Genetic Susceptibility to Astrovirus Diarrhea in Bangladeshi Infants.

Background: Astroviral infections commonly cause acute nonbacterial gastroenteritis in children globally. However, these infections often go undiagnosed outside of research settings. There is no treatment available for astrovirus, and Astroviridae strain diversity presents a challenge to potential vaccine development. Methods: To address our hypothesis that host genetic risk factors are associated with astrovirus disease susceptibility, we performed a genome-wide association study of astrovirus infection in the first year of life from children enrolled in 2 Bangladeshi birth cohorts. Results: We identified a novel region on chromosome 1 near the loricrin gene (LOR) associated with astrovirus diarrheal infection (rs75437404; meta-analysis P = 8.82 × 10-9; A allele odds ratio, 2.71) and on chromosome 10 near the prolactin releasing hormone receptor gene (PRLHR) (rs75935441; meta-analysis P = 1.33 × 10-8; C allele odds ratio, 4.17). The prolactin-releasing peptide has been shown to influence feeding patterns and energy balance in mice. In addition, several single-nucleotide polymorphisms in the chromosome 1 locus have previously been associated with expression of innate immune system genes PGLYRP4, S100A9, and S100A12. Conclusions: This study identified 2 significant host genetic regions that may influence astrovirus diarrhea susceptibility and should be considered in further studies.

Genome-Wide Association Studies of Diarrhea Frequency and Duration in the First Year of Life in Bangladeshi Infants.

BACKGROUND: Diarrhea is the second leading cause of death in children under 5 years old worldwide. Known diarrhea risk factors include sanitation, water sources, and pathogens but do not fully explain the heterogeneity in frequency and duration of diarrhea in young children. We evaluated the role of host genetics in diarrhea. METHODS: Using 3 well-characterized birth cohorts from an impoverished area of Dhaka, Bangladesh, we compared infants with no diarrhea in the first year of life to those with an abundance, measured by either frequency or duration. We performed a genome-wide association analysis for each cohort under an additive model and then meta-analyzed across the studies. RESULTS: For diarrhea frequency, we identified 2 genome-wide significant loci associated with not having any diarrhea, on chromosome 21 within the noncoding RNA AP000959 (C allele odds ratio [OR] = 0.31, P = 4.01 × 10-8), and on chromosome 8 within SAMD12 (T allele OR = 0.35, P = 4.74 × 10-7). For duration of diarrhea, we identified 2 loci associated with no diarrhea, including the same locus on chromosome 21 (C allele OR = 0.31, P = 1.59 × 10-8) and another locus on chromosome 17 near WSCD1 (C allele OR = 0.35, P = 1.09 × 10-7). CONCLUSIONS: These loci are in or near genes involved in enteric nervous system development and intestinal inflammation and may be potential targets for diarrhea therapeutics.

Prospective Cohort Study of Cryptosporidium Infection and Shedding in Infants and Their Households.

BACKGROUND: Cryptosporidium spp. are responsible for significant diarrheal morbidity and mortality in under-5 children. There is no vaccine; thus, a focus on prevention is paramount. Prior studies suggest that person-to-person spread may be an important pathway for transmission to young children. Here we describe a longitudinal cohort study of 100 families with infants to determine rates of cryptosporidiosis within households during the coronavirus disease 2019 (COVID-19) pandemic. METHODS: Families living in Mirpur, Bangladesh, with 1 infant aged 6-8 months were enrolled and followed with weekly illness survey and stool testing for Cryptosporidium for 8 months. RESULTS: From December 2020 to August 2021, 100 families were enrolled. Forty-four percent of index children and 35% of siblings had at least 1 Cryptosporidium infection. Shedding of Cryptosporidium occurred for a mean (standard deviation) of 19 (8.3) days in index infants, 16.1 (11.6) days in children 1-5 years, and 16.2 (12.8) days in adults. A longer duration of Cryptosporidium shedding was associated with growth faltering in infants. There was a spike in Cryptosporidium cases in May 2021, which coincided with a spike in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cases in the region. CONCLUSIONS: In this intensive, longitudinal study of Cryptosporidium infection in families we found high rates of cryptosporidiosis in infants and children, and prolonged parasite shedding, especially among malnourished children. These data support that transmission within the household is an important route of exposure for young infants and that treatment of nondiarrheal infection to interrupt person-to-person transmission within the home may be essential for preventing cryptosporidiosis in infants.

