Malnutrition as an enteric infectious disease with long-term effects on child development

Immunogenicity of rotavirus vaccine (RotarixTM) in infants with environmental enteric dysfunction

Introduction

Deployment of rotavirus vaccines has contributed to significant declines in diarrheal morbidity and mortality globally. Unfortunately, vaccine performance in low-middle income countries (LMICs) is generally lower than in developed countries. The cause for this has been associated with several host and maternal factors including poor water sanitation and hygiene (WASH) status, which are predominant in LMICs. More recently, environmental enteric dysfunction (EED) has specifically been hypothesized to contribute to poor vaccine uptake and response. The aim of this study was to examine the association between serological biomarkers of EED and seroconversion to rotavirus vaccine in Zambian infants.

Methods

This was a retrospective cohort study of 142 infants who had been fully immunized with Rotarix™, and had known seroconversion status. Seroconversion was defined as 4-fold or more increase in rotavirus-specific IgA titres between pre-vaccination and one month post-dose two vaccination. We performed ELISA assays to assess soluble CD14 (sCD14), Endotoxin Core IgG Antibodies (EndoCAb), intestinal fatty acid binding protein (i-FABP) and Zonulin according to the manufacturers protocols. Generalised linear model with family-poisson, link-log and robust standard error was used to estimate the independent effects of biomarkers on seroconversion adjusting for important cofounders.

Results

The median concentration of Zonulin, Soluble CD14, EndoCaB, and IFABP were 209.3 (IQR = 39.7, 395.1), 21.5 (IQR = 21.5, 21.5), 0.3 (IQR = 0.3, 0.3), and 107.7 (IQR = 6.4, 1141.4) respectively. In multivariable analyses adjusting for the independent effect of other biomarkers and confounders (i.e. age of child at vaccination, breast-milk anti-rotavirus IgA, infant serum anti-rotavirus IgG, and IgA seropositivity at baseline), there was strong evidence of about 24% increase in seroconversion due to doubling Zonulin concentration (Adjusted risk ratio (aRR) = 1.24; 95% CI = 1.12 to1.37; p<0.0001). Similarly, we found about 7% increase in seroconversion due to doubling IFABP concentration (aRR = 1.07; 95% CI = 1.02 to 1.13; p = 0.006).

Conclusion

We found that high levels of zonulin and IFABP played a role in seroconversion. It is plausible that increased gut permeability in EED allows greater uptake of the live virus within the vaccine, but later consequences result in deleterious local structural distortions and malabsorption syndromes.

Enteric Infections in Young Children are Associated with Environmental Enteropathy and Impaired Growth

OBJECTIVE

To investigate the relationship between faecal contamination in child play spaces, enteric infections, environmental enteropathy (EE) and impaired growth among young children.

METHODS

A prospective cohort study was conducted of 203 children 6-30 months of age in rural Bangladesh. Stool samples were analysed by quantitative PCR for Shigella, Enterotoxigenic Escherichia coli (ETEC), Campylobacter jejuni, Giardia intestinalis and Cryptosporidium spp. Four faecal markers of intestinal inflammation were also measured: alpha-1-antitrypsin, myeloperoxidase, neopterin and calprotectin. Child growth was measured at baseline and 9 months after enrolment. E. coli was measured in soil in child play spaces.

RESULTS

Forty-seven percent of study children had three or more enteric pathogens in their stool. Thirty five percent (71/203) of children had Shigella, 30% (61/203) had ETEC, 73% (148/203) had C. jejuni, 79% (160/203) had Giardia intestinalis and none had Cryptosporidium. Children with ETEC had significantly higher calprotectin concentrations (Coefficient: 1.35, 95% Confidence Interval [CI]: 1.005, 1.82). Children with Shigella had a significantly higher odds of being stunted at our 9-month follow-up (OR: 2.01, 95% CI: 1.02, 3.93). Children with Giardia intestinalis had significantly higher E.coli counts in the soil collected from their play spaces (OR: 1.23, 95% CI: 1.02, 1.48).

CONCLUSION

Enteric infections were significantly associated with EE and impaired growth in rural Bangladesh. These findings provide further evidence to support the hypothesis that contaminated soil in child play spaces can lead to enteric infections, many of which are likely subclinical, resulting in EE and impaired growth in young children.

Determinant Variables, Enteric Pathogen Burden, Gut Function and Immune-related Inflammatory Biomarkers Associated With Childhood Malnutrition: A Prospective Case-Control Study in Northeastern Brazil

Malnutrition results in serious consequences for growth and cognitive development in children. We studied select child and maternal biologic factors, socioeconomic factors, enteric pathogenic burden and gut function biomarkers in 402 children 6-24 months of age in Northeastern Brazil. In this prospective case-control study, not being fed colostrum [odds ratio (OR): 3.29, 95% confidence interval (CI): 1.73-6.26], maternal age ≥18 years (OR: 1.88, 95% CI: 1.10-3.22) and no electric fan (OR: 2.46, 95% CI: 1.22-4.96) or bicycle (OR: 1.80, 95% CI: 1.10-2.95) in the household were positively associated, and higher birth weight (OR: 0.27, 95% CI: 0.19-0.38), larger head circumference (OR: 0.74, 95% CI: 0.66-0.82) and shortness of breath in the last 2 weeks (OR: 0.49, 95% CI: 0.27-0.90) were negatively associated with malnutrition. Subclinical enteric pathogen infections were common, and enteroaggregative Escherichia coli infections were more prevalent in malnourished children (P = 0.045). Biomarkers such as the lactulose-mannitol test, myeloperoxidase, neopterin and calprotectin were highly elevated in both malnourished and nourished children. Nourished children had a better systemic immune response than the malnourished children, as detected by elevated serum amyloid A-1 and soluble cluster of differentiation protein 14 biomarkers (P < 0.001). Serum amyloid A-1 and soluble cluster of differentiation protein 14 were also associated with better nutritional Z scores. Neonatal, maternal and socioeconomic factors were associated with malnutrition in children. There was a substantial subclinical enteric pathogen burden, particularly with enteroaggregative E. coli, in malnourished children.

Using a monitoring and evaluation framework to improve study efficiency and quality during a prospective cohort study in infants receiving rotavirus vaccination in El Alto, Bolivia: the Infant Nutrition, Inflammation, and Diarrheal Illness (NIDI) study

BACKGROUND

Implementing rigorous epidemiologic studies in low-resource settings involves challenges in participant recruitment and follow-up (e.g., mobile populations, distrust), biological sample collection (e.g., cold-chain, laboratory equipment scarcity) and data collection (e.g., literacy, staff training, and infrastructure). This article describes the use of a monitoring and evaluation (M&E) framework to improve study efficiency and quality during participant engagement, and biological sample and data collection in a longitudinal cohort study of Bolivian infants.

METHODS

The study occurred between 2013 and 2015 in El Alto, Bolivia, a high-altitude, urban, low-resource community. The study's M&E framework included indicators for participant engagement (e.g., recruitment, retention, safety), biological sample (e.g., stool and blood), and data (e.g., anthropometry, questionnaires) collection and quality. Monitoring indicators were measured regularly throughout the study and used for course correction, communication, and staff retraining.

RESULTS

Participant engagement indicators suggested that enrollment objectives were met (461 infants), but 15% loss-to-follow-up resulted in only 364 infants completing the study. Over the course of the study, there were four study-related adverse events (minor swelling and bruising related to a blood draw) and five severe adverse events (infant deaths) not related to study participation. Biological sample indicators demonstrated two blood samples collected from 95% (333 of 350 required) infants and stool collected for 61% of reported infant diarrhea episodes. Anthropometry data quality indicators were extremely high (median SDs for weight-for-length, length-for-age and weight-for-age z-scores 1.01, 0.98, and 1.03, respectively), likely due to extensive training, standardization, and monitoring efforts.

CONCLUSIONS

Conducting human subjects research studies in low-resource settings often presents unique logistical difficulties, and collecting high-quality data is often a challenge. Investing in comprehensive M&E is important to improve participant recruitment, retention and safety, and sample and data quality. The M&E framework from this study can be applied to other longitudinal studies.

Exposure to Animal Feces and Human Health: A Systematic Review and Proposed Research Priorities

Humans can be exposed to pathogens from poorly managed animal feces, particularly in communities where animals live in close proximity to humans. This systematic review of peer-reviewed and gray literature examines the human health impacts of exposure to poorly managed animal feces transmitted via water, sanitation, and hygiene (WASH)-related pathways in low- and middle-income countries, where household livestock, small-scale animal operations, and free-roaming animals are common. We identify routes of contamination by animal feces, control measures to reduce human exposure, and propose research priorities for further inquiry. Exposure to animal feces has been associated with diarrhea, soil-transmitted helminth infection, trachoma, environmental enteric dysfunction, and growth faltering. Few studies have evaluated control measures, but interventions include reducing cohabitation with animals, provision of animal feces scoops, controlling animal movement, creating safe child spaces, improving veterinary care, and hygiene promotion. Future research should evaluate: behaviors related to points of contact with animal feces; animal fecal contamination of food; cultural behaviors of animal fecal management; acute and chronic health risks associated with exposure to animal feces; and factors influencing concentrations and shedding rates of pathogens originating from animal feces.

