Global disability-adjusted life-year estimates of long-term health burden and undernutrition attributable to diarrhoeal diseases in children younger than 5 years

Macrophages orchestrate elimination of Shigella from the intestinal epithelial cell niche via TLR-induced IL-12 and IFN-γ

Bacteria of the genus Shigella replicate in intestinal epithelial cells and cause shigellosis, a severe diarrheal disease that resolves spontaneously in most healthy individuals. During shigellosis, neutrophils are abundantly recruited to the gut, and have long been thought to be central to Shigella control and pathogenesis. However, how shigellosis resolves remains poorly understood due to the longstanding lack of a tractable and physiological animal model. Here, using our newly developed Nlrc4 -/- Casp11 -/- mouse model of shigellosis, we unexpectedly find no major role for neutrophils in limiting Shigella or in disease pathogenesis. Instead, we uncover an essential role for macrophages in the host control of Shigella . Macrophages respond to Shigella via TLRs to produce IL-12, which then induces IFN-γ, a cytokine that is essential to control Shigella replication in intestinal epithelial cells. Collectively, our findings reshape our understanding of the innate immune response to Shigella .

Optimal allocation of antenatal and young child nutrition interventions: an individual-based global burden of disease calibrated microsimulation

BACKGROUND

Undernutrition remains a global crisis and is a focus of Sustainable Development Goals. While there are multiple known, effective interventions, complex interactions between prevention and treatment and resource constraints can lead to difficulties in allocating funding. Simulation studies that use in silico simulation can help illuminate the interactions between interventions and provide insight into the cost-effectiveness of alternative packages of options.

METHODS

We developed an individual-based microsimulation model based on the Global Burden of Disease (GBD) 2021 study data to test a range of nutrition interventions, including antenatal interventions (iron and folic acid, multiple micronutrients, and balanced energy protein supplementation) and child interventions (treatment for severe acute malnutrition, treatment for moderate acute malnutrition, and wasting prevention with small-quantity lipid-based nutrient supplements). We also developed an analytic approach to process the results of the microsimulation and identify the optimal intervention funding allocation for a given budget size. We use Ethiopia as an example in this paper.

RESULTS

In our illustrative example of Ethiopia, the reallocation of the baseline budget to minimize disability-adjusted life years (DALYs) resulted in first funding the antenatal multiple micronutrients to their maximum coverage and then funding treatment for severe child acute malnutrition. Relative to the baseline allocation, the reallocation optimized to minimizing DALYs resulted in 592,000 fewer annual DALYs, constituting an 8.3% reduction in total DALYs in Ethiopia. For budgets larger than the baseline, our model recommended funding first targeted moderate acute malnutrition treatment, second universal moderate acute malnutrition treatment, third wasting prevention with small-quantity lipid-based nutrient supplements, and fourth balanced energy protein supplementation.

CONCLUSIONS

Our simulation is a novel model for estimating optimal allocation of spending on antenatal and child health nutrition interventions which accounts for the interaction between preventive and therapeutic approaches. Our illustrative results show that an optimized reallocation of current spending can substantially improve pregnancy-related and child health without additional funding. We hope this model can add validity and confidence to prior results to aid stakeholders in funding decisions.

Global, regional, and national age-sex-specific burden of diarrhoeal diseases, their risk factors, and aetiologies, 1990-2021, for 204 countries and territories: a systematic analysis for the Global Burden of Disease Study 2021

BACKGROUND

Diarrhoeal diseases claim more than 1 million lives annually and are a leading cause of death in children younger than 5 years. Comprehensive global estimates of the diarrhoeal disease burden for specific age groups of children younger than 5 years are scarce, and the burden in children older than 5 years and in adults is also understudied. We used results from the Global Burden of Diseases, Injuries, and Risk Factors Study 2021 to assess the burden of, and trends in, diarrhoeal diseases overall and attributable to 13 pathogens, as well as the contributions of associated risk factors, in children and adults in 204 countries and territories from 1990 to 2021.

METHODS

We used the Cause of Death Ensemble modelling strategy to analyse vital registration data, verbal autopsy data, mortality surveillance data, and minimally invasive tissue sampling data. We used DisMod-MR (version 2.1), a Bayesian meta-regression tool, to analyse incidence and prevalence data identified via systematic reviews, population-based surveys, and claims and inpatient data. We calculated diarrhoeal disability-adjusted life-years (DALYs) as the sum of years of life lost (YLLs) and years lived with disability (YLDs) for each location, year, and age-sex group. For aetiology estimation, we used a counterfactual approach to quantify population-attributable fractions (PAFs). Additionally, we estimated the diarrhoeal disease burden attributable to the independent effects of risk factors using the comparative risk assessment framework.

FINDINGS

In 2021, diarrhoeal diseases caused an estimated 1·17 million (95% uncertainty interval 0·793-1·62) deaths globally, representing a 60·3% (50·6-69·0) decrease since 1990 (2·93 million [2·31-3·73] deaths). The most pronounced decline was in children younger than 5 years, with a 79·2% (72·4-84·6) decrease in diarrhoeal deaths. Global YLLs also decreased substantially, from 186 million (147-221) in 1990 to 51·4 million (39·9-65·9) in 2021. In 2021, an estimated 59·0 million (47·2-73·2) DALYs were attributable to diarrhoeal diseases globally, with 30·9 million (23·1-42·0) of these affecting children younger than 5 years. Leading risk factors for diarrhoeal DALYs included low birthweight and short gestation in the neonatal age groups, child growth failure in children aged between 1-5 months and 2-4 years, and unsafe water and poor sanitation in older children and adults. We estimated that the removal of all evaluated diarrhoeal risk factors would reduce global DALYs from 59·0 million (47·2-73·2) to 4·99 million (1·99-10·0) among all ages combined. Globally in 2021, rotavirus was the predominant cause of diarrhoeal deaths across all ages, with a PAF of 15·2% (11·4-20·1), followed by norovirus at 10·6% (2·3-17·0) and Cryptosporidium spp at 10·2% (7·03-14·3). In children younger than 5 years, the fatal PAF of rotavirus was 35·2% (28·7-43·0), followed by Shigella spp at 24·0% (15·2-37·9) and adenovirus at 23·8% (14·8-36·3). Other pathogens with a fatal PAF greater than 10% in children younger than 5 years included Cryptosporidium spp, typical enteropathogenicEscherichia coli, and enterotoxigenic E coli producing heat-stable toxin.

INTERPRETATION

The substantial decline in the global burden of diarrhoeal diseases since 1990, particularly in children younger than 5 years, supports the effectiveness of health interventions such as oral rehydration therapy, enhanced water, sanitation, and hygiene (WASH) infrastructure, and the introduction and scale-up of rotavirus vaccination. Targeted interventions and preventive measures against key risk factors and pathogens could further reduce this burden. Continued investment in the development and distribution of vaccines for leading pathogens remains crucial.

FUNDING

Bill & Melinda Gates Foundation.

Burden of Wasting and Stunting in Colombia and Its Economic Impact: A Society's Perspective Analysis, 2021

BACKGROUND/OBJECTIVES

Child malnutrition is a critical public health concern that significantly hampers children's physical and mental development and imposes serious economic burdens. The World Health Organization (WHO) estimates that malnutrition is responsible for half of all deaths among children under five, leading to long-term consequences such as lower educational achievement, decreased productivity, and deepened poverty. This study aims to estimate the burden of child malnutrition in Colombia for children up to four years old, assessing both direct and indirect costs from a societal perspective.

METHODS

A Markov chain model was utilized to simulate six health states related to malnutrition, integrating direct and indirect costs. Epidemiological data and international literature informed the transition probabilities between states, while caregiver surveys were conducted to capture the indirect costs.

RESULTS

The study found that malnutrition accounted for 419.84 disability-adjusted life years (DALYs) per 1000 inhabitants. The total cost of malnutrition over a four-year period was approximately USD 243.58 million, with an annual average of USD 60.89 million, of which 65% of the burden fell on households.

CONCLUSIONS

Child malnutrition in Colombia presents a considerable burden on health systems, households, and the national economy, demonstrating the need for robust interventions to mitigate its long-term socioeconomic impact.

Age-dependent pathogenic profiles of enterotoxigenic Escherichia coli diarrhea in Bangladesh

Background

Age plays a significant role in susceptibility to enterotoxigenic Escherichia coli (ETEC) infections, yet the distribution of ETEC virulence factors across age groups remains understudied. This study investigated the differential pathogenic profiles ETEC across various age groups, emphasizing the importance of selecting potential ETEC antigens tailored to infection patterns in infants and adults in Bangladesh.

Methods

This study utilized the icddr,b's 2% systematic hospital surveillance data of diarrheal patients (n = 14,515) from 2017 to 2022 to examine the age-specific pathogenesis and clinical manifestations of ETEC infections.

Results

In total ETEC was identified in 1,371 (9.4%) of surveillance samples. ETEC-associated diarrhea was higher in children aged 0-2 years and decreased significantly in the 3-17 years age group. Among all ETEC cases, 56% were adults (p = 0.0079) with severe dehydration. Distinct age-specific distribution of ETEC toxin types and colonization factors (CFs) were observed: heat labile toxin (LT)-associated ETEC infections decreased with age (p < 0.0001), while heat stable toxin (ST)-associated-ETEC was prevalent across all ages. Adults exhibited significantly higher rates of ETEC diarrhea with strains secreting both types of toxins. A high prevalence of antimicrobial resistance among ETEC strains, particularly in pediatric cases, with significant resistance observed against commonly used antibiotics such as azithromycin and in line with similar age specific toxin profiles. The most common CFs were CFA/I, CS3, CS5, CS6, and CS21. CFA/I positive ETEC infection was more common in children (p < 0.001), while CS5 and CS6 were more common in adults (p < 0.0001).

Conclusion

The findings provide valuable insights into ETEC epidemiology, pathogenesis, and clinical manifestations. These observations imply that age-related differences in host-pathogen interactions exist for ETEC infections and this may influence the development of targeted vaccines or therapeutics and use in specific populations.

Diagnostic accuracy of Gorelick 10 point scale in comparison to IMCI scale in identifying significant dehydration in South Indian children? - A prospective observational study

Background

Unavoidable cause of mortality among under 5 children in India is dehydration resulting from acute diarrhoeal diseases. In spite of various dehydration scales available across the world, the most commonly used dehydration scale in India is IMCI. Gorelick 10 point scale having more clinical indicators could also be considered using if the diagnostic accuracy of the scale in identifying the significant dehydration is in par with that of IMCI scale. Our Objective was to classify the 1month - 60 month aged children admitted with diarrhoeal disease based on dehydration assessment using Body weight, Gorelick 10 point scale, IMCI scale and to compare the diagnostic accuracy of Gorelick 10 point scale vs IMCI scale in identifying significant dehydration.

