admission proportions of colonized and infected patients, the probability of developing an MRSA infection, and control strategies on MRSA prevalence among patients.

Results

The increasing proportion of colonized and infected patients at admission, along with the higher proportion of high-risk patients in an ICU, may significantly increase MRSA prevalence. In addition, the prevalence becomes higher if patients in the high-risk group are more likely to develop an MRSA infection. Our results also suggest that additional infection prevention and control measures targeting high-risk patients may considerably help reduce MRSA prevalence as compared to those targeting low-risk patients.

Conclusions

The proportion of high-risk patients and the proportion of colonized and infected patients in the high-risk group at admission may play an important role on MRSA prevalence. Control strategies targeting high-risk patients may help reduce MRSA prevalence.

Methicillin-resistant Staphylococcus aureus in solid organ transplantation-Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated guidelines from the American Society of Transplantation Infectious Diseases Community of Practice review the epidemiology, diagnosis, prevention, and management of methicillin-resistant Staphylococcus aureus (MRSA) infections in solid organ transplantation. Despite an increasing armamentarium of antimicrobials active against MRSA, improved diagnostic tools, and overall declining rates of infection, MRSA infections remain a substantial cause of morbidity and mortality in solid organ transplant recipients. Pre- and post-transplant MRSA colonization is a significant risk factor for post-transplant MRSA infection. The preferred initial treatment of MRSA bacteremia remains vancomycin. Hand hygiene, chlorhexidine bathing in the ICU, central-line bundles that focus on reducing unnecessary catheter use, disinfection of patient equipment, and the environment along with antimicrobial stewardship are all aspects of an infection prevention approach to prevent MRSA transmission and decrease healthcare-associated infections.

How often are health care personnel hands colonized with multidrug- resistant organisms? A systematic review and meta-analysis

BACKGROUND

Hands of health care personnel (HCP) can transmit multidrug-resistant organisms (MDROs), resulting in infections. Our aim was to determine MDRO prevalence on HCP hands in adult acute care and nursing facility settings.

METHODS

A systematic search of PubMed/MEDLINE, Web of Science, CINAHL, Embase, and Cochrane CENTRAL was performed. Studies were included if they reported microbiologic culture results following HCP hands sampling; included prevalent MDROs, such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus, Clostridium difficile, Acinetobacter baumannii, or Pseudomonas aeruginosa, and were conducted in acute care or nursing facility settings.

RESULTS

Fifty-nine articles comprising 6,840 hand cultures were included. Pooled prevalence for MRSA, P aeruginosa, A baumannii, and vancomycin-resistant Enterococcus were 4.26%, 4.59%, 6.18%, and 9.03%, respectively. Substantial heterogeneity in rates of pathogen isolation were observed across studies (I² = 81%-95%). Only 4 of 59 studies sampled for C difficile, with 2 of 4 finding no growth. Subgroup analysis of MRSA revealed the highest HCP hand contamination rates in North America (8.28%). Sample collection methods used were comparable for MRSA isolation (4%-7%) except for agar direct contact (1.55%).

CONCLUSIONS

Prevalence of common MDROs on HCP hands vary by pathogen, care setting, culture acquisition method, study design, and geography. When obtained at an institutional level, these prevalence data can be utilized to enhance knowledge, practice, and research to prevent health care-associated infections.

Real-time PCR assay for detection of Staphylococcus aureus, Panton-Valentine Leucocidin and Methicillin Resistance directly from clinical samples

Rapid detection of Methicillin Resistant Staphylococcus aureus (MRSA) is an important concern for both treatment and implementation of infection control policies. The present study provides an ‘in house’ real-time PCR assay to detect directly nuc, pvl, and mecA genes. The assay is able to perform identification of MRSA, Methicillin-Sensitive S. aureus, Methicillin-Resistant Coagulase Negative Staphylococci and the Panton-Valentine leukocidin virulence gene from rectal and pharyngeal swab samples in a screening context. We found an analytical sensitivity of this current Triplex PCR assay of 514 CFU/mL. Analytical specificity was tested with different Gram-positive and Gram-negative species and yielded no false-positive PCR signal. The sensitivity and specificity of the Triplex Real Time PCR were both 100% for these targets when compared with the culture and conventional methods. This assay is readily adaptable for routine use in a microbiology laboratory, as it will enable the implementation of timely and properly guided therapy and infection control strategies.

