Evidence of widespread endemic populations of highly multidrug resistant Klebsiella pneumoniae in hospital settings in Hanoi, Vietnam: a prospective cohort study.

BACKGROUND: Patients with prolonged hospitalisation have a significant risk of carriage of and subsequent infection with extended spectrum ß-lactamase (ESBL)-producing and carbapenemase-producing Klebsiella pneumoniae. However, the distinctive roles of the community and hospital environments in the transmission of ESBL-producing or carbapenemase-producing K pneumoniae remain elusive. We aimed to investigate the prevalence and transmission of K pneumoniae within and between the two tertiary hospitals in Hanoi, Viet Nam, using whole-genome sequencing. METHODS: We did a prospective cohort study of 69 patients in intensive care units (ICUs) from two hospitals in Hanoi, Viet Nam. Patients were included if they were aged 18 years or older, admitted for longer than the mean length of stay in their ICU, and cultured K pneumoniae from their clinical samples. Longitudinally collected samples from patients (collected weekly) and the ICU environment (collected monthly) were cultured on selective media, and whole-genome sequences from K pneumoniae colonies analysed. We did phylogenetic analyses and correlated phenotypic antimicrobial susceptibility testing with genotypic features of K pneumoniae isolates. We constructed transmission networks of patient samples, relating ICU admission times and locations with genetic similarity of infecting K pneumoniae. FINDINGS: Between June 1, 2017, and Jan 31, 2018, 69 patients were in the ICUs and eligible for inclusion, and a total of 357 K pneumoniae isolates were cultured and successfully sequenced. 228 (64%) of K pneumoniae isolates carried between two and four different ESBL-encoding and carbapenemase-encoding genes, with 164 (46%) isolates carrying genes encoding both, with high minimum inhibitory concentrations. We found a novel co-occurrence of blaKPC-2 and blaNDM-1 in 46·6% of samples from the globally successful ST15 lineage. Despite being physically and clinically separated, the two hospitals shared closely related strains carrying the same array of antimicrobial resistance genes. INTERPRETATION: These results highlight the high prevalence of ESBL-positive carbapenem-resistant K pneumoniae in ICUs in Viet Nam. Through studying K pneumoniae ST15 in detail, we showed how important resistance genes are contained within these strains that are carried broadly by patients entering the two hospitals directly or through referral. FUNDING: Medical Research Council Newton Fund, Ministry of Science and Technology, Wellcome Trust, Academy of Medical Sciences, Health Foundation, and National Institute for Health and Care Research Cambridge Biomedical Research Centre.

Genomic characterisation of multidrug-resistant Escherichia coli, Klebsiella pneumoniae, and Acinetobacter baumannii in two intensive care units in Hanoi, Viet Nam: a prospective observational cohort study.

BACKGROUND: Viet Nam has high rates of antimicrobial resistance (AMR) but little capacity for genomic surveillance. This study used whole genome sequencing to examine the prevalence and transmission of three key AMR pathogens in two intensive care units (ICUs) in Hanoi, Viet Nam. METHODS: A prospective surveillance study of all adults admitted to ICUs at the National Hospital for Tropical Diseases and Bach Mai Hospital was done between June 19, 2017, and Jan 16, 2018. Clinical and environmental samples were cultured on selective media, characterised with MALDI TOF mass spectrometry, and sequenced with Illumina. Phylogenies based on the de-novo assemblies (SPAdes) were constructed with MAFFT (PARsnp), Gubbins, and RAxML. Resistance genes were detected with Abricate against the US National Center for Biotechnology Information database. FINDINGS: 3153 Escherichia coli, Klebsiella pneumoniae, and Acinetobacter baumannii isolates from 369 patients were analysed. Phylogenetic analysis revealed predominant lineages within A baumannii (global clone 2, sequence types ST2 and ST571) and K pneumoniae (ST15, ST16, ST656, ST11, and ST147) isolates. Isolation from stool was most common with E coli (87·0%) followed by K pneumoniae (62·5%). Of the E coli, 85·0% carried a blaCTX-M variant, while 81·8% of K pneumoniae isolates carried blaNDM (54·4%), or blaKPC (45·1%), or both. Transmission analysis with single nucleotide polymorphisms identified 167 clusters involving 251 (68%) of 369 patients, in some cases involving patients from both ICUs. There were no clear differences between the lineages or AMR genes recovered between the two ICUs. INTERPRETATION: This study represents the largest prospective surveillance study of key AMR pathogens in Vietnamese ICUs. Clusters of closely related isolates in patients across both ICUs suggests recent transmission before ICU admission in other health-care settings or in the community. FUNDING: UK Medical Research Council Newton Fund, Viet Nam Ministry of Science and Technology, Wellcome Trust, Academy of Medical Sciences, Health Foundation, and UK National Institute for Health and Care Research Cambridge Biomedical Research Centre.

