Isolation and characterization of cefotaxime resistant Escherichia coli from household floors in rural Bangladesh.

Antimicrobial resistance (AMR) is a rising health concern worldwide. As an indicator organism, E. coli, specifically extended-spectrum ß-lactamase (ESBL) producing E. coli, can be used to detect AMR in the environment and estimate the risk of transmitting resistance among humans, animals and the environment. This study focused on detecting cefotaxime resistant E. coli in floor swab samples from 49 households in rural villages in Bangladesh. Following isolation of cefotaxime resistant E. coli, DNA extracted from isolates was subjected to molecular characterization for virulence and resistance genes, determination of resistance to multiple classes of antibiotics to define multidrug resistant (MDR) and extensively drug resistant (XDR) strains, and the biofilm forming capacity of the isolates. Among 49 households, floor swabs from 35 (71 %) households tested positive for cefotaxime resistant E. coli. Notably, all of the 91 representative isolates were ESBL producers, with the majority (84.6 %) containing the bla CTX-M gene, followed by the bla TEM and bla SHV genes detected in 22.0 % and 6.6 % of the isolates, respectively. All isolates were MDR, and one isolate was XDR. In terms of pathogenic strains, 8.8 % of the isolates were diarrheagenic and 5.5 % were extraintestinal pathogenic E. coli (ExPEC). At 25 °C, 45 % of the isolates formed strong biofilm, whereas 43 % and 12 % formed moderate and weak biofilm, respectively. On the other hand, at 37 °C, 1.1 %, 4.4 % and 93.4 % of the isolates were strong, moderate and weak biofilm formers, respectively, and 1.1 % showed no biofilm formation. The study emphasizes the importance of screening and characterizing cefotaxime resistant E. coli from household floors in a developing country setting to understand AMR exposure associated with floors.

Knowledge, attitude, and practices related to lead pollution among adolescents and caregivers of young children living near Used Lead Acid Battery (ULAB) recycling sites in Bangladesh: a cross-sectional study.

BACKGROUND: Lead, a potent neurotoxin, causes irreversible damage to the nervous system, and low- and middle-income countries face huge health and economic productivity losses due to childhood lead exposure. In Bangladesh, informal Used Lead Acid Battery (ULAB) recycling sites are an important source of lead pollution. Little is known about lead awareness among communities exposed to ULAB recycling. Therefore, this study aims to assess knowledge, attitudes, and practices related to lead pollution among caregivers of young children and adolescents living adjacent to informal ULAB sites. METHODS: A cross-sectional study was conducted among 732 mothers of young children and adolescents in 4 districts of Bangladesh (survey and observation). Simple and multiple linear regression was conducted to describe patterns and predictors of lead-related knowledge and practices. RESULTS: 60% of respondents had heard the name 'lead' ("shisha"). The mean knowledge score was low (19 out of 44). Residents of high-risk districts, male respondents, and those with more than 5 years of schooling were significantly more likely to have higher knowledge scores than others. In terms of attitude, 52% of respondents perceived lead to be risky for human health but 43% thought lead pollution was controllable. Observation of households for lead exposure revealed that 63% of children and adolescents play or pass by ULAB sites, 29% ate non-food items, 41% of households had visible paint chips on the walls, 59% households used polished turmeric and 15% used lead-soldered cans to store foods. Among protective practices, 70% reported cleaning floors, 84% consumed iron-rich foods, and 48% consumed calcium-rich foods. CONCLUSIONS: The population had a high potential for lead exposure. Their knowledge about lead was limited, and risk perception was moderate. To reduce lead exposure and increase knowledge and awareness among the at-risk population, it is crucial to take measures such as mass awareness campaigns through media and schools. It is important to strengthen the implementation of existing policies, such as policies on leaded gasoline, paints, and lead-acid batteries, that can address the sources of lead exposure for the community.

Effects of household concrete floors on maternal and child health - the CRADLE trial: a randomised controlled trial protocol.