Integration of genomic and clinical data augments surveillance of healthcare-acquired infections

BACKGROUND

Determining infectious cross-transmission events in healthcare settings involves manual surveillance of case clusters by infection control personnel, followed by strain typing of clinical/environmental isolates suspected in said clusters. Recent advances in genomic sequencing and cloud computing now allow for the rapid molecular typing of infecting isolates.

OBJECTIVE

To facilitate rapid recognition of transmission clusters, we aimed to assess infection control surveillance using whole-genome sequencing (WGS) of microbial pathogens to identify cross-transmission events for epidemiologic review.

METHODS

Clinical isolates of Staphylococcus aureus, Enterococcus faecium, Pseudomonas aeruginosa, and Klebsiella pneumoniae were obtained prospectively at an academic medical center, from September 1, 2016, to September 30, 2017. Isolate genomes were sequenced, followed by single-nucleotide variant analysis; a cloud-computing platform was used for whole-genome sequence analysis and cluster identification.

RESULTS

Most strains of the 4 studied pathogens were unrelated, and 34 potential transmission clusters were present. The characteristics of the potential clusters were complex and likely not identifiable by traditional surveillance alone. Notably, only 1 cluster had been suspected by routine manual surveillance.

CONCLUSIONS

Our work supports the assertion that integration of genomic and clinical epidemiologic data can augment infection control surveillance for both the identification of cross-transmission events and the inclusion of missed and exclusion of misidentified outbreaks (ie, false alarms). The integration of clinical data is essential to prioritize suspect clusters for investigation, and for existing infections, a timely review of both the clinical and WGS results can hold promise to reduce HAIs. A richer understanding of cross-transmission events within healthcare settings will require the expansion of current surveillance approaches.

Chlorhexidine versus routine bathing to prevent multidrug-resistant organisms and all-cause bloodstream infections in general medical and surgical units (ABATE Infection trial): a cluster-randomised trial

BACKGROUND

Universal skin and nasal decolonisation reduces multidrug-resistant pathogens and bloodstream infections in intensive care units. The effect of universal decolonisation on pathogens and infections in non-critical-care units is unknown. The aim of the ABATE Infection trial was to evaluate the use of chlorhexidine bathing in non-critical-care units, with an intervention similar to one that was found to reduce multidrug-resistant organisms and bacteraemia in intensive care units.

METHODS

The ABATE Infection (active bathing to eliminate infection) trial was a cluster-randomised trial of 53 hospitals comparing routine bathing to decolonisation with universal chlorhexidine and targeted nasal mupirocin in non-critical-care units. The trial was done in hospitals affiliated with HCA Healthcare and consisted of a 12-month baseline period from March 1, 2013, to Feb 28, 2014, a 2-month phase-in period from April 1, 2014, to May 31, 2014, and a 21-month intervention period from June 1, 2014, to Feb 29, 2016. Hospitals were randomised and their participating non-critical-care units assigned to either routine care or daily chlorhexidine bathing for all patients plus mupirocin for known methicillin-resistant Staphylococcus aureus (MRSA) carriers. The primary outcome was MRSA or vancomycin-resistant enterococcus clinical cultures attributed to participating units, measured in the unadjusted, intention-to-treat population as the HR for the intervention period versus the baseline period in the decolonisation group versus the HR in the routine care group. Proportional hazards models assessed differences in outcome reductions across groups, accounting for clustering within hospitals. This trial is registered with ClinicalTrials.gov, number NCT02063867.

