The Antimicrobial Resistance of Enterotoxigenic Escherichia coli from Diarrheal Patients and the Environment in Two Geographically Distinct Rural Areas in Bangladesh over the Years.

Antimicrobial resistance (AMR) is an unprecedented global health challenge, involving the transfer of bacteria and genes between humans and the environment. We simultaneously and longitudinally determined the AMR of enterotoxigenic Escherichia coli (ETEC) strains isolated from diarrheal patients and an aquatic environment over two years from two geographically distinct locations, Coastal Mathbaria and Northern Chhatak in Bangladesh. A total of 60% and 72% of ETEC strains from the patients in Mathbaria and Chhatak, respectively, were multi-drug resistant (MDR) with a high proportion of ETEC resistant to nalidixic acid (80.7%), macrolides (49.1-89.7%), ampicillin (57.9-69%), and trimethoprim/sulfamethoxazole (55.2%). From the surface water, 68.8% and 30% of ETEC were MDR in Mathbaria and Chhatak, respectively, with a high proportion of ETEC strains resistant to macrolides (87.5-100%), ampicillin (50-75%), ceftriaxone (62.5%), and nalidixic acid (40%). Notably, 80-100% of the ETEC strains were susceptible to tetracycline and quinolones (ciprofloxacin and norfloxacin), both in clinical and aquatic ETEC. The AMR varied by the ETEC toxin types. The patterns of excessive or limited consumption of drugs to treat diarrhea over time in Bangladesh were reflected in the ETEC AMR from the patients and the environment. The high prevalence of MDR-ETEC strains in humans and the environment is of concern, which calls for vaccines and other preventative measures against ETEC.

Epidemiology of Enterotoxigenic Escherichia coli among Children and Adults Seeking Care at Hospitals in Two Geographically Distinct Rural Areas in Bangladesh.

Enterotoxigenic Escherichia coli (ETEC) infections undeniably continue to have substantial morbidity and mortality in younger children; however, limited data are available on the disease burden of older children and adults and on ETEC epidemiology by geographical location at the subnational level. Facility-based surveillance over the years was established to identify patients with ETEC diarrhea in two geographically distinct areas in rural Bangladesh, Chhatak in the north and Mathbaria in the southern coastal area. ETEC was highly prevalent in both areas, while the proportions, toxin types and colonization factors varied by location, season and age groups. Children < 5 years old and adults between 20 and 60 years old were at the highest risk of ETEC diarrhea which required urgent care. This study underscores the importance of capturing subnational and seasonal variations in ETEC epidemiology. ETEC vaccine developers and public health stakeholders may need to target adults between 20 and 60 years of age in addition to young children as new vaccines currently under development become licensed and introduction begins.

Gut microbiota shifts favorably with delivery of handwashing with soap and water treatment intervention in a prospective cohort (CHoBI7 trial).

BACKGROUND: Cholera can result in the expulsion of important microbiota from the gut and result in death if left untreated. The disease transmits mainly via drinking water carrying Vibrio cholerae; and household contacts (HHC) of cholera patients are at elevated risk during the first week of infection. The gut microbiota profiles of HHC-children of cholera patients at Dhaka city slums were investigated before (day 0) and after (day 8) delivery of chlorinated water as part of the major study 'CHoBI7 trial (cholera-hospital-based intervention for 7 days)'. RESULT: Results of sequencing and analysis of bacterial community DNA revealed the predominance of two bacterial phyla: Bacteroidetes and Firmicutes at day 0 with a relative abundance of 62 ± 6 (mean ± SEM%) and 32 ± 7, respectively. The pattern reversed at day 8 with a decreased relative abundance of Bacteroidetes (39 ± 12; p = 0.034) and an increased abundance of Firmicutes (49 ± 12; p = 0.057). Of 65 bacterial families confirmed at day 0, six belonging to Proteobacteria including Vibrionaceae disappeared at day 8. Interestingly, the relative abundance of four Firmicutes families-Lachnospiraceae, Bifidobacteriaceae, Clostridiaceae, and Ruminococcaceae was increased in all five study children at day 8. CONCLUSION: The observed exclusion of pathogenic Proteobacteria and enhancement of beneficial Firmicutes in the gut of children delivered with chlorinated water as part of WASH intervention reflect a great promise of the CHoBI7 program in preventing cholera and improving child health.

