Early-Life Enteric Pathogen Exposure, Socioeconomic Status, and School-Age Cognitive Outcomes.

Early-life experiences of enteric infections and diarrheal illness are common in low-resource settings and are hypothesized to affect child development. However, longer-term associations of enteric infections with school-age cognitive outcomes are difficult to estimate due to lack of long-term studies. The objective of this study was to examine the relationship between enteropathogen exposure in the first 2 years of life with school-age cognitive skills in a cohort of children followed from birth until 6 to 8 years in low-resource settings in Brazil, Tanzania, and South Africa. The study included participants from three sites from the Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health Study who were enrolled just after birth and followed for enteric infections, diarrheal illness, and cognitive development until 2 years of age. When the children were school-age, further data were collected on reasoning skills and semantic/phonemic fluency. We estimated associations between the burden of specific enteric pathogens and etiology-specific diarrhea from 0 to 2 years with cognitive test scores at 6 to 8 years using linear regression and adjusting for confounding variables. In this study, children who carried more enteric pathogens in the first 2 years of life showed overall decreases in school-age cognitive abilities, particularly children who carried protozoa, although this was not statistically significant in this sample. Socioeconomic factors such as maternal education and income were more closely associated with school-age cognitive abilities. Early-life enteric pathogens may have a small, lasting influence on school-age cognitive outcomes, although other socioeconomic factors likely contribute more significantly.

Impact of Shigella infections and inflammation early in life on child growth and school-aged cognitive outcomes: Findings from three birth cohorts over eight years.

BACKGROUND: Shigella infections cause inflammation, which has been hypothesized to mediate the associations between Shigella and child development outcomes among children in low-resource settings. We aimed to assess whether early life inflammation and Shigella infections affect school-aged growth and cognitive outcomes from 6-8 years of age. METHODOLOGY/PRINCIPAL FINDINGS: We conducted follow-up assessments of anthropometry, reasoning skills, and verbal fluency in 451 children at 6-8 years of age in the Brazil, Tanzania, and South Africa sites of MAL-ED, a longitudinal birth cohort study. We estimated the associations between Shigella burden and inflammation with linear growth at 2, 5, and 6-8 years of age, and with the cognitive test scores using linear regression and adjusting for potential confounding variables. We also assessed whether inflammation mediated the associations between Shigella and school-aged outcomes using a regression-based approach to mediation analysis. A high prevalence of Shigella was associated with a 0.32 (95% CI: 0.08, 0.56) z-score lower height-for-age z-score (HAZ) at 6-8 years compared to a low prevalence of Shigella. Intestinal inflammation had a smaller association with HAZ at 6-8 years. Shigella burden had small and consistently negative associations with cognitive outcomes in Brazil and Tanzania, but not South Africa, and the estimates were not statistically significant. Systemic inflammation was strongly associated with lower verbal fluency scores in Brazil (semantic fluency z-score difference: -0.57, 95% CI: -1.05, -0.10; phonemic fluency z-score difference: -0.48, 95% CI: -0.93, -0.03). There was no evidence that intestinal inflammation mediated the association between Shigella and HAZ or cognitive outcomes. CONCLUSIONS/SIGNIFICANCE: While Shigella infections were consistently associated with long-term deficits in linear growth, the estimates of the negative associations between Shigella and cognitive outcomes were imprecise and only observed in the Brazil and Tanzania sites. Systemic inflammation was strongly associated with lower semantic and phonemic fluency scores in Brazil only, highlighting the site-specificity of effects.

Cognitive Outcomes at 18 Months: Findings from the Early Life Interventions for Childhood Growth and Development in Tanzania (ELICIT) Trial.

Micronutrient deficiencies and enteric infections negatively impact child growth and development. We enrolled children shortly after birth in a randomized, placebo-controlled, 2 × 2 factorial interventional trial in Haydom, Tanzania, to assess nicotinamide and/or antimicrobials (azithromycin and nitazoxanide) effect on length at 18 months of age. Cognitive score at 18 months using the Malawi Developmental Assessment Tool (MDAT), which includes gross motor, fine motor, language, and social assessments, was a secondary outcome. Here, we present the MDAT results of 1,032 children. There was no effect of nicotinamide (change in development-for-age Z score [DAZ] -0.08; 95% CI: -0.16, 0) or antimicrobials (change in DAZ 0.04; 95% CI: -0.06, 0.13) on overall MDAT score. The interventions had no effect on cognitive outcomes in subgroups defined by gender, socioeconomic status, birthweight, and birth season or on MDAT subscores. Further analyses are needed to identify targetable risk factors for impaired cognitive development in these settings.

