Geospatial inequalities and determinants of nutritional status among women and children in Afghanistan: an observational study

Summary: Background: Undernutrition is a pervasive condition in Afghanistan, and prevalence is among the highest in the world. We aimed to comprehensively assess district-level geographical disparities and determinants of nutritional status (stunting, wasting, or underweight) among women and children in Afghanistan. Methods: The study used individualised data from the recent Afghanistan National Nutrition Survey 2013. Outcome variables were based on growth and weight anthropometry data, which we analysed linearly as Z scores and as dichotomous categories. We analysed data from a total of almost 14 000 index mother–child pairs using Bayesian spatial and generalised least squares regression models accounting for the complex survey design. Findings: We noted that childhood stunting, underweight, and combined stunting and wasting were consistently highest in districts in Farah, Nangarhar, Nuristan, Kunar, Paktia, and Badakhshan provinces. District prevalence ranged from 4% to 84% for childhood stunting and 5% to 66% for underweight. Child wasting exceeded 20% in central and high-conflict regions that bordered Pakistan including east, southeast, and south. Among mothers, dual burden of underweight and overweight or obesity existed in districts of north, northeast, central, and central highlands (prevalence of 15–20%). Linear growth and weight of children were independently associated with household wealth, maternal literacy, maternal anthropometry, child age, food security, geography, and improved hygiene and sanitation conditions. The mother's body-mass index was determined by many of the same factors, in addition to ethnolinguistic status and parity. Younger mothers (<20 years old) were more underweight and shorter than older mothers (aged 20–49 years). Interpretation: Afghanistan's rapidly changing political, socioeconomic, and insecurity landscape has both direct and indirect implications on population nutrition. Novel evidence from our study can be used to understand these multifactorial determinants and to identify granular disparities for local level tracking, planning, and implementation of nutritional interventions. Funding: None

Use of quantitative molecular diagnostic methods to investigate the effect of enteropathogen infections on linear growth in children in low-resource settings: longitudinal analysis of results from the MAL-ED cohort study

Summary: Background: Enteropathogen infections in early childhood not only cause diarrhoea but contribute to poor growth. We used molecular diagnostics to assess whether particular enteropathogens were associated with linear growth across seven low-resource settings. Methods: We used quantitative PCR to detect 29 enteropathogens in diarrhoeal and non-diarrhoeal stools collected from children in the first 2 years of life obtained during the Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development (MAL-ED) multisite cohort study. Length was measured monthly. We estimated associations between aetiology-specific diarrhoea and subclinical enteropathogen infection and quantity and attained length in 3 month intervals, at age 2 and 5 years, and used a longitudinal model to account for temporality and time-dependent confounding. Findings: Among 1469 children who completed 2 year follow-up, 35 622 stool samples were tested and yielded valid results. Diarrhoeal episodes attributed to bacteria and parasites, but not viruses, were associated with small decreases in length after 3 months and at age 2 years. Substantial decrements in length at 2 years were associated with subclinical, non-diarrhoeal, infection with Shigella (length-for-age Z score [LAZ] reduction −0·14, 95% CI −0·27 to −0·01), enteroaggregative Escherichia coli (−0·21, −0·37 to −0·05), Campylobacter (−0·17, −0·32 to −0·01), and Giardia (−0·17, −0·30 to −0·05). Norovirus, Cryptosporidium, typical enteropathogenic E coli, and Enterocytozoon bieneusi were also associated with small decrements in LAZ. Shigella and E bieneusi were associated with the largest decreases in LAZ per log increase in quantity per g of stool (−0·13 LAZ, 95% CI −0·22 to −0·03 for Shigella; −0·14, −0·26 to −0·02 for E bieneusi). Based on these models, interventions that successfully decrease exposure to Shigella, enteroaggregative E coli, Campylobacter, and Giardia could increase mean length of children by 0·12–0·37 LAZ (0·4–1·2 cm) at the MAL-ED sites. Interpretation: Subclinical infection and quantity of pathogens, particularly Shigella, enteroaggregative E coli, Campylobacter, and Giardia, had a substantial negative association with linear growth, which was sustained during the first 2 years of life, and in some cases, to 5 years. Successfully reducing exposure to certain pathogens might reduce global stunting. Funding: Bill & Melinda Gates Foundation