Can water, sanitation and hygiene help eliminate stunting? Current evidence and policy implications

Stunting is a complex and enduring challenge with far‐reaching consequences for those affected and society as a whole. To accelerate progress in eliminating stunting, broader efforts are needed that reach beyond the nutrition sector to tackle the underlying determinants of undernutrition. There is growing interest in how water, sanitation and hygiene (WASH) interventions might support strategies to reduce stunting in high‐burden settings, such as South Asia and sub‐Saharan Africa. This review article considers two broad questions: (1) can WASH interventions make a significant contribution to reducing the global prevalence of childhood stunting, and (2) how can WASH interventions be delivered to optimize their effect on stunting and accelerate progress? The evidence reviewed suggests that poor WASH conditions have a significant detrimental effect on child growth and development resulting from sustained exposure to enteric pathogens but also due to wider social and economic mechanisms. Realizing the potential of WASH to reduce stunting requires a redoubling of efforts to achieve universal access to these services as envisaged under the Sustainable Development Goals. It may also require new or modified WASH strategies that go beyond the scope of traditional interventions to specifically address exposure pathways in the first 2 years of life when the process of stunting is concentrated.

Measuring home environments across cultures: Invariance of the HOME scale across eight international sites from the MAL-ED study

The home environment provides the context for much of a child's early development. Examples of important aspects of the home environment include safety, cleanliness, and opportunities for cognitive stimulation. This study sought to examine the psychometric properties of an adapted form of the Home Observation for the Measurement of the Environment (HOME; Caldwell & Bradley, 1984, 2003) across the eight international sites of the MAL-ED project (Dhaka, Bangladesh; Vellore, India; Bhakatapur, Nepal; Naushahro Feroze, Pakistan; Fortaleza, Brazil; Loreto, Peru; Venda, South Africa; Haydom, Tanzania), to identify a factor structure that fit the data at all sites, and to derive a subset of items that could be used to examine home environmental characteristics across sites. A three-factor structure (i.e., Emotional and Verbal Responsivity; Clean and Safe Environment; Child Cleanliness) was identified, and partial measurement equivalence/invariance across sites was supported. Overall, these findings lend support for the use of portions of this abbreviated and adapted version of the HOME for use among heterogeneous, cross-cultural groups in low- and middle-income nations.

Persistent diarrhea: a persistent infection with enteropathogens or a gut commensal dysbiosis?

In children from developing countries 5-10% of acute diarrhea (AD) episodes develop into persistent diarrhea (PD) defined by > 14 days of diarrhea duration. PD represents a major health burden leading to growth faltering. It is also associated with half of all diarrhea mortality. A rational intervention is thus crucial, but depends on an understanding of the pathogenesis of PD, which is still lacking. Many surveys were conducted in Latin America and in South Asia; they differ, however, with respect to enteropathogens associated with PD. Enteroaggregative strains of Escherichia coli (EAEC) were identified by several studies, but they may reflect selection by the frequent antibiotic use during the preceding AD episode. Epidemiologists have in fact identified antibiotic misuse as a major risk factor for PD. Together with the effectiveness of empirical treatment based on nutritional interventions with lactose-reduced and lactose-free diets and particularly complex plant polysaccharides from green banana, one might suspect a role of commensal gut microbiota dysbiosis instead of a persistent infection with enteropathogens in many PD cases. An analysis of the commensal gut microbiota development in persistent diarrhea during nutritional interventions is likely to increase our understanding of PD pathogenesis.

Tissue compartmentalization of T cell responses during early life

The immune system in early life is tasked with transitioning from a relatively protected environment to one in which it encounters a wide variety of innocuous antigens and dangerous pathogens. The immaturity of the developing immune system, and particularly the distinct functionality of T lymphocytes in early life, has been implicated in increased susceptibility to infection. Previous work has demonstrated that immune responses in early life are skewed toward limited inflammation and atopy; however, there is mounting evidence that such responses are context- and tissue-dependent. The regulation, differentiation, and maintenance of infant T cell responses, particularly as it relates to tissue compartmentalization, remains poorly understood. How the tissue environment impacts early-life immune responses and whether the development of localized protective immune memory cell subsets are established is an emerging area of research. As infectious diseases affecting the respiratory and digestive tracts are a leading cause of morbidity and mortality worldwide in infants and young children, a deeper understanding of site-specific immunity is essential to addressing these challenges. Here, we review the current paradigms of T cell responses during infancy as they relate to tissue localization and discuss implications for the development of vaccines and therapeutics.

Innate immune responses play a key role in controlling infection of the intestinal epithelium by Cryptosporidium

Cryptosporidium infection leads to acute diarrhea worldwide. The development of cryptosporidiosis is closely related to the immune status of its host, affecting primarily young ruminants, infants, and immunocompromised individuals. In recent years, several studies have improved our knowledge on the immune mechanisms responsible for the control of the acute phase of the infection and have highlighted the importance of innate immunity. The parasite develops in the apical side of intestinal epithelial cells, giving these cells a central role, as they are both the exclusive host cell for replication of the parasite and participate in the protective immune response. Epithelial cells signal the infection by producing chemokines, attracting immune cells to the infected area. They also actively participate in host defense by inducing apoptosis and releasing antimicrobial peptides, free or incorporated into luminal exosomes, with parasiticidal activity. The parasite has developed several escape mechanisms to slow down these protective mechanisms. Recent development of several three-dimensional culture models and the ability to genetically manipulate Cryptosporidium will greatly help to further investigate host-pathogen interactions and identify virulence factors. Intestinal epithelial cells require the help of immune cells to clear the infection. Intestinal dendritic cells, well known for their ability to induce and orchestrate adaptive immunity, play a key role in controlling the very early steps of Cryptosporidium parvum infection by acting as immunological sentinels and active effectors. However, inflammatory monocytes, which are quickly and massively recruited to the infected mucosa, seem to participate in the loss of epithelial integrity. In addition to new promising chemotherapies, we must consider stimulating the innate immunity of neonates to strengthen their ability to control Cryptosporidium development. The microbiota plays a fundamental role in the development of intestinal immunity and may be considered to be a third actor in host-pathogen interactions. There is an urgent need to reduce the incidence of this yet poorly controlled disease in the populations of developing countries, and decrease economic losses due to infected livestock.

Seasonal Bushmeat Hunger in the Congo Basin

Unlike the Sudano-sahelian regions, which are confronted to severe periods of food shortage, tropical rainforests are known to provide a constant supply of a great diversity of food resources that mitigates the risk of food starvation for omnivorous humans. Nevertheless, several African forest ethnic groups suffer from a seasonal hunger induced by depletion in the procurement of bushmeat, which is a food of paramount importance. Although the diet remains well balanced and meets all the nutritional needs, the bushmeat cravers loose weight and experience a stress that affects their well-being. Bushmeat hunger is a psychocultural form of hunger that generates several mental disorders. We present results from nutritional anthropology studies carried out among various Congo Basin forest peoples, which regularly suffer from bushmeat hunger. We expose the physiological risks that result from this psychological unrest, we argue that this type of unsatisfied compiling desire for meat should be considered as a factor of food insecurity and we conclude on its incidence on bushmeat trade. The immoderate craving for bushmeat compromises the attempts to replace bushmeat by other sources of meat and is a persisting obstacle to conservation initiatives that fail to take the psychocultural values of bushmeat into consideration.

Genomic dissection of conserved transcriptional regulation in intestinal epithelial cells

The intestinal epithelium serves critical physiologic functions that are shared among all vertebrates. However, it is unknown how the transcriptional regulatory mechanisms underlying these functions have changed over the course of vertebrate evolution. We generated genome-wide mRNA and accessible chromatin data from adult intestinal epithelial cells (IECs) in zebrafish, stickleback, mouse, and human species to determine if conserved IEC functions are achieved through common transcriptional regulation. We found evidence for substantial common regulation and conservation of gene expression regionally along the length of the intestine from fish to mammals and identified a core set of genes comprising a vertebrate IEC signature. We also identified transcriptional start sites and other putative regulatory regions that are differentially accessible in IECs in all 4 species. Although these sites rarely showed sequence conservation from fish to mammals, surprisingly, they drove highly conserved IEC expression in a zebrafish reporter assay. Common putative transcription factor binding sites (TFBS) found at these sites in multiple species indicate that sequence conservation alone is insufficient to identify much of the functionally conserved IEC regulatory information. Among the rare, highly sequence-conserved, IEC-specific regulatory regions, we discovered an ancient enhancer upstream from her6/HES1 that is active in a distinct population of Notch-positive cells in the intestinal epithelium. Together, these results show how combining accessible chromatin and mRNA datasets with TFBS prediction and in vivo reporter assays can reveal tissue-specific regulatory information conserved across 420 million years of vertebrate evolution. We define an IEC transcriptional regulatory network that is shared between fish and mammals and establish an experimental platform for studying how evolutionarily distilled regulatory information commonly controls IEC development and physiology.