Vibrio cholerae O1 associated with recent endemic cholera shows temporal changes in serotype, genotype, and drug-resistance patterns in Bangladesh.

BACKGROUND: Despite the advancement in our understanding of cholera and its etiological agent, Vibrio cholerae, the prevention and treatment of the disease are often hindered due to rapid changes in drug response pattern, serotype, and the major genomic islands namely, the CTX-prophage, and related genetic characteristics. In the present study, V. cholerae (n = 172) associated with endemic cholera in Dhaka during the years 2015-2021 were analyzed for major phenotypic and genetic characteristics, including drug resistance patterns. RESULTS: Results revealed that the V. cholerae strains belonged to serogroup O1 biotype El Tor carrying El Tor -specific genes rtxC, tcpA El Tor, and hlyA El Tor, but possessed classical-biotype cholera toxin. Serotypes of V. cholerae strains differed temporally in predominance with Inaba during 2015-2017, and again in 2020-2021, while Ogawa was the predominant serotype in 2018-2019. Also, ctxB1 was predominant in V. cholerae associated with cholera during 2015-2017, while ctxB7 was predominant in 2018, and in the subsequent years, as observed until 2021. V. cholerae strains differed in their antibiotic resistance pattern with a majority (97%) being multi-drug resistant (MDR) and belonging to six sub-groups. Notably, one of these MDR strains was resistant to eleven of the eighteen antibiotics tested, with resistance to fourth-generation cephalosporin (cefepime), and aztreonam. This extreme drug resistant (XDR) strain carried resistance-related genes namely, extended-spectrum ß-lactamases (ESBL), blaOXA-1 and blaPER-3. CONCLUSION: The observed temporal switching of serotypes, as well as the ctxB genotype, and the emergence of MDR/XDR V. cholerae and their association with endemic cholera in Dhaka underscore the need for routine monitoring of the pathogen for proper patient management.

Genomic attributes of Vibrio cholerae O1 responsible for 2022 massive cholera outbreak in Bangladesh.

In 2022, one of its worst cholera outbreaks began in Bangladesh and the icddr,b Dhaka hospital treated more than 1300 patients and ca. 42,000 diarrheal cases from March-1 to April-10, 20221. Here, we present genomic attributes of V. cholerae O1 responsible for the 2022 Dhaka outbreak and 960 7th pandemic El Tor (7PET) strains from 88 countries. Results show strains isolated during the Dhaka outbreak cluster with 7PET wave-3 global clade strains, but comprise subclade BD-1.2, for which the most recent common ancestor appears to be that responsible for recent endemic cholera in India. BD-1.2 strains are present in Bangladesh since 2016, but not establishing dominance over BD-2 lineage strains2 until 2018 and predominantly associated with endemic cholera. In conclusion, the recent shift in lineage and genetic attributes, including serotype switching of BD-1.2 from Ogawa to Inaba, may explain the increasing number of cholera cases in Bangladesh.

Food Hygiene and Fecal Contamination on the Household Compound are Associated with Increased Pediatric Diarrhea in Urban Bangladesh (CHoBI7 Program).

In this prospective cohort study, we explored individual- and household-level risk factors associated with diarrheal diseases among 251 children younger than 5 years in slum areas of urban Dhaka, Bangladesh. During the 3-month study period, diarrhea surveillance was conducted monthly, and spot checks of the household compound were performed at baseline to assess the presence of feces (animal or human) in the household compound and in cooking and food storage areas, and to assess whether cooked food was covered and refrigerated. We also collected caregiver reports on child mouthing behaviors. Children living in households with feces within 10 steps of cooking and food storage areas (odds ratio [OR], 8.43; 95% CI, 1.01-70.18), those with visible feces found on the ground of the household compound (OR, 4.05; 95% CI, 1.24-13.22), and those in households found to keep cooked food uncovered and without refrigeration (OR, 6.16; 95% CI, 1.11-34.25) during spot checks had a significantly greater odds of diarrhea. There was no significant association between pediatric diarrhea and caregiver-reported child mouthing behaviors or presence of animals in the cooking area. These study findings demonstrate that presence of visible feces in the household compound and near cooking and food storage areas, and poor household food hygiene practices, were significant risk factors for diarrheal disease among young children in Dhaka, Bangladesh. Health communication programs are needed to target these exposure pathways to fecal pathogens.