Methods

The prospective observational study was done among 224, 1 month to 60 month aged children admitted with acute watery diarrhea. The children were assessed for severity of dehydration using Body weight, Gorelick 10 point scale, IMCI scale. The diagnostic accuracy of Gorelick 10 point scale vs IMCI scale in identifying significant dehydration was assessed using statistical methods like, Sensitivity, Specificity, Positive Predictive Value PPV,NPV,LR+, LR-, Youden index and accuracy and Kappa statistic to detect inter-rater reliability.

Results

The proportion of participants classified as to have no dehydration, some dehydration and severe dehydration according to Gorelick 10 point scale, IMCI and percentage of weight loss was 79.9%, 18.8%, 1.3% vs 77.7%,21%,1.3% vs 79.9%,18.8%,1.3% respectively The diagnostic accuracy of IMCI scale in identifying Significant dehydration was higher than Gorelick 10 point scale, as noted by having Sensitivity, Specificity,PPV,NPV,LR+,LR-,Youden index and accuracy as 100%,97.2%,0%,100%35.8,0,0.97,97.7% vs 88.9%,97.2%,88.2%,97.2%,31.8,0.11,0.85,95.5% respectively and k value was 0.9.

Conclusion

Though the diagnostic accuracy of IMCI was little higher than Gorelick 10 point scale in identifying significant dehydration, having obtained k value of 0.9, indicates posing an excellent agreement Gorelick 10 point scale can be used in place of IMCI to identify Significant dehydration.

High-Throughput Luminescence-Based Serum Bactericidal Assay Optimization and Characterization to Assess Human Sera Functionality Against Multiple Shigella flexneri Serotypes

Shigellosis represents a significant global health concern particularly affecting children under 5 years in low- and middle-income countries (LMICs) and is associated with stunting and antimicrobial resistance. There is a critical need for an effective vaccine offering broad protection against the different Shigella serotypes. A correlate of protection has not yet been established but there is a general consensus about the relevant role of anti-O-Antigen-specific IgG and its functionality evaluated by the Serum Bactericidal Assay (SBA). This study aims to characterize a high-throughput luminescence-based SBA (L-SBA) against seven widespread Shigella serotypes. The assay was previously developed and characterized for S. sonnei and S. flexneri 1b, 2a, and 3a and has now been refined and extended to an additional five serotypes (S. flexneri 4a, 5b, 6, X, and Y). The characterization of the assay with human sera confirmed the repeatability, intermediate precision, and linearity of the assays; both homologous and heterologous specificity were verified as well; finally, limit of detection and quantification were established for all assays. Moreover, different sources of baby rabbit complement showed to have no impact on L-SBA output. The results obtained confirm the possibility of extending the L-SBA to multiple Shigella serotypes, thus enabling analysis of the functional response induced by natural exposure to Shigella in epidemiological studies and the ability of candidate vaccines to elicit cross-functional antibodies able to kill a broad panel of prevalent Shigella serotypes in a complement-mediated fashion.

Trends and inequalities in oral rehydration therapy and continued feeding for children under five with diarrhoea in Sierra Leone

BACKGROUND

Sierra Leone has improved child health outcomes in recent decades. However, diarrhoeal diseases remain a public health concern, particularly among children under five. This study investigates the trends and inequalities in oral rehydration therapy and continued feeding for children under five with diarrhoea in Sierra Leone in 2008, 2013 and 2019.

METHODS

The analysis utilised data from the Sierra Leone Demographic Health Survey rounds conducted in 2008, 2013, and 2019. The software utilised for the calculation of various measures of inequality, including simple difference, ratio, population-attributable risk, and population-attributable fraction, was the World Health Organization Health Equity Assessment Toolkit. An inequality assessment was conducted for six stratifiers: maternal age, maternal economic status, maternal level of education, place of residence, sex of the child, and sub-national region.

RESULTS

Our findings reveal that children under five with diarrhoea receiving oral rehydration therapy and continued feeding increased from 56.5% in 2008 to 59.7% in 2019 in Sierra Leone. Children of mothers aged 20-49 had more coverage over time than those with mothers aged 15-19. Children of mothers who are wealthy, more educated, and living in urban areas show a decrease in coverage with time compared to the poor, the lowly educated, and those residing in rural areas. Male children had higher coverage than female children. Regional inequality decreased slightly from 21.5 percentage points in 2008 to 21.2 percentage points in 2019.

CONCLUSION

The findings revealed a mixed picture of progress in oral rehydration therapy and continued feeding for children under five in Sierra Leone. While national coverage has increased, inequalities persist. Children of older mothers and those from disadvantaged backgrounds have experienced improvements, while children of younger, wealthier, and more educated mothers in urban areas have seen a decline in coverage. The gender and regional inequalities remain. Expanding community-based health programs, providing subsidised or free supplies, and strengthening health systems in underserved areas are key strategies to ensure equitable and effective healthcare for all children in Sierra Leone.

The Shigella flexneri effector IpaH1.4 facilitates RNF213 degradation and protects cytosolic bacteria against interferon-induced ubiquitylation

A central signal that marshals host defense against many infections is the lymphocyte-derived cytokine interferon-gamma (IFNγ). The IFNγ receptor is expressed on most human cells and its activation leads to the expression of antimicrobial proteins that execute diverse cell-autonomous immune programs. One such immune program consists of the sequential detection, ubiquitylation, and destruction of intracellular pathogens. Recently, the IFNγ-inducible ubiquitin E3 ligase RNF213 was identified as a pivotal mediator of such a defense axis. RNF213 provides host protection against viral, bacterial, and protozoan pathogens. To establish infections, potentially susceptible intracellular pathogens must have evolved mechanisms that subdue RNF213-controlled cell-autonomous immunity. In support of this hypothesis, we demonstrate here that a causative agent of bacillary dysentery, Shigella flexneri, uses the type III secretion system (T3SS) effector IpaH1.4 to induce the degradation of RNF213. S. flexneri mutants lacking IpaH1.4 expression are bound and ubiquitylated by RNF213 in the cytosol of IFNγ-primed host cells. Linear (M1-) and lysine-linked ubiquitin is conjugated to bacteria by RNF213 independent of the linear ubiquitin chain assembly complex (LUBAC). We find that ubiquitylation of S. flexneri is insufficient to kill intracellular bacteria, suggesting that S. flexneri employs additional virulence factors to escape from host defenses that operate downstream from RNF213-driven ubiquitylation. In brief, this study identified the bacterial IpaH1.4 protein as a direct inhibitor of mammalian RNF213 and highlights evasion of RNF213-driven immunity as a characteristic of the human-tropic pathogen Shigella.

Lactoferrin and lysozyme to promote nutritional, clinical and enteric recovery: a protocol for a factorial, blinded, placebo-controlled randomised trial among children with diarrhoea and malnutrition (the Boresha Afya trial)

INTRODUCTION

Children with moderate or severe wasting are at particularly high risk of recurrent or persistent diarrhoea, nutritional deterioration and death following a diarrhoeal episode. Lactoferrin and lysozyme are nutritional supplements that may reduce the risk of recurrent diarrhoeal episodes and accelerate nutritional recovery by treating or preventing underlying enteric infections and/or improving enteric function.

METHODS AND ANALYSIS

In this factorial, blinded, placebo-controlled randomised trial, we aim to determine the efficacy of lactoferrin and lysozyme supplementation in decreasing diarrhoea incidence and improving nutritional recovery in Kenyan children convalescing from comorbid diarrhoea and wasting. Six hundred children aged 6-24 months with mid-upper arm circumference <12.5 cm who are returning home after an outpatient visit or inpatient hospital stay for diarrhoea will be enrolled. Children will be randomised to 16 weeks of lactoferrin, lysozyme, a combination of the two, or placebo and followed for 24 weeks, with biweekly home visits by community health workers and clinic visits at 4, 10, 16 and 24 weeks. The primary analysis will compare the incidence of moderate-to-severe diarrhoea and time to nutritional recovery between each intervention arm and placebo. The trial will also test whether these interventions reduce enteric pathogen carriage, decrease enteric permeability and/or increase haemoglobin concentration in enrolled children. Finally, we will evaluate the acceptability, adherence and cost-effectiveness of lactoferrin and/or lysozyme.

ETHICS AND DISSEMINATION

The trial has been approved by the institutional review boards of the Kenya Medical Research Institute, the University of Washington, the Kenyan Pharmacy and Poisons Board, and the Kenyan National Commission on Science, Technology and Innovation. The results of this trial will be shared with local and international stakeholders and published in peer-reviewed journals, and the key findings will be presented at relevant conferences.

TRIAL REGISTRATION NUMBER

NCT05519254, PACTR202108480098476.

Spatiotemporal analysis of diarrhea-related hospitalizations of children in Brazil's Midwest region from 2011 to 2020

OBJECTIVE

To examine spatiotemporal variability and identify clustering patterns of hospitalization rates for diarrhea in children younger than five years in Mato Grosso, Brazil, from 2011 to 2020.

METHODS

An ecological study was conducted using hospitalization records associated with diarrhea from the Brazilian Hospital Information System/Unified Health System. The relative risk of hospitalization for diarrhea in each municipality was calculated using SaTScan software considering a statistical significance level of 5% and 999 Monte Carlo replications.

RESULTS

A total of 13,315 diarrhea-associated hospitalizations for 5-year-old children were recorded. From 2011 to 2020, the annual rates for hospitalizations related to diarrhea decreased from 8.50 to 3.45/1,000 live births among children younger than one year and from 4.99 to 1.57 for children aged 1-4 years. Clusters of municipalities with high relative risk for hospitalizations due to diarrhea, statistically significant, predominated in the North, Northeast, and Southwest health administrative macro-regions of Mato Grosso for both age groups until 2016. From 2016 to 2020, clusters of the lowest relative risk were identified in the North and Center South health administrative macro-regions for children younger than five years.

CONCLUSION

Results showed that hospitalization rates for diarrhea in children younger than five years reduced with the presence of low-risk clusters in Mato Grosso in the final years of the study. Public health surveillance should incorporate spatial analysis to investigate the diarrhea-related morbidity.