Introduction: Early life soil-transmitted helminth infection and diarrhea are associated with growth faltering, anemia, impaired child development, and mortality. Exposure to fecally contaminated soil inside the home may be a key contributor to enteric infections, and a large fraction of rural homes in low-income countries have soil floors. The objective of this study is to measure the effect of installing concrete floors in homes with soil floors on child soil-transmitted helminth infection and other maternal and child health outcomes in rural Bangladesh. Methods and analysis: The Cement-based flooRs AnD chiLd hEalth (CRADLE) trial is an individually randomised trial in Sirajganj and Tangail districts, Bangladesh. Households with a pregnant woman, a soil floor, walls that are not made of mud will be eligible, and no plan to relocate for 3 years. We will randomise 800 households to intervention or control (1:1) within geographic blocks of 10 households to account for strong geographic clustering of enteric infection. Laboratory staff and data analysts will be blinded; participants will be unblinded. We will install concrete floors when the birth cohort is in utero and measure outcomes at child ages 3, 6, 12, 18, and 24 months. The primary outcome is prevalence of any soil-transmitted helminth infection (Ascaris lumbricoides, Necator americanus, or Trichuris trichiura) detected by qPCR at 6, 12, 18, or 24 months follow-up in the birth cohort. Secondary outcomes include household floor and child hand contamination with E. coli, extended-spectrum beta-lactamase producing E. coli, and soil-transmitted helminth DNA; child diarrhea, growth, and cognitive development; and maternal stress and depression. Ethics and dissemination: Study protocols have been approved by institutional review boards at Stanford University and the International Centre for Diarrheal Disease Research, Bangladesh (icddr,b). We will report findings on ClinicalTrials.gov, in peer-reviewed publications, and in stakeholder workshops in Bangladesh. Trial registration number: NCT05372068, pre-results.

Trends in prevalence and correlates of tobacco use among school-going adolescents in Bhutan: A secondary data analysis of the 2004-2019 Global Youth Tobacco Survey.

Tobacco use remains a major public health challenge globally. In Bhutan, despite the implementation of strict tobacco control measures, the tobacco uses among the students continue to be alarmingly high compared to neighboring countries. This study aims to analyze the trends and correlates of tobacco use among students in Bhutan, utilizing the nationally representative Global Youth Tobacco Survey (GYTS) data from multiple survey years. Secondary analyses of GYTS data collected during 2004-2019 with 12,594 students aged 11-18 years were employed. Use of tobacco was defined as either smoked or smokeless tobacco use in last 30 days of the survey. Prevalence was estimated over time and multivariable log-binomial regression was used to determine the correlates of current tobacco use. Overall tobacco use prevalence increased from 18.5% in 2004 to 27.3% in 2019. Males had higher prevalence (20.4% in 2019) than females (7.0% in 2019). Smokeless tobacco use increased substantially from 8.2% to 19.4% over the study period. Earlier age of initiation had adjusted odds ratio (aOR) of 9.2 for <11 years and 12.8 for 13-16 years vs. never smoking), betel quid use (aOR 3.3), peer pressure (aOR 3.6), and lower cost were significant correlates of adolescent tobacco use. Despite tobacco control policies, tobacco use among Bhutanese students is high and has been increasing over time, especially smokeless forms. Tobacco uses regulation, targeted interventions for high-risk junior high school students, and addressing social influences are urgently needed to curb this epidemic. Sustained tobacco use surveillance and public health action is imperative to protect students in Bhutan from this harmful habit.

Effectiveness of soil remediation intervention in abandoned used lead acid battery (ULAB) recycling sites to reduce lead exposure among the children.

Lead (Pb) is a neurotoxin, and children are vulnerable due to their evolving physiology and high-risk behaviours. Soil remediation interventions have proven effective in reducing Pb exposure. The primary objective is to measure the effectiveness of soil remediation at abandoned used lead acid battery (ULAB) recycling sites, nearby household cleaning, and community awareness in reducing blood lead levels (BLLs) in children. Additionally, this study aims to examine associations of Pb exposure with hematological, cardiovascular, renal, immunological, and endocrinological parameters in children aged 0-12 years. This study employs a quasi-experimental design, with abandoned ULAB sites as intervention sites and two control sites in Bangladesh. The intervention includes soil remediation coupled with community education. Data will be collected prior to the intervention and at a 12-month follow-up, including a comprehensive Pb exposure survey and collect environmental, turmeric samples, and blood from the child. Pb concentrations in environmental samples and turmeric samples will be determined using XRF analyser. Child BLL will be measured using Graphite Furnace Atomic Absorption Spectrometry (GF-AAS) and proposed biochemical parameters will be analysed using routine laboratory methods. This study could provide valuable insights for designing targeted interventions in similar settings and mitigating exposure to Pb.

Sex-Specific Association of Ambient Temperature With Urine Biomarkers in Southwest Coastal Bangladesh.