Vibrio cholerae O1 El Tor strains linked to global cholera show region-specific patterns by pulsed-field gel electrophoresis.

Vibrio cholerae O1 El Tor, causative agent of the ongoing seventh cholera pandemic, is native to the aquatic environment of the Ganges Delta, Bay of Bengal (GDBB). Recent studies traced pandemic strains to the GDBB and proposed global spread of cholera had occurred via intercontinental transmission. In the research presented here, NotI-digested genomic DNA extracted from V. cholerae O1 clinical and environmental strains isolated in Bangladesh during 20042014 was analyzed by pulsed-field gel electrophoresis (PFGE). Results of cluster analysis showed 94.67% of the V. cholerae strains belonged to clade A and included the majority of clinical strains of spatio-temporal origin and representing different cholera endemic foci. The rest of the strains were estuarine, all environmental strains from Mathbaria, Bangladesh, and occurred as singletons, clustered in clades B and C, or in the small clades D and E. Cluster analysis of the Bangladeshi strains and including 157 El Tor strains from thirteen countries in Asia, Africa, and the Americas revealed 85% of the total set of strains belonged to clade A, indicating all were related, yet did not form an homogeneous cluster. Overall, 15% of the global strains comprised multiple small clades or segregated as singletons. Three sub-clades could be discerned within the major clade A, reflecting distinct lineages of V. cholerae O1 El Tor associated with cholera in Asia, Africa, and the Americas. The presence in Asia and the Americas of non-pandemic V. cholerae O1 El Tor populations differing by PFGE and from strains associated with cholera globally suggests different ecotypes are resident in distant geographies.

Intermittent Needs for Family Planning among Women with an Internal Migrant Husband in Bangladesh: A Qualitative Study.

Bangladesh is one of the major labour-exporting countries in the world, with large-scale labour migration flows occurring both internationally and domestically. Spousal separation due to migration has the potential to disrupt women's ability to use contraception in line with their reproductive goals. This qualitative study complements the 2014 Bangladesh Demographic and Health Survey (BDHS) data; we conducted in-depth interviews with a sub-sample of 23 BDHS respondents whose husbands stayed elsewhere but returned at least once a year to Barisal Division, Bangladesh. The study explores how husbands' migration patterns influence couples' fertility intentions, contraceptive decision-making and behaviour, and unintended pregnancies. Results showed that contraceptive use was high among the study participants, with nearly all couples using some method to avoid pregnancy - usually pills and condoms. However, the use was episodic and inconsistent, reducing effectiveness. Experiences of side effects were commonplace, which contributed to this pattern of inconsistent use: women used pills only during the duration of their husband's visits. Half of the informants experienced unintended pregnancies either due to the inconsistent use of pills or other method failures. The study findings indicate that women with migrant husbands need family planning education related to their particular circumstances and access to a wider range of family planning choices. Quality counselling should respect women's experiences with side effects and include thorough discussion of viable alternatives.

Fecal Sampling of Soil, Food, Hand, and Surface Samples from Households in Urban Slums of Dhaka, Bangladesh: An Evidence-Based Development of Baby Water, Sanitation, and Hygiene Interventions.

The aim of this study was to identify the exposure pathways of fecal pathogens for a pediatric population living in the urban slums of Bangladesh. A total of 252 soil, food, surface, and hand rinse samples were collected from the pilot households with children less than 5 years of age. All samples were analyzed using the IDEXX Quanti-Tray System (Colilert-18) to enumerate fecal indicator bacteria Escherichia coli. Escherichia coli was detected in all soil samples collected from children play spaces (N = 46), 35% of objects and surfaces children frequently put in their mouths, and 31% of child food samples. Thirty-three percent of hand samples from the child and 46% of hand samples from the caregiver had detectable E. coli. These findings showed high fecal contamination of soil, food, and on hands and surfaces in households with young children and demonstrate the need for interventions reducing these exposure pathways for susceptible pediatric populations.

Genomic Characteristics of Recently Recognized Vibrio cholerae El Tor Lineages Associated with Cholera in Bangladesh, 1991 to 2017.