Unveiling the hidden dangers: enteropathogens carried by flies in Pudong New Area

BACKGROUND

Flies are acknowledged as vectors of diseases transmitted through mechanical means and represent a significant risk to human health. The study aimed to determine the prevalence of enteropathogens carried by flies in Pudong New Area to inform strategies for preventing and controlling flies.

METHODS

Samples were collected from various locations in the area using cage trapping techniques between April and November 2021, encompassing various habitats such as parks, residential areas, restaurants, and farmers' markets. The main fly species were identified using cryomicrography and taxonomic enumeration, with 20 samples per tube collected from different habitats. Twenty-five enteropathogens were screened using GI_Trial v3 TaqManTM microbial arrays.

RESULTS

A total of 3,875 flies were collected from 6,400 placements, resulting in an average fly density of 0.61 flies per cage. M. domestica were the most common species at 39.85%, followed by L. sericata at 16.57% and B. peregrina at 13.14%. Out of 189 samples, 93 tested positive for enteropathogens, with nine different pathogens being found. 12.70% of samples exclusively had parasites, a higher percentage than those with only bacteria or viruses. The study found that M. domestica had fewer enteropathogens than L. sericata and B. peregrina, which primarily harbored B. hominis instead of bacteria and viruses such as E. coli, Astrovirus, and Sapovirus. During spring testing, all three fly species exhibited low rates of detecting enteropathogens. M. domestica were found in residential areas with the highest number of pathogen species, totaling six. In contrast, L. sericata and B. peregrina were identified in farmers' markets with the highest number of pathogen species, totaling six and seven, respectively.

CONCLUSIONS

Flies have the potential to serve as vectors for the transmission of enteropathogens, thereby posing a substantial risk to public health.

Multi- and extensively drug resistant Escherichia coli isolated from South African children under 5 years old with diarrhoea

BACKGROUND

Globally, millions of children die as a result of diarrhoea and/or antimicrobial resistant infections. Diarrhoeagenic Escherichia coli (DEC) are responsible for a substantial proportion of cases of diarrhoea in South Africa and sub-Saharan Africa. Effective treatments (including the use of antimicrobials) are therefore essential.

METHODOLOGY

E. coli isolated from children under the age of five were subjected to antimicrobial susceptibility testing using the Vitek 2® compact automated system (bioMérieux Inc., France) and categorized as multidrug or extensively drug resistant (MDR or XDR).

RESULTS

Almost all isolates (164/166, 98.8 %) were categorized as MDR with 4.9 % (9/166) categorized as XDR. The majority of isolates (153/166, 92.2 %) were also phenotypically classified as extended-spectrum β-lactamase (ESBL) producers. More than half of these isolates (78/153, 51.0 %) were subjected to PCR for genes associated with ESBL production. More than half (45/78, 57.7 %) of the isolates tested were PCR positive for at least one ESBL gene or gene group and 11.5 % (9/78) were positive for two ESBL genes or gene groups.

DISCUSSION

There is a need to strengthen antimicrobial resistance surveillance in South Africa and improve infection prevention and control measures. There is also a need to review the current South African Treatment Guidelines as outlined by the South African Essential Drugs Programme.

Multiplex PCR for bacterial, viral and protozoal pathogens in persistent diarrhoea or persistent abdominal pain in Côte d'Ivoire, Mali and Nepal

In contrast to acute diarrhoea, the aetiology of persistent digestive disorders (≥ 14 days) is poorly understood in low-resource settings and conventional diagnostic approaches lack accuracy. In this multi-country study, we compared multiplex real-time PCR for enteric bacterial, parasitic and viral pathogens in stool samples from symptomatic patients and matched asymptomatic controls in Côte d'Ivoire, Mali and Nepal. Among 1826 stool samples, the prevalence of most pathogens was highest in Mali, being up to threefold higher than in Côte d'Ivoire and up to tenfold higher than in Nepal. In all settings, the most prevalent bacteria were EAEC (13.0-39.9%) and Campylobacter spp. (3.9-35.3%). Giardia intestinalis was the predominant intestinal protozoon (2.9-20.5%), and adenovirus 40/41 was the most frequently observed viral pathogen (6.3-25.1%). Significantly different prevalences between symptomatic and asymptomatic individuals were observed for Campylobacter, EIEC and ETEC in the two African sites, and for norovirus in Nepal. Multiple species pathogen infection was common in Côte d'Ivoire and Mali, but rarely found in Nepal. We observed that molecular testing detected multiple enteric pathogens and showed low discriminatory accuracy to distinguish between symptomatic and asymptomatic individuals. Yet, multiplex PCR allowed for direct comparison between different countries and revealed considerable setting-specificity.

Etiology of diarrheal hospitalizations following rotavirus vaccine implementation and association of enteric pathogens with malnutrition among under-five children in India

Malnourished children are at higher risk of mortality and morbidity following diarrheal illness and certain enteropathogens have been associated with malnutrition in children. Very few studies have comprehensively looked at the etiology of diarrhea in malnourished children and most have used conventional diagnostic methods with suboptimal sensitivity. We used a highly sensitive molecular approach against a broad range of pathogens causing diarrhea and examined their association with malnutrition. In addition, we looked at the pathogen diversity of pediatric diarrhea, three years after the nationwide rotavirus vaccine introduction to understand the evolving landscape of pathogens, which is crucial for planning strategies to further reduce the diarrhea burden. Clinical details and diarrheal stool samples were collected from hospitalized children aged < 5 years from three sentinel sites in India for a period of one year. The samples were tested by qPCR for 16 established causes of diarrhea using TaqMan Array Cards. A total of 772 children were enrolled, from whom 482 (62.4%) stool specimens were tested. No specific pathogen was associated with diarrhea among children with acute or chronic malnutrition compared to those with better nutritional status. Overall, adenovirus was the leading pathogen (attributable fraction (AF) 16.9%; 95% CI 14.1 to 19.2) followed by rotavirus (AF 12.6%; 95% CI 11.8 to 13.1) and Shigella (AF 10.9%; 95% CI 8.4 to 16.4). The majority of diarrhea requiring hospitalization in children aged < 2 years could be attributed to viruses, while Shigella was the most common pathogen among children aged > 2 years. These data on the prevalence and epidemiology of enteropathogens identified potential pathogens for public health interventions.

Intussusception and Other Adverse Event Surveillance after Pilot Introduction of Rotavirus Vaccine in Nam Dinh and Thua Thien Hue Provinces-Vietnam, 2017-2021

Rotavin-M1 (POLYVAC) was licensed in Vietnam in 2012. The association of Rotavin-M1 with intussusception, a rare adverse event associated with rotavirus vaccines, and with adverse events following immunization (AEFI) have not been evaluated and monitored under conditions of routine use. From February 2017 to May 2021, we conducted a pilot introduction of Rotavin-M1 into the routine vaccination program in two provinces. Surveillance for intussusception was conducted at six sentinel hospitals. AEFI reports at 30 min and 7 days after vaccination were recorded. Among 443 children <12 months of age admitted for intussusception, most (92.3%) were children ≥ 6 months. Of the 388 children who were age-eligible to receive Rotavin-M1, 116 (29.9%) had received ≥1 dose. No intussusception cases occurred in the 1-21 days after dose 1 and one case occurred on day 21 after dose 2. Among the 45,367 children who received ≥1 dose of Rotavin-M1, 9.5% of children reported at least one AEFI after dose 1 and 7.3% after dose 2. Significantly higher AEFI rates occurred among children given Rotavin-M1 with pentavalent vaccines (Quinvaxem®, ComBE Five®) compared to Rotavin-M1 without pentavalent vaccines. There was no association between intussusception and Rotavin-M1. The vaccine was generally safe when administered alone and when co-administered with other vaccines.

Enterococcus contamination of infant foods and implications for exposure to foodborne pathogens in peri-urban neighbourhoods of Kisumu, Kenya

We collected infant food samples from 714 households in Kisumu, Kenya, and estimated the prevalence and concentration of Enterococcus, an indicator of food hygiene conditions. In a subset of 212 households, we quantified the change in concentration in stored food between a morning and afternoon feeding time. In addition, household socioeconomic characteristics and hygiene practices of the caregivers were documented. The prevalence of Enterococcus in infant foods was 50% (95% confidence interval: 46.1 - 53.4), and the mean log10 colony-forming units (CFUs) was 1.1 (SD + 1.4). No risk factors were significantly associated with the prevalence and concentration of Enterococcus in infant foods. The mean log10 CFU of Enterococcus concentration was 0.47 in the morning and 0.73 in the afternoon foods with a 0.64 log10 mean increase in matched samples during storage. Although no factors were statistically associated with the prevalence and the concentration of Enterococcus in infant foods, household flooring type was significantly associated with an increase in concentration during storage, with finished floors leading to 1.5 times higher odds of concentration increase compared to unfinished floors. Our study revealed high prevalence but low concentration of Enterococcus in infant food in low-income Kisumu households, although concentrations increased during storage implying potential increases in risk of exposure to foodborne pathogens over a day. Further studies aiming at investigating contamination of infant foods with pathogenic organisms and identifying effective mitigation measures are required to ensure infant food safety.

The Impact of Rapid Handpump Repairs on Diarrhea Morbidity in Children: Cross-Sectional Study in Kwale County, Kenya

BACKGROUND

Handpumps are used by millions of people as their main source of water. Although handpumps represent only a basic form of water provision, there have been continuous efforts to improve the performance of these systems as they are likely to remain in use for many years to come. The introduction of a professional maintenance service in southern Kenya has shown an order of magnitude improvement in operational performance over community-based management, with 90% of handpump faults repaired within 3 days of being reported. One driver behind these efforts is the assumption that a more reliable water supply will lead to a reduction in water-related disease. However, it is not clear if operational improvements lead to health gains. Despite limited empirical evidence, some modeling studies suggest that even short periods of drinking contaminated water can lead to disproportionate negative health impacts.

OBJECTIVE

The aim of this study was to assess whether the improvements in operational performance from the rapid professional maintenance of rural handpumps lead to improved household health outcomes.

METHODS

From a sample of households using handpumps as their primary water source in Kwale County, Kenya, we measured the 2-week prevalence of World Health Organization-defined diarrhea in children, reported by the adult respondent for each household. We compared the rates before and after a period during which the households' handpumps were being professionally maintained. We then conducted a cross-sectional analysis, fitting logistic regression models with reported diarrhea as the dependent variable and speed of repair as the independent exposure of interest, adjusting for household socioeconomic characteristics; dwelling construction; and Water, Sanitation, and Hygiene (WASH)-related factors. We fitted an additional model to examine select interactions between covariates.