The epithelium lining the intestine is an ancient animal tissue that serves as a primary site of nutrient absorption and interaction with microbiota. Its formation and function require complex patterns of gene transcription that vary along the intestine and in specialized intestinal epithelial cell (IEC) subtypes. However, it is unknown how the underlying transcriptional regulatory mechanisms have changed over the course of vertebrate evolution. Here, we used genome-wide profiling of mRNA levels and chromatin accessibility to identify conserved IEC genes and regulatory regions in 4 vertebrate species (zebrafish, stickleback, mouse, and human) separated from a common ancestor by 420 million years. We identified substantial similarities in genes expressed along the vertebrate intestine. These data disclosed putative conserved transcription factor binding sites (TFBS) enriched in accessible chromatin near IEC genes and in regulatory sites with accessibility restricted to IECs. Fluorescent reporter assays in transparent zebrafish showed that these regions, which frequently lacked sequence conservation, were still capable of driving conserved expression patterns. We also found a highly conserved region near mammalian and fish hes1 sufficient to drive expression in a specific population of IECs with active Notch signaling. These results establish a platform to define the conserved transcriptional networks underlying vertebrate IEC physiology.

Factors associated with stunting in healthy children aged 5 years and less living in Bangui (RCA)

Stunting remains a major public health concern worldwide. Although its global prevalence is slowly decreasing, the actual number of affected children is still rising in Sub-Saharan Africa. In the Central African Republic (CAR), about one third of all children below the age of five are stunted. Stunting is correlated with many long-term consequences, including poor cognitive development and a higher rate of morbidity and mortality, making stunting a major contributor to poverty. In CAR, little is known about the factors that contribute to stunting. This study aimed at analysing, in a cross-sectional study, the main factors associated with stunting in a group of 414 children recruited between December 2011 and November 2013, aged five years or less and living in Bangui. For all children, demographic, socio-economic and anthropometric data were recorded and asymptomatic enteropathogen carriage was assessed in stool samples using classical microbiological assays. The study group had a mean age of 14.2±10 months. Fifty-eight percent (292/414) were boys, and 36 percent (148/414) exhibited stunted growth. Of the stunted children, 51% (75/148) showed a moderate delay in linear growth for their age group [height-for-age z-score (HAZ) between -2 and -3 SD] while 49% (73/148) presented a severe delay (HAZ < -3). Factors significantly associated with stunting included gender (aOR: 1.67; 95% CI: 1.07; 2.62 for boys compared to girls) and age (aOR of 3.98 (95% CI: 2.45; 6.46) for toddlers and aOR 4.42 (95% CI: 2.36; 8.28) for children compared to infants). Most importantly, we identified being overweight [weight-for-height z-score (WHZ) > 2 SD; aOR: 3.21; 95% CI: 1.50; 6.90 of overweight compared to normal weight] as also being significantly associated with stunting. This is the first study showing that even in the poorest countries of the world there is an association of stunting with being overweight.

Infant Nutritional Status and Markers of Environmental Enteric Dysfunction are Associated with Midchildhood Anthropometry and Blood Pressure in Tanzania

OBJECTIVE

To assess whether growth and biomarkers of environmental enteric dysfunction in infancy are related to health outcomes in midchildhood in Tanzania.

STUDY DESIGN

Children who participated in 2 randomized trials of micronutrient supplements in infancy were followed up in midchildhood (4.6-9.8 years of age). Anthropometry was measured at age 6 and 52 weeks in both trials, and blood samples were available from children at 6 weeks and 6 months from 1 trial. Linear regression was used for height-for-age z-score, body mass index-for-age z-score, and weight for age z-score, and blood pressure analyses; log-binomial models were used to estimate risk of overweight, obesity, and stunting in midchildhood.

RESULTS

One hundred thirteen children were followed-up. Length-for-age z-score at 6 weeks and delta length-for-age z-score from 6 to 52 weeks were associated independently and positively with height-for-age z-score and inversely associated with stunting in midchildhood. Delta weight-for-length and weight-for-age z-score were also positively associated with midchildhood height-for-age z-score. The 6-week and delta weight-for-length z-scores were associated independently and positively with midchildhood body mass index-for-age z-score and overweight, as was the 6-week and delta weight-for-age z-score. Delta length-for-age z-score was also associated with an increased risk of overweight in midchildhood. Body mass index-for-age z-score in midchildhood was associated positively with systolic blood pressure. Serum anti-flagellin IgA concentration at 6 weeks was also associated with increased blood pressure in midchildhood.

CONCLUSIONS

Anthropometry at 6 weeks and growth in infancy independently predict size in midchildhood, while anti-flagellin IgA, a biomarker of environmental enteric dysfunction, in early infancy is associated with increased blood pressure in midchildhood. Interventions in early life should focus on optimizing linear growth while minimizing excess weight gain and environmental enteric dysfunction.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00197730 and NCT00421668.

Global Disability: Empowering Children of all Abilities

Worldwide, children are often not meeting their developmental potential owing to malnutrition, infection, lack of stimulation, and toxic stress. Children with disabilities are more likely to experience poverty, neglect, and abuse, and are less likely to have adequate access to education and medical care. Early childhood developmental stimulation can improve language, learning, and future participation in communities. Therapeutic supports and endeavors to reduce stigma for people of all abilities strengthen communities and allow for human thriving.

Combination vaccine strategies to prevent enteric infections

New vaccine candidates entering the current routine immunization schedule can best be accommodated as combination vaccines. A combined Shigella and enterotoxigenic E. coli (ETEC) vaccine could greatly benefit children in disease-endemic areas. New candidates are getting closer to being able to meet these needs, but they raise numerous strategic questions related to presentation, formulation, and regulatory approach. The "Combination Vaccine Strategies to Prevent Enteric Infections" workshop at the 2016 Vaccines Against Shigella and ETEC (VASE) Conference examined some of the considerations for developing such vaccines against enteric pathogens.

Increased Urinary Trimethylamine N-Oxide Following Cryptosporidium Infection and Protein Malnutrition Independent of Microbiome Effects

Cryptosporidium infections have been associated with growth stunting, even in the absence of diarrhea. Having previously detailed the effects of protein deficiency on both microbiome and metabolome in this model, we now describe the specific gut microbial and biochemical effects of Cryptosporidium infection. Protein-deficient mice were infected with Cryptosporidium parvum oocysts for 6-13 days and compared with uninfected controls. Following infection, there was an increase in the urinary excretion of choline- and amino-acid-derived metabolites. Conversely, infection reduced the excretion of the microbial-host cometabolite (3-hydroxyphenyl)propionate-sulfate and disrupted metabolites involved in the tricarboxylic acid (TCA) cycle. Correlation analysis of microbial and biochemical profiles resulted in associations between various microbiota members and TCA cycle metabolites, as well as some microbial-specific degradation products. However, no correlation was observed between the majority of the infection-associated metabolites and the fecal bacteria, suggesting that these biochemical perturbations are independent of concurrent changes in the relative abundance of members of the microbiota. We conclude that cryptosporidial infection in protein-deficient mice can mimic some metabolic changes seen in malnourished children and may help elucidate our understanding of long-term metabolic consequences of early childhood enteric infections.

Treatment outcome of children with persistent Diarrhoea admitted to an Urban Hospital, Dhaka during 2012-2013

BACKGROUND

Despite availability of treatment guidelines, persistent diarrhoea (PD) has been a major contributor of diarrhoeal deaths in low and middle income countries. We evaluated the outcome of children under the age of 5 years who were treated for PD using management algorithm with locally available foods in a diarrhoeal disease hospital in Dhaka.

METHODS

We extracted retrospective data from electronic database for all the under-five children admitted for PD in the Longer Stay Ward and Intensive Care Unit of the Dhaka hospital at icddr,b between 2012 and 2013. Descriptive analysis was done to explore available baseline socio-demographic, nutritional, and co-morbid statuses, pathogens from stool isolates, duration of treatment, use of antibiotics, duration of hospital stay and treatment success rates. We sought to investigate above mentioned descriptive features in addition to associated factors with time to recover from PD using survival analysis with Cox proportional hazard model.