Comparative genomic analysis of Vibrio cholerae El Tor associated with endemic cholera in Asia revealed two distinct lineages, one dominant in Bangladesh and the other in India. An in-depth whole-genome study of V. cholerae El Tor strains isolated during endemic cholera in Bangladesh (1991 to 2017) included reference genome sequence data obtained online. Core genome phylogeny established using single nucleotide polymorphisms (SNPs) showed V. cholerae El Tor strains comprised two lineages, BD-1 and BD-2, which, according to Bayesian phylodynamic analysis, originated from paraphyletic group BD-0 around 1981. BD-1 and BD-2 lineages overlapped temporally but were negatively associated as causative agents of cholera during 2004 to 2017. Genome-wide association study (GWAS) revealed 140 SNPs and 31 indels, resulting in gene alleles unique to BD-1 and BD-2. Regression analysis of root to tip distance and year of isolation indicated early BD-0 strains at the base, whereas BD-1 and BD-2 subsequently emerged and progressed by accumulating SNPs. Pangenome analysis provided evidence of gene acquisition by both BD-1 and BD-2, of which six crucial proteins of known function were predominant in BD-2. BD-1 and BD-2 diverged and have distinctively different genomic traits, namely, heterogeneity in VSP-2, VPI-1, mobile elements, toxin encoding elements, and total gene abundance. In addition, the observed phage-inducible chromosomal island-like element (PLE1), and SXT ICE elements (ICETET) in BD-2 presumably provided a fitness advantage for the lineage to outcompete BD-1 as the etiological agent of endemic cholera in Bangladesh, with implications for global cholera epidemiology. IMPORTANCE Cholera is a global disease with specific reference to the Bay of Bengal Ganges Delta where Vibrio cholerae O1 El Tor, the causative agent of the disease showed two circulating lineages, one dominant in Bangladesh and the other in India. Results of an in-depth genomic study of V. cholerae associated with endemic cholera during the past 27 years (1991 to 2017) indicate emergence and succession of the two lineages, BD-1 and BD-2, arising from a common ancestral paraphyletic group, BD-0, comprising the early strains and short-term evolution of the bacterium in Bangladesh. Among the two V. cholerae lineages, BD-2 supersedes BD-1 and is predominant in the most recent endemic cholera in Bangladesh. The BD-2 lineage contained significantly more SNPs and indels, and showed richness in gene abundance, including antimicrobial resistance genes, gene cassettes, and PLE to fight against bacteriophage infection, acquired over time. These findings have important epidemic implications on a global scale.

Dynamic Subspecies Population Structure of Vibrio cholerae in Dhaka, Bangladesh.

Cholera has been endemic to the Ganges Delta for centuries. Although the causative agent, Vibrio cholerae, is autochthonous to coastal and brackish water, cholera occurs continually in Dhaka, the inland capital city of Bangladesh which is surrounded by fresh water. Despite the persistence of this problem, little is known about the environmental abundance and distribution of lineages of V. cholerae, the most important being the pandemic generating (PG) lineage consisting mostly of serogroup O1 strains. To understand spatial and temporal dynamics of PG lineage and other lineages belonging to the V. cholerae species in surface water in and around Dhaka City, we used qPCR and high-throughput amplicon sequencing. Seven different freshwater sites across Dhaka were investigated for six consecutive months, and physiochemical parameters were measured in situ. Total abundance of V. cholerae was found to be relatively stable throughout the 6-month sampling period, with 2 × 105 to 4 × 105 genome copies/L at six sites and around 5 × 105 genome copies/L at the site located in the most densely populated part of Dhaka City. PG O1 V. cholerae was present in high abundance during the entire sampling period and composed between 24 and 92% of the total V. cholerae population, only showing occasional but sudden reductions in abundance. In instances where PG O1 lost its dominance, other lineages underwent a rapid expansion while the size of the total V. cholerae population remained almost unchanged. Intraspecies richness of V. cholerae was positively correlated with salinity, conductivity, and total dissolved solids (TDS), while it was negatively correlated with dissolved oxygen (DO) concentration in water. Interestingly, negative correlation was observed specifically between PG O1 and salinity, even though the changes in this variable were minor (0-0.8 ppt). Observations in this study suggest that at the subspecies level, population composition of naturally occurring V. cholerae can be influenced by fluctuations in environmental factors, which can lead to altered competition dynamics among the lineages.

