A longitudinal study of household water, sanitation, and hygiene characteristics and environmental enteropathy markers in children less than 24 months in Iquitos, Peru

Funding Information: Financial support: The MAL-ED is carried out as a collaborative project supported by the Bill & Melinda Gates Foundation, the Foundation for the National Institutes of Health, and the National Institutes of Health, Fogarty International Center. While conducting this work, Natalie Exum was supported by The NSF IGERT Grant 1069213, The Osprey Foundation of Maryland Grant 1602030014, the Johns Hopkins Water Institute, Johns Hopkins Fisher Center Discovery Program Grant 010 KOS2015, The Kazuyoshi Kawata fund in Sanitary Engineering and Science, and the Dr. C. W. Kruse Memorial Fund Scholarship. Publisher Copyright: © 2018 by The American Society of Tropical Medicine and Hygiene.Peer reviewedPublisher PD

Gut microbiota features associated with Campylobacter burden and postnatal linear growth deficits in a Peruvian birth cohort

BACKGROUND: Campylobacter infection is associated with impaired growth of children, even in the absence of symptoms. To examine the underlying mechanisms, we evaluated associations between Campylobacter infection, linear growth, and fecal microbial community features in a prospective birth cohort of 271 children with a high burden of diarrhea and stunting in the Amazonian lowlands of Peru. METHODS: Campylobacter was identified using a broadly reactive, genus-specific enzyme-linked immunosorbent assay. 16S rRNA-based analyses were used to identify bacterial taxa in fecal samples at ages 6, 12, 18, and 24 months (N = 928). Associations between infection, growth, and gut microbial community composition were investigated using multiple linear regression adjusting for within-child correlations, age, and breastfeeding. Indicator species analyses identified taxa specifically associated with Campylobacter burden. RESULTS: Ninety-three percent (251) of children had Campylobacter present in asymptomatic fecal samples during the follow-up period. A 10% increase in the proportion of stools infected was associated with mean reductions of 0.02 length-for-age z scores (LAZ) at 3, 6, and 9 months thereafter (P \u3c .01). We identified 13 bacterial taxa indicative of cumulative Campylobacter burden and 14 taxa significantly associated with high or low burden of enteroaggregative Escherichia coli, norovirus, or Giardia. CONCLUSIONS: Campylobacter infection is common in this cohort and associated with changes in microbial community composition. These results support the notion that disruptions to the fecal microbiota may help explain the observed effects of asymptomatic infections on growth in early life

Diarrhea as a potential cause and consequence of reduced gut microbial diversity among undernourished children in Peru

BACKGROUND: Detrimental effects of diarrhea on child growth and survival are well documented, but details of the underlying mechanisms remain poorly understood. Recent evidence demonstrates that perturbations to normal development of the gut microbiota in early life may contribute to growth faltering and susceptibility to related childhood diseases. We assessed associations between diarrhea, gut microbiota configuration, and childhood growth in the Peruvian Amazon. METHODS: Growth, diarrhea incidence, illness, pathogen infection, and antibiotic exposure were assessed monthly in a birth cohort of 271 children aged 0-24 months. Gut bacterial diversity and abundances of specific bacterial taxa were quantified by sequencing 16S rRNA genes in fecal samples collected at 6, 12, 18, and 24 months. Linear and generalized linear models were used to determine whether diarrhea was associated with altered microbiota and, in turn, if features of the microbiota were associated with the subsequent risk of diarrhea. RESULTS: Diarrheal frequency, duration, and severity were negatively associated with bacterial diversity and richness (P \u3c .05). Children born stunted (length-for-age z-score [LAZ] ≤ -2) who were also severely stunted (LAZ ≤ -3) at the time of sampling exhibited the greatest degree of diarrhea-associated reductions in bacterial diversity and the slowest recovery of bacterial diversity after episodes of diarrhea. Increased bacterial diversity was predictive of reduced subsequent diarrhea from age 6 to 18 months. CONCLUSIONS: Persistent, severe growth faltering may reduce the gut microbiota\u27s resistance and resilience to diarrhea, leading to greater losses of diversity and longer recovery times. This phenotype, in turn, denotes an increased risk of future diarrheal disease and growth faltering