Evaluating Electrolyte-Anode Interface Stability in Sodium All-Solid-State Batteries.

All-solid-state batteries have recently gained considerable attention due to their potential improvements in safety, energy density, and cycle-life compared to conventional liquid electrolyte batteries. Sodium all-solid-state batteries also offer the potential to eliminate costly materials containing lithium, nickel, and cobalt, making them ideal for emerging grid energy storage applications. However, significant work is required to understand the persisting limitations and long-term cyclability of Na all-solid-state-based batteries. In this work, we demonstrate the importance of careful solid electrolyte selection for use against an alloy anode in Na all-solid-state batteries. Three emerging solid electrolyte material classes were chosen for this study: the chloride Na2.25Y0.25Zr0.75Cl6, sulfide Na3PS4, and borohydride Na2(B10H10)0.5(B12H12)0.5. Focused ion beam scanning electron microscopy (FIB-SEM) imaging, X-ray photoelectron spectroscopy (XPS), and electrochemical impedance spectroscopy (EIS) were utilized to characterize the evolution of the anode-electrolyte interface upon electrochemical cycling. The obtained results revealed that the interface stability is determined by both the intrinsic electrochemical stability of the solid electrolyte and the passivating properties of the formed interfacial products. With appropriate material selection for stability at the respective anode and cathode interfaces, stable cycling performance can be achieved for Na all-solid-state batteries.

Investigating the abnormal conductivity behaviour of divalent cations in low dielectric constant tetraglyme-based electrolytes.

Solutions made of tetraglyme (G4) containing Ca(TFSI)2 have been studied as models to understand the solvation structure and the conductivity properties of multivalent ions in low dielectric constant ethereal electrolytes. These solutions have been characterised using electrochemical impedance spectroscopy, rheological measurement, and Raman spectroscopy. The ionic conductivity of these electrolytes shows an intriguing non-monotonic behaviour with temperature which deviates from the semi-empirical Vogel-Tammann-Fulcher equation at a critical temperature. This behaviour is observed for both Mg(TFSI)2 and Ca(TFSI)2, but not LiTFSI, indicating a difference in the solvation structure and the thermodynamic properties of divalent ions compared to Li+. The origin of this peculiar behaviour is demystified using temperature-controlled Raman spectroscopy and first-principles calculations combined with a thermodynamic analysis of the chemical equilibrium of Ca2+ ion-pairing versus solvation. As long-range electrostatic interactions are critical in solutions based on low dielectric ethereal solvents, a periodic approach is here proposed to capture their impact on the solvation structure of the electrolyte at different salt concentrations. The obtained results reveal that the thermodynamic and transport properties of Ca(TFSI)2/G4 solutions stem from a competition between enthalpic (ionic strength) and entropic factors that are directly controlled by the solution concentration and temperature, respectively. At high salt concentrations, the ionic strength of the solution favours the existence of free ions thanks to the strong solvation energy of the polydentate G4 solvent conjugated with the weak complexation ability of TFSI-. At elevated temperatures, the configurational entropy associated with the release of a coordinated G4 favours the formation of contact ion-pairs due to its flat potential energy surface (weak strain energy), offering a large configuration space. Such a balance between ion-pair association and dissociation not only rationalises the ionic conductivity behaviour observed for Ca(TFSI)2/G4 solutions, but also provides valuable information to extrapolate the ionic transport properties of other electrolytes with different M(TFSI)n salts dissolved in longer-chain glymes or even poly(ethylene oxide). These findings are essential for the understanding of solvation structures and ionic transport in low-dielectric media, which can further be used to design new electrolytes for Li-ion and post Li-ion batteries as well as electrocatalysts.

