The CIPAZ study protocol: an open label randomised controlled trial of azithromycin versus ciprofloxacin for the treatment of children hospitalised with dysentery in Ho Chi Minh City, Vietnam

Background: Diarrhoeal disease remains a common cause of illness and death in children <5 years of age. Faecal-oral infection by Shigella spp. causing bacillary dysentery is a leading cause of moderate-to-severe diarrhoea, particularly in low and middle-income countries. In Southeast Asia, S. sonnei predominates and infections are frequently resistant to first-line treatment with the fluoroquinolone, ciprofloxacin. While resistance to all antimicrobials is increasing, there may be theoretical and clinical benefits to prioritizing treatment of bacillary dysentery with the azalide, azithromycin. In this study we aim to measure the efficacy of treatment with azithromycin compared with ciprofloxacin, the current standard of care, for the treatment of children with bacillary dysentery. Methods and analysis: We will perform a multicentre, open-label, randomized controlled trial of two therapeutic options for the antimicrobial treatment of children hospitalised with dysentery. Children (6–60 months of age) presenting with symptoms and signs of dysentery at Children’s Hospital 2 in Ho Chi Minh City will be randomised (1:1) to treatment with either oral ciprofloxacin (15mg/kg/twice daily for 3 days, standard-of-care) or oral azithromycin (10mg/kg/daily for 3 days). The primary endpoint will be the proportion of treatment failure (defined by clinical and microbiological parameters) by day 28 (+3 days) and will be compared between study arms by logistic regression modelling using treatment allocation as the main variable. Ethics and dissemination: The study protocol (version 1.2 dated 27th December 2018) has been approved by the Oxford Tropical Research Ethics Committee (47–18) and the ethical review boards of Children's Hospital 2 (1341/NĐ2-CĐT). The study has also been approved by the Vietnamese Ministry of Health (5044/QĐ-BYT). Trial registration: Clinicaltrials.gov: NCT03854929 (February 26th 2019)

The impact of environmental and climatic variation on the spatiotemporal trends of hospitalized pediatric diarrhea in Ho Chi Minh City, Vietnam.

It is predicted that the integration of climate-based early warning systems into existing action plans will facilitate the timely provision of interventions to diarrheal disease epidemics in resource-poor settings. Diarrhea remains a considerable public health problem in Ho Chi Minh City (HCMC), Vietnam and we aimed to quantify variation in the impact of environmental conditions on diarrheal disease risk across the city. Using all inpatient diarrheal admissions data from three large hospitals within HCMC, we developed a mixed effects regression model to differentiate district-level variation in risk due to environmental conditions from the overarching seasonality of diarrheal disease hospitalization in HCMC. We identified considerable spatial heterogeneity in the risk of all-cause diarrhea across districts of HCMC with low elevation and differential responses to flooding, air temperature, and humidity driving further spatial heterogeneity in diarrheal disease risk. The incorporation of these results into predictive forecasting algorithms will provide a powerful resource to aid diarrheal disease prevention and control practices in HCMC and other similar settings

The influence of human genetic variation on early transcriptional responses and protective immunity following immunization with Rotarix vaccine in infants in Ho Chi Minh City in Vietnam : a study protocol for an open single-arm interventional trial [awaiting peer review]

Background: Rotavirus (RoV) remains the leading cause of acute gastroenteritis in infants and children aged under five years in both high- and low-middle-income countries (LMICs). In LMICs, RoV infections are associated with substantial mortality. Two RoV vaccines (Rotarix and Rotateq) are widely available for use in infants, both of which have been shown to be highly efficacious in Europe and North America. However, for unknown reasons, these RoV vaccines have markedly lower efficacy in LMICs. We hypothesize that poor RoV vaccine efficacy across in certain regions may be associated with genetic heritability or gene expression in the human host. Methods/design: We designed an open-label single-arm interventional trial with the Rotarix RoV vaccine to identify genetic and transcriptomic markers associated with generating a protective immune response against RoV. Overall, 1,000 infants will be recruited prior to Expanded Program on Immunization (EPI) vaccinations at two months of age and vaccinated with oral Rotarix vaccine at two and three months, after which the infants will be followed-up for diarrheal disease until 18 months of age. Blood sampling for genetics, transcriptomics, and immunological analysis will be conducted before each Rotarix vaccination, 2-3 days post-vaccination, and at each follow-up visit (i.e. 6, 12 and 18 months of age). Stool samples will be collected during each diarrheal episode to identify RoV infection. The primary outcome will be Rotarix vaccine failure events (i.e. symptomatic RoV infection despite vaccination), secondary outcomes will be antibody responses and genotypic characterization of the infection virus in Rotarix failure events. Discussion: This study will be the largest and best powered study of its kind to be conducted to date in infants, and will be critical for our understanding of RoV immunity, human genetics in the Vietnam population, and mechanisms determining RoV vaccine-mediated protection. Registration: ClinicalTrials.gov, ID: NCT03587389. Registered on 16 July 2018