Introduction: Men are vulnerable to ambient heat-related kidney disease burden; however, limited evidence exists on how vulnerable women are when exposed to high ambient heat. We evaluated the sex-specific association between ambient temperature and urine electrolytes, and 24-hour urine total protein, and volume. Methods: We pooled a longitudinal 5624 person-visits data of 1175 participants' concentration and 24-hour excretion of urine electrolytes and other biomarkers (24-hour urine total protein and volume) from southwest coastal Bangladesh (Khulna, Satkhira, and Mongla districts) during November 2016 to April 2017. We then spatiotemporally linked ambient temperature data from local weather stations to participants' health outcomes. For evaluating the relationships between average ambient temperature and urine electrolytes and other biomarkers, we plotted confounder-adjusted restricted cubic spline (RCS) plots using participant-level, household-level, and community-level random intercepts. We then used piece-wise linear mixed-effects models for different ambient temperature segments determined by inflection points in RCS plots and reported the maximum likelihood estimates and cluster robust standard errors. By applying interaction terms for sex and ambient temperature, we determined the overall significance using the Wald test. Bonferroni correction was used for multiple comparisons. Results: The RCS plots demonstrated nonlinear associations between ambient heat and urine biomarkers for males and females. Piecewise linear mixed-effects models suggested that sex did not modify the relationship of ambient temperature with any of the urine parameters after Bonferroni correction (P < 0.004). Conclusion: Our findings suggest that women are as susceptible to the effects of high ambient temperature exposure as men.

Near coding-complete genome sequence of 12 dengue serotype 2 viruses from the 2023 outbreak in Bangladesh.

We report the near coding-complete genomes of 12 DENV serotype 2 strains collected during the 2023 dengue outbreak in Bangladesh. Analyses showed that all 12 strains were closely related and belonged to genotype II-Cosmopolitan.

Influence of hydrometeorological risk factors on child diarrhea and enteropathogens in rural Bangladesh.

BACKGROUND: A number of studies have detected relationships between weather and diarrhea. Few have investigated associations with specific enteric pathogens. Understanding pathogen-specific relationships with weather is crucial to inform public health in low-resource settings that are especially vulnerable to climate change. OBJECTIVES: Our objectives were to identify weather and environmental risk factors associated with diarrhea and enteropathogen prevalence in young children in rural Bangladesh, a population with high diarrheal disease burden and vulnerability to weather shifts under climate change. METHODS: We matched temperature, precipitation, surface water, and humidity data to observational longitudinal data from a cluster-randomized trial that measured diarrhea and enteropathogen prevalence in children 6 months-5.5 years from 2012-2016. We fit generalized additive mixed models with cubic regression splines and restricted maximum likelihood estimation for smoothing parameters. RESULTS: Comparing weeks with 30°C versus 15°C average temperature, prevalence was 3.5% higher for diarrhea, 7.3% higher for Shiga toxin-producing Escherichia coli (STEC), 17.3% higher for enterotoxigenic E. coli (ETEC), and 8.0% higher for Cryptosporidium. Above-median weekly precipitation (median: 13mm; range: 0-396mm) was associated with 29% higher diarrhea (adjusted prevalence ratio 1.29, 95% CI 1.07, 1.55); higher Cryptosporidium, ETEC, STEC, Shigella, Campylobacter, Aeromonas, and adenovirus 40/41; and lower Giardia, sapovirus, and norovirus prevalence. Other associations were weak or null. DISCUSSION: Higher temperatures and precipitation were associated with higher prevalence of diarrhea and multiple enteropathogens; higher precipitation was associated with lower prevalence of some enteric viruses. Our findings emphasize the heterogeneity of the relationships between hydrometeorological variables and specific enteropathogens, which can be masked when looking at composite measures like all-cause diarrhea. Our results suggest that preventive interventions targeted to reduce enteropathogens just before and during the rainy season may more effectively reduce child diarrhea and enteric pathogen carriage in rural Bangladesh and in settings with similar meteorological characteristics, infrastructure, and enteropathogen transmission.

Inadequate sanitation in healthcare facilities: A comprehensive evaluation of toilets in major hospitals in Dhaka, Bangladesh.