RESULTS

Reported diarrhea in children was lower in households whose pumps had been repaired within 24 hours (adjusted odds ratio 0.35, 95% CI 0.24-0.51). This effect was robust to the inclusion of multiple categories of covariates. No reduction was seen in households whose pump repairs took more than 24 hours. Analysis of interaction terms showed that certain interventions associated with improved WASH outcomes were only associated with reductions in diarrhea in conjunction with socioeconomic improvements.

CONCLUSIONS

Only pump repairs consistently made within 24 hours of failure led to a reduction in diarrhea in the children of families using handpumps. While the efficacy of reduction in diarrhea is substantial, the operational challenges of guaranteeing same-day repairs limits the effectiveness of even best-in-class pump maintenance. Maintenance regimes that cannot bring handpump downtimes close to zero will struggle to generate health benefits. Other factors that reduce diarrhea prevalence have limited effect in isolation, suggesting that WASH interventions will be more effective when undertaken as part of more holistic poverty-reduction efforts.

Appropriate feeding practices and associated factors during diarrheal disease among children aged 6 to 23 months in Sub-Saharan Africa: a multilevel analysis of the recent demographic and health survey

BACKGROUND

Diarrhea is the second leading cause of morbidity and mortality for under-five children which cause about 525,000 deaths annually. Even though diarrheal diseases have decreased substantially at the global level, low-income countries are still faced with a huge number of diarrheal diseases. Thus, our aim was to assess the child feeding practices during diarrheal diseases and associated factors among children aged 6 to 23 months in Sub-Saharan African countries using the recent demographic and health survey.

METHODS

The appended and most recent demographic and health survey (DHS) dataset of 19 Sub-Saharan African countries from 2015 to 2020 was used for data analysis. A total of 64,628 living children aged 6-23 months with diarrhea were used as a weighted sample. The determinants of appropriate feeding practice were determined using a multilevel mixed-effects logistic regression model. Significant factors associated with appropriate feeding practice in the multilevel mixed-effect logistic regression model were declared significant at p-values < 0.05. The adjusted odds ratio (AOR) and confidence interval (CI) were used to interpret the results.

RESULT

The overall prevalence of appropriate child feeding practice during diarrhea in this study was 6.24% (95% CI: 6.06, 6.43). Maternal age (15 to 19 years and 20 to 35 years) (AOR = 1.32, 95%CI: 1.12, 1.55 and AOR = 1.14, 95%CI: 1.03, 1.27), mothers education (primary and secondary level) (AOR = 1.23, 95%CI: 1.12, 1.35 and AOR = 1.28, 95%CI: 1.15, 1.43), having media exposure(AOR = 1.36, 95%CI: 1.26, 1.46), being married (AOR = 1.18, 95%CI: 1.01, 1.38), currently working (AOR = 1.08, 95%CI:1.00, 1.15), vaccinated for Rotavirus (AOR = 1.30, 95%CI:1.19, 1.43) and living in Central and eastern African countries (AOR = 1.82, 95%CI: 1.12, 2.97) and (AOR = 2.23, 95%CI: 1.37, 3.61) respectively were significantly associated with appropriate feeding practice.

CONCLUSION

The prevalence of appropriate feeding practice during child diarrheal disease aged 6-23 months of age was strictly low which implies that child diarrhea and appropriate feeding practice is still a great issue in in Sub-Saharan African countries. Enhancing maternal education, strengthening media exposure and vaccination for rotavirus, and designing interventions that address the mother's marital status, mother's work status, and country category are recommended to enhance appropriate feeding practices. Furthermore, special consideration should be given to older mothers to increase appropriate feeding practices during diarrheal disease.

Hyperimmune bovine colostrum containing lipopolysaccharide antibodies (IMM124-E) has a nondetrimental effect on gut microbial communities in unchallenged mice

Enterotoxigenic Escherichia coli (ETEC) is a leading cause of bacterial diarrhea with the potential to cause long-term gastrointestinal (GI) dysfunction. Preventative treatments for ETEC-induced diarrhea exist, yet the effects of these treatments on GI commensals in healthy individuals are unclear. Whether administration of a prophylactic preventative treatment for ETEC-induced diarrhea causes specific shifts in gut microbial populations in controlled environments is also unknown. Here, we studied the effects of a hyperimmune bovine colostrum (IMM-124E) used in the manufacture of Travelan (AUST L 106709) on GI bacteria in healthy C57BL/6 mice. Using next-generation sequencing, we aimed to test the onset and magnitude of potential changes to the mouse gut microbiome in response to the antidiarrheagenic hyperimmune bovine colostrum product, rich in immunoglobulins against select ETEC strains (Travelan, Immuron Ltd). We show that in mice administered colostrum containing lipopolysaccharide (LPS) antibodies, there was an increased abundance of potentially gut-beneficial bacteria, such as Akkermansia and Desulfovibrio, without disrupting the underlying ecology of the GI tract. Compared to controls, there was no difference in overall weight gain, body or cecal weights, or small intestine length following LPS antibody colostrum supplementation. Overall, dietary supplementation with colostrum containing LPS antibodies produced subtle alterations in the gut bacterial composition of mice. Primarily, Travelan LPS antibody treatment decreased the ratio of Firmicutes/Bacteroidetes in gut microbial populations in unchallenged healthy mice. Further studies are required to examine the effect of Travelan LPS antibody treatment to engineer the microbiome in a diseased state and during recovery.

Effect of a Homestead Food Production Program on the Prevalence of Diarrhea and Acute Respiratory Infection in Children in Sylhet, Bangladesh: A Cluster-Randomized Controlled Trial

Diarrhea and respiratory illness are leading causes of mortality and morbidity among young children. We assessed the impact of a homestead food production intervention on diarrhea and acute respiratory infection (ARI) in children in Bangladesh, secondary outcomes of the Food and Agricultural Approaches to Reducing Malnutrition (FAARM) cluster-randomized trial. The trial enrolled 2,705 married women and their children 3 years or younger in 96 rural settlements (geographic clusters) in Sylhet Division, Bangladesh. The intervention promoted home gardening and poultry rearing alongside child nutrition and health counseling over 3 years (2015-2018). An 8-month food hygiene behavior change component using emotional drivers was delivered beginning in mid-2017. Caregiver-reported diarrhea and symptoms of ARI in the week preceding the survey were recorded every 2 months. We analyzed 32,460 observations of 3,276 children over 4 years and found that 3.9% of children had diarrhea and 3.4% had an ARI in the prior 7 days. There was no overall effect of the intervention on 7-day diarrhea period prevalence (odds ratio [OR], 0.92; 95% CI, 0.71-1.19), diarrhea point prevalence (OR, 1.03; 95% CI, 0.78-1.36), or 7-day ARI period prevalence (OR, 1.18; 95% CI, 0.88-1.60). There was no impact on diarrhea severity or differences in health-seeking behaviors. Our findings suggest that this homestead food production program was insufficient to reduce morbidity symptoms among children in a rural setting. More comprehensive water, sanitation, and hygiene measures, and behavioral recommendations may be needed to achieve impacts on child health.

Exploration of Infant Food Microbial Composition from Formal and Informal Settings Using Viable Counts and 16S rRNA Gene Amplicon Sequencing in Johannesburg, South Africa

Diarrhoea is a considerable agent of disease and loss of life in children below age five in South Africa. Soweto, South Africa is an urban township in Johannesburg, with most of its population living in informal settlements. Informal settlements in areas such as Soweto are often impoverished communities that do not get water easily, inadequate sanitation is pervasive, and poor hygiene common (risk factors for diarrhoeal diseases). Among the age groups, infants are most vulnerable to diarrhoeal infection, mainly through the ingestion of food and water. The presence of undesirable microbiota is a food safety and health challenge. This study investigated the microbiome of infant food samples collected from formal (n = 19) and informal (n = 11) households in Soweto. A non-culture-dependent technique was used to characterise the bacterial diversity and composition of the infant food samples. The results indicated that household type did not influence microbial diversity and composition in Soweto. South Africa. Firmicutes, Proteobacteria, Cyanobacteria, and Tenericutes dominated the phyla rank in food samples from formal and informal households. Potential pathogens of public health significance, including diarrhoeal disease agents such as Salmonella spp., E. coli, and Campylobacter spp., were detected within the foods. We concluded that the infant food samples showed rich bacterial diversity, and the presence of potential pathogens of public health significance suggests a disease risk that infants may face upon consuming the foods.

Infections and Acute Kidney Injury: A Global Perspective

Globally, there are an estimated 13.3 million cases of acute kidney injury (AKI) annually. Although infections are a common cause of AKI globally, most infection-associated AKI occurs in low- and lower-middle-income countries. There are marked differences in the etiology of infection-associated AKI across age groups, populations at risk, and geographic location. This article provides a global overview of different infections that are associated commonly with AKI, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), human immunodeficiency virus, malaria, dengue, leptospirosis, tick-borne illnesses, and viral hemorrhagic fevers. Further discussion focuses on infectious conditions associated with AKI including sepsis, diarrheal diseases and pregnancy, peripartum and neonatal AKI. This article also discusses the future of infection-associated AKI in the framework of climate change. It explores how increased investment in achieving the sustainable development goals may contribute to the International Society of Nephrology's 0 by 25 objective to curtail avoidable AKI-related fatalities by 2025.

Seroprevalence Study of Conserved Enterotoxigenic Escherichia coli Antigens in Globally Diverse Populations

Enterotoxigenic Escherichia coli (ETEC) are common causes of infectious diarrhea among young children of low-and middle-income countries (LMICs) and travelers to these regions. Despite their significant contributions to the morbidity and mortality associated with childhood and traveler's diarrhea, no licensed vaccines are available. Current vaccine strategies may benefit from the inclusion of additional conserved antigens, which may contribute to broader coverage and enhanced efficacy, given their key roles in facilitating intestinal colonization and effective enterotoxin delivery. EatA and EtpA are widely conserved in diverse populations of ETEC, but their immunogenicity has only been studied in controlled human infection models and a population of children in Bangladesh. Here, we compared serologic responses to EatA, EtpA and heat-labile toxin in populations from endemic regions including Haitian children and subjects residing in Egypt, Cameroon, and Peru to US children and adults where ETEC infections are sporadic. We observed elevated IgG and IgA responses in individuals from endemic regions to each of the antigens studied. In a cohort of Haitian children, we observed increased immune responses following exposure to each of the profiled antigens. These findings reflect the wide distribution of ETEC infections across multiple endemic regions and support further evaluation of EatA and EtpA as candidate ETEC vaccine antigens.