FINDINGS

There were 189 081 patients in the baseline period and 339 902 patients (156 889 patients in the routine care group and 183 013 patients in the decolonisation group) in the intervention period across 194 non-critical-care units in 53 hospitals. For the primary outcome of unit-attributable MRSA-positive or VRE-positive clinical cultures (figure 2), the HR for the intervention period versus the baseline period was 0·79 (0·73-0·87) in the decolonisation group versus 0·87 (95% CI 0·79-0·95) in the routine care group. No difference was seen in the relative HRs (p=0·17). There were 25 (<1%) adverse events, all involving chlorhexidine, among 183 013 patients in units assigned to chlorhexidine, and none were reported for mupirocin.

INTERPRETATION

Decolonisation with universal chlorhexidine bathing and targeted mupirocin for MRSA carriers did not significantly reduce multidrug-resistant organisms in non-critical-care patients.

FUNDING

National Institutes of Health.

The Role of the Environment and Colonization in Healthcare-Associated Infections

Healthcare-associated infections (HAIs) can be caused by endogenous host microbial flora or by exogenous microbes, including those found in the hospital environment. Efforts to decrease endogenous pathogens via decolonization and skin antisepsis may decrease the risk of infection in some settings. Controlling the spread of potential pathogens from the environment requires meticulous attention to cleaning and disinfection practices. In addition to selection of the appropriate cleaning agent, use of tools that assess the adequacy of cleaning and addition of no-touch cleaning technology may decrease environmental contamination. Hand hygiene is also a critical component of preventing transmission of pathogens from the environment to patients via healthcare worker hands.

General Information

Many bacteria, viruses, parasites, fungi and prions may cause serious infections and lead to the isolation of those who are infected from those who are susceptible. Isolation may be done in single rooms or in special isolation units. A modern isolate for patients with infections comprises (1) a sluice with a good space for dressing and undressing of personal protective equipment (PPE) and for hand hygiene, (2) a large patient room and (3) a bathroom/disinfection room with own decontaminator or autoclave and with separate entrance from the patient’s room. Isolates for airborne and droplet-transmitted infections have in addition a defined negative air pressure and hepafiltered exhaust. In all isolates, doors must be closed in such a way that contaminants do not escape the isolate. A modern isolate for patients with impaired immune defence is similar to the infection isolates, with following exceptions: usually no need for decontaminator, hepafiltered clean air into the room and with a defined positive air pressure. A positive pressure isolate should never be used for patients with infections, and a negative pressure isolate should never be used for patients with impaired immune defence, except if the patient also has an infection that needs isolation.

Background Information: Isolation Routines

The isolation of patients with suspected or documented infections—to not spread to others—has been discussed for hundreds of years. Guidelines are many, methods are different, attitudes show vide variations, routines and procedures are still changing, regulations by law may be absent, and some healthcare professionals may be afraid of adverse outcomes of isolation [1–44]. Microbes that are spread in the environment, on the hands and equipment are invisible. The invisible agent does not call on attention before the infection; clinical disease, hospital infection or nosocomial infection is a factum that can be registered [23, 28, 29, 35–37]. How to stop the transmission is often “to believe and not believe” in infection control.

Airborne/Droplet Infection Isolation

Airborne/droplet infection is caused by infected agents in the air around a person. Microbial pathogenic agents that are mainly transmitted airborne are aerosols, re-aerosols, microbe-carrying particles, huge amounts of bacteria-carrying airborne skin cells, dust, droplets and droplet nuclei. At the same time, there is always a contact transmission from contaminated environment, equipment, textiles and waste. Droplet nuclei are small evaporated droplet residues (<5 μm) produced by coughing, sneezing, shouting, singing and speaking very distinct—especially the consonants. Droplet nuclei remain for many hours in the air and may be carried by normal air currents in long distances outside the room. Therefore, “droplet isolation and droplet precaution” is included in the airborne isolation regime. The source of infection is usually a patient but may also be a healthy carrier. The patient should be placed in isolate dedicated for airborne infections.