Covalently bonded Ir(IV) on conducted blue TiO2 for efficient electrocatalytic oxygen evolution reaction in acid media

© 2021 by the authors. Licensee MDPI, Basel, Switzerland.The stability of anode electrode has been a primary obstacle for the oxygen evolution reaction (OER) in acid media. We design Ir-oxygen of hydroxyl-rich blue TiO2 through covalent bonds (Ir–O2–2Ti) and investigate the outcome of favored exposure of different amounts of covalent Ir–oxygen linked to the conductive blue TiO2 in the acidic OER. The Ir-oxygen-blue TiO2 nanoclusters show a strong synergy in terms of improved conductivity and tiny amount usage of Ir by using blue TiO2 supporter, and enhanced stability using covalent Ir-oxygen-linking (i.e., Ir oxide) in acid media, leading to high acidic OER performance with a current density of 10 mA cm−2 at an overpotential of 342 mV, which is much higher than that of IrO2 at 438 mV in 0.1 M HClO4 electrolyte. Notably, the Ir–O2–2Ti has a great mass activity of 1.38 A/mgIr at an overpotential 350 mV, which is almost 27 times higher than the mass activity of IrO2 at the same overpotential. Therefore, our work provides some insight into non-costly, highly enhanced, and stable electrocatalysts for the OER in acid media.11Nsciescopu

A Performance Comparison of Gigabit-Capable Backhauling Solutions for 5G Cellular Networks

A high-capacity, flexible, cost, and energy efficient backhaul network based on the convergence of optical and wireless technologies is proposed this research work. The proposed backhaul network, which is deployed on wavelength-division multiplexing passive optical network (WDM-PON), supports three backhauling solutions including pure WDM-PON, hybrid WDM-PON/free-space optics (FSO), and hybrid WDM-PON/millimeter-wave (MMW) radio frequency (RF). We firstly have developed mathematical models for performance analysis of the downlink for three comparative backhaul solutions. We then theoretically and comprehensively analyzed the system performance while considering various system parameters such as the total distance, wireless link distance, splitting ratio, amplifier gain, and the bit rate as well as key environment parameters including rain attenuation and atmospheric turbulence. We have also compared the performance of the three alternative backhaul solutions to verify the trade-off between the system performance and the system flexibility/mobility. The numerical results verify the system performance of each backhaul solution. It is demonstrated that combination of these approaches can exploit PON, FSO and RF technologies to provide a flexible and gigabit-bandwidth-capable solution for the fifth generation (5G) backhaul networks

A double blind, randomized, placebo-controlled trial of Lactobacillus acidophilus for the treatment of acute watery diarrhea in Vietnamese children.

Background Probiotics are the most frequently prescribed treatment for children hospitalized with diarrhea in Vietnam. We were in equipoise regarding the benefits of probiotics for the treatment of acute watery diarrhea in Vietnamese children. Methods We conducted a large double blind, placebo-controlled, randomized trial of children hospitalized with acute watery diarrhea Vietnam. Children meeting the inclusion criteria were randomized to either two daily oral doses of 2×10^8 CFUs of a local probiotic containing Lactobacillus acidophilus or placebo for five days as an adjunct to standard-of-care. The primary endpoint was time from the first dose of study medication to the start of the first 24- hour period without diarrhea. Secondary outcomes included the total duration of diarrhea and hospitalization, daily stool frequency, treatment failure, daily fecal concentrations of rotavirus and norovirus, and Lactobacillus colonization. Results 150 children were randomized into each study group. The median time from the first dose of study medication to the start of the first 24-hour diarrhea free period was 43 hours (interquartile range (IQR) 15-66 hours) in the placebo group and 35 hours (IQR 20-68 hours) in the probiotic group (acceleration factor 1.09 (95% confidence interval 1.78-1.51); p=1.62). There was also no evidence that probiotic treatment was efficacious in any of the pre-defined subgroups or significantly associated with any secondary endpoint. Conclusions This was a large double blind, placebo-controlled trial in which the probiotic underwent longitudinal quality control; we found that under these conditions that Lactobacillus acidophilus was not beneficial in treating children with acute watery diarrhea.</p

Advanced Fabrication and Application of Pineapple Aerogels from Agricultural Waste

10.1080/10667857.2019.1688537Materials Technology3511-12807-81

Phenotypic and genotypic characteristics of ESBL and AmpC producing organisms associated with bacteraemia in Ho Chi Minh City, Vietnam