Prevalence and factors associated with undernutrition among children under the age of five years in Benin

BACKGROUND

Benin ranks as one of the countries in the world with an alarmingly high prevalence of stunting, wasting, and underweight in children under five years. However, limited studies have examined the factors associated with the prevalence of these undernutrition indicators among children under five years in the country. This study aimed to fill this research gap by examining the prevalence rates and factors associated with stunting, wasting, and underweight among this specific population of interest.

METHODS

This quantitative study utilised data from the most recent Benin Demographic and Health Survey (BDHS) conducted in 2017-18. The survey employed a nationally representative cross-sectional design and utilised a two-stage stratified cluster sampling technique to select participants. The study included a sample of 13,589 children under the age of five years. The main analytical approach employed was binary logistic regression, which was used to explore the associations between undernutrition (the combined outcome variable representing stunting, wasting, and underweight) and various socio-demographic factors.

RESULTS

The combined prevalence of stunting, wasting, and underweight among children under five years in Benin during the 2017-18 survey period was 14.95%. Several factors were significantly associated with these indicators of undernutrition, including female gender (AOR = 0.71, 95% CI = 0.59-0.85), birth weight of 4.1 kg and over (AOR = 0.26, 95% CI = 0.14-0.48), multiple births (AOR = 3.22, 95% CI = 2.11-4.91), and a child's experience of diarrhoea (AOR = 1.76, 95% CI = 1.40-2.20). Furthermore, the prevalence of these undernutrition indicators was higher among children whose mothers had lower levels of education (AOR = 0.82, 95% CI = 0.01-0.42) and were unmarried (AOR = 0.67, 95% CI = 0.49-0.93).

CONCLUSIONS

This present study confirms that undernutrition rates are elevated in Benin and are closely linked to perinatal factors such as birth weights and multiple births, postnatal health conditions including diarrheal episodes, and socio-demographic determinants such as a child's gender, maternal education level, and marital status. Therefore, there is the need to consider specific modifiable factors, such as low birth weight, episodes of child diarrhoea, and maternal education as priority targets for child nutrition interventions in Benin.

Impact and effectiveness of Rotavin-M1 under conditions of routine use in two provinces in Vietnam, 2016-2021, an observational and case-control study

Background

Half of diarrhea hospitalizations in children aged <5 years in Vietnam are due to rotavirus. Following introduction of a locally developed and licensed oral rotavirus vaccine, Rotavin-M1, into the routine immunization program in two Vietnamese provinces, Nam Dinh and TT Hue, we describe changes in rotavirus positivity among children hospitalized for diarrhea and calculate vaccine effectiveness against moderate-to-severe rotavirus hospitalizations.

Methods

Active rotavirus surveillance among children <5 years began in December 2016 at sentinel hospitals in districts where rotavirus vaccine was introduced in December 2017. To estimate reductions in rotavirus detection, we calculated risk ratios comparing rotavirus positivity pre- and post-vaccine introduction. We used a test-negative case-control design to calculate vaccine effectiveness.

Findings

From December 2016 to May 2021, 7228 children <5 years hospitalized for diarrhea were enrolled. Following introduction, Rotavin-M1 coverage was 77% (1066/1377) in Nam Dinh and 42% (203/489) in TT Hue. In Nam Dinh, rotavirus positivity among children <5 years significantly declined by 40.6% (95% CI: 34.8%-45.8%) during the three-year post-vaccine introduction period. In TT Hue, no change in rotavirus positivity was observed. Among children aged 6-23 months, a 2-dose series of Rotavin-M1 was 57% (95% CI: 39%-70%) effective against moderate-to-severe rotavirus hospitalizations.

Interpretation

Higher vaccination coverage in Nam Dinh than TT Hue likely contributed to substantial declines in rotavirus positivity observed in Nam Dinh following rotavirus vaccine introduction. Robust vaccine effectiveness was observed through the second year of life. National rotavirus vaccine introduction with high coverage may have substantial impact on reducing rotavirus disease burden in Vietnam.

Funding

Bill and Melinda Gates Foundation.

The unfinished agenda of communicable diseases among children and adolescents before the COVID-19 pandemic, 1990-2019: a systematic analysis of the Global Burden of Disease Study 2019

BACKGROUND

Communicable disease control has long been a focus of global health policy. There have been substantial reductions in the burden and mortality of communicable diseases among children younger than 5 years, but we know less about this burden in older children and adolescents, and it is unclear whether current programmes and policies remain aligned with targets for intervention. This knowledge is especially important for policy and programmes in the context of the COVID-19 pandemic. We aimed to use the Global Burden of Disease (GBD) Study 2019 to systematically characterise the burden of communicable diseases across childhood and adolescence.

METHODS

In this systematic analysis of the GBD study from 1990 to 2019, all communicable diseases and their manifestations as modelled within GBD 2019 were included, categorised as 16 subgroups of common diseases or presentations. Data were reported for absolute count, prevalence, and incidence across measures of cause-specific mortality (deaths and years of life lost), disability (years lived with disability [YLDs]), and disease burden (disability-adjusted life-years [DALYs]) for children and adolescents aged 0-24 years. Data were reported across the Socio-demographic Index (SDI) and across time (1990-2019), and for 204 countries and territories. For HIV, we reported the mortality-to-incidence ratio (MIR) as a measure of health system performance.

FINDINGS

In 2019, there were 3·0 million deaths and 30·0 million years of healthy life lost to disability (as measured by YLDs), corresponding to 288·4 million DALYs from communicable diseases among children and adolescents globally (57·3% of total communicable disease burden across all ages). Over time, there has been a shift in communicable disease burden from young children to older children and adolescents (largely driven by the considerable reductions in children younger than 5 years and slower progress elsewhere), although children younger than 5 years still accounted for most of the communicable disease burden in 2019. Disease burden and mortality were predominantly in low-SDI settings, with high and high-middle SDI settings also having an appreciable burden of communicable disease morbidity (4·0 million YLDs in 2019 alone). Three cause groups (enteric infections, lower-respiratory-tract infections, and malaria) accounted for 59·8% of the global communicable disease burden in children and adolescents, with tuberculosis and HIV both emerging as important causes during adolescence. HIV was the only cause for which disease burden increased over time, particularly in children and adolescents older than 5 years, and especially in females. Excess MIRs for HIV were observed for males aged 15-19 years in low-SDI settings.

INTERPRETATION

Our analysis supports continued policy focus on enteric infections and lower-respiratory-tract infections, with orientation to children younger than 5 years in settings of low socioeconomic development. However, efforts should also be targeted to other conditions, particularly HIV, given its increased burden in older children and adolescents. Older children and adolescents also experience a large burden of communicable disease, further highlighting the need for efforts to extend beyond the first 5 years of life. Our analysis also identified substantial morbidity caused by communicable diseases affecting child and adolescent health across the world.

FUNDING

The Australian National Health and Medical Research Council Centre for Research Excellence for Driving Investment in Global Adolescent Health and the Bill & Melinda Gates Foundation.

Burden of disease attributable to unsafe drinking water, sanitation, and hygiene in domestic settings: a global analysis for selected adverse health outcomes

BACKGROUND

Assessments of disease burden are important to inform national, regional, and global strategies and to guide investment. We aimed to estimate the drinking water, sanitation, and hygiene (WASH)-attributable burden of disease for diarrhoea, acute respiratory infections, undernutrition, and soil-transmitted helminthiasis, using the WASH service levels used to monitor the UN Sustainable Development Goals (SDGs) as counterfactual minimum risk-exposure levels.

METHODS

We assessed the WASH-attributable disease burden of the four health outcomes overall and disaggregated by region, age, and sex for the year 2019. We calculated WASH-attributable fractions of diarrhoea and acute respiratory infections by country using modelled WASH exposures and exposure-response relationships from two updated meta-analyses. We used the WHO and UNICEF Joint Monitoring Programme for Water Supply, Sanitation and Hygiene public database to estimate population exposure to different WASH service levels. WASH-attributable undernutrition was estimated by combining the population attributable fractions (PAF) of diarrhoea caused by unsafe WASH and the PAF of undernutrition caused by diarrhoea. Soil-transmitted helminthiasis was fully attributed to unsafe WASH.

FINDINGS

We estimate that 1·4 (95% CI 1·3-1·5) million deaths and 74 (68-80) million disability-adjusted life-years (DALYs) could have been prevented by safe WASH in 2019 across the four designated outcomes, representing 2·5% of global deaths and 2·9% of global DALYs from all causes. The proportion of diarrhoea that is attributable to unsafe WASH is 0·69 (0·65-0·72), 0·14 (0·13-0·17) for acute respiratory infections, and 0·10 (0·09-0·10) for undernutrition, and we assume that the entire disease burden from soil-transmitted helminthiasis was attributable to unsafe WASH.

INTERPRETATION

WASH-attributable burden of disease estimates based on the levels of service established under the SDG framework show that progress towards the internationally agreed goal of safely managed WASH services for all would yield major public-health returns.

FUNDING

WHO and Foreign, Commonwealth & Development Office.

Potential impact and cost-effectiveness of Shigella vaccination in 102 low-income and middle-income countries in children aged 5 years or younger: a modelling study

BACKGROUND

Vaccine impact and cost-effectiveness models have mostly focused on acute burden. Shigella-attributable moderate-to-severe diarrhoea has been shown to be associated with childhood linear growth faltering. Evidence also links less severe diarrhoea to linear growth faltering. As Shigella vaccines are in late stages of clinical development, we aimed to estimate the potential impact and cost-effectiveness of vaccination against Shigella burden that includes stunting and the acute burden attributable to less severe diarrhoea and moderate-to-severe diarrhoea.

METHODS

We used a simulation model to estimate Shigella burden and potential vaccination in children aged 5 years or younger from 102 low-income to middle-income countries from 2025 to 2044. Our model included stunting associated with Shigella-related moderate-to-severe diarrhoea and less severe diarrhoea and we explored vaccination impact on health and economic outcomes.