Prospective cohort study of Cryptosporidium infection and shedding in infants and their households.

Background: Cryptosporidium spp are responsible for significant diarrheal morbidity and mortality in under-five children. There is no vaccine, thus a focus on prevention is paramount. Prior studies suggest that person-to-person spread may be an important pathway for transmission to young children. Here we describe a longitudinal cohort study of 100 families with infants to determine rates of cryptosporidiosis within households during the COVID-19 pandemic. Methods: Families living in Mirpur, Bangladesh with one infant age 6-8 months were enrolled and followed with weekly illness survey and stool testing for Cryptosporidium for 8 months. Results: From December 2020 to August 2021, 100 families were enrolled. Forty-four percent of index children, and 35% of siblings had at least one Cryptosporidium infection. Shedding of Cryptosporidium occurred for a mean of 19 days (sd 8.3 days) in index infants, 16.1 days (sd 11.6) in children 1-5 years, and 16.2 days (sd 12.8) in adults. A longer duration of Cryptosporidium shedding was associated with growth faltering in infants. There was a spike in Cryptosporidium cases in May 2021, which coincided with a spike in SARS-CoV-2 cases in the region. Conclusion: In this intensive, longitudinal study of Cryptosporidium infection in families we found high rates of cryptosporidiosis in infants and children, and prolonged parasite shedding, especially among malnourished children. These data support that transmission within the household is an important route of exposure for young infants, and that treatment of non-diarrheal infection to interrupt person-to-person transmission within the home may be essential for preventing cryptosporidiosis in infants. summary: Cryptosporidiosis is a leading cause of morbidity and mortality among children. We followed 100 families with infants living in Bangladesh and studied the incidence of Cryptosporidium infection. We found prolonged Cryptosporidium shedding in stool was common among infants and adults.

Genome-Wide Association Study of Campylobacter-Positive Diarrhea Identifies Genes Involved in Toxin Processing and Inflammatory Response.

Diarrhea is responsible for the deaths of more than 500,000 children each year, many of whom reside in low-to-middle-income countries (LMICs). Additionally, children with multiple diarrheal infections early in life have increased growth stunting and malnutrition and decreased vaccine efficacy. Two bacteria that contribute to the burden of diarrhea are Campylobacter jejuni and Campylobacter coli, both are endemic in Bangladesh. However, not all children that are exposed to these pathogens, including Campylobacter, will experience diarrhea. We hypothesized that host genetics may influence susceptibility to Campylobacter infections and performed a genome-wide association study in 534 children from two independent birth cohorts in Dhaka, Bangladesh. Infants were monitored for diarrhea for the first 2 years of life and only defined as controls if all diarrheal samples in the first year were negative for Campylobacter jejuni/C. coli. Each cohort was analyzed separately under an additive model and adjusted for length-for-age z-scores at birth and 12 months, sex, water treatment, and ancestry. In a fixed effect inverse-variance weighted meta-analysis of these two cohorts, we identified a genome-wide significant region on chromosome 8 in intron 4 of the rho guanine nucleotide exchange factor 10 gene (ARHGEF10). Individuals with the G allele (rs13281104) had a 2-fold lower risk of having a Campylobacter-associated diarrheal episode than individuals with the A allele (OR 0.41, 95% CI 0.29 to 0.58, P = 3.6 × 10-7). This SNP is associated with decreased expression of the neighboring gene, CLN8, which may be involved in the transport of the cytolethal distending toxin produced by Campylobacter. IMPORTANCE Children in low-to-middle-income countries often suffer from multiple enteric infections in their first few years of life, many of which have the potential for long-lasting effects. These children are already likely to be malnourished and underweight, and chronic intestinal disturbances exacerbate these conditions. Despite public health interventions aimed at improving water, sanitation, and hygiene, enteric infections are still a leading cause of death for children under five. Previous work has included transmission dynamics, pathogen characteristics, and evaluation of interventions. Here, we examined the role of host genetic variation in susceptibility to diarrhea-associated Campylobacter infection. In our meta-analysis of two independent birth cohorts from Dhaka, Bangladesh, we found that children carrying a specific genetic variant (rs13281104, in an intron of ARHGEF10) were half as likely to have a diarrhea-associated Campylobacter infection in their first year of life. This protective effect may be achieved by decreasing gene expression and thereby impacting host-pathogen interactions and host immune response.