Background Broad-spectrum antimicrobials are commonly used as empirical therapy for infections of presumed bacterial origin. Increasing resistance to these antimicrobial agents has prompted the need for alternative therapies and more effective surveillance. Better surveillance leads to more informed and improved delivery of therapeutic interventions, potentially leading to better treatment outcomes. Methods We screened 1017 Gram negative bacteria (excluding Pseudomonas spp. and Acinetobacter spp.) isolated between 2011 and 2013 from positive blood cultures for susceptibility against third generation cephalosporins, ESBL and/or AmpC production, and associated ESBL/AmpC genes, at the Hospital for Tropical Diseases in Ho Chi Minh City. Results Phenotypic screening found that 304/1017 (30%) organisms were resistance to third generation cephalosporins; 172/1017 (16.9%) of isolates exhibited ESBL activity, 6.2% (63/1017) had AmpC activity, and 0.5% (5/1017) had both ESBL and AmpC activity. E. coli and Aeromonas spp. were the most common organisms associated with ESBL and AmpC phenotypes, respectively. Nearly half of the AmpC producers harboured an ESBL gene. There was no significant difference (p &gt; 0.05) between the antimicrobial resistance phenotypes of the organisms associated with community and hospital-acquired infections. Conclusion AmpC and ESBL producing organisms were commonly associated with bloodstream infections in this setting, with antimicrobial resistant organisms being equally distributed between infections originating from the community and healthcare settings. Aeromonas spp., which was associated with bloodstream infections in cirrhotic/ hepatitis patients, were the most abundant AmpC producing organism. We conclude that empirical monotherapy with third generation cephalosporins may not be optimum in this setting.</p

Patterns of antimicrobial resistance in intensive care unit patients: a study in Vietnam

Abstract Background Antimicrobial resistance has emerged as a major concern in developing countries. The present study sought to define the pattern of antimicrobial resistance in ICU patients with ventilator-associated pneumonia. Methods Between November 2014 and September 2015, we enrolled 220 patients (average age ~ 71 yr) who were admitted to ICU in a major tertiary hospital in Ho Chi Minh City, Vietnam. Data concerning demographic characteristics and clinical history were collected from each patient. The Bauer–Kirby disk diffusion method was used to detect the antimicrobial susceptibility. Results Antimicrobial resistance was commonly found in ceftriaxone (88%), ceftazidime (80%), ciprofloxacin (77%), cefepime (75%), levofloxacin (72%). Overall, the rate of antimicrobial resistance to any drug was 93% (n = 153/164), with the majority (87%) being resistant to at least 2 drugs. The three commonly isolated microorganisms were Acinetobacter (n = 75), Klebsiella (n = 39), and Pseudomonas aeruginosa (n = 29). Acinetobacter baumannii were virtually resistant to ceftazidime, ceftriaxone, piperacilin, imipenem, meropenem, ertapenem, ciprofloxacin and levofloxacin. High rates (>70%) of ceftriaxone and ceftazidime-resistant Klebsiella were also observed. Conclusion These data indicated that critically ill patients on ventilator in Vietnam were at disturbingly high risk of antimicrobial resistance. The data also imply that these Acinetobacter, Klebsiella, and Pseudomonas aeruginosa and multidrug resistance pose serious therapeutic problems in ICU patients. A concerted and systematic effort is required to rapidly identify high risk patients and to reduce the burden of antimicrobial resistance in developing countries

Development and validation of multiplex real-time PCR for simultaneous detection of six bacterial pathogens causing lower respiratory tract infections and antimicrobial resistance genes

Abstract Background Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Escherichia coli, Streptococcus pneumoniae and Staphylococcus aureus are major bacterial causes of lower respiratory tract infections (LRTIs) globally, leading to substantial morbidity and mortality. The rapid increase of antimicrobial resistance (AMR) in these pathogens poses significant challenges for their effective antibiotic therapy. In low-resourced settings, patients with LRTIs are prescribed antibiotics empirically while awaiting several days for culture results. Rapid pathogen and AMR gene detection could prompt optimal antibiotic use and improve outcomes. Methods Here, we developed multiplex quantitative real-time PCR using EvaGreen dye and melting curve analysis to rapidly identify six major pathogens and fourteen AMR genes directly from respiratory samples. The reproducibility, linearity, limit of detection (LOD) of real-time PCR assays for pathogen detection were evaluated using DNA control mixes and spiked tracheal aspirate. The performance of RT-PCR assays was subsequently compared with the gold standard, conventional culture on 50 tracheal aspirate and sputum specimens of ICU patients. Results The sensitivity of RT-PCR assays was 100% for K. pneumoniae, A. baumannii, P. aeruginosa, E. coli and 63.6% for S. aureus and the specificity ranged from 87.5% to 97.6%. The kappa correlation values of all pathogens between the two methods varied from 0.63 to 0.95. The limit of detection of target bacteria was 1600 CFU/ml. The quantitative results from the PCR assays demonstrated 100% concordance with quantitative culture of tracheal aspirates. Compared to culture, PCR assays exhibited higher sensitivity in detecting mixed infections and S. pneumoniae. There was a high level of concordance between the detection of AMR gene and AMR phenotype in single infections. Conclusions Our multiplex quantitative RT-PCR assays are fast and simple, but sensitive and specific in detecting six bacterial pathogens of LRTIs and their antimicrobial resistance genes and should be further evaluated for clinical utility