RESULTS

A total number of 426 children with a median age of 7.46 (inter-quartile range IQR; 5.39, 9.43) months were admitted for PD during the study period. Of these, 95% of children were recovered from PD and discharged from the hospital. The median duration of treatment response was 6 (IQR 4, 9) days. The case fatality rate was 1.17%. Multivariate analysis among the children of 6 months or less showed that the rate of recovery from PD was 57% lower in children with severe stunting compared to those without severe stunting (HR 0.43, 95% CI 0.22, 0.88, p < 0.05), 42% lower in children with severe wasting (HR 0.58, 95% CI 0.36, 0.95, p < 0.05), and 81% reduced in children who developed hospital acquired infection (HAI) compared to those without HAI (HR 0.19, 95% CI 0.06, 0.62, p < 0.05). Among the children who were more than 6 months old, age in months (HR 1.05, 95% CI 1.02, 1.09) and female gender (HR 1.41, 95% CI 1.09, 1.84) had better rates of recovery from PD (p < 0.05). Moreover, among children more than 6 months of age, HAI (HR 0.44, 95% CI 0.26, 0.75), and antibiotic use (HR 0.40, 95% CI 0.28, 0.56) were associated with impeded recovery rates from PD (p < 0.05).

CONCLUSION

The treatment guideline for persistent diarrhoea patients followed at icddr,b Dhaka hospital was found to be successful and can be used in other treatment facilities of Bangladesh and other developing countries where any treatment algorithm for PD is unavailable. More emphasis is required to be given for the prevention of hospital acquired infection that may help to limit the use of antibiotic in order to enhance the recovery rate from PD.

Association of enteric parasitic infections with intestinal inflammation and permeability in asymptomatic infants of São Tomé Island

The cumulative effect of repeated asymptomatic enteric infections on intestinal barrier is not fully understood in infants. We aimed to evaluate the association between previous enteric parasitic infections and intestinal inflammation and permeability at 24-months of age, in asymptomatic infants of São Tomé Island. A subset of infants from a birth cohort, with intestinal parasite evaluations in at least four points of assessment, was eligible. Intestinal inflammatory response and permeability were assessed using fecal S100A12 and alpha-1-antitrypsin (A1AT), respectively. The cutoff <-1SD for weight-for-length and length-for-age was used to define wasting and stunting. Multivariable linear regression analysis explored if cumulative enteric parasitic infections explained variability of fecal biomarkers, after adjusting for potential confounders. Eighty infants were included. Giardia duodenalis and soil-transmitted helminths (STH) were the most frequent parasites. The median (interquartile range) levels were 2.87 μg/g (2.41-3.92) for S100A12 and 165.1 μg/g (66.0-275.6) for A1AT. Weak evidence of association was found between S100A12 levels and G. duodenalis (p = 0.080) and STH infections (p = 0.089), and between A1AT levels and parasitic infection of any etiology (p = 0.089), at 24-months of age. Significant associations between A1AT levels and wasting (p = 0.006) and stunting (p = 0.044) were found. Previous parasitic infections were not associated with fecal biomarkers at 24 months of age. To summarize, previous asymptomatic parasitic infections showed no association with intestinal barrier dysfunction. Notwithstanding, a tendency toward increased levels of the inflammatory biomarker was observed for current G. duodenalis and STH infections, and increased levels of the permeability biomarker were significantly associated with stunting and wasting.

Breastfeeding modifies the impact of diarrhoeal disease on relative weight: a longitudinal analysis of 2-12 month-old Filipino infants

Undernutrition and diarrhoeal disease are major causes of infant mortality. We investigated the combined roles of breastfeeding and diarrhoea on infant size in 2940 infants from the Cebu Longitudinal Health and Nutrition Survey. The study aimed to assess whether breastfeeding status modified the deficits associated with diarrhoeal disease. The primary exposures were combinations of current breastfeeding status (yes/no), the presence of diarrhoeal disease in previous week (yes/no) and a categorical survey variable (six surveys taken at bimonthly intervals when infants were 2-12 months of age). Relative weight (weight-for-length z-scores), calculated using the WHO growth standards, was estimated using sex-stratified, fixed-effects longitudinal models that also adjusted for energy from complementary foods. Post-estimation Wald tests were conducted to identify subgroup differences in relative weight. Diarrhoea was associated with reduced relative weight in both breastfed and non-breastfed infants of 6-12 months. Diarrhoea-related deficits in relative weight were significantly exacerbated in non-breastfed girls of 6 and 8 months. Importantly, in infants <6 months, being breastfed and having diarrhoea was still associated with greater relative weight compared with being non-breastfed and diarrhoea-free. Breastfeeding emerged as a strong contributor to relative weight in younger infants (<6 months) while diarrhoeal disease strongly contributed to deficits in relative weight in older infants (6-12 months). These findings underscore the importance of breastfeeding for promoting infant nutritional status in infants with or without diarrhoea from birth to 12 months.

Design and rationale of a matched cohort study to assess the effectiveness of a combined household-level piped water and sanitation intervention in rural Odisha, India

INTRODUCTION

Government efforts to address massive shortfalls in rural water and sanitation in India have centred on construction of community water sources and toilets for selected households. However, deficiencies with water quality and quantity at the household level and community coverage and actual use of toilets have led Gram Vikas, a local non-governmental organization in Odisha, India, to develop an approach that provides household-level piped water connections contingent on full community-level toilet coverage.

METHODS

This matched cohort study was designed to assess the effectiveness of a combined piped water and sanitation intervention. Households with children <5 years in 45 randomly selected intervention villages and 45 matched control villages will be followed over 17 months. The primary outcome is prevalence of diarrhoeal diseases; secondary health outcomes include soil-transmitted helminth infection, nutritional status, seroconversion to enteric pathogens, urogenital infections and environmental enteric dysfunction. In addition, intervention effects on sanitation and water coverage, access and use, environmental fecal contamination, women's empowerment, as well as collective efficacy, and intervention cost and cost-effectiveness will be assessed.

ETHICS AND DISSEMINATION

The study protocol has been reviewed and approved by the ethics boards of the London School of Hygiene and Tropical Medicine, UK and KIIT University, Bhubaneswar, India. Findings will be disseminated via peer-reviewed literature and presentation to stakeholders, government officials, implementers and researchers.

TRIAL REGISTRATION NUMBER

NCT02441699.

Vitamin-D deficiency predicts infections in young north Indian children: A secondary data analysis

Background

Recent studies have demonstrated a relationship between poor vitamin D status and respiratory infections and diarrhea among young children. Acute lower respiratory infections (ALRI) and diarrhea are among the two most important causes of death in under-5 children. In this paper, we examined the extent to which vitamin-D deficiency (<10 ng/ml) predicts ALRI, clinical pneumonia and diarrhea among 6 to 30 months old children.

Methods

We used data from a randomized controlled trial (RCT) of daily folic acid and/or vitamin B12 supplementation for six months in 6 to 30 months old children conducted in Delhi, India. Generalized estimating equations (GEE) were used to examine the associations between vitamin-D deficiency and episodes of ALRI, clinical pneumonia and diarrhea.

Results

Of the 960 subjects who had vitamin-D concentrations measured, 331(34.5%) were vitamin-D deficient. We found, after controlling for relevant potential confounders (age, sex, breastfeeding status, wasting, stunting, underweight, anemia status and season), that the risk of ALRI was significantly higher among vitamin-D deficient (OR 1.26; 95% CI: 1.03 to 1.55) compared to vitamin-D-replete children in the six months follow-up period. Vitamin-D status was not associated with episodes of diarrhea or clinical pneumonia.

Conclusion

Vitamin-D deficiency is common in young children in New Delhi and is associated with a higher risk of ALRI. The role of vitamin D in Indian children needs to be elucidated in further studies.

Mechanisms of cross-talk between the diet, the intestinal microbiome, and the undernourished host

Undernutrition remains one of the most pressing global health challenges today, contributing to nearly half of all deaths in children under five years of age. Although insufficient dietary intake and environmental enteric dysfunction are often inciting factors, evidence now suggests that unhealthy gut microbial populations perpetuate the vicious cycle of pathophysiology that results in persistent growth impairment in children. The metagenomics era has facilitated new research identifying an altered microbiome in undernourished hosts and has provided insight into a number of mechanisms by which these alterations may affect growth. This article summarizes a range of observational studies that highlight differences in the composition and function of gut microbiota between undernourished and healthy children; discusses dietary, environmental and host factors that shape this altered microbiome; examines the consequences of these changes on host physiology; and considers opportunities for microbiome-targeting therapies to combat the global challenge of child undernutrition.

