Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development (MAL-ED)

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Overview

This program completed in October 2017.

One in every five children in low and middle income countries (LMICs) is undernourished. Poor nutrition, not all of which is due to food insecurity, is associated with nearly half of child deaths under the age of five. Early childhood malnutrition is considered one of the most prevalent risk factors for morbidity and mortality in children under five and may lead to cognitive and physical deficits later in life.

For children living in resource-constrained areas in LMICs, malnutrition, frequently identified by a severe shortfall in physical growth (i.e. stunting), is associated with the chronic exposure to infectious disease-causing enteric pathogens. These pathogens may alter gut integrity and impair absorption of nutrients resulting in further malnutrition and increased susceptibility to and incidence of infection and disease and in diminished immune responses to childhood vaccines. Moreover, the effects of these pathogens may also lead to cognitive and related developmental deficits. The cumulative effects of high rates of disease, malnutrition, and impaired child development place an enormous and disproportionate social and economic burden on poor families and the societies in which they reside.

Increased understanding of the complex inter-relationship between enteric infections and malnutrition in the context of poor socioeconomic conditions is needed to design and implement better intervention strategies to reduce childhood morbidity and mortality.

An international network of investigators collaborated on a project entitled Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development to gain a comprehensive understanding of environmental factors affecting child development. For this project, abbreviated as MAL-ED, investigators conducted research at eight geographically distinct sites, within populations known to have high rates of malnutrition and enteric infections. Children were closely monitored beginning in each child’s first month of life in an effort to determine those early life exposures that pose the greatest risk through two-years of age, afterwhich they were periodically monitored up to five-years of age.

Partners

Public-Sector Partners:

  • Fogarty International Center
  • National Institutes of Health

Private-Sector Partners:

  • Bill & Melinda Gates Foundation*
  • Haydom Lutheran Hospital, Haydom, Tanzania
  • Henry M Jackson Foundation
  • icddr,b, Dhaka, Bangladesh

Academic Partners:

  • Armed Forces Research Institute of Medical Sciences
  • Aga Khan University, Karachi, Pakistan
  • Christian Medical College, Vellore, India
  • Federal University of Ceará, Fortaleza, Ceará, Brazil
  • Haydom Lutheran Hospital, Haydom, Tanzania
  • Henry M Jackson Foundation
  • icddr,b, Dhaka, Bangladesh
  • Institute of Medicine, Kathmandu, Nepal
  • Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
  • NIH, Fogarty International Center
  • Pennsylvania State University
  • University of Venda, Limpopo, South Africa
  • University of Virginia

*Provided financial or in-kind support for this program.

FNIH Contact

Investigators working at institutions and sites, identified below, in Bangladesh, Brazil, India, Nepal, Pakistan, Peru, South Africa, Tanzania, along with investigators at institutions in the United States designed and executed the first-of-its-kind comprehensive study of early child growth and development.

The study was implemented using shared and harmonized protocols across the eight sites to gather an enormous amount of data (physical, cognitive assessments, diet, illness and enteric infection, socio-economic status, etc.) to enable identification and characterization of factors associated with negative impacts on a child’s growth, development and vaccine response early in life.

With approval from institutional ethical review committees, the children and their mothers were recruited for this study to establish a birth cohort at each of eight sites. Each site enrolled at least 200 children within the first 17 days of each childn's life over the course of two years. As per the protocol, during the first two years of life each child and mother pair was visited twice weekly by field workers who collected survey and health data as well as biospecimens for further testing. From three to five years of age, each child was visited once a quarter at a minimum.

A central hypothesis of the project was that enteric infections and poor nutrition result in changes in gut function (e.g. malabsorption of nutrients, inflammation) that are detrimental to healthy child growth and development.

The MAL-ED study generated a large-scale, high-quality data set, possibly the largest of its kind. Analyses both on individual site and multisite basis have evaluated, and will continue to evaluate data obtained for various research areas including infectious etiology of diarrheal disease, cognitive abilities, gut functioning, nutritional status, and socio-economic and educational status as well as immunological responses. It is anticipated that the data will be used far into the future to further improve scientific understanding, to promote intervention strategy development and to test research hypotheses as a catalyst for new research projects.

Download the infographic as a PDF. 

Goals

  • Identify those environmental exposures (infection, symptomatic diseases, nutrition, socioeconomic) early in a child’s life that are associated with shortfalls in physical growth, cognitive development and immunity.
  • Characterize a series of gut function biomarkers that are on the causal pathway from environmental exposure to growth and development deficits.
  • Assess diversity across the sites with respect to exposures and child health and development.

Results & Accomplishments

Media

Selected Publications

Data Access

An interactive platform that will include data visualization and analysis tools, ClinEpiDB, has been developed to facilitate interrogation of the MAL-ED study data.