Temporal shifts in antibiotic resistance elements govern phage-pathogen conflicts.

Bacteriophage predation selects for diverse antiphage systems that frequently cluster on mobilizable defense islands in bacterial genomes. However, molecular insight into the reciprocal dynamics of phage-bacterial adaptations in nature is lacking, particularly in clinical contexts where there is need to inform phage therapy efforts and to understand how phages drive pathogen evolution. Using time-shift experiments, we uncovered fluctuations in Vibrio cholerae's resistance to phages in clinical samples. We mapped phage resistance determinants to SXT integrative and conjugative elements (ICEs), which notoriously also confer antibiotic resistance. We found that SXT ICEs, which are widespread in γ-proteobacteria, invariably encode phage defense systems localized to a single hotspot of genetic exchange. We identified mechanisms that allow phage to counter SXT-mediated defense in clinical samples, and document the selection of a novel phage-encoded defense inhibitor. Phage infection stimulates high-frequency SXT ICE conjugation, leading to the concurrent dissemination of phage and antibiotic resistances.

Dynamics, Diversity, and Virulence of Aeromonas spp. in Homestead Pond Water in Coastal Bangladesh.

Aeromonads are aquatic bacteria associated with frequent outbreaks of diarrhea in coastal Bangladesh, but their potential risks from environmental sources have remained largely unexplored. This study, over 2 years, examined homestead pond waters in the region for monthly dynamics and diversity of Aeromonas spp. The bacterial counts showed bi-modal annual growth peak, pre- and post-monsoon, strongly correlating (p < 0.0005) with temperature. Of 200 isolates characterized, Aeromonas veronii bv. sobria (27%) was predominant among co-existent Aeromonas schubertii (20%), Aeromonas hydrophila (17%), Aeromonas caviae (13%), and three more. PCR screening of virulence-related genes identified 15 genotypes (I to XV), however, enterotoxigenicity in animal model was observed for five genotypes, ca. 18% (nine of 50) strains, prevalent in A. veronii bv. sobria, A. hydrophila, and A. caviae. Pathogenic strains were distinguishable by possessing at least three of the major virulence genes: ascV, hlyA, ela, ast, and alt, together with accessory virulence factors. PFGE of XbaI-digested genomic DNA revealed high genetic diversity and distant lineage of potentially toxigenic clones. Therefore, along with increased global warming, Aeromonas spp. having multi-factorial virulence potential in coastal ponds that serve as drinking water sources pose a potential health risk, and underscores the need for routine monitoring.

Fecal Contamination on the Household Compound and in Water Sources are Associated with Subsequent Diarrhea in Young Children in Urban Bangladesh (CHoBI7 Program).

We investigated the environmental and individual-level risk factors for diarrheal disease among young children in slum areas of Dhaka, Bangladesh. A prospective cohort study was conducted among 884 children under 5 years of age. Caregiver reports were collected on sociodemographic factors and hygiene behaviors. Diarrhea surveillance data was collected monthly based on caregiver-reported diarrhea for children in the past 2 weeks during the 12-month study period. Unannounced spot checks of the household compound were performed at 1, 3, 6, 9, and 12 months after enrollment to check for the presence of feces (animal or human) and the presence of animals in the child's sleeping space, to assess child and caregiver hands for the presence of dirt, and to collect samples of the household's source and stored drinking water. Children with feces found on the household compound during spot checks had a significantly higher odds of diarrhea (odds ratio: 1.71; 95% confidence interval: 1.23-2.38). Children residing in households with > 100 colony forming units/100 mL Escherichia coli in source drinking water had a significantly higher odds of diarrhea (OR: 1.43; 95% CI: 1.06-1.92). The presence of feces on the household compound and source drinking water with > 100 colony forming units/100 mL E. coli were significant risk factors for diarrheal disease for children < 5 years of age in slum areas of Dhaka, Bangladesh. These findings demonstrate the urgent need for comprehensive interventions to reduce fecal contamination on the household compound to protect the health of susceptible pediatric populations.

Evolutionary Sweeps of Subviral Parasites and Their Phage Host Bring Unique Parasite Variants and Disappearance of a Phage CRISPR-Cas System.