Protein Malnutrition Modifies Innate Immunity and Gene Expression by Intestinal Epithelial Cells and Human Rotavirus Infection in Neonatal Gnotobiotic Pigs

Malnutrition and rotavirus infection, prevalent in developing countries, individually and in combination, affect the health of millions of children, compromising their immunity and increasing the rates of death from infectious diseases. However, the interactions between the two and their combined effects on immune and intestinal functions are poorly understood. We have established the first human infant microbiota-transplanted neonatal pig model of childhood malnutrition that reproduced the impaired immune, intestinal, and other physiological functions seen in malnourished children. This model can be used to evaluate relevant dietary and other health-promoting interventions. Our findings provide an explanation of why adequate nutrition alone may lack efficacy in malnourished children.

Malnutrition affects millions of children in developing countries, compromising immunity and contributing to increased rates of death from infectious diseases. Rotavirus is a major etiological agent of childhood diarrhea in developing countries, where malnutrition is prevalent. However, the interactions between the two and their combined effects on immune and intestinal functions are poorly understood. In this study, we used neonatal gnotobiotic (Gn) pigs transplanted with the fecal microbiota of a healthy 2-month-old infant (HIFM) and fed protein-deficient or -sufficient bovine milk diets. Protein deficiency induced hypoproteinemia, hypoalbuminemia, hypoglycemia, stunting, and generalized edema in Gn pigs, as observed in protein-malnourished children. Irrespective of the diet, human rotavirus (HRV) infection early, at HIFM posttransplantation day 3 (PTD3), resulted in adverse health effects and higher mortality rates (45 to 75%) than later HRV infection (PTD10). Protein malnutrition exacerbated HRV infection and affected the morphology and function of the small intestinal epithelial barrier. In pigs infected with HRV at PTD10, there was a uniform decrease in the function and/or frequencies of natural killer cells, plasmacytoid dendritic cells, and CD103⁺ and apoptotic mononuclear cells and altered gene expression profiles of intestinal epithelial cells (chromogranin A, mucin 2, proliferating cell nuclear antigen, SRY-Box 9, and villin). Thus, we have established the first HIFM-transplanted neonatal pig model that recapitulates major aspects of protein malnutrition in children and can be used to evaluate physiologically relevant interventions. Our findings provide an explanation of why nutrient-rich diets alone may lack efficacy in malnourished children.

IMPORTANCE Malnutrition and rotavirus infection, prevalent in developing countries, individually and in combination, affect the health of millions of children, compromising their immunity and increasing the rates of death from infectious diseases. However, the interactions between the two and their combined effects on immune and intestinal functions are poorly understood. We have established the first human infant microbiota-transplanted neonatal pig model of childhood malnutrition that reproduced the impaired immune, intestinal, and other physiological functions seen in malnourished children. This model can be used to evaluate relevant dietary and other health-promoting interventions. Our findings provide an explanation of why adequate nutrition alone may lack efficacy in malnourished children.

Nonrandomized Trial of Feasibility and Acceptability of Strategies for Promotion of Soapy Water as a Handwashing Agent in Rural Bangladesh

We conducted a nonrandomized trial of strategies to promote soapy water for handwashing in rural Bangladesh and measured uptake. We enrolled households with children < 3 years for three progressively intensive study arms: promotion of soapy water (N = 120), soapy water promotion plus handwashing stations (N = 103), and soapy water promotion, stations plus detergent refills (N = 90); we also enrolled control households (N = 72). Our handwashing stations included tap-fitted buckets and soapy water bottles. Community promoters visited households and held community meetings to demonstrate soapy water preparation and promote handwashing at key times. Field workers measured uptake 4 months later. In-depth interviews and focus group discussions assessed factors associated with uptake. More households had soapy water at the handwashing place in progressively intensive arms: 18% (promotion), 60% (promotion plus station), and 71% (promotion, station with refills). Compared with the promotion-only arm, more households that received stations had soapy water at the primary handwashing station (44%, P ≤ 0.001; 71%, P < 0.001 with station plus detergent refill). Qualitative findings highlighted several dimensions that affected use: contextual (shared courtyard), psychosocial (perceived value), and technology dimensions (ease of use, convenience). Soapy water may increase habitual handwashing by addressing barriers of cost and availability of handwashing agents near water sources. Further research should inform optimal strategies to scale-up soapy water as a handwashing agent to study health impact.

Nutrition, infection and stunting: the roles of deficiencies of individual nutrients and foods, and of inflammation, as determinants of reduced linear growth of children

The regulation of linear growth by nutritional and inflammatory influences is examined in terms of growth-plate endochondral ossification, in order to better understand stunted growth in children. Linear growth is controlled by complex genetic, physiological, and nutrient-sensitive endocrine/paracrine/autocrine mediated molecular signalling mechanisms, possibly including sleep adequacy through its influence on growth hormone secretion. Inflammation, which accompanies most infections and environmental enteric dysfunction, inhibits endochondral ossification through the action of mediators including proinflammatory cytokines, the activin A-follistatin system, glucocorticoids and fibroblast growth factor 21 (FGF21). In animal models linear growth is particularly sensitive to dietary protein as well as Zn intake, which act through insulin, insulin-like growth factor-1 (IGF-1) and its binding proteins, triiodothyronine, amino acids and Zn2+ to stimulate growth-plate protein and proteoglycan synthesis and cell cycle progression, actions which are blocked by corticosteroids and inflammatory cytokines. Observational human studies indicate stunting to be associated with nutritionally poor, mainly plant-based diets. Intervention studies provide some support for deficiencies of energy, protein, Zn and iodine and for multiple micronutrient deficiencies, at least during pregnancy. Of the animal-source foods, only milk has been specifically and repeatedly shown to exert an important influence on linear growth in both undernourished and well-nourished children. However, inflammation, caused by infections, environmental enteric dysfunction, which may be widespread in the absence of clean water, adequate sanitation and hygiene (WASH), and endogenous inflammation associated with excess adiposity, in each case contributes to stunting, and may explain why nutritional interventions are often unsuccessful. Current interventions to reduce stunting are targeting WASH as well as nutrition.

Diagnosing Polyparasitism in a High-Prevalence Setting in Beira, Mozambique: Detection of Intestinal Parasites in Fecal Samples by Microscopy and Real-Time PCR

BACKGROUND

Many different intestinal parasite species can co-occur in the same population. However, classic diagnostic tools can only frame a particular group of intestinal parasite species. Hence, one or two tests do not suffice to provide a complete picture of infecting parasite species in a given population. The present study investigated intestinal parasitic infections in Beira, Mozambique, i.e. in the informal settlement of Inhamudima. Diagnostic accuracy of five classical microscopy techniques and real-time PCR for the detection of a broad spectrum of parasites was compared.

METHODOLOGY/PRINCIPAL FINDINGS

A cross-sectional population-based survey was performed. One stool sample per participant (n = 303) was examined by direct smear, formal-ether concentration (FEC), Kato smear, Baermann method, coproculture and real-time PCR. We found that virtually all people (96%) harbored at least one helminth, and that almost half (49%) harbored three helminths or more. Remarkably, Strongyloides stercoralis infections were widespread with a prevalence of 48%, and Ancylostoma spp. prevalence was higher than that of Necator americanus (25% versus 15%), the hookworm species that is often assumed to prevail in East-Africa. Among the microscopic techniques, FEC was able to detect the broadest spectrum of parasite species. However, FEC also missed a considerable number of infections, notably S. stercoralis, Schistosoma mansoni and G. intestinalis. PCR outperformed microscopy in terms of sensitivity and range of parasite species detected.

CONCLUSIONS/SIGNIFICANCE

We showed intestinal parasites-especially helminths-to be omnipresent in Inhamudima, Beira. However, it is a challenge to achieve high diagnostic sensitivity for all species. Classical techniques such as FEC are useful for the detection of some intestinal helminth species, but they lack sensitivity for other parasite species. PCR can detect intestinal parasites more accurately but is generally not feasible in resource-poor settings, at least not in peripheral labs. Hence, there is a need for a more field-friendly, sensitive approach for on-the-spot diagnosis of parasitic infections.

Etiology of Diarrhea, Nutritional Outcomes, and Novel Intestinal Biomarkers in Tanzanian Infants

OBJECTIVE

Diarrheal diseases are a leading cause of morbidity and mortality worldwide, but the etiology of diarrhea and its relation to nutritional outcomes in resource-limited settings is poorly defined. We sought to determine the etiology of community-acquired diarrhea in Tanzanian infants and to assess the association with anthropometrics and novel intestinal biomarkers.

METHODS

A convenience sample of infants in a trial of zinc and/or multivitamin supplementation in Tanzania was selected. Subjects were enrolled at age 6 weeks and studied for 18 months. Stool samples were obtained from children with acute diarrhea. A novel, polymerase chain reaction-based TaqMan array was used to screen stool for 15 enteropathogens. A subset of subjects had serum gastrointestinal biomarkers measured.