Early Life Child Micronutrient Status, Maternal Reasoning, and a Nurturing Household Environment have Persistent Influences on Child Cognitive Development at Age 5 years : Results from MAL-ED

Funding Information: The Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development Project (MAL-ED) is carried out as a collaborative project supported by the Bill & Melinda Gates Foundation, the Foundation for the NIH, and the National Institutes of Health/Fogarty International Center. This work was also supported by the Fogarty International Center, National Institutes of Health (D43-TW009359 to ETR). Author disclosures: BJJM, SAR, LEC, LLP, JCS, BK, RR, RS, ES, LB, ZR, AM, RS, BN, SH, MR, RO, ETR, and LEM-K, no conflicts of interest. Supplemental Tables 1–5 and Supplemental Figures 1–3 are available from the “Supplementary data” link in the online posting of the article and from the same link in the online table of contents at https://academic.oup.com/jn/. Address correspondence to LEM-K (e-mail: [email protected]). Abbreviations used: HOME, Home Observation for Measurement of the Environment inventory; MAL-ED, The Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development Project; TfR, transferrin receptor; WPPSI, Wechsler Preschool Primary Scales of Intelligence.Peer reviewe

Early life child micronutrient status, maternal reasoning, and a nurturing household environment have persistent influences on child cognitive development at age 5 years: Results from MAL-ED

Background: Child cognitive development is influenced by early-life insults and protective factors. To what extent these factors have a long-term legacy on child development and hence fulfillment of cognitive potential is unknown. Objective: The aim of this study was to examine the relation between early-life factors (birth to 2 y) and cognitive development at 5 y. Methods: Observational follow-up visits were made of children at 5 y, previously enrolled in the community-based MAL-ED longitudinal cohort. The burden of enteropathogens, prevalence of illness, complementary diet intake, micronutrient status, and household and maternal factors from birth to 2 y were extensively measured and their relation with the Wechsler Preschool Primary Scales of Intelligence at 5 y was examined through use of linear regression. Results: Cognitive T-scores from 813 of 1198 (68%) children were examined and 5 variables had significant associations in multivariable models: mean child plasma transferrin receptor concentration (β: −1.81, 95% CI: −2.75, −0.86), number of years of maternal education (β: 0.27, 95% CI: 0.08, 0.45), maternal cognitive reasoning score (β: 0.09, 95% CI: 0.03, 0.15), household assets score (β: 0.64, 95% CI: 0.24, 1.04), and HOME child cleanliness factor (β: 0.60, 95% CI: 0.05, 1.15). In multivariable models, the mean rate of enteropathogen detections, burden of illness, and complementary food intakes between birth and 2 y were not significantly related to 5-y cognition. Conclusions: A nurturing home context in terms of a healthy/clean environment and household wealth, provision of adequate micronutrients, maternal education, and cognitive reasoning have a strong and persistent influence on child cognitive development. Efforts addressing aspects of poverty around micronutrient status, nurturing caregiving, and enabling home environments are likely to have lasting positive impacts on child cognitive development.publishedVersio

The other <i>Campylobacters</i>: Not innocent bystanders in endemic diarrhea and dysentery in children in low-income settings