BACKGROUND: Lack of access to functional and hygienic toilets in healthcare facilities (HCFs) is a significant public health issue in low- and middle-income countries (LMICs), leading to the transmission of infectious diseases. Globally, there is a lack of studies characterising toilet conditions and estimating user-to-toilet ratios in large urban hospitals in LMICs. We conducted a cross-sectional study in 10-government and two-private hospitals to explore the availability, functionality, cleanliness, and user-to-toilet ratio in Dhaka, Bangladesh. METHODS: From Aug-Dec 2022, we undertook infrastructure assessments of toilets in selected hospitals. We observed all toilets and recorded attributes of intended users, including sex, disability status, patient status (in-patient/out-patient/caregiver) and/or staff (doctor/nurse/cleaner/mixed-gender/shared). Toilet functionality was defined according to criteria used by the WHO/UNICEF Joint-Monitoring Programme in HCFs. Toilet cleanliness was assessed, considering visible feces on any surface, strong fecal odor, presence of flies, sputum, insects, and rodents, and solid waste. RESULTS: Amongst 2875 toilets, 2459 (86%) were observed. Sixty-eight-percent of government hospital toilets and 92% of private hospital toilets were functional. Only 33% of toilets in government hospitals and 56% in private hospitals were clean. A high user-to-toilet ratio was observed in government hospitals' outpatients service (214:1) compared to inpatients service (17:1). User-to-toilet ratio was also high in private hospitals' outpatients service (94:1) compared to inpatients wards (19:1). Only 3% of toilets had bins for menstrual-pad disposal and <1% of toilets had facilities for disabled people. CONCLUSION: A high percentage of unclean toilets coupled with high user-to-toilet ratio hinders the achievement of SDG by 2030 and risks poor infection-control. Increasing the number of usable, clean toilets in proportion to users is crucial. The findings suggest an urgent call for attention to ensure basic sanitation facilities in Dhaka's HCFs. The policy makers should allocate resources for adequate toilets, maintenance staff, cleanliness, along with strong leadership of the hospital administrators.

Hormonal, liver, and renal function associated with electronic waste (e-waste) exposure in Dhaka, Bangladesh.

Electronic waste (e-waste) contains numerous metals and organic pollutants that have detrimental impacts on human health. We studied 199 e-waste recycling workers and 104 non-exposed workers; analyzed blood, urine, and hair samples to measure heavy metals, hormonal, liver, and renal function. We used quantile regression models to evaluate the impact of Pb, Cd, and Hg on hormonal, liver and renal function, and the role of DNA oxidative damage in mediating the relationship between exposures and outcomes. Exposed workers had higher blood lead (Pb) (median 11.89 vs 3.63 µg/dL), similar blood cadmium (Cd) (1.04 vs 0.99 µg/L) and lower total mercury (Hg) in hair (0.38 vs 0.57 ppm) than non-exposed group. Exposed workers also had elevated median concentrations of total triiodothyronine (TT3), aspartate aminotransferase (AST), alanine aminotransferase (ALT), urinary albumin, albumin creatinine ratio (ACR) and estimated glomerular filtration rate (eGFR) were significantly higher than non-exposed group (p≤0.05). Sex hormones including luteinizing hormone, follicle stimulating hormone, estrogen, progesterone and testosterone concentrations were not significantly different between exposed and non-exposed (all p≥0.05). The median concentration of ALT was 4.00 (95% CI: 0.23, 7.77), urinary albumin was 0.09 (95% CI: 0.06, 0.12) and ACR was 1.31 (95% CI: 0.57, 2.05) units higher in the exposed group compared to non-exposed group. Pb was associated with a 3.67 unit increase in the ALP (95% CI: 1.53, 5.80), 0.01 unit increase in urinary albumin (95% CI: 0.002, 0.01), and 0.07 unit increase in ACR (95% CI: 0.01, 0.13). However, no hormonal, renal, and hepatic parameters were associated with Cd or Hg. Oxidative DNA damage did not mediate exposure-outcome relationships (p≥0.05). Our data indicate e-waste exposure impairs liver and renal functions secondary to elevated Pb levels. Continuous monitoring, longitudinal studies to evaluate the dose-response relationship and effective control measure are required to protect workers from e-waste exposure.

Influence of Temperature and Precipitation on the Effectiveness of Water, Sanitation, and Handwashing Interventions against Childhood Diarrheal Disease in Rural Bangladesh: A Reanalysis of the WASH Benefits Bangladesh Trial.