RESULTS

One hundred twenty-three subjects with diarrhea were enrolled. The mean ± SD age at stool sample collection was 12.4 ± 3.9 months. Thirty-five enteropathogens were identified in 34 (27.6%) subjects: 11 rotavirus, 9 Cryptosporidium spp, 7 Shigella spp, 3 Campylobacter jejuni/coli, 3 heat stable-enterotoxigenic Escherichia coli, and 2 enteropathogenic E coli. Subjects with any identified enteropathogen had significantly lower weight-for-length z scores (-0.55 ± 1.10 vs 0.03 ± 1.30, P = 0.03) at the final clinic visit than those without an identified pathogen. Fifty of the 123 subjects (40.7%) had serum analyzed for antibodies to lipopolysaccharide (LPS) and flagellin. Subjects with any identified enteropathogen had lower immunoglobulin (IgA) antibodies to LPS (0.75 ± 0.27 vs 1.13 ± 0.77, P = 0.01) and flagellin (0.52 ± 0.16 vs 0.73 ± 0.47, P = 0.02) than those without an identified pathogen.

CONCLUSIONS

This quantitative polymerase chain reaction method may allow identification of enteropathogens that place children at higher risk for suboptimal growth. IgA anti-LPS and flagellin antibodies hold promise as emerging intestinal biomarkers.

Protein Malnutrition Impairs Intestinal Epithelial Cell Turnover, a Potential Mechanism of Increased Cryptosporidiosis in a Murine Model

Malnutrition and cryptosporidiosis form a vicious cycle and lead to acute and long-term growth impairment in children from developing countries. Insights into mechanisms underlying the vicious cycle will help to design rational therapies to mitigate this infection. We tested the effect of short-term protein malnutrition on Cryptosporidium parvum infection in a murine model by examining stool shedding, tissue burden, and histologic change and explored the mechanism underlying the interaction between malnutrition and cryptosporidiosis through immunostaining and immunoblotting. Protein malnutrition increased stool shedding and the number of intestine-associated C. parvum organisms, accompanied by significant suppression of C. parvum-induced caspase 3 activity and expression of PCNA and Ki67, but activation of the Akt survival pathway in intestinal epithelial cells. We find that even very brief periods of protein malnutrition may enhance (or intensify) cryptosporidiosis by suppressing C. parvum-induced cell turnover and caspase-dependent apoptosis of intestinal epithelial cells. This implicates a potential strategy to attenuate C. parvum's effects by modulating apoptosis and promoting regeneration in the intestinal epithelium.

Biomarkers of Environmental Enteropathy, Inflammation, Stunting, and Impaired Growth in Children in Northeast Brazil

Critical to the design and assessment of interventions for enteropathy and its developmental consequences in children living in impoverished conditions are non-invasive biomarkers that can detect intestinal damage and predict its effects on growth and development. We therefore assessed fecal, urinary and systemic biomarkers of enteropathy and growth predictors in 375 6–26 month-old children with varying degrees of malnutrition (stunting or wasting) in Northeast Brazil. 301 of these children returned for followup anthropometry after 2-6m. Biomarkers that correlated with stunting included plasma IgA anti-LPS and anti-FliC, zonulin (if >12m old), and intestinal FABP (I-FABP, suggesting prior barrier disruption); and with citrulline, tryptophan and with lower serum amyloid A (SAA) (suggesting impaired defenses). In contrast, subsequent growth was predicted in those with higher fecal MPO or A1AT and also by higher L/M, plasma LPS, I-FABP and SAA (showing intestinal barrier disruption and inflammation). Better growth was predicted in girls with higher plasma citrulline and in boys with higher plasma tryptophan. Interactions were also seen with fecal MPO and neopterin in predicting subsequent growth impairment.

Biomarkers clustered into markers of 1) functional intestinal barrier disruption and translocation, 2) structural intestinal barrier disruption and inflammation and 3) systemic inflammation. Principle components pathway analyses also showed that L/M with %L, I-FABP and MPO associate with impaired growth, while also (like MPO) associating with a systemic inflammation cluster of kynurenine, LBP, sCD14, SAA and K/T. Systemic evidence of LPS translocation associated with stunting, while markers of barrier disruption or repair (A1AT and Reg1 with low zonulin) associated with fecal MPO and neopterin.

We conclude that key noninvasive biomarkers of intestinal barrier disruption, LPS translocation and of intestinal and systemic inflammation can help elucidate how we recognize, understand, and assess effective interventions for enteropathy and its growth and developmental consequences in children in impoverished settings.

How does poverty affect children's nutritional status in Nairobi slums? A qualitative study of the root causes of undernutrition

Objective

Children in slums are at high risk of undernutrition, which has long-term negative consequences on their physical growth and cognitive development. Severe undernutrition can lead to the child’s death. The present paper aimed to understand the causes of undernutrition in children as perceived by various groups of community members in Nairobi slums, Kenya.

Design

Analysis of ten focus group discussions and ten individual interviews with key informants. The main topic discussed was the root causes of child undernutrition in the slums. The focus group discussions and key informant interviews were recorded and transcribed verbatim. The transcripts were coded in NVivo by extracting concepts and using a constant comparison of data across the different categories of respondents to draw out themes to enable a thematic analysis.

Setting

Two slum communities in Nairobi, Kenya.

Subjects

Women of childbearing age, community health workers, elders, leaders and other knowledgeable people in the two slum communities (n 90).

Results

Participants demonstrated an understanding of undernutrition in children.

Conclusions

Findings inform target criteria at community and household level that can be used to identify children at risk of undernutrition. To tackle the immediate and underlying causes of undernutrition, interventions recommended should aim to: (i) improve maternal health and nutrition; (ii) promote optimal infant and young children feeding practices; (iii) support mothers in their working role; (iv) increase access to family planning; (v) improve water, sanitation and hygiene (WASH); (vi) address alcohol problems at all levels; and (vii) address street food issues with infant feeding counselling.

Unsafe Child Feces Disposal is Associated with Environmental Enteropathy and Impaired Growth

OBJECTIVE

To investigate the relationship between unsafe child feces disposal, environmental enteropathy, and impaired growth, we conducted a prospective cohort study of 216 young children in rural Bangladesh.

STUDY DESIGN

Using a prospective cohort study design in rural Bangladesh, unsafe child feces disposal, using the Joint Monitoring Program definition, was assessed using 5-hour structured observation by trained study personnel as well as caregiver reports. Anthropometric measurements were collected at baseline and at a 9-month follow-up. Stool was analyzed for fecal markers of environmental enteropathy: alpha-1-antitrypsin, myeloperoxidase, neopterin (combined to form an environmental enteropathy disease activity score), and calprotectin.

FINDINGS

Among 216 households with young children, 84% had an unsafe child feces disposal event during structured observation and 75% had caregiver reported events. There was no significant difference in observed unsafe child feces disposal events for households with or without an improved sanitation option (82% vs 85%, P = .72) or by child's age (P = .96). Children in households where caregivers reported unsafe child feces disposal had significantly higher environmental enteropathy scores (0.82-point difference, 95% CI 0.11-1.53), and significantly greater odds of being wasted (weight-for-height z score <-2 SDs) (9% vs 0%, P = .024). In addition, children in households with observed unsafe feces disposal had significantly reduced change in weight-for-age z-score (-0.34 [95% CI -0.68, -0.01] and weight-for-height z score (-0.52 [95% CI -0.98, -0.06]).

CONCLUSION

Unsafe child feces disposal was significantly associated with environmental enteropathy and impaired growth in a pediatric population in rural Bangladesh. Interventions are needed to reduce this high-risk behavior to protect the health of susceptible pediatric populations.

Vitamin A deficiency impacts the structural segregation of gut microbiota in children with persistent diarrhea

To investigate whether gut microbiota is associated with vitamin A nutritional levels in children with persistent diarrhea, a total of 59 pediatric patients with persistent diarrhea aged 1-12 months were selected from the Department of Gastroenterology at the Children's Hospital of Chongqing Medical University, China. Subjects were hospitalized and divided into VA-deficient (n = 30) and VA-normal (n = 29) groups according to their venous serum retinol levels. Fecal samples from all 59 subjects were collected immediately after admission and analyzed by Illumina MiSeq for 16S rRNA genes to characterize the overall microbiota of the samples. The gut microbiota of the VA-deficient and VA-normal groups were compared using a bioinformatic statistical approach. The Shannon index (p = 0.02), Simpson index (p = 0.01) and component diagram data indicated significantly lower diversity in the VA-deficient than the VA-normal group. A metagenome analysis (LEfSe) and a differentially abundant features approach using Metastats revealed that Escherichia coli and Clostridium butyricum were the key phylotypes of the VA-normal group, while Enterococcus predominated the VA-deficient group. In conclusion, the diversity of gut microbiota and the key phylotypes are significantly different in children with persistent diarrhea at different VA nutritional levels.

Maternal Antiretroviral Therapy Is Associated with Lower Risk of Diarrhea in Early Childhood

OBJECTIVES

To identify risk factors, including maternal antiretroviral therapy (ART), for diarrhea in Tanzanian children exposed to HIV during the first 2 years of life.