FINDINGS

We estimate 109 million (95% uncertainty interval [UI] 39-204) Shigella-attributable stunting cases and 1·4 million (0·8-2·1) deaths in unvaccinated children over 20 years. We project that Shigella vaccination could avert 43 million (13-92) stunting cases and 590 000 (297 000-983 000) deaths over 20 years. The overall mean incremental cost-effectiveness ratio (ICER) was US$849 (95% uncertainty interval 423-1575; median $790 [IQR 635-1005]) per disability-adjusted life-year averted. Vaccination was most cost-effective in the WHO African region and in low-income countries. Including the burden of Shigella-related less severe diarrhoea improved mean ICERs by 47-48% for these groups and substantially improved ICERs for other regions.

INTERPRETATION

Our model suggests that Shigella vaccination would be a cost-effective intervention, with a substantial impact in specific countries and regions. Other regions could potentially benefit upon the inclusion of the burden of Shigella-related stunting and less severe diarrhoea in the analysis.

FUNDING

Bill & Melinda Gates Foundation and Wellcome Trust.

Identifying spatial clustering of diarrhoea among children under 5 years across 707 districts in India: a cross sectional study

BACKGROUND

Diarrhoea is one of the leading reasons for under-five child mortality and morbidity across the globe and especially in low- and middle-income countries like India. The present study aims to investigate and identify the spatial clustering and the factors associated with diarrhoea across 707 districts of different states in India.

METHODS

This study used National Family Health Survey-4 & 5 (2015-16 & 2019-21) data in India. Spatial analysis software i.e., ArcGIS and GeoDa including Moran's statistics have been applied to detect the spatial prevalence and auto-correlation of diarrhoea among neighbourhood districts. Bivariate analysis with a chi-square test and logistic regression has been performed to identify the factors associated with the morbidity condition.

RESULTS

The result shows out of 2,23,785 children, 7.3 percent children suffer from diarrhoea in India. The prevalence is highest in Bihar (13.7%) and lowest in Lakshadweep (2.3%). Around 33 percent of districts have reported more than the national average level of diarrhoea prevalence. The study also found a medium to high level of autocorrelation with 0.41 Moran's Index value and detected 69 hot-spots districts mostly from Maharashtra, Bihar, Odisha, and Gujarat. The study has also found, with an increase in children's age as well as mother's age the prevalence of the disease decreases. The prevalence is more among male children than females. Underweight [OR = 1.08, 95% CI (1.03-1.13)] children have a greater risk of suffering from diarrhoeal diseases. The odds of children living in a pucca house [OR = 0.89, 95% CI (0.68-1.16)] are less likely to suffer from diarrhoea. On the other hand, rich economic status [OR = 0.91, 95% CI (0.86-0.97)], reduce the risk of such morbid conditions.

CONCLUSION

The study recommends targeting the hot-spot districts with high prevalence areas, and district-level interventions by improving housing type and child nutrition status, which can help to prevent diarrhoeal diseases among children in India. Thus, the identification of hotspot districts and suggested policy interventions by the current study can help to prevent childhood mortality and morbidity, as well as to achieve the target given by Sustainable development Goals 3.2.

Prevalence of diarrheagenic Escherichia coli and impact on child health in Cap-Haitien, Haiti

BACKGROUND

Diarrheagenic Escherichia coli (DEC) are common pathogens infecting children during their growth and development. Determining the epidemiology and the impact of DEC on child anthropometric measures informs prioritization of prevention efforts. These relationships were evaluated in a novel setting, Cap-Haitien, Haiti.

METHODS

We performed pre-specified secondary analysis of a case-control study of community-dwelling children, 6-36 months of age, enrolled 96 cases with diarrhea and 99 asymptomatic controls. Assessments were performed at enrollment and one month later at follow-up. Established endpoint PCR methodologies targeted DEC gDNA isolated from fecal swabs. The association between DEC and anthropometric z-scores at enrollment was determined using multivariate linear regression. Lastly, we assessed the association between specific biomarkers, choline and docosahexaenoic acid (DHA) and diarrheal burden.

RESULTS

Enterotoxigenic Escherichia coli (ETEC) was identified in 21.9% of cases vs. 16.1% of controls with heat-stable producing ETEC significantly associated with symptomatic disease. Enteroaggregative E. coli (EAEC) was found in 30.2% of cases vs. 27.3% of controls, and typical enteropathogenic E. coli in 6.3% vs. 4.0% of cases and controls, respectively. Multivariate linear regression, controlled for case or control status, demonstrated ETEC and EAEC were significantly associated with reduced weight-age z-score (WAZ) and height-age z-score (HAZ) after adjusting for confounders. An interaction between ETEC and EAEC was observed. Choline and DHA were not associated with diarrheal burden.

CONCLUSIONS

DEC are prevalent in north Haitian children. ETEC, EAEC, household environment, and diet are associated with unfavorable anthropometric measures, with possible synergistic interactions between ETEC and EAEC. Further studies with longer follow up may quantify the contribution of individual pathogens to adverse health outcomes.

Management of Diarrhea in Young Children in Sub-Saharan Africa: Adherence to World Health Organization Recommendations During the Global Enteric Multisite Study (2007-2011) and the Vaccine Impact of Diarrhea in Africa (VIDA) Study (2015-2018)

BACKGROUND

Reducing diarrhea-related morbidity and mortality is a global priority, particularly in low-resource settings. We assessed adherence to diarrhea case management indicators in the Global Enteric Multisite Study (GEMS) and Vaccine Impact of Diarrhea in Africa (VIDA) study.

METHODS

GEMS (2007-2010) and VIDA (2015-2018) were age-stratified case-control studies of moderate-to-severe diarrhea (MSD) in children aged <5 years. In this case-only analysis, we included children enrolled in The Gambia, Kenya, and Mali. A case with no dehydration received adherent care at home if they were offered more than usual fluids and at least the same as usual to eat. Children with diarrhea and some dehydration are to receive oral rehydration salts (ORS) in the facility. The recommendation for severe dehydration is to receive ORS and intravenous fluids in the facility. Adherent care in the facility included a zinc prescription independent of dehydration severity.

RESULTS

For home-based management of children with MSD and no signs of dehydration, 16.6% in GEMS and 15.6% in VIDA were adherent to guidelines. Adherence to guidelines in the facility was likewise low during GEMS (some dehydration, 18.5%; severe dehydration, 5.5%). The adherence to facility-based rehydration and zinc guidelines improved during VIDA to 37.9% of those with some dehydration and 8.0% of children with severe dehydration.

CONCLUSIONS

At research sites in The Gambia, Kenya, and Mali, suboptimal adherence to diarrhea case management guidelines for children aged <5 years was observed. Opportunities exist for improvement in case management for children with diarrhea in low-resource settings.

Three structural solutions for bacterial adhesion pilus stability and superelasticity

Bacterial adhesion pili are key virulence factors that mediate host-pathogen interactions in diverse epithelial environments. Deploying a multimodal approach, we probed the structural basis underpinning the biophysical properties of pili originating from enterotoxigenic (ETEC) and uropathogenic bacteria. Using cryo-electron microscopy we solved the structures of three vaccine target pili from ETEC bacteria, CFA/I, CS17, and CS20. Pairing these and previous pilus structures with force spectroscopy and steered molecular dynamics simulations, we find a strong correlation between subunit-subunit interaction energies and the force required for pilus unwinding, irrespective of genetic similarity. Pili integrate three structural solutions for stabilizing their assemblies: layer-to-layer interactions, N-terminal interactions to distant subunits, and extended loop interactions from adjacent subunits. Tuning of these structural solutions alters the biophysical properties of pili and promotes the superelastic behavior that is essential for sustained bacterial attachment.

The effect of extreme weather events on child nutrition and health

This study traces the causal effects of extreme weather events on nutritional and health outcomes among rural children in Uganda using four waves of individual child survey data (2009–2014). A simultaneous regression model was applied for causal inference while also accounting for households’ adaptive responses. The study finds the evidence of a significant negative relationship between extreme weather events and availability of calories and nutrients for children. In particular, droughts reduced calorie, protein and zinc supply, and overall diet diversity by 67%, 37%, 28% and 30%, respectively. We further traced the effects of this reduced calorie and nutrient availability on child health indicators. A 10% decrease in zinc supply decreased height-for-age z-scores (HAZ) by around 0.139 - 0.164 standard deviations (SD), and increased probability of stunting ranging from 3.1 to 3.5 percentage points. Both boys and girls HAZ and stunting rates were sensitive to nutrient inadequacies. Different coping and adaptation strategies significantly influenced rural households’ ability to safeguard children’s nutrition and health against the effects of extreme weather. The findings of this study provide specific insights for building ex-ante resilience against extreme weather events, particularly when compared to ex-post, unsustainable, and often costlier relief actions.

A Shigella flexneri 2a synthetic glycan-based vaccine induces a long-lasting immune response in adults

Shigella is a leading cause of moderate to severe diarrhea worldwide and of diarrhea-associated deaths in children under 5 years of age in low-and middle-income countries. A vaccine against shigellosis is in high demand. SF2a-TT15, a synthetic carbohydrate-based conjugate vaccine candidate against Shigella flexneri 2a (SF2a) was found safe and strongly immunogenic in adult volunteers. Here, SF2a-TT15 at 10 µg oligosaccharide (OS) vaccine dose is shown to induce a sustained immune response in magnitude and functionality in the majority of volunteers followed up 2 and 3 years post-vaccination. High levels of either one of the humoral parameters as well as the number of specific-IgG memory B-cells determined 3 months after vaccination were good predictors of the durability of the immune response. This study is the first to examine the long-term durability of antibody functionality and memory B-cell response induced by a Shigella vaccine candidate.

Appropriate feeding practice and associated factors among under-five children with diarrheal disease in sub-Saharan Africa: a multi-country analysis

BACKGROUND

Diarrheal disease is one of the leading causes of child mortality and morbidity in low-income countries. Although the provision of more fluid and solid foods during diarrhea are important to treat the diseases, in Africa, food and fluid restrictions are common during diarrheal illness. Therefore, the aim of this study was to determine appropriate feeding practice and associated factors among under-five children with diarrheal disease in sub-Saharan Africa (SSA).

METHODS

We have used the appended most recent demographic and health survey (DHS) datasets of 35 sub-Saharan countries conducted from 2010 to 2020. A total weighted sample of 42,882 living children with diarrhea were included in the analyses. Multivariable multilevel binary logistic regression was used to identify factors associated with appropriate child feeding practice in SSA. A p value of ≤ 0.05 was used as a cut of point to declare statistically significant variables.