Host Genome-Wide Association Study of Infant Susceptibility to Shigella-Associated Diarrhea.

Shigella is a leading cause of moderate-to-severe diarrhea globally and the causative agent of shigellosis and bacillary dysentery. Associated with 80 to 165 million cases of diarrhea and >13% of diarrheal deaths, in many regions, Shigella exposure is ubiquitous while infection is heterogenous. To characterize host-genetic susceptibility to Shigella-associated diarrhea, we performed two independent genome-wide association studies (GWAS) including Bangladeshi infants from the PROVIDE and CBC birth cohorts in Dhaka, Bangladesh. Cases were infants with Shigella-associated diarrhea (n = 143) and controls were infants with no Shigella-associated diarrhea in the first 13 months of life (n = 446). Shigella-associated diarrhea was identified via quantitative PCR (qPCR) threshold cycle (CT ) distributions for the ipaH gene, carried by all four Shigella species and enteroinvasive Escherichia coli Host GWAS were performed under an additive genetic model. A joint analysis identified protective loci on chromosomes 11 (rs582240, within the KRT18P59 pseudogene; P = 6.40 × 10-8; odds ratio [OR], 0.43) and 8 (rs12550437, within the lincRNA RP11-115J16.1; P = 1.49 × 10-7; OR, 0.48). Conditional analyses identified two previously suggestive loci, a protective locus on chromosome 7 (rs10266841, within the 3' untranslated region [UTR] of CYTH3; Pconditional = 1.48 × 10-7; OR, 0.44) and a risk-associated locus on chromosome 10 (rs2801847, an intronic variant within MPP7; Pconditional = 8.37 × 10-8; OR, 5.51). These loci have all been indirectly linked to bacterial type 3 secretion system (T3SS) activity, its components, and bacterial effectors delivered into host cells. Host genetic factors that may affect bacterial T3SS activity and are associated with the host response to Shigella-associated diarrhea may provide insight into vaccine and drug development efforts for Shigella-associated diarrheal disease.

Genome-Wide Association Study of Cryptosporidiosis in Infants Implicates PRKCA.