STUDY DESIGN

Using generalized estimating equations, we analyzed data from a cohort of 2387 Tanzanian children exposed to HIV from age 6 weeks to 2 years, as well as data from their mothers, to determine risk factors for diarrhea in children. Mothers recorded diarrhea in a diary and reported results at visits scheduled every four weeks.

RESULTS

Body mass index was ≥18.5 in 95.6% of mothers. World Health Organization HIV stage was 1/2 for 1255 (87.8%) mothers. ART was received by 24.3% of mothers, most initiating ART during pregnancy. At baseline (6 weeks of age) 264 (11.3%) children were infected with HIV. In children whose mothers received ART, the relative risk of diarrhea in children was 0.79 (95% CI 0.68-0.92), after we adjusted for multiple factors, including child HIV status and exclusive breastfeeding duration. Exclusive breastfeeding (relative risk 0.67, 95% CI 0.56-0.80) also was protective.

CONCLUSION

Our results provide additional support to increase ART coverage for all pregnant mothers, to control clinical HIV progression, reduce perinatal HIV infection, but also to reduce the risk of a major cause of death and morbidity in young children worldwide.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00197730.

Systemic inflammation, growth factors, and linear growth in the setting of infection and malnutrition

Objectives

Deficits in weight gain and linear growth are seen frequently among children in areas where malnutrition and recurrent infections are common. Although both inflammation and malnutrition can result in growth hormone (GH) resistance, the interrelationships of infection, inflammation, and growth deficits in developing areas remain unclear. The aim of this study was to evaluate relationships between low levels of systemic inflammation, growth factors, and anthropometry in a case–control cohort of underweight and normal weight children in northern Brazil.

Methods

We evaluated data from 147 children ages 6 to 24 mo evaluated in the MAL-ED (Interactions of Malnutrition and Enteric Disease) case–control study following recruitment from a nutrition clinic for impoverished families in Fortaleza, Brazil. We used nonparametric tests and linear regression to evaluate relationships between current symptoms of infections (assessed by questionnaire), systemic inflammation (assessed by high-sensitivity C-reactive protein [hsCRP]), the GH insulin-like growth factor-1 (IGF-1) axis, and measures of anthropometry. All models were adjusted for age and sex.

Results

Children with recent symptoms of diarrhea, cough, and fever (compared with those without symptoms) had higher hsCRP levels; those with recent diarrhea and fever also had lower IGF-1 and higher GH levels. Stool myeloperoxidase was positively associated with serum hsCRP. hsCRP was in turn positively associated with GH and negatively associated with IGF-1 and IGF-binding protein-3 (IGFBP-3), suggesting a state of GH resistance. After adjustment for hsCRP, IGF-1 and IGFBP-3 were positively and GH was negatively associated with Z scores for height and weight.

Conclusions

Infection and inflammation were linked to evidence of GH resistance, whereas levels of GH, IGF-1, and IGFBP-3 were associated with growth indices independent of hsCRP. These data implicate complex interrelationships between infection, nutritional status, GH axis, and linear growth in children from a developing area.

•

Among children in this developing area, symptoms of illness correlated with high-sensitivity C-reactive protein (hsCRP).

•

hsCRP correlated positively with growth hormone (GH) and negatively with insulin-like growth factor (IGF)-1 and IGF-binding protein-3 (IGFBP-3).

•

IGF-1 and IGFBP-3 correlated positively with height.

•

These data are consistent with a model of inflammation-induced GH resistance.

Diarrheal disease and enteric infections in LMIC communities: how big is the problem?

Studies of enteric diseases have historically focused on observations of clinical diarrhea as a cause of mortality and morbidity. Emerging evidence suggests that diarrhea dramatically underestimates both exposure to enteropathogens and the long-term consequences arising from infection. High burden of pathogens in the gut, even in the absence of diarrhea, is common in infants in low and middle income countries. Continual challenge by pathogens, in conjunction with an inadequate diet stimulates an inflammatory disease that alters the structure of the gut, metabolic and immunological pathways and changes the microbiome. Both diarrhea and enteropathogen infection have been associated with reduced growth, reduced cognitive development, and reduced vaccine efficacy suggesting that the burden of diarrheal disease is dramatically underestimated.

Fecal Markers of Environmental Enteropathy and Subsequent Growth in Bangladeshi Children

Environmental enteropathy (EE), a subclinical intestinal disorder characterized by mucosal inflammation, reduced barrier integrity, and malabsorption, appears to be associated with increased risk of stunting in children in low- and middle-income countries. Fecal biomarkers indicative of EE (neopterin [NEO], myeloperoxidase [MPO], and alpha-1-antitrypsin [AAT]) have been negatively associated with 6-month linear growth. Associations between fecal markers (NEO, MPO, and AAT) and short-term linear growth were examined in a birth cohort of 246 children in Bangladesh. Marker concentrations were categorized in stool samples based on their distribution (< first quartile, interquartile range, > third quartile), and a 10-point composite EE score was calculated. Piecewise linear mixed-effects models were used to examine the association between markers measured quarterly (in months 3-21, 3-9, and 12-21) and 3-month change in length-for-age z-score (ΔLAZ). Children with high MPO levels at quarterly time points lost significantly more LAZ per 3-month period during the second year of life than those with low MPO (ΔLAZ = -0.100; 95% confidence interval = -0.167 to -0.032). AAT and NEO were not associated with growth; however, composite EE score was negatively associated with subsequent 3-month growth. In this cohort of children from an urban setting in Bangladesh, elevated MPO levels, but not NEO or AAT levels, were associated with decreases in short-term linear growth during the second year of life, supporting previous data suggesting the relevance of MPO as a marker of EE.

Child diarrhoea and nutritional status in rural Rwanda: a cross-sectional study to explore contributing environmental and demographic factors

OBJECTIVE

To explore associations of environmental and demographic factors with diarrhoea and nutritional status among children in Rusizi district, Rwanda.

METHODS

We obtained cross-sectional data from 8847 households in May-August 2013 from a baseline survey conducted for an evaluation of an integrated health intervention. We collected data on diarrhoea, water quality, and environmental and demographic factors from households with children <5, and anthropometry from children <2. We conducted log-binomial regression using diarrhoea, stunting and wasting as dependent variables.

RESULTS

Among children <5, 8.7% reported diarrhoea in the previous 7 days. Among children <2, stunting prevalence was 34.9% and wasting prevalence was 2.1%. Drinking water treatment (any method) was inversely associated with caregiver-reported diarrhoea in the previous 7 days (PR = 0.79, 95% CI: 0.68-0.91). Improved source of drinking water (PR = 0.80, 95% CI: 0.73-0.87), appropriate treatment of drinking water (PR = 0.88, 95% CI: 0.80-0.96), improved sanitation facility (PR = 0.90, 95% CI: 0.82-0.97), and complete structure (having walls, floor and roof) of the sanitation facility (PR = 0.65, 95% CI: 0.50-0.84) were inversely associated with stunting. None of the exposure variables were associated with wasting. A microbiological indicator of water quality was not associated with diarrhoea or stunting.

CONCLUSIONS

Our findings suggest that in Rusizi district, appropriate treatment of drinking water may be an important factor in diarrhoea in children <5, while improved source and appropriate treatment of drinking water as well as improved type and structure of sanitation facility may be important for linear growth in children <2. We did not detect an association with water quality.

The Knowledge Base for Achieving the Sustainable Development Goal Targets on Water Supply, Sanitation and Hygiene

Safe drinking water, sanitation, and hygiene (WASH) are fundamental to an improved standard of living. Globally, 91% of households used improved drinking water sources in 2015, while for improved sanitation it is 68%. Wealth disparities are stark, with rural populations, slum dwellers and marginalized groups lagging significantly behind. Service coverage is significantly lower when considering the new water and sanitation targets under the sustainable development goals (SDGs) which aspire to a higher standard of ‘safely managed’ water and sanitation. Lack of access to WASH can have an economic impact as much as 7% of Gross Domestic Product, not including the social and environmental consequences. Research points to significant health and socio-economic consequences of poor nutritional status, child growth and school performance caused by inadequate WASH. Groundwater over-extraction and pollution of surface water bodies have serious impacts on water resource availability and biodiversity, while climate change exacerbates the health risks of water insecurity. A significant literature documents the beneficial impacts of WASH interventions, and a growing number of impact evaluation studies assess how interventions are optimally financed, implemented and sustained. Many innovations in behavior change and service delivery offer potential for scaling up services to meet the SDGs.