BACKGROUND: Diarrheal disease is a leading cause of childhood morbidity and mortality globally. Household water, sanitation, and handwashing (WASH) interventions can reduce exposure to diarrhea-causing pathogens, but meteorological factors may impact their effectiveness. Information about effect heterogeneity under different weather conditions is critical to refining these targeted interventions. OBJECTIVES: We aimed to determine whether temperature and precipitation modified the effect of low-cost, point-of-use WASH interventions on child diarrhea. METHODS: We analyzed data from a trial in rural Bangladesh that compared child diarrhea prevalence between clusters (N=720) that were randomized to different WASH interventions between 2012 and 2016 (NCT01590095). We matched temperature and precipitation measurements to diarrhea outcomes (N=12,440 measurements, 6,921 children) by geographic coordinates and date. We estimated prevalence ratios (PRs) using generative additive models and targeted maximum likelihood estimation to assess the effectiveness of each WASH intervention under different weather conditions. RESULTS: Generally, WASH interventions most effectively prevented diarrhea during monsoon season, particularly following weeks with heavy rain or high temperatures. The PR for diarrhea in the WASH interventions group compared with the control group was 0.49 (95% CI: 0.35, 0.68) after 1 d of heavy rainfall, with a less-protective effect [PR=0.87 (95% CI: 0.60, 1.25)] when there were no days with heavy rainfall. Similarly, the PR for diarrhea in the WASH intervention group compared with the control group was 0.60 (95% CI: 0.48, 0.75) following above-median temperatures vs. 0.91 (95% CI: 0.61, 1.35) following below-median temperatures. The influence of precipitation and temperature varied by intervention type; for precipitation, the largest differences in effectiveness were for the sanitation and combined WASH interventions. DISCUSSION: WASH intervention effectiveness was strongly influenced by precipitation and temperature, and nearly all protective effects were observed during the rainy season. Future implementation of these interventions should consider local environmental conditions to maximize effectiveness, including targeted efforts to maintain latrines and promote community adoption ahead of monsoon seasons. https://doi.org/10.1289/EHP13807.

Emergence of SARS-CoV-2 Omicron sub-lineage JN.1 in Bangladesh.

We report complete genome sequences of 14 severe acute respiratory syndrome coronavirus 2 Omicron sub-lineage JN.1 obtained from Bangladeshi individuals between 19 December 2023 and 21 January 2024. All sequence data were generated by Oxford Nanopore Sequencing Technology using the amplicon sequencing approach developed by the ARTIC network.

Treatment Heterogeneity of Water, Sanitation, Hygiene, and Nutrition Interventions on Child Growth by Environmental Enteric Dysfunction and Pathogen Status for Young Children in Bangladesh.

Background: Water, sanitation, hygiene (WSH), nutrition (N), and combined (N+WSH) interventions are often implemented by global health organizations, but WSH interventions may insufficiently reduce pathogen exposure, and nutrition interventions may be modified by environmental enteric dysfunction (EED), a condition of increased intestinal permeability and inflammation. This study investigated the heterogeneity of these treatments' effects based on individual pathogen and EED biomarker status with respect to child linear growth. Methods: We applied cross-validated targeted maximum likelihood estimation and super learner ensemble machine learning to assess the conditional treatment effects in subgroups defined by biomarker and pathogen status. We analyzed treatment (N+WSH, WSH, N, or control) randomly assigned in-utero, child pathogen and EED data at 14 months of age, and child LAZ at 28 months of age. We estimated the difference in mean child length for age Z-score (LAZ) under the treatment rule and the difference in stratified treatment effect (treatment effect difference) comparing children with high versus low pathogen/biomarker status while controlling for baseline covariates. Results: We analyzed data from 1,522 children, who had median LAZ of -1.56. We found that myeloperoxidase (N+WSH treatment effect difference 0.0007 LAZ, WSH treatment effect difference 0.1032 LAZ, N treatment effect difference 0.0037 LAZ) and Campylobacter infection (N+WSH treatment effect difference 0.0011 LAZ, WSH difference 0.0119 LAZ, N difference 0.0255 LAZ) were associated with greater effect of all interventions on growth. In other words, children with high myeloperoxidase or Campylobacter infection experienced a greater impact of the interventions on growth. We found that a treatment rule that assigned the N+WSH (LAZ difference 0.23, 95% CI (0.05, 0.41)) and WSH (LAZ difference 0.17, 95% CI (0.04, 0.30)) interventions based on EED biomarkers and pathogens increased predicted child growth compared to the randomly allocated intervention. Conclusions: These findings indicate that EED biomarker and pathogen status, particularly Campylobacter and myeloperoxidase (a measure of gut inflammation), may be related to impact of N+WSH, WSH, and N interventions on child linear growth.

A cluster-randomized trial of water, sanitation, handwashing and nutritional interventions on stress and epigenetic programming.