<div><p>Background</p><p><i>Campylobacter</i> is one of the main causes of gastroenteritis worldwide. Most of the current knowledge about the epidemiology of this food-borne infection concerns two species, <i>C</i>. <i>coli</i> and <i>C</i>. <i>jejuni</i>. Recent studies conducted in developing countries and using novel diagnostic techniques have generated evidence of the increasing burden and importance of other <i>Campylobacter</i> species, i.e. non-<i>C</i>. <i>coli/jejuni</i>. We performed a nested case-control study to compare the prevalence of <i>C</i>. <i>coli/jejuni</i> and other <i>Campylobacter</i> in children with clinical dysentery and severe diarrhea as well as without diarrhea to better understand the clinical importance of infections with <i>Campylobacter</i> species other than <i>C</i>. <i>coli/jejuni</i>.</p><p>Methodology/Principal findings</p><p>Our nested case-control study of 439 stool samples included dysenteric stools, stools collected during severe diarrhea episodes, and asymptomatic stools which were systematically selected to be representative of clinical phenotypes from 9,160 stools collected during a birth cohort study of 201 children followed until two years of age. Other <i>Campylobacter</i> accounted for 76.4% of the 216 <i>Campylobacter</i> detections by qPCR and were more prevalent than <i>C</i>. <i>coli/jejuni</i> across all clinical groups. Other <i>Campylobacter</i> were also more prevalent than <i>C</i>. <i>coli/jejuni</i> across all age groups, with older children bearing a higher burden of other <i>Campylobacter</i>. Biomarkers of intestinal inflammation and injury (methylene blue, fecal occult test, myeloperoxidase or MPO) showed a strong association with dysentery, but mixed results with infection. MPO levels were generally higher among children infected with <i>C</i>. <i>coli/jejuni</i>, but <i>Shigella</i>-infected children suffering from dysentery recorded the highest levels (26,224 ng/mL); the lowest levels (10,625 ng/mL) were among asymptomatic children infected with other <i>Campylobacter</i>. Adjusting for age, sex, and <i>Shigella</i> infection, dysentery was significantly associated with <i>C</i>. <i>coli/jejuni</i> but not with other <i>Campylobacter</i>, whereas severe diarrhea was significantly associated with both <i>C</i>. <i>coli/jejuni</i> and other <i>Campylobacter</i>. Compared to asymptomatic children, children suffering from dysentery had a 14.6 odds of <i>C</i>. <i>coli/jejuni</i> infection (p-value < 0.001, 95% CI 5.5–38.7) but were equally likely to have other <i>Campylobacter</i> infections–odds ratio of 1.3 (0.434, 0.7–2.4). Children suffering from severe diarrhea were more likely than asymptomatic children to test positive for both <i>C</i>. <i>coli/jejuni</i> and other <i>Campylobacter</i>–OR of 2.8 (0.034, 1.1–7.1) and 1.9 (0.018, 1.1–3.1), respectively. Compared to the <i>Campylobacter</i>-free group, the odds of all diarrhea given <i>C</i>. <i>coli/jejuni</i> infection and other <i>Campylobacter</i> infection were 8.8 (<0.001, 3.0–25.7) and 2.4 (0.002, 1.4–4.2), respectively. Eliminating other <i>Campylobacter</i> in this population would eliminate 24.9% of the diarrhea cases, which is almost twice the population attributable fraction of 15.1% due to <i>C</i>. <i>coli/jejuni</i>.</p><p>Conclusions/Significance</p><p>Eighty-seven percent of the dysentery and 59.5% of the severe diarrhea samples were positive for <i>Campylobacter</i>, <i>Shigella</i>, or both, emphasizing the importance of targeting these pathogens to limit the impact of dysentery and severe diarrhea in children. Notably, the higher prevalence of other <i>Campylobacter</i> compared to <i>C</i>. <i>coli/jejuni</i>, their increasing burden during early childhood, and their association with severe diarrhea highlight the importance of these non-<i>C</i>. <i>coli/jejuni Campylobacter</i> species and suggest a need to clarify their importance in the etiology of clinical disease across different epidemiological contexts.</p></div

List of primers and probes used for the detection of <i>Campylobacter</i> (genus specific), <i>Campylobacte</i>r <i>coli/jejuni</i>, and <i>Shigella</i>.

<p>List of primers and probes used for the detection of <i>Campylobacter</i> (genus specific), <i>Campylobacte</i>r <i>coli/jejuni</i>, and <i>Shigella</i>.</p

Prevalence of <i>Campylobacter</i> and <i>Shigella</i> among children suffering from dysentery and severe diarrhea in peri-urban communities in Loreto, Peru.

<p>Prevalence of <i>Campylobacter</i> and <i>Shigella</i> among children suffering from dysentery and severe diarrhea in peri-urban communities in Loreto, Peru.</p

<i>C</i>. <i>coli/jejuni</i>, other <i>Campylobacter</i>, and <i>Shigella</i> prevalence by clinical outcome (asymptomatic infection, dysentery, severe diarrhea) using the qPCR assay.

<p><i>C</i>. <i>coli/jejuni</i>, other <i>Campylobacter</i>, and <i>Shigella</i> prevalence by clinical outcome (asymptomatic infection, dysentery, severe diarrhea) using the qPCR assay.</p

Study population characteristics by clinical outcome (control, dysentery, and severe diarrhea).

<p>Study population characteristics by clinical outcome (control, dysentery, and severe diarrhea).</p