Diarrhea is a major cause of both morbidity and mortality worldwide, especially among young children. Cryptosporidiosis is a leading cause of diarrhea in children, particularly in South Asia and sub-Saharan Africa, where it is responsible for over 200,000 deaths per year. Beyond the initial clinical presentation of diarrhea, it is associated with long-term sequelae such as malnutrition and neurocognitive developmental deficits. Risk factors include poverty and overcrowding, and yet not all children with these risk factors and exposure are infected, nor do all infected children develop symptomatic disease. One potential risk factor to explain these differences is their human genome. To identify genetic variants associated with symptomatic cryptosporidiosis, we conducted a genome-wide association study (GWAS) examining 6.5 million single nucleotide polymorphisms (SNPs) in 873 children from three independent cohorts in Dhaka, Bangladesh, namely, the Dhaka Birth Cohort (DBC), the Performance of Rotavirus and Oral Polio Vaccines in Developing Countries (PROVIDE) study, and the Cryptosporidiosis Birth Cohort (CBC). Associations were estimated separately for each cohort under an additive model, adjusting for length-for-age Z-score at 12 months of age, the first two principal components to account for population substructure, and genotyping batch. The strongest meta-analytic association was with rs58296998 (P = 3.73 × 10-8), an intronic SNP and expression quantitative trait locus (eQTL) of protein kinase C alpha (PRKCA). Each additional risk allele conferred 2.4 times the odds of Cryptosporidium-associated diarrhea in the first year of life. This genetic association suggests a role for protein kinase C alpha in pediatric cryptosporidiosis and warrants further investigation.IMPORTANCE Globally, diarrhea remains one of the major causes of pediatric morbidity and mortality. The initial symptoms of diarrhea can often lead to long-term consequences for the health of young children, such as malnutrition and neurocognitive developmental deficits. Despite many children having similar exposures to infectious causes of diarrhea, not all develop symptomatic disease, indicating a possible role for human genetic variation. Here, we conducted a genetic study of susceptibility to symptomatic disease associated with Cryptosporidium infection (a leading cause of diarrhea) in three independent cohorts of infants from Dhaka, Bangladesh. We identified a genetic variant within protein kinase C alpha (PRKCA) associated with higher risk of cryptosporidiosis in the first year of life. These results indicate a role for human genetics in susceptibility to cryptosporidiosis and warrant further research to elucidate the mechanism.

Fecal Immunoglobulin A Against a Sporozoite Antigen at 12 Months Is Associated With Delayed Time to Subsequent Cryptosporidiosis in Urban Bangladesh: A Prospective Cohort Study.

In this prospective cohort study of Bangladeshi children, greater fecal immunoglobulin A, but not plasma immunoglobulin G, directed against the Cryptosporidium sporozoite-expressed antigen Cp23 at 12 months of age was associated with delayed time to subsequent cryptosporidiosis. This finding suggests a protective role for mucosal antibody-mediated immunity in naturally exposed children.

Case-Control Study of Cryptosporidium Transmission in Bangladeshi Households.

BACKGROUND: Cryptosporidium is a leading contributor to diarrheal morbidity and mortality in under-5 children worldwide. As there is no vaccine and no effective drug therapy in young children for this infection, preventing infection is critical. We undertook a pilot case-control study to define the extent of person-to-person transmission of cryptosporidiosis within an urban and a rural community in Bangladesh. METHODS: We enrolled 48 case families with a Cryptosporidium-infected child aged 6-18 months. Controls were age- and sex-matched Cryptosporidium-negative children in 12 households. Children and household members were followed for 8 weeks with weekly illness survey and stool testing with quantitative polymerase chain reaction for Cryptosporidium. RESULTS: In the 24 urban case families, the secondary attack rate was 35.8% (19/53) vs 0% (0/11) in controls (P = .018, χ2 test). In contrast, in the 24 rural case families, the secondary attack rate was 7.8% (5/64) vs 0% (0/21) in controls (P = .19, χ2 test). Genotyping by gp60 demonstrated infection with the same subspecies in 5 families, and evidence of transmission in 2. Serologic response to Cryptosporidium infection was associated with younger age, longer duration of infection, and Cryptosporidium hominis gp60_IbA9G3R2 infection. CONCLUSIONS: In the urban site, the high rate of secondary infection and infection with the same subspecies within families suggests that person-to-person transmission is a major source of Cryptosporidium infection for young children living in this region. Molecular genotyping can be applied to determine transmission of Cryptosporidium in endemic regions. Further work is needed to understand the differences in parasite transmissibility and immunity to different genotypes.

A high-throughput sequencing assay to comprehensively detect and characterize unicellular eukaryotes and helminths from biological and environmental samples.