A regulated stress response is essential for healthy child growth and development trajectories. We conducted a cluster-randomized trial in rural Bangladesh (funded by the Bill & Melinda Gates Foundation, ClinicalTrials.gov NCT01590095) to assess the effects of an integrated nutritional, water, sanitation, and handwashing intervention on child health. We previously reported on the primary outcomes of the trial, linear growth and caregiver-reported diarrhea. Here, we assessed additional prespecified outcomes: physiological stress response, oxidative stress, and DNA methylation (N = 759, ages 1-2 years). Eight neighboring pregnant women were grouped into a study cluster. Eight geographically adjacent clusters were block-randomized into the control or the combined nutrition, water, sanitation, and handwashing (N + WSH) intervention group (receiving nutritional counseling and lipid-based nutrient supplements, chlorinated drinking water, upgraded sanitation, and handwashing with soap). Participants and data collectors were not masked, but analyses were masked. There were 358 children (68 clusters) in the control group and 401 children (63 clusters) in the intervention group. We measured four F2-isoprostanes isomers (iPF(2α)-III; 2,3-dinor-iPF(2α)-III; iPF(2α)-VI; 8,12-iso-iPF(2α)-VI), salivary alpha-amylase and cortisol, and methylation of the glucocorticoid receptor (NR3C1) exon 1F promoter including the NGFI-A binding site. Compared with control, the N + WSH group had lower concentrations of F2-isoprostanes isomers (differences ranging from -0.16 to -0.19 log ng/mg of creatinine, P < 0.01), elevated post-stressor cortisol (0.24 log µg/dl; P < 0.01), higher cortisol residualized gain scores (0.06 µg/dl; P = 0.023), and decreased methylation of the NGFI-A binding site (-0.04; P = 0.037). The N + WSH intervention enhanced adaptive responses of the physiological stress system in early childhood.

Rapid Switching of a C-Series Linear Accelerator Between Conventional and Ultrahigh-Dose-Rate Research Mode With Beamline Modifications and Output Stabilization.

PURPOSE: In this study, a C-series linear accelerator was configured to enable rapid and reliable conversion between the production of conventional electron beams and an ultrahigh-dose-rate (UHDR) electron beamline to the treatment room isocenter for FLASH radiation therapy. Efforts to tune the beam resulted in a consistent, stable UHDR beamline. METHODS AND MATERIALS: The linear accelerator was configured to allow for efficient switching between conventional and modified electron output modes within 2 minutes. Additions to the air system allow for retraction of the x-ray target from the beamline when the 10 MV photon mode is selected. With the carousel set to an empty port, this grants access to the higher current pristine electron beam normally used to produce clinical photon fields. Monitoring signals related to the automatic frequency control system allows for tuning of the waveguide while the machine is in a hold state so a stable beam is produced from the initial pulse. A pulse counting system implemented on an field-programmable gate array-based controller platform controls the delivery to a desired number of pulses. Beam profiles were measured with Gafchromic film. Pulse-by-pulse dosimetry was measured using a custom electrometer designed around the EDGE diode. RESULTS: This method reliably produces a stable UHDR electron beam. Open-field measurements of the 16-cm full-width, half-maximum gaussian beam saw average dose rates of 432 Gy/s at treatment isocenter. Pulse overshoots were limited and ramp up was eliminated. Over the last year, there have been no recorded incidents that resulted in machine downtime due to the UHDR conversions. CONCLUSIONS: Stable 10 MeV UHDR beams were generated to produce an average dose rate of 432 Gy/s at the treatment room isocenter. With a reliable pulse-counting beam control system, consistent doses can be delivered for FLASH experiments with the ability to accommodate a wide range of field sizes, source-to-surface distances, and other experimental apparatus that may be relevant for future clinical translation.

Improved Child Feces Management Mediates Reductions in Childhood Diarrhea from an On-Site Sanitation Intervention: Causal Mediation Analysis of a Cluster-Randomized Trial in Rural Bangladesh.

BACKGROUND: The WASH benefits Bangladesh trial multi-component sanitation intervention reduced diarrheal disease among children < 5 years. Intervention components included latrine upgrades, child feces management tools, and behavioral promotion. It remains unclear which components most impacted diarrhea. METHODS: We conducted mediation analysis within a subset of households (n = 720) from the sanitation and control arms. Potential mediators were categorized into indicators of latrine quality, latrine use practices, and feces management practices. We estimated average causal mediation effects (ACME) as prevalence differences (PD), defined as the intervention's effect on diarrhea through its effect on the mediator. RESULTS: The intervention improved all indicators compared to controls. We found significant mediation through multiple latrine use and feces management practice indicators. The strongest mediators during monsoon seasons were reduced open defecation among children aged < 3 and 3-8 years, and increased disposal of child feces into latrines. The strongest mediators during dry seasons were access to a flush/pour-flush latrine, reduced open defecation among children aged 3-8 years, and increased disposal of child feces into latrines. Individual mediation effects were small (PD = 0.5-2 percentage points) compared to the overall intervention effect but collectively describe significant mediation pathways. DISCUSSION: The effect of the WASH Benefits Bangladesh sanitation intervention on diarrheal disease was mediated through improved child feces management and reduced child open defecation. Although the intervention significantly improved latrine quality, relatively high latrine quality at baseline may have limited benefits from additional improvements. Targeting safe child feces management may increase the health benefits of rural sanitation interventions.