Early-life enteric infections: relation between chronic systemic inflammation and poor cognition in children

The intestinal microbiota undergoes active remodeling in the first 6 to 18 months of life, during which time the characteristics of the adult microbiota are developed. This process is strongly influenced by the early diet and enteric pathogens. Enteric infections and malnutrition early in life may favor microbiota dysbiosis and small intestinal bacterial overgrowth, resulting in intestinal barrier dysfunction and translocation of intestinal bacterial products, ultimately leading to low-grade, chronic, subclinical systemic inflammation. The leaky gut-derived low-grade systemic inflammation may have profound consequences on the gut-liver-brain axis, compromising normal growth, metabolism, and cognitive development. This review examines recent data suggesting that early-life enteric infections that lead to intestinal barrier disruption may shift the intestinal microbiota toward chronic systemic inflammation and subsequent impaired cognitive development.

Microbial-Derived Metabolites Reflect an Altered Intestinal Microbiota during Catch-Up Growth in Undernourished Neonatal Mice

BACKGROUND

Protein-energy undernutrition during early development confers a lifelong increased risk of obesity-related metabolic disease. Mechanisms by which metabolic abnormalities persist despite catch-up growth are poorly understood.

OBJECTIVE

We sought to determine whether abnormal metabolomic and intestinal microbiota profiles from undernourished neonatal mice remain altered during catch-up growth.

METHODS

Male and female CD1 mouse pups were undernourished by timed separation from lactating dams for 4 h at 5 d of age, 8 h at 6 d of age, and 12 h/d from 7 to 15 d of age, then resumed ad libitum nursing, whereas controls fed uninterrupted. Both groups were weaned simultaneously to a standard unpurified diet. At 3 time points (0, 1, and 3 wk after ending feed deprivation), metabolites in urine, plasma, and stool were identified with the use of mass spectrometry, and fecal microbes were identified with the use of 16S metagenomic sequencing.

RESULTS

Undernourished mice completely recovered deficits of 36% weight and 9% length by 3 wk of refeeding, at which time they had 1.4-fold higher plasma phenyllactate and 2.0-fold higher urinary p-cresol sulfate concentrations than did controls. Plasma serotonin concentrations in undernourished mice were 25% lower at 0 wk but 1.5-fold higher than in controls at 3 wk. Whereas most urine and plasma metabolites normalized with refeeding, 117 fecal metabolites remained altered at 3 wk, including multiple N-linked glycans. Microbiota profiles from undernourished mice also remained distinct, with lower mean proportions of Bacteroidetes (67% compared with 83%) and higher proportions of Firmicutes (26% compared with 16%). Abundances of the mucolytic organisms Akkermansia muciniphila and Mucispirillum schaedleri were altered at 0 and 1 wk. Whereas microbiota from undernourished mice at 0 wk contained 11% less community diversity (P = 0.015), refed mice at 3 wk harbored 1.2-fold greater diversity (P = 0.0006) than did controls.

CONCLUSION

Microbial-derived metabolites and intestinal microbiota remain altered during catch-up growth in undernourished neonatal mice.

Improving health in cities through systems approaches for urban water management

BACKGROUND

As human populations become more and more urban, decision-makers at all levels face new challenges related to both the scale of service provision and the increasing complexity of cities and the networks that connect them. These challenges may take on unique aspects in cities with different cultures, political and institutional frameworks, and at different levels of development, but they frequently have in common an origin in the interaction of human and environmental systems and the feedback relationships that govern their dynamic evolution. Accordingly, systems approaches are becoming recognized as critical to understanding and addressing such complex problems, including those related to human health and wellbeing. Management of water resources in and for cities is one area where such approaches hold real promise.

RESULTS

This paper seeks to summarize links between water and health in cities and outline four main elements of systems approaches: analytic methods to deal with complexity, interdisciplinarity, transdisciplinarity, and multi-scale thinking. Using case studies from a range of urban socioeconomic and regional contexts (Maputo, Mozambique; Surat and Kolkata, India; and Vienna, Austria).

CONCLUSION

We show how the inclusion of these elements can lead to better research design, more effective policy and better outcomes.

Modeling-Enabled Systems Nutritional Immunology

This review highlights the fundamental role of nutrition in the maintenance of health, the immune response, and disease prevention. Emerging global mechanistic insights in the field of nutritional immunology cannot be gained through reductionist methods alone or by analyzing a single nutrient at a time. We propose to investigate nutritional immunology as a massively interacting system of interconnected multistage and multiscale networks that encompass hidden mechanisms by which nutrition, microbiome, metabolism, genetic predisposition, and the immune system interact to delineate health and disease. The review sets an unconventional path to apply complex science methodologies to nutritional immunology research, discovery, and development through “use cases” centered around the impact of nutrition on the gut microbiome and immune responses. Our systems nutritional immunology analyses, which include modeling and informatics methodologies in combination with pre-clinical and clinical studies, have the potential to discover emerging systems-wide properties at the interface of the immune system, nutrition, microbiome, and metabolism.

Etiology of Diarrhea in Children Younger Than 5 Years Attending the Bengo General Hospital in Angola

BACKGROUND

Diarrheal disease is among the leading causes of death in children younger than 5 years, especially in developing countries. The aim of this study was to investigate the most frequent etiological agents of diarrhea and its associated factors in children younger than 5 years attending the Bengo General Hospital in Angola.

METHODS

From September 2012 through December 2013, stool samples were collected from 344 children presenting with diarrhea to investigate the presence of viral, bacterial and parasitic agents. Relevant sociodemographic and clinical data were obtained from parents and caregivers.

RESULTS

An enteric pathogen was detected in 66.6% of stool samples: Cryptosporidium spp. (30.0%), rotavirus (25.1%), Giardia lamblia (21.6%), diarrheagenic Escherichia coli (6.3%), Ascaris lumbricoides (4.1%), adenovirus (3.8%), Strongyloides stercoralis (3.5%), astrovirus (2.6%), Hymenolepis nana (1.7%), Entamoeba histolytica/dispar (0.9%), Taenia spp. (0.6%), Trichuris trichiura (0.3%) and Entamoeba histolytica (0.3%). Children younger than 12 months were more frequently infected with Cryptosporidium spp. compared with older children (age: 12-59 months), independently of sex, season, lethargy and wasting [odds ratio (OR): 3.5, 95% confidence interval (95% CI): 2.0-6.2]. Age (OR: 5.0, 95% CI: 2.6-9.3), vomiting (OR: 2.7, 95% CI: 1.5-4.8) and type of admission (inpatients, OR: 0.5, 95% CI: 0.3-0.9) were significantly associated with rotavirus infection.

CONCLUSIONS

This study demonstrates high rates of infection with an enteric pathogen, particularly in children younger than 12 months, emphasizing the need to address diarrheal disease in this age group.

Food Policies’ Roles on Nutrition Goals and Outcomes: Connecting of Food and Public Health Systems

Nutrition exists when food security is combined with a sanitary environment, adequate health services, and proper care and feeding practices to ensure a healthy life for all household members. Despite increased attention to undernutrition, it remains a devastating multi-faceted problem for infants, young children, and women around the world, resulting in increased morbidity, mortality, and long-term disability. Undernutrition can also lead to poor health into adulthood, which affects social and economic development of nations. On the other end of the malnutrition spectrum, overweight and obesity are growing problems, linked to changing diets and activity patterns, which also lead to serious health problems and impact the economies of nations. This chapter attempts to unpack the importance of food and agriculture policies on nutrition outcomes and why engagement of food and public health systems remain critically important. External pressures, such as climate variability and population growth, that tax these systems are discussed, as well as the globalization of our food system and why that has shifted dietary patterns and nutrition and health status trends. The multi-sectoral integration of food and health systems and its importance to improve nutrition is demonstrated through three models. Three very brief case studies are presented that help exemplify some of the food and health system trends that influence policy and ultimately, nutrition outcomes.

A global perspective on the influence of environmental exposures on the nervous system

Economic transitions in the era of globalization warrant a fresh look at the neurological risks associated with environmental change. These are driven by industrial expansion, transfer and mobility of goods, climate change and population growth. In these contexts, risk of infectious and non-infectious diseases are shared across geographical boundaries. In low- and middle-income countries, the risk of environmentally mediated brain disease is augmented several fold by lack of infrastructure, poor health and safety regulations, and limited measures for environmental protection. Neurological disorders may occur as a result of direct exposure to chemical and/or non-chemical stressors, including but not limited to, ultrafine particulate matters. Individual susceptibilities to exposure-related diseases are modified by genetic, epigenetic and metagenomic factors. The existence of several uniquely exposed populations, including those in the areas surrounding the Niger Delta or north western Amazon oil operations; those working in poorly regulated environments, such as artisanal mining industries; or those, mostly in sub-Saharan Africa, relying on cassava as a staple food, offers invaluable opportunities to advance the current understanding of brain responses to environmental challenges. Increased awareness of the brain disorders that are prevalent in low- and middle-income countries and investments in capacity for further environmental health-related research are positive steps towards improving human health.