The willingness to perform first aid among high school students and associated factors in Hue, Vietnam.

BACKGROUND: Adolescents who are willing to perform first aid can help prevent injuries and ultimately death among themselves and others involved in accidents or injuries. This study aims to estimate the prevalence of students' willingness to perform first aid procedures and additionally examine associated factors among high school students in Hue, Vietnam. METHODS: A cross-sectional study utilizing multi-stage stratified random sampling was conducted between April to July 2020 by investigating 798 high school students in Hue, Vietnam. Participants were invited to complete a self-reported questionnaire pertaining to individual demographic characteristics, personal perception of self-efficacy, and willingness to perform first aid. To better interpret these findings, both multivariable linear and Poisson regression models were fitted to evaluate the association between individual student characteristics and the willingness to perform first aid. RESULTS: The prevalence of having willingness to perform first aid (defined as ≥4 points out of 5 to all three questions) was 49.9% (95%CI:28.6-71.2%). The major reported barriers in performing first aid were fear of making mistakes and hurting victims (34.4%, 95%CI:31.9-37.0%), no prior first aid training (29.8%, 95%CI:25.9-33.9%), and forgetting first aid steps (23.0%, 95%CI:15.8-32.2%). By employing the multivariable linear regression model, it was identified that students with high (ß = 0.614, 95%CI:0.009-1.219) or very high (ß = 1.64, 95%CI:0.857-2.422) levels of self-efficacy appeared to be more willing to perform first aid. Similarly, in the Poisson regression models, compared to neutral students, students who reported high (PR = 1.214, 95%CI:1.048-1.407) or very high (PR = 1.871, 95%CI:1.049-3.337) levels of self-efficacy were more willing to perform first aid. CONCLUSIONS: The level of willingness to perform first aid among high school students in this study population was found to be moderate. Therefore, integrating activities to promote self-efficacy in first aid training could be considered a progressive step towards improving a student's willingness to provide such life-saving procedures.

Continuous versus intermittent endotracheal cuff pressure control for the prevention of ventilator-associated respiratory infections in Vietnam: study protocol for a randomised controlled trial.

BACKGROUND: Ventilator-associated respiratory infection (VARI) comprises ventilator-associated pneumonia (VAP) and ventilator-associated tracheobronchitis (VAT). Although their diagnostic criteria vary, together these are the most common hospital-acquired infections in intensive care units (ICUs) worldwide, responsible for a large proportion of antibiotic use within ICUs. Evidence-based strategies for the prevention of VARI in resource-limited settings are lacking. Preventing the leakage of oropharyngeal secretions into the lung using continuous endotracheal cuff pressure control is a promising strategy. The aim of this study is to investigate the efficacy of automated, continuous endotracheal cuff pressure control in preventing the development of VARI and reducing antibiotic use in ICUs in Vietnam. METHODS/DESIGN: This is an open-label randomised controlled multicentre trial. We will enrol 600 adult patients intubated for ≤ 24 h at the time of enrolment. Eligible patients will be stratified according to admission diagnosis (180 tetanus, 420 non-tetanus) and site and will be randomised in a 1:1 ratio to receive either (1) automated, continuous control of endotracheal cuff pressure or (2) intermittent measurement and control of endotracheal cuff pressure using a manual cuff pressure meter. The primary outcome is the occurrence of VARI, defined as either VAP or VAT during the ICU admission up to a maximum of 90 days after randomisation. Patients in both groups who are at risk for VARI will receive a standardised battery of investigations if their treating physician feels a new infection has occurred, the results of which will be used by an endpoint review committee, blinded to the allocated arm and independent of patient care, to determine the primary outcome. All enrolled patients will be followed for mortality and endotracheal tube cuff-related complications at 28 days and 90 days after randomisation. Other secondary outcomes include antibiotic use; days ventilated, in ICU and in hospital; inpatient mortality; costs of antibiotics in ICU; duration of ICU stay; and duration of hospital stay. DISCUSSION: This study will provide high-quality evidence concerning the use of continuous endotracheal cuff pressure control as a method to reduce VARI, antibiotic use and hospitalisation costs and to shorten stay. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02966392 . Registered on November 9, 2016. Protocol version: 2.0; issue date March 3, 2017.