First Monte Carlo beam model for ultra-high dose rate radiotherapy with a compact electron LINAC.

BACKGROUND: FLASH radiotherapy based on ultra-high dose rate (UHDR) is actively being studied by the radiotherapy community. Dedicated UHDR electron devices are currently a mainstay for FLASH studies. PURPOSE: To present the first Monte Carlo (MC) electron beam model for the UHDR capable Mobetron (FLASH-IQ) as a dose calculation and treatment planning platform for preclinical research and FLASH-radiotherapy (RT) clinical trials. METHODS: The initial beamline geometry of the Mobetron was provided by the manufacturer, with the first-principal implementation realized in the Geant4-based GAMOS MC toolkit. The geometry and electron source characteristics, such as energy spectrum and beamline parameters, were tuned to match the central-axis percentage depth dose (PDD) and lateral profiles for the pristine beam measured during machine commissioning. The thickness of the small foil in secondary scatter affected the beam model dominantly and was fine tuned to achieve the best agreement with commissioning data. Validation of the MC beam modeling was performed by comparing the calculated PDDs and profiles with EBT-XD radiochromic film measurements for various combinations of applicators and inserts. RESULTS: The nominal 9 MeV electron FLASH beams were best represented by a Gaussian energy spectrum with mean energy of 9.9 MeV and variance (σ) of 0.2 MeV. Good agreement between the MC beam model and commissioning data were demonstrated with maximal discrepancy < 3% for PDDs and profiles. Hundred percent gamma pass rate was achieved for all PDDs and profiles with the criteria of 2 mm/3%. With the criteria of 2 mm/2%, maximum, minimum and mean gamma pass rates were (100.0%, 93.8%, 98.7%) for PDDs and (100.0%, 96.7%, 99.4%) for profiles, respectively. CONCLUSIONS: A validated MC beam model for the UHDR capable Mobetron is presented for the first time. The MC model can be utilized for direct dose calculation or to generate beam modeling input required for treatment planning systems for FLASH-RT planning. The beam model presented in this work should facilitate translational and clinical FLASH-RT for trials conducted on the Mobetron FLASH-IQ platform.

Tolperisone hydrochloride improves motor functions in Parkinson's disease via MMP-9 inhibition and by downregulating p38 MAPK and ERK1/2 signaling cascade.

The mitogen-activated protein kinase (MAPK) signaling pathway, particularly the p38 MAPK and ERK1/2, has been implicated in the pathogenesis of Parkinson's disease (PD). Recent studies have shown that MAPK signaling pathway can influence the expression of matrix metalloproteinase 9 (MMP-9), known for its involvement in various physiological and pathological processes, including neurodegenerative diseases. This study explores the modulation of MMP-9 expression via the MAPK/ERK signaling cascade and its potential therapeutic implications in the context of PD-associated motor dysfunction. Here, tolperisone hydrochloride (TL), a muscle relaxant that blocks voltage-gated sodium and calcium channels, was used as a treatment to observe its effect on MAPK signaling and MMP-9 expression. Rotenone (RT) exposure in mice resulted in a significant reduction in substantia nigra and primary motor cortex neurons, which were further evidenced by impairments in motor function. When TL was administered, neuron count was restored (89.0 ± 4.78 vs 117.0 ± 4.46/mm2), and most of the motor dysfunction was alleviated. Mechanistically, TL reduced the protein expression of phospho-p38MAPK (1.06 fold vs 1.00 fold) and phospho-ERK1/2 (1.16 fold vs 1.02 fold), leading to the inhibition of MAPK signaling, as well as reduced MMP-9 concentrations (2.76 ± 0.10 vs 1.94 ± 0.10 ng/mL) in the process of rescuing RT-induced neuronal cell death and motor dysfunction. Computational analysis further revealed TL's potential inhibitory properties against MMP-9 along with N and L-type calcium channels. These findings shed light on TL's neuroprotective effects via MMP-9 inhibition and MAPK signaling downregulation, offering potential therapeutic avenues for PD-associated motor dysfunction.

Stress biomarkers and child development in young children in Bangladesh.