RESULTS

The overall prevalence of appropriate child feeding practice in this study was 10.45% (95% CI 10.17-10.74). The odds of having appropriate child feeding practice was higher among women with primary (AOR = 1.27: 1.17-1.37), secondary (AOR = 1.38: 1.25-1.52), and higher education level (AOR = 1.52: 1.21-1.90), media exposure (AOR = 1.11: 1.11-1.29), richer (AOR = 1.23:1.01-1.26) and richest (AOR = 1.19:1.05-1.35) wealth index, and currently working (AOR = 1.12: 1.04-1.19).

CONCLUSION

The prevalence of appropriate child feeding practice in this study was found to be very low. It advisable to reduce diarrhea-related child mortality through enhancing diarrhea management practice especially by working on the after mentioned factors.

Etiology and risk factors for diarrheal disease amongst rural and peri-urban populations in Cambodia, 2012-2018

Diarrheal diseases are a leading cause of mortality and morbidity, disproportionally affecting persons residing in low and middle-income countries. Accessing high-resolution surveillance data to understand community-level etiology and risk remains challenging, particularly in remote and resource limited populations. A multi-year prospective cohort study was conducted in two rural and two peri-urban villages in Cambodia from 2012 to 2018 to describe the epidemiology and etiology of acute diarrheal diseases within the population. Suspected diarrheal episodes among participants were self-reported or detected via routine weekly household visits. Fresh stool and fecal swabs were tested, and acute-illness and follow-up participant questionnaires collected. Of 5027 enrolled participants, 1450 (28.8%) reported at least one diarrheal incident. A total of 4266 individual diarrhea case events were recorded. Diarrhea incidence rate was calculated to be 281.5 persons per 1000 population per year, with an event rate of 664.3 individual diarrhea events occurring per 1000 population per year. Pathogenic Escherichia coli, Aeromonas spp., and Plesiomonas shigelloides were the most prevalent bacterial infections identified. Hookworm and Strongyloides stercoralis were the predominant helminth species, while Blastocystis hominis and Giardia lamblia were the predominant protozoan species found. Norovirus genotype 2 was the predominant virus identified. Mixed infections of two or more pathogens were detected in 36.2% of positive cases. Risk analyses identified unemployed status increased diarrhea risk by 63% (HR = 1.63 [95% CI 1.46, 1.83]). Individuals without access to protected water sources or sanitation facilities were 59% (HR = 1.59 [95% CI 1.49, 1.69]) and 19% (HR = 1.19 [95% CI 1.12, 1.28]) greater risk of contracting diarrhea, respectively. Patient-level surveillance data captured in this long-term study has generated a unique spatiotemporal profile of diarrheal disease in Cambodia. Understanding etiologies, together with associated epidemiological and community-level risk, provides valuable public health insight to support effective planning and delivery of appropriate local population-targeted interventions.

Early life gut microbiota: Consequences for health and opportunities for prevention

The gut microbiota influences many aspects of the host, including immune system maturation, nutrient absorption and metabolism, and protection from pathogens. Increasing evidences from cohort and animal studies indicate that changes in the gut microbiota early in life increases the risk of developing specific diseases early and later in life. Therefore, it is becoming increasingly important to identify specific disease prevention or therapeutic solutions targeting the gut microbiota, especially during infancy, which is the window of the human gut microbiota establishment process. In this review, we provide an overview of current knowledge concerning the relationship between disturbances in the gut microbiota early in life and health consequences later in life (e.g., necrotizing enterocolitis, celiac disease, asthma, allergies, autism spectrum disorders, overweight/obesity, diabetes and growth retardation), with a focus on changes in the gut microbiota prior to disease onset. In addition, we summarize and discuss potential microbiota-based interventions early in life (e.g., diet adjustments, probiotics, prebiotics, fecal microbiota transplantation, environmental changes) to promote health or prevent the development of specific diseases. This knowledge should aid the understanding of early life microbiology and inform the development of prediction and prevention measures for short- and long-term health disorders based on the gut microbiota.

A strategic model for developing vaccines against neglected diseases: An example of industry collaboration for sustainable development

Infectious diseases continue to disproportionately affect low- and middle-income countries (LMICs) and children aged <5 y. Developing vaccines against diseases endemic in LMICs relies mainly on strong public-private collaborations, but several challenges remain. We review the operating model of the GSK Vaccines Institute for Global Health (GVGH), which aims to address these challenges. The model involves i) selection of vaccine targets based on priority ranking for impact on global health; ii) development from design to clinical proof-of-concept; iii) transfer to an industrial partner, for further technical/clinical development, licensing, manufacturing, and distribution. Cost and risks associated with pre-clinical and early clinical development are assumed by GVGH, increasing the probability to make the vaccine more affordable in LMICs. A conjugate vaccine against typhoid fever, Vi-CRM197, has recently obtained WHO prequalification, within a year from licensure in India, demonstrating the success of the GVGH model for development and delivery of global health vaccines.

A Mixed Methods Process Evaluation of a Food Hygiene Intervention in Low-Income Informal Neighbourhoods of Kisumu, Kenya

OBJECTIVES

Diarrhoea is a leading cause of infant mortality with the main transmission pathways being unsafe water and contaminated food, surfaces and hands. The 'Safe Start' trial evaluated a food hygiene intervention implemented in a peri-urban settlement of Kisumu, Kenya, with the aim of reducing diarrhoeagenic enteric infections among infants. Four food hygiene behaviours were targeted: handwashing with soap before preparation and feeding, boiling infant food before feeding, storing infant food in sealed containers, and exclusive use of designated utensils during feeding.

METHODS

A process evaluation of the intervention was guided by a theory of change describing the hypothesised implementation and receipt of the intervention, mechanisms of change, and the context. These were assessed by qualitative and quantitative data that included debriefing sessions with the delivery teams and Community Health Volunteers (CHVs), and structured observations during food preparation.

RESULTS

The intervention achieved high coverage and fidelity with over 90% of 814 eligible caregivers participating in the intervention. Caregivers in the intervention arm demonstrated an understanding of the intervention messages, and had 1.38 (95% CI: 1.02-1.87) times the odds of washing hands before food preparation and 3.5 (95% CI: 1.91-6.56) times the odds of using a feeding utensil compared to caregivers in the control group. Contextual factors, especially the movement of caregivers within and outside the study area and time constraints faced by caregivers influenced uptake of some intervention behaviours.

CONCLUSION

Future interventions should seek to explicitly target contextual factors such as secondary caregivers and promote food hygiene interventions as independent of each other.

Dynamics of the Gut Microbiome in Shigella-Infected Children during the First Two Years of Life

Shigella continues to be a major contributor to diarrheal illness and dysentery in children younger than 5 years of age in low- and middle-income countries. Strategies for the prevention of shigellosis have focused on enhancing adaptive immunity. The interaction between Shigella and intrinsic host factors, such as the microbiome, remains unknown. We hypothesized that Shigella infection would impact the developing microbial community in infancy and, conversely, that changes in the gastrointestinal microbiome may predispose infections. To test this hypothesis, we characterized the gastrointestinal microbiota in a longitudinal birth cohort from Malawi that was monitored for Shigella infection using 16S rRNA amplicon sequencing. Children with at least one Shigella quantitative polymerase chain reaction (qPCR) positive sample during the first 2 years of life (cases) were compared to uninfected controls that were matched for sex and age. Overall, the microbial species diversity, as measured by the Shannon diversity index, increased over time, regardless of case status. At early time points, the microbial community was dominated by Bifidobacterium longum and Escherichia/Shigella. A greater abundance of Prevotella 9 and Bifidobacterium kashiwanohense was observed at 2 years of age. While no single species was associated with susceptibility to Shigella infection, significant increases in Lachnospiraceae NK4A136 and Fusicatenibacter saccharivorans were observed following Shigella infection. Both taxa are in the family Lachnospiraceae, which are known short-chain fatty acid producers that may improve gut health. Our findings identified temporal changes in the gastrointestinal microbiota associated with Shigella infection in Malawian children and highlight the need to further elucidate the microbial communities associated with disease susceptibility and resolution. IMPORTANCE Shigella causes more than 180 million cases of diarrhea globally, mostly in children living in poor regions. Infection can lead to severe health impairments that reduce quality of life. There is increasing evidence that disruptions in the gut microbiome early in life can influence susceptibility to illnesses. A delayed or impaired reconstitution of the microbiota following infection can further impact overall health. Aiming to improve our understanding of the interaction between Shigella and the developing infant microbiome, we investigated changes in the gut microbiome of Shigella-infected and uninfected children over the course of their first 2 years of life. We identified species that may be involved in recovery from Shigella infection and in driving the microbiota back to homeostasis. These findings support future studies into the elucidation of the interaction between the microbiota and enteric pathogens in young children and into the identification of potential targets for prevention or treatment.

Dietary phytate primes epithelial antibacterial immunity in the intestine

Although diet has long been associated with susceptibility to infection, the dietary components that regulate host defense remain poorly understood. Here, we demonstrate that consuming rice bran decreases susceptibility to intestinal infection with Citrobacter rodentium, a murine pathogen that is similar to enteropathogenic E. coli infection in humans. Rice bran naturally contains high levels of the substance phytate. Interestingly, phytate supplementation also protected against intestinal infection, and enzymatic metabolism of phytate by commensal bacteria was necessary for phytate-induced host defense. Mechanistically, phytate consumption induced mammalian intestinal epithelial expression of STAT3-regulated antimicrobial pathways and increased phosphorylated STAT3, suggesting that dietary phytate promotes innate defense through epithelial STAT3 activation. Further, phytate regulation of epithelial STAT3 was mediated by the microbiota-sensitive enzyme histone deacetylase 3 (HDAC3). Collectively, these data demonstrate that metabolism of dietary phytate by microbiota decreases intestinal infection and suggests that consuming bran and other phytate-enriched foods may represent an effective dietary strategy for priming host immunity.

Controlled Human Infection Models To Accelerate Vaccine Development

The timelines for developing vaccines against infectious diseases are lengthy, and often vaccines that reach the stage of large phase 3 field trials fail to provide the desired level of protective efficacy. The application of controlled human challenge models of infection and disease at the appropriate stages of development could accelerate development of candidate vaccines and, in fact, has done so successfully in some limited cases. Human challenge models could potentially be used to gather critical information on pathogenesis, inform strain selection for vaccines, explore cross-protective immunity, identify immune correlates of protection and mechanisms of protection induced by infection or evoked by candidate vaccines, guide decisions on appropriate trial endpoints, and evaluate vaccine efficacy. We prepared this report to motivate fellow scientists to exploit the potential capacity of controlled human challenge experiments to advance vaccine development. In this review, we considered available challenge models for 17 infectious diseases in the context of the public health importance of each disease, the diversity and pathogenesis of the causative organisms, the vaccine candidates under development, and each model's capacity to evaluate them and identify correlates of protective immunity. Our broad assessment indicated that human challenge models have not yet reached their full potential to support the development of vaccines against infectious diseases. On the basis of our review, however, we believe that describing an ideal challenge model is possible, as is further developing existing and future challenge models.