BACKGROUND: Several of the most devastating human diseases are caused by eukaryotic parasites transmitted by arthropod vectors or through food and water contamination. These pathogens only represent a fraction of all unicellular eukaryotes and helminths that are present in the environment and many uncharacterized organisms might have subtle but pervasive effects on health, including by modifying the microbiome where they reside. Unfortunately, while we have modern molecular tools to characterize bacterial and, to a lesser extent, fungal communities, we lack suitable methods to comprehensively investigate and characterize most unicellular eukaryotes and helminths: the detection of these organisms often relies on microscopy that cannot differentiate related organisms, while molecular assays can only detect the pathogens specifically tested. RESULTS: Here, we describe a novel sequencing-based assay, akin to bacterial 16S rRNA sequencing, that enables high-throughput detection and characterization of a wide range of unicellular eukaryotes and helminths, including those from taxonomical groups containing all common human parasites. We designed and evaluated taxon-specific PCR primer pairs that selectively amplify all species from eight taxonomical groups (Apicomplexa, Amoeba, Diplomonadida, Kinetoplastida, Parabasalia, Nematoda, Platyhelminthes, and Microsporidia). We then used these primers to screen DNA extracted from clinical, biological, and environmental samples, and after next-generation sequencing, identified both known and previously undescribed organisms from most taxa targeted. CONCLUSIONS: This novel high-throughput assay enables comprehensive detection and identification of eukaryotic parasites and related organisms, from a wide range of complex biological and environmental samples. This approach can be easily deployed to many settings and will efficiently complement existing methods and provide a holistic perspective on the microbiome.

Species of Cryptosporidia Causing Subclinical Infection Associated With Growth Faltering in Rural and Urban Bangladesh: A Birth Cohort Study.

Background: Cryptosporidiosis is a major cause of childhood diarrhea in low- and middle-income countries and has been linked to impairment of child growth. This study investigated the burden of cryptosporidiosis and its impact on child growth in both a rural and an urban site in Bangladesh. Methods: Pregnant women in the second trimester were identified at 2 sites in Bangladesh, 1 urban and 1 rural. Their offspring were enrolled at birth into the study (urban, n = 250; rural, n = 258). For 2 years, the children were actively monitored for diarrhea and anthropometric measurements were obtained every 3 months. Stool samples were collected monthly and during diarrheal episodes with Cryptosporidium infection and causative species determined by quantitative polymerase chain reaction assays. Results: Cryptosporidium infections were common at both sites and mostly subclinical. In the urban site, 161 (64%) children were infected and 65 (26%) had ≥2 infections. In the rural site, 114 (44%) were infected and 24 (9%) had multiple infections. Adjusted for potential confounders, cryptosporidiosis was associated with a significantly greater drop in the length-for-age z score (LAZ) at 24 months from LAZ at enrollment (Δ-LAZ), an effect greatest in the children with multiple episodes of cryptosporidiosis. The most common species in Mirpur was Cryptosporidium hominis, whereas Cryptosporidium meleagridis predominated in Mirzapur. Conclusions: Cryptosporidiosis is common in early childhood and associated with early growth faltering in Bangladeshi children. Predominant Cryptosporidium species differed between the 2 sites, suggesting different exposures or modes of transmission but similar consequences for child growth. Clinical Trials Registration: NCT02764918.

Morbidity, mortality, and long-term consequences associated with diarrhoea from Cryptosporidium infection in children younger than 5 years: a meta-analyses study.