BACKGROUND: Hundreds of millions of children in low- and middle-income countries are exposed to chronic stressors, such as poverty, poor sanitation and hygiene, and sub-optimal nutrition. These stressors can have physiological consequences for children and may ultimately have detrimental effects on child development. This study explores associations between biological measures of chronic stress in early life and developmental outcomes in a large cohort of young children living in rural Bangladesh. METHODS: We assessed physiologic measures of stress in the first two years of life using measures of the hypothalamic-pituitary-adrenal (HPA) axis (salivary cortisol and glucocorticoid receptor gene methylation), the sympathetic-adrenal-medullary (SAM) system (salivary alpha-amylase, heart rate, and blood pressure), and oxidative status (F2-isoprostanes). We assessed child development in the first two years of life with the MacArthur-Bates Communicative Development Inventories (CDI), the WHO gross motor milestones, and the Extended Ages and Stages Questionnaire (EASQ). We compared development outcomes of children at the 75th and 25th percentiles of stress biomarker distributions while adjusting for potential confounders using generalized additive models, which are statistical models where the outcome is predicted by a potentially non-linear function of predictor variables. RESULTS: We analyzed data from 684 children (49% female) at both 14 and 28 months of age; we included an additional 765 children at 28 months of age. We detected a significant relationship between HPA axis activity and child development, where increased HPA axis activity was associated with poor development outcomes. Specifically, we found that cortisol reactivity (coefficient -0.15, 95% CI (-0.29, -0.01)) and post-stressor levels (coefficient -0.12, 95% CI (-0.24, -0.01)) were associated with CDI comprehension score, post-stressor cortisol was associated with combined EASQ score (coefficient -0.22, 95% CI (-0.41, -0.04), and overall glucocorticoid receptor methylation was associated with CDI expression score (coefficient -0.09, 95% CI (-0.17, -0.01)). We did not detect a significant relationship between SAM activity or oxidative status and child development. CONCLUSIONS: Our observations reveal associations between the physiological evidence of stress in the HPA axis with developmental status in early childhood. These findings add to the existing evidence exploring the developmental consequences of early life stress.

Is detection of enteropathogens and human or animal faecal markers in the environment associated with subsequent child enteric infections and growth: an individual participant data meta-analysis.

BACKGROUND: Quantifying contributions of environmental faecal contamination to child diarrhoea and growth faltering can illuminate causal mechanisms behind modest health benefits in recent water, sanitation, and hygiene (WASH) trials. We aimed to assess associations between environmental detection of enteropathogens and human or animal microbial source tracking markers (MSTM) and subsequent child health outcomes. METHODS: In this individual participant data meta-analysis we searched we searched PubMed, Embase, CAB Direct Global Health, Agricultural and Environmental Science Database, Web of Science, and Scopus for WASH intervention studies with a prospective design and concurrent control that measured enteropathogens or MSTM in environmental samples, or both, and subsequently measured enteric infections, diarrhoea, or height-for-age Z-scores (HAZ) in children younger than 5 years. We excluded studies that only measured faecal indicator bacteria. The initial search was done on Jan 19, 2021, and updated on March 22, 2023. One reviewer (AM) screened abstracts, and two independent reviewers (AM and RT) examined the full texts of short-listed articles. All included studies include at least one author that also contributed as an author to the present Article. Our primary outcomes were the 7-day prevalence of caregiver-reported diarrhoea and HAZ in children. For specific enteropathogens in the environment, primary outcomes also included subsequent child infection with the same pathogen ascertained by stool testing. We estimated associations using covariate-adjusted regressions and pooled estimates across studies. FINDINGS: Data from nine published reports from five interventions studies, which included 8603 children (4302 girls and 4301 boys), were included in the meta-analysis. Environmental pathogen detection was associated with increased infection prevalence with the same pathogen and lower HAZ (ΔHAZ -0·09 [95% CI -0·17 to -0·01]) but not diarrhoea (prevalence ratio 1·22 [95% CI 0·95 to 1·58]), except during wet seasons. Detection of MSTM was not associated with diarrhoea (no pooled estimate) or HAZ (ΔHAZ -0·01 [-0·13 to 0·11] for human markers and ΔHAZ -0·02 [-0·24 to 0·21] for animal markers). Soil, children's hands, and stored drinking water were major transmission pathways. INTERPRETATION: Our findings support a causal chain from pathogens in the environment to infection to growth faltering, indicating that the lack of WASH intervention effects on child growth might stem from insufficient reductions in environmental pathogen prevalence. Studies measuring enteropathogens in the environment should subsequently measure the same pathogens in stool to further examine theories of change between WASH, faecal contamination, and health. Given that environmental pathogen detection was predictive of infection, programmes targeting specific pathogens (eg, vaccinations and elimination efforts) can environmentally monitor the pathogens of interest for population-level surveillance instead of collecting individual biospecimens. FUNDING: The Bill & Melinda Gates Foundation and the UK Foreign and Commonwealth Development Office.