Higher Energy and Zinc Intakes from Complementary Feeding Are Associated with Decreased Risk of Undernutrition in Children from South America, Africa, and Asia.

BACKGROUND: Few studies have focused on quantitatively analyzing nutrients from infant diets, compromising complementary feeding evaluation and health promotion worldwide. OBJECTIVES: This study aimed to describe dietary intake in infants from 9 to 24 mo of age, determining nutrient intakes associated with the risk of underweight, wasting, and stunting. METHODS: Usual nutrient intakes from complementary feeding were determined by 24-h recalls collected when infants were 9-24 mo of age in communities from 7 low- and middle-income countries: Brazil (n = 169), Peru (n = 199), South Africa (n = 221), Tanzania (n = 210), Bangladesh (n = 208), India (n = 227), and Nepal (n = 229), totaling 1463 children and 22,282 food recalls. Intakes were corrected for within- and between-person variance and energy intake. Multivariable regression models were constructed to determine nutrient intakes associated with the development of underweight, wasting, and stunting at 12, 18, and 24 mo of age. RESULTS: Children with malnutrition presented significantly lower intakes of energy and zinc at 12, 18, and 24 mo of age, ranging from -16.4% to -25.9% for energy and -2.3% to -48.8% for zinc. Higher energy intakes decreased the risk of underweight at 12 [adjusted odds ratio (AOR): 0.90; 95% CI: 0.84, 0.96] and 24 mo (AOR: 0.91; 95% CI: 0.86, 0.96), and wasting at 18 (AOR: 0.91; 95% CI: 0.83, 0.99) and 24 mo (AOR: 0.83; 95% CI: 0.74, 0.92). Higher zinc intakes decreased the risk of underweight (AOR: 0.12; 95% CI: 0.03, 0.55) and wasting (AOR: 0.19; 95% CI: 0.04, 0.92) at 12 mo, and wasting (AOR: 0.05; 95% CI: 0.00, 0.76) at 24 mo. CONCLUSIONS: Higher intakes of energy and zinc in complementary feeding were associated with decreased risk of undernutrition in the studied children. Data suggest these are characteristics to be improved in children's complementary feeding across countries.

Seasonal Food Insecurity in Haydom, Tanzania, Is Associated with Low Birthweight and Acute Malnutrition: Results from the MAL-ED Study.

In rural agricultural communities in Africa, particularly those with a single annual harvest, the preharvest period has been associated with increased food insecurity. We estimated the association between seasonal food insecurity and childhood malnutrition in Haydom, Tanzania. Children enrolled in a birth cohort study were followed twice weekly to document food intake and monthly for anthropometry until the age of 2 years. Household food insecurity was reported by caregivers every 6 months. We modeled the seasonality of food insecurity and food consumption, and estimated the impact of birth season on enrollment weight and subsequent malnutrition. Finally, we described the seasonality of admissions for acute malnutrition at a local referral hospital (Haydom Lutheran Hospital) from 2010 to 2015. Food insecurity was highly seasonal, with a peak from December to February. Children born during these 3 months had an average 0.35 z-score (95% CI: 0.12, 0.58) lower enrollment weight than children born in other months. In addition, weight-for-length z-scores measured in these months were on average 0.15 z-scores lower (95% CI: 0.10, 0.20) than that in other months, adjusting for enrollment weight and seasonal infectious diseases, and this disparity was sustained up to the age of 2 years. Correspondingly, the number of admissions with acute malnutrition at the local hospital was highest at this time, with twice as many cases in December-February compared with June-August. We identified acute and chronic malnutrition associated with seasonal food insecurity and intake. Targeting of prenatal care and child-feeding interventions during high food insecurity months may help reduce child malnutrition.