Vibrio cholerae is a significant threat to global public health in part due to its propensity for large-scale evolutionary sweeps where lineages emerge and are replaced. These sweeps may originate from the Bay of Bengal, where bacteriophage predation and the evolution of antiphage counterdefenses is a recurring theme. The bacteriophage ICP1 is a key predator of epidemic V. cholerae and is notable for acquiring a CRISPR-Cas system to combat PLE, a defensive subviral parasite encoded by its V. cholerae host. Here, we describe the discovery of four previously unknown PLE variants through a retrospective analysis of >3,000 publicly available sequences as well as one additional variant (PLE10) from recent surveillance of cholera patients in Bangladesh. In recent sampling we also observed a lineage sweep of PLE-negative V. cholerae occurring within the patient population in under a year. This shift coincided with a loss of ICP1's CRISPR-Cas system in favor of a previously prevalent PLE-targeting endonuclease called Odn. Interestingly, PLE10 was resistant to ICP1-encoded Odn, yet it was not found in any recent V. cholerae strains. We also identified isolates from within individual patient samples that revealed both mixed PLE(+)/PLE(-) V. cholerae populations and ICP1 strains possessing CRISPR-Cas or Odn with evidence of in situ recombination. These findings reinforce our understanding of the successive nature of V. cholerae evolution and suggest that ongoing surveillance of V. cholerae, ICP1, and PLE in Bangladesh is important for tracking genetic developments relevant to pandemic cholera that can occur over relatively short timescales. IMPORTANCE With 1 to 4 million estimated cases annually, cholera is a disease of serious global concern in regions where access to safe drinking water is limited by inadequate infrastructure, inequity, or natural disaster. The Global Task Force on Cholera Control (GTFCC.org) considers outbreak surveillance to be a primary pillar in the strategy to reduce mortality from cholera worldwide. Therefore, developing a better understanding of temporal evolutionary changes in the causative agent of cholera, Vibrio cholerae, could help in those efforts. The significance of our research is in tracking the genomic shifts that distinguish V. cholerae outbreaks, with specific attention paid to current and historical trends in the arms race between V. cholerae and a cooccurring viral (bacteriophage) predator. Here, we discover additional diversity of a specific phage defense system in epidemic V. cholerae and document the loss of a phage-encoded CRISPR-Cas system, underscoring the dynamic nature of microbial populations across cholera outbreaks.

Formative Research for the Design of a Baby Water, Sanitation, and Hygiene Mobile Health Program in Bangladesh (CHoBI7 Mobile Health Program).

Poor food hygiene practices, child feces not being disposed of in a latrine, child mouthing of contaminated fomites, and poor hand hygiene of caregivers have been associated with diarrheal diseases, environmental enteropathy, and impaired growth in young children. Mobile health (mHealth) programs present a low-cost approach to delivering water, sanitation, and hygiene (WASH) programs. We conducted a theory-driven and evidence-based approach to formative research and intervention development to design and pilot test a Baby WASH mHealth program targeting food hygiene, child mouthing, and child feces disposal behaviors in urban Dhaka, Bangladesh. Formative research activities included 31 semi-structured interviews, five group discussions, six mHealth workshops, and a three-phase iterative pilot study among 102 households. Findings from semi-structured interviews and group discussions indicate that caregivers of young children have relatively high awareness of the need for safer food hygiene, child mouthing, and child feces disposal practices, but are limited by existing household responsibilities and restricted access to enabling technology that would facilitate practicing recommended behaviors. The piloted Baby WASH mHealth program was well-received by households. This study presents a theory-driven and evidence-based approach for intervention development that can be implemented for the development of future WASH mHealth programs in low-resource settings.

Effects of a Water, Sanitation, and Hygiene Mobile Health Program on Diarrhea and Child Growth in Bangladesh: A Cluster-randomized Controlled Trial of the Cholera Hospital-based Intervention for 7 Days (CHoBI7) Mobile Health Program.