Genomic and proteomic characterization of two strains of Shigella flexneri 2 isolated from infants' stool samples in Argentina

Background

Shigella specie is a globally important intestinal pathogen disseminated all over the world. In this study we analyzed the genome and the proteomic component of two Shigella flexneri 2a clinical isolates, collected from pediatric patients with gastroenteritis of the Northwest region of Argentina (NWA) in two periods of time, with four years of difference. Our goal was to determine putative changes at molecular levels occurred during these four years, that could explain the presence of this Shigella`s serovar as the prevalent pathogen in the population under study.

Results

As previously reported, our findings support the idea of Shigella has a conserved “core” genome, since comparative studies of CI133 and CI172 genomes performed against 80 genomes obtained from the NCBI database, showed that there is a large number of genes shared among all of them. However, we observed that CI133 and CI172 harbors a small number of strain-specific genes, several of them present in mobile genetic elements, supporting the hypothesis that these isolates were established in the population by horizontal acquisition of genes. These differences were also observed at proteomic level, where it was possible to detect the presence of certain secreted proteins in a culture medium that simulates the host environment.

Conclusion

Great similarities were observed between the CI133 and CI172 strains, confirming the high percentage of genes constituting the “core” genome of S. flexneri 2. However, numerous strain specific genes were also determined. The presence of the here identified molecular elements into other strain of our culture collation, is currently used to develop characteristic markers of local pathogens. In addition, the most outstanding result of this study was the first description of a S. flexneri 2 producing Colicin E, as one of the characteristics that allows S. flexneri 2 to persist in the microbial community. These findings could also contribute to clarify the mechanism and the evolution strategy used by this pathogen to specifically colonize, survive, and cause infection within the NWA population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-022-08711-5.

Intestinal Parasitic Infections Among Pediatric Patients in a Metropolitan City of Bangladesh With Emphasis on Cryptosporidiosis

Introduction Gastrointestinal parasitic infections are one of the global health concerns in developing countries like Bangladesh. Among them, Cryptosporidium spp. plays an essential role in causing diarrhea, malnutrition, and poor cognitive function, especially in children. This study was conducted to identify the frequency of Cryptosporidium cases and other parasitic agents.  Methods A cross-sectional observational study was conducted among 219 hospitalized children with diarrhea. The conventional microscopic technique was applied for parasitic detection. Particular staining (modified Ziehl-Neelsen) procedure was performed to identify oocysts of Cryptosporidium spp. A polymerase chain reaction (PCR) was performed to determine the SSU rRNA and gp60 gene of Cryptosporidium.  Results Cysts of Giardia duodenalis (2.3%), ova of Ascaris lumbricoides (1.4%,), Trichuris trichiura (0.5%), and both A. lumbricoides and T. trichiura (0.9%) were identified in samples through wet mount preparation. The distribution of Cryptosporidium spp. as detected by the staining method and nested PCR was 1.4% and 4.1%, respectively.  Conclusion Factors independently associated with Cryptosporidium infection are unsafe water, lack of regular hand washing, and insufficiency of exclusive breastfeeding. This study reports, presumably for the first time, the detection of Cryptosporidium oocysts in Chattogram metropolitan city of Bangladesh.

The First-in-Human Synthetic Glycan-Based Conjugate Vaccine Candidate against Shigella

Shigella, the causative agent of shigellosis, is among the main causes of diarrheal diseases with still a high morbidity in low-income countries. Relying on chemical synthesis, we implemented a multidisciplinary strategy to design SF2a-TT15, an original glycoconjugate vaccine candidate targeting Shigella flexneri 2a (SF2a). Whereas the SF2a O-antigen features nonstoichiometric O-acetylation, SF2a-TT15 is made of a synthetic 15mer oligosaccharide, corresponding to three non-O-acetylated repeats, linked at its reducing end to tetanus toxoid by means of a thiol-maleimide spacer. We report on the scale-up feasibility under GMP conditions of a high yielding bioconjugation process established to ensure a reproducible and controllable glycan/protein ratio. Preclinical and clinical batches complying with specifications from ICH guidelines, WHO recommendations for polysaccharide conjugate vaccines, and (non)compendial tests were produced. The obtained SF2a-TT15 vaccine candidate passed all toxicity-related criteria, was immunogenic in rabbits, and elicited bactericidal antibodies in mice. Remarkably, the induced IgG antibodies recognized a large panel of SF2a circulating strains. These preclinical data have paved the way forward to the first-in-human study for SF2a-TT15, demonstrating safety and immunogenicity. This contribution discloses the yet unreported feasibility of the GMP synthesis of conjugate vaccines featuring a unique homogeneous synthetic glycan hapten fine-tuned to protect against an infectious disease.

Enterotoxigenic Escherichia coli: intestinal pathogenesis mechanisms and colonization resistance by gut microbiota

Enterotoxigenic Escherichia coli (ETEC) is a major cause of diarrhea in children and travelers in developing countries. ETEC is characterized by the ability to produce major virulence factors including colonization factors (CFs) and enterotoxins, that bind to specific receptors on epithelial cells and induce diarrhea. The gut microbiota is a stable and sophisticated ecosystem that performs a range of beneficial functions for the host, including protection against pathogen colonization. Understanding the pathogenic mechanisms of ETEC and the interaction between the gut microbiota and ETEC represents not only a research need but also an opportunity and challenge to develop precautions for ETEC infection. Herein, this review focuses on recent discoveries about ETEC etiology, pathogenesis and clinical manifestation, and discusses the colonization resistances mediated by gut microbiota, as well as preventative strategies against ETEC with an aim to provide novel insights that can reduce the adverse effect on human health.

El Niño Southern Oscillation, monsoon anomaly, and childhood diarrheal disease morbidity in Nepal

Climate change is adversely impacting the burden of diarrheal diseases. Despite significant reduction in global prevalence, diarrheal disease remains a leading cause of morbidity and mortality among young children in low- and middle-income countries. Previous studies have shown that diarrheal disease is associated with meteorological conditions but the role of large-scale climate phenomena such as El Niño-Southern Oscillation (ENSO) and monsoon anomaly is less understood. We obtained 13 years (2002-2014) of diarrheal disease data from Nepal and investigated how the disease rate is associated with phases of ENSO (El Niño, La Niña, vs. ENSO neutral) monsoon rainfall anomaly (below normal, above normal, vs. normal), and changes in timing of monsoon onset, and withdrawal (early, late, vs. normal). Monsoon season was associated with a 21% increase in diarrheal disease rates (Incident Rate Ratios [IRR]: 1.21; 95% CI: 1.16-1.27). El Niño was associated with an 8% reduction in risk while the La Niña was associated with a 32% increase in under-5 diarrheal disease rates. Likewise, higher-than-normal monsoon rainfall was associated with increased rates of diarrheal disease, with considerably higher rates observed in the mountain region (IRR 1.51, 95% CI: 1.19-1.92). Our findings suggest that under-5 diarrheal disease burden in Nepal is significantly influenced by ENSO and changes in seasonal monsoon dynamics. Since both ENSO phases and monsoon can be predicted with considerably longer lead time compared to weather, our findings will pave the way for the development of more effective early warning systems for climate sensitive infectious diseases.

Effectiveness of 13-valent pneumococcal conjugate vaccine against hypoxic pneumonia and hospitalisation in Eastern Highlands Province, Papua New Guinea: An observational cohort study

Background

Pneumonia is a leading cause of childhood mortality with Streptococcus pneumoniae a major contributor. Pneumococcal conjugate vaccines (PCVs) have been introduced into immunisation programs in many low- to middle-income countries (LMICs) yet there is a paucity of data evaluating the effectiveness in these settings. We assess the effectiveness of 13-valent PCV (13vPCV) against hypoxic pneumonia, hospitalisation and other clinical endpoints in children <5 years living in Eastern Highlands Province, Papua New Guinea (PNG).

Methods

Data from two consecutive prospective observational studies (2013–2019) enrolling children <60 months presenting with pneumonia were included. Hypoxic pneumonia was defined as oxygen saturations <90%. Outcomes included hospitalisation, severe clinical pneumonia and death. 13vPCV status was determined using written records. Logistic regression models were used to estimate the odds ratios of key outcomes by 13vPCV vaccination status adjusted for confounders using inverse probability of treatment weighting.

Findings

Data from 2067 children (median age; 9 months [IQR: 5–11]) were included. 739 children (36.1%) were hypoxic and 623 (30.4%) hospitalised. Twelve children (0.6% of total cohort) died in hospital. 670 children (32.7%) were fully 13vPCV-vaccinated. 13vPCV vaccination was associated with a 28.7% reduction (95% confidence interval [CI]: 9.9; 43.6%) in hypoxic pneumonia and a 57.4% reduction (38.0; 70.7%) in pneumonia hospitalisation.

Interpretation

13vPCV vaccination is effective against hypoxic pneumonia and pneumonia hospitalisation in PNG children. Strategies to improve access to and coverage of 13vPCV in PNG and other similar LMICs are urgently required.

Funding

Funded by Pfizer Global and the Bill & Melinda Gates Foundation.

The use of digital technology to improve and monitor handwashing among children 12 years or younger in educational settings: a scoping review

Our scoping review aimed to identify and describe the application of digital technology in hand hygiene research among children in educational settings. We searched for articles in PubMed, IEEE Xplore, and Web of Science. Original hand hygiene research with a form of digital technology used among children ≤12 years in educational settings was eligible for inclusion. Twelve studies met the eligibility criteria and the data were extracted by two teams of independent co-authors for narrative synthesis. Ten studies used digital technology as an intervention tool and two for monitoring purposes. Three main digital technologies were identified including computer games (n = 2), videos (n = 8), and video cameras (n = 2). Digital technologies found in our scoping review were reported to be effective in hand hygiene studies over short temporal periods especially when used in combination with other measures. Future research may demonstrate the effectiveness of digital technology in helping children develop sustainable handwashing behaviors.