BACKGROUND: The protozoan Cryptosporidium is a leading cause of diarrhoea morbidity and mortality in children younger than 5 years. However, the true global burden of Cryptosporidium infection in children younger than 5 years might have been underestimated in previous quantifications because it only took account of the acute effects of diarrhoea. We aimed to demonstrate whether there is a causal relation between Cryptosporidium and childhood growth and, if so, to quantify the associated additional burden. METHODS: The Global Burden of Diseases, Injuries, and Risk Factors study (GBD) 2016 was a systematic and scientific effort to quantify the morbidity and mortality associated with more than 300 causes of death and disability, including diarrhoea caused by Cryptosporidium infection. We supplemented estimates on the burden of Cryptosporidium in GBD 2016 with findings from a systematic review of published and unpublished cohort studies and a meta-analysis of the effect of childhood diarrhoea caused by Cryptosporidium infection on physical growth. FINDINGS: In 2016, Cryptosporidium infection was the fifth leading diarrhoeal aetiology in children younger than 5 years, and acute infection caused more than 48 000 deaths (95% uncertainty interval [UI] 24 600-81 900) and more than 4·2 million disability-adjusted life-years lost (95% UI 2·2 million-7·2 million). We identified seven data sources from the scientific literature and six individual-level data sources describing the relation between Cryptosporidium and childhood growth. Each episode of diarrhoea caused by Cryptosporidium infection was associated with a decrease in height-for-age Z score (0·049, 95% CI 0·014-0·080), weight-for-age Z score (0·095, 0·055-0·134), and weight-for-height Z score (0·126, 0·057-0·194). We estimated that diarrhoea from Cryptosporidium infection caused an additional 7·85 million disability-adjusted life-years (95% UI 5·42 million-10·11 million) after we accounted for its effect on growth faltering-153% more than that estimated from acute effects alone. INTERPRETATION: Our findings show that the substantial short-term burden of diarrhoea from Cryptosporidium infection on childhood growth and wellbeing is an underestimate of the true burden. Interventions designed to prevent and effectively treat infection in children younger than 5 years will have enormous public health and social development impacts. FUNDING: The Bill & Melinda Gates Foundation.

Burden and Risk Factors of Antimicrobial Use in Children Less Than 5 Years of Age with Diarrheal Illness in Rural Bangladesh.

Antimicrobial overuse contributes to antimicrobial resistance. Empiric use of antimicrobials for diarrheal illness is warranted only in a minority of cases, because of its self-limiting nature and multifactorial etiology. This study aims to describe the factors contributing to antimicrobial overuse for diarrheal disease among children less than 5 years of age in rural Bangladesh. A total of 3,570 children less than 5 years of age presenting with diarrhea in a tertiary level hospital were enrolled in the study. The rate of antimicrobial use at home was 1,395 (39%), compared with 2,084 (89%) during a hospital visit. In a multivariate analysis, factors associated with antimicrobial use at home included residence located more than 5 miles from a hospital; use of zinc and oral rehydration salts at home; vomiting; greater than 10 stools per 24 hours; diarrheal duration greater than 3 days; and rotavirus diarrhea (P < 0.05 for all). Characteristics of children more likely to be given antimicrobials in a health-care setting included greater than 10 stools per 24 hours; duration of diarrhea greater than 3 days; use of antimicrobials before hospital presentation; fever (≥ 37.8°C); rectal straining; and Shigella infection (P < 0.05 for all). The most commonly used drugs in rotavirus diarrhea were azithromycin and erythromycin, both before hospital presentation and during hospital admission. Our study underscores the importance of diligent vigilance on the rationale use of antimicrobials both at home and in health-care facilities with a special concern for children less than 5 years of age living in rural Bangladesh.

Epidemiology and Risk Factors for Cryptosporidiosis in Children From 8 Low-income Sites: Results From the MAL-ED Study.