BACKGROUND: The Cholera Hospital-Based Intervention for 7 Days (CHoBI7) mobile health (mHealth) program was a cluster-randomized controlled trial of diarrhea patient households conducted in Dhaka, Bangladesh. METHODS: Patients were block-randomized to 3 arms: standard message on oral rehydration solution use; health facility delivery of CHoBI7 plus mHealth (no home visits); and health facility delivery of CHoBI7 plus 2 home visits and mHealth. The primary outcome was reported diarrhea in the past 2 weeks collected monthly for 12 months. The secondary outcomes were stunting, underweight, and wasting at a 12-month follow-up. Analysis was intention-to-treat. RESULTS: Between 4 December 2016 and 26 April 2018, 2626 participants in 769 households were randomly allocated to 3 arms: 849 participants to the standard message arm, 886 to mHealth with no home visits arm, and 891 to the mHealth with 2 home visits. Children <5 years had significantly lower 12-month diarrhea prevalence in both the mHealth with 2 home visits arm (prevalence ratio [PR]: 0.73 [95% confidence interval {CI}, .61-.87]) and the mHealth with no home visits arm (PR: 0.82 [95% CI, .69-.97]). Children <2 years were significantly less likely to be stunted in both the mHealth with 2 home visits arm (33% vs 45%; odds ratio [OR]: 0.55 [95% CI, .31-.97]) and the mHealth with no home visits arm (32% vs 45%; OR: 0.54 [95% CI, .31-.96]) compared with children in the standard message arm. CONCLUSIONS: The CHoBI7 mHealth program lowered pediatric diarrhea and stunting among diarrhea patient households. CLINICAL TRIALS REGISTRATION: NCT04008134.

Whole-Genome Analysis of Clinical Vibrio cholerae O1 in Kolkata, India, and Dhaka, Bangladesh, Reveals Two Lineages of Circulating Strains, Indicating Variation in Genomic Attributes.

Vibrio cholerae serogroup O1 is responsible for epidemic and pandemic cholera and remains a global public health threat. This organism has been well established as a resident flora of the aquatic environment that alters its phenotypic and genotypic attributes for better adaptation to the environment. To reveal the diversity of clinical isolates of V. cholerae O1 in the Bay of Bengal, we performed whole-genome sequencing of isolates from Kolkata, India, and Dhaka, Bangladesh, collected between 2009 and 2016. Comparison with global isolates by phylogenetic analysis placed the current isolates in two Asian lineages, with lineages 1 and 2 predominant in Dhaka and Kolkata, respectively. Each lineage possessed different genetic traits in the cholera toxin B subunit gene, Vibrio seventh pandemic island II, integrative and conjugative element, and antibiotic-resistant genes. Thus, although recent global transmission of V. cholerae O1 from South Asia has been attributed only to isolates of lineage 2, another distinct lineage exists in Bengal.IMPORTANCE Cholera continues to be a global concern, as large epidemics have occurred recently in Haiti, Yemen, and countries of sub-Saharan Africa. A single lineage of Vibrio cholerae O1 has been considered to be introduced into these regions from South Asia and to cause the spread of cholera. Using genomic epidemiology, we showed that two distinct lineages exist in Bengal, one of which is linked to the global lineage. The other lineage was found only in Iran, Iraq, and countries in Asia and differed from the global lineage regarding cholera toxin variant and drug resistance profile. Therefore, the potential transmission of this lineage to other regions would likely cause worldwide cholera spread and may result in this lineage replacing the current global lineage.

Fabrication of Carbon-Like, π-Conjugated Organic Layer on a Nano-Porous Silica Surface.

This paper presents a new type of black organic material-porous silica composite providing an extremely highly selective adsorption surface. This black composite was prepared by lamination on nano-sized pores with a carbon-like, π-extended structure, which can be converted via the on-site polymerization of 1,5-dihydroxynaphthalene with a triazinane derivative and a thermally induced condensation reaction with denitrification. This bottom-up fabrication method on porous materials had the great advantage of maintaining the pore characteristics of a raw porous material, but also the resultant black surface exhibited an extremely high molecular-shape selectivity; for example, that for trans- and cis-stilbenes reached 14.0 with the black layer-laminated porous silica, whereas it was below 1.2 with simple hydrophobized silica.

Prospective cohort study of child mouthing of faeces and fomites in Dhaka, Bangladesh (CHoBI7 Program).