Background: Cryptosporidium species are enteric protozoa that cause significant morbidity and mortality in children worldwide. We characterized the epidemiology of Cryptosporidium in children from 8 resource-limited sites in Africa, Asia, and South America. Methods: Children were enrolled within 17 days of birth and followed twice weekly for 24 months. Diarrheal and monthly surveillance stool samples were tested for Cryptosporidium by enzyme-linked immunosorbent assay. Socioeconomic data were collected by survey, and anthropometry was measured monthly. Results: Sixty-five percent (962/1486) of children had a Cryptosporidium infection and 54% (802/1486) had at least 1 Cryptosporidium-associated diarrheal episode. Cryptosporidium diarrhea was more likely to be associated with dehydration (16.5% vs 8.3%, P < .01). Rates of Cryptosporidium diarrhea were highest in the Peru (10.9%) and Pakistan (9.2%) sites. In multivariable regression analysis, overcrowding at home was a significant risk factor for infection in the Bangladesh site (odds ratio, 2.3 [95% confidence interval {CI}, 1.2-4.6]). Multiple linear regression demonstrated a decreased length-for-age z score at 24 months in Cryptosporidium-positive children in the India (ß = -.26 [95% CI, -.51 to -.01]) and Bangladesh (ß = -.20 [95% CI, -.44 to .05]) sites. Conclusions: This multicountry cohort study confirmed the association of Cryptosporidium infection with stunting in 2 South Asian sites, highlighting the significance of cryptosporidiosis as a risk factor for poor growth. We observed that the rate, age of onset, and number of repeat infections varied per site; future interventions should be targeted per region to maximize success.

Natural History of Cryptosporidiosis in a Longitudinal Study of Slum-Dwelling Bangladeshi Children: Association with Severe Malnutrition.

BACKGROUND: Cryptosporidiosis is a common cause of infectious diarrhea in young children worldwide, and is a significant contributor to under-five mortality. Current treatment options are limited in young children. In this study, we describe the natural history of Cryptosporidium spp. infection in a birth cohort of children in Bangladesh and evaluate for association with malnutrition. METHODOLOGY/PRINCIPAL FINDINGS: This is a longitudinal birth cohort study of 392 slum-dwelling Bangladeshi children followed over the first two years of life from 2008 to 2014. Children were monitored for diarrheal disease, and stool was tested for intestinal protozoa. Anthropometric measurements were taken at 3-month intervals. A subset of Cryptosporidium positive stools were genotyped for species and revealed that C. hominis was isolated from over 90% of samples. In the first two years of life, 77% of children experienced at least one infection with Cryptosporidium spp. Non-diarrheal infection (67%) was more common than diarrheal infection (6.3%) although 27% of children had both types of infection. Extreme poverty was associated with higher rates of infection (chi-square, 49.7% vs 33.3%, p = 0.006). Malnutrition was common in this cohort, 56% of children had stunted growth by age two. Children with Cryptosporidium spp. infection had a greater than 2-fold increased risk of severe stunting at age two compared to uninfected children (odds ratio 2.69, 95% CI 1.17, 6.15, p = 0.019) independent of sex, income, maternal body-mass index, maternal education and weight for age adjusted z (WAZ) score at birth. CONCLUSIONS/SIGNIFICANCE: Cryptosporidium infection is common (77%) in this cohort of slum-dwelling Bangladeshi children, and both non-diarrheal and diarrheal infections are significantly associated with a child's growth at 2 years of age.

Plasma endotoxin core antibody concentration and linear growth are unrelated in rural Malawian children aged 2-5 years.

BACKGROUND: Environmental enteropathy is subclinical inflammation of the upper gastrointestinal tract associated with reduced linear growth in developing countries. Usually investigators have used biopsy or a dual sugar absorption test to assess environmental enteropathy. Such tests are time and resource intensive, restricting their utility as screening methods. Serum endotoxin core antibody (EndoCab) concentration is a potential indicator of intestinal inflammation and integrity, and thus may be useful to predict environmental enteropathy. We analyzed the association of serum EndoCab levels versus linear growth and lactulose-mannitol assay results in 2-5 year old rural Malawian children. METHODS: This was an observational study of 388 rural, asymptomatic Malawian children who had anthropometric measurements taken at least every 3 months since birth. In June and July 2011, dual sugar permeability tests were performed and serum samples were drawn for EndoCab assays. Pearson correlation, Student's t test and multivariable linear regression were used to compare ln EndoCab concentrations with height-for-age z scores (HAZ) at time of sampling and 3 months later. Identical analysis was also performed for ln EndoCab versus measurements from dual sugar permeability testing performed in conjunction with serum sampling. In a subgroup of children with anthropometric data in the months prior to serum sampling, Pearson correlation was used to estimate the relationship between ln EndoCab and recent linear growth. RESULTS: Ln EndoCab concentrations were not correlated with HAZ at time of measurement (B = -0.078, P = 0.14) nor change in HAZ over the subsequent 3 months HAZ (B = -0.018, P = 0.27). EndoCab concentration was not associated with %lactulose excretion (B < 0.001, P = 0.98) nor the lactulose:mannitol ratio (B = 0.021, P = 0.62). Subgroup analysis also did not reveal any significant association between EndoCab and recent growth. CONCLUSION: EndoCab titers were not correlated with measurements of growth or intestinal permeability in rural pre-school aged Malawian children.

Calcified neurocysticercus, perilesional edema, and histologic inflammation.

Abstract. Here, we present the second report of the histopathology of a Taenia solium calcification giving rise to perilesional edema. This has important implications, because if perilesional edema lesions are inflammatory in character, immunosuppressive or anti-inflammatory medications, not just antiepileptic drugs alone, may be useful to prevent or treat recurring episodes in such patients.

Oral polio vaccine response in breast fed infants with malnutrition and diarrhea.

Oral vaccines for polio (OPV) and rotavirus are less effective in children in the developing world. The reasons for this are not well understood. We tested for risk factors for poor response to OPV in infants from an urban slum of Dhaka, Bangladesh. Diminished serum neutralizing response to OPV, but not failure of intramuscularly administered vaccines, was associated with malnutrition, diarrhea, and shorter breastfeeding duration. Children with malnutrition (WAZ <-2) had significantly lower OPV 3 titers (p=0.029). Children who had 2 or more diarrhea episodes during the 1st months of life were more than twice as likely to experience OPV failure as those who had 1 diarrhea episode or no diarrhea (p=0.0245). In contrast, each additional month in exclusive breastfeeding was associated with an increase in OPV 3 titer by 0.41 (p=0.0072) and 0.16 (p=0.0065) at the 25th and 50th percentiles of OPV 3 titers respectively. These data are consistent with a defect in induction of immunity in the gut for OPV but not parenteral vaccines, a defect that may be amenable to intervention in part via promotion of exclusive breastfeeding.

REG1B as a predictor of childhood stunting in Bangladesh and Peru.

BACKGROUND: Undernutrition remains a significant problem worldwide, with environmental enteropathy implicated as a contributing factor. An understanding of the pathogenesis and identification of children at risk are critical to the design of more-effective interventions. OBJECTIVE: The stool regenerating gene 1ß (REG1B) protein, which is a putative measure of intestinal injury and repair, was tested as a noninvasive biomarker of future childhood stunting. DESIGN: A total of 222 children from Bangladesh and 97 children from Peru, who were from impoverished communities, were followed from birth through 24 mo of age with anthropometric measures obtained every 3 mo. Stool REG1B protein concentrations were obtained by using an REG1B polyclonal-polyclonal ELISA at 3 mo of age. We tested for the ability of REG1B to forecast future anthropometric shortfalls, independent of known predictors of undernutrition of family income and baseline height and weight. RESULTS: In the Bangladesh cohort of 222 children, higher REG1B concentrations at month 3 were significantly and independently associated with a growth shortfall in a linear regression analysis at months 9, 12, 18, 21, and 24 and, in the Peru cohort, at months 12, 15, 18, 21, and 24. With the use of a mixed model for repeated measurements, higher stool REG1B concentrations at 3 mo were also independently predictive of a lower future length-for-age z score through 24 mo of age (Bangladesh P = 0.006; Peru P = 0.058). CONCLUSION: The ability of fecal REG1B to predict growth shortfall in independent cohorts of impoverished children from the developing world offers promise as a malnutrition biomarker and supports a role for environmental enteropathy in the pathogenesis of growth shortfall.