OBJECTIVE: To characterise childhood mouthing and handling behaviours and to assess the association between hand-to-object and object-to-mouth contacts and diarrhoea prevalence in young children in urban Dhaka, Bangladesh. METHODS: A prospective cohort study was conducted among 494 children under 5 years of age in Dhaka, Bangladesh. This study was nested within the randomised controlled trial of the Cholera Hospital-Based Intervention for 7 Days (CHoBI7) mobile health (mHealth) program. The CHoBI7 mHealth program focuses on promoting handwashing with soap and water treatment to diarrhoea patients and their household members through mobile messages and a single in person visit. Mouthing and handling of faeces and fomites among young children was measured by five-hour structured observation and caregiver reports. Diarrhoea surveillance data was collected monthly for 12 months. RESULTS: Fifty five percent of caregivers reported that their child put a visibly dirty fomite (object or soil) in their mouth in the past week. Caregivers reported that 50% of children had mouthed visibly dirty objects, 26% had mouthed dirt, and 2% had mouthed faeces. Forty five percent of children were observed mouthing a visibly dirty fomite during structured observation, 40% of children were observed mouthing a visibly dirty object, 10% were observed mouthing soil, and one child (0.2%) was observed mouthing faeces. Mouthing of visibly dirty fomites was highest for children 12-18 months of age with 69% of these children having caregiver reports and 54% having observed events. Children with caregiver reports of mouthing faeces had a significantly higher odds of diarrhoea over the subsequent month (Odds Ratio: 4.54; 95% Confidence Interval: 1.06, 19.48). CONCLUSION: These findings demonstrate that mouthing of contaminated fomites among young children is frequent in urban environments in Bangladesh, and that mouthing faeces is associated with a significantly higher odds of diarrhoea. Interventions are urgently needed to protect young children from faecal pathogens in their play spaces.

OBJECTIF: Caractériser les comportements de mâchouillement et de manipulation par les enfants et évaluer l'association entre les contacts main-objet et objet-bouche et la prévalence de la diarrhée chez les jeunes enfants dans la ville de Dhaka, au Bangladesh. MÉTHODES: Une étude de cohorte prospective a été menée auprès de 494 enfants de moins de 5 ans à Dhaka, au Bangladesh. Cette étude s'inscrivait dans le cadre de l'essai contrôlé randomisé du programme CHoBI7 (Cholera-Hospital-Based-Intervention-for-7-days) de santé mobile (mHealth. Le programme de santé mobile CHoBI7 se concentre sur la promotion du traitement de l'eau et du lavage des mains avec à l'eau et au savon aux patients atteints de diarrhée et aux membres de leur foyer par le biais de messages mobiles et de visites de face à face. Le mâchouillement et la manipulation des excréments et des fomites chez les jeunes enfants ont été mesurés par des observations structurées de cinq heures et par les rapports des personnes s'occupant d'enfants (soignants). Les données de surveillance de la diarrhée ont été recueillies chaque mois pendant 12 mois. RÉSULTATS: 55% des soignants ont déclaré que leur enfant avait mis un fomite visiblement sale (objet ou terre) dans sa bouche au cours de la semaine précédente. Les soignants ont indiqué que 50% des enfants avaient mâchouillé des objets visiblement sales, 26% avaient mâchouillé de la terre et 2% avaient mâchouillé des excréments. 45% des enfants ont été observés en train de mâchouiller un fomite visiblement sale au cours d'une observation structurée. 40% des enfants ont été observés en train de mâchouiller un objet, 10% ont été observés en train de mâchouiller de la terre et un enfant (0,2%) a été observé en train de mâchouiller des excréments. Le mâchouillement de fomites visiblement sales était le plus fréquent chez les enfants de 12 à 18 mois; 69% de ces enfants ont été signalés par les soignants et 54% ont été observés en train de le faire. Les enfants dont les soignants avaient signalé un mâchouillement d'excréments présentaient un risque de diarrhée nettement plus élevé au cours du mois suivant (rapport de cotes: 4,54; intervalle de confiance à 95%: 1,06-19,48). CONCLUSION: Ces résultats démontrent que le fait de mâchouiller des fomites contaminés chez les jeunes enfants est fréquent en milieu urbain au Bangladesh et que le fait de mâchouiller des excréments est associé à un risque de diarrhée nettement plus élevé. Des interventions sont urgemment nécessaires pour protéger les jeunes enfants des agents pathogènes fécaux dans leurs espaces de jeu.