MAL-ED Network Project Design

Birth Cohort

Each of the eight sites is enrolling 200 children (10-12 children per month over two years) as part of a longitudinal birth cohort. Each child is followed for up to three years in accordance with a standardized set of protocols and with documented consent of the birth mother or other legal guardian.

Case Control

Two of the sites (Brazil and Bangladesh) are also conducting a case control study of 500 children with moderate to severe malnutrition (defined as weight for age Z score [WAZ] of <-2) and 500 matched control children with WAZ scores of >-1.

The following table identifies the data and samples that will be collected in the course of the study:

1 Microbiological assays include bacterial culture, ELISA, microscopy and PCR for identification of specific bacterial, viral and parasitic pathogens.  Assays are performed on monthly surveillance stool samples and stool samples from all diarrheal episodes.

2 Diarrhea is defined as three or more unformed stools in a day; episodes are separated by two diarrhea free days.

Data Coordinating Center (DCC)

While each site has ownership of the data and samples collected from the children enrolled at that site, a centralized resource has been established to acquire, store and query the data, which are securely transferred electronically to the DCC, from all of the sites.  The DCC provides mechanisms for quality control of the submitted data.  In collaboration with the participating investigators, the DCC provides additional support for multisite analysis and comparisons of the data across the sites.

MAL-ED Mapping and Modeling Project

In addition to the prospective, birth cohort and case control studies, the project is developing and providing public access to temporal and geospatial models, using data from secondary sources as well as from this project when available, to estimate the distribution and burden of malnutrition and enteric infections, as well as the attributable benefits of various interventions.

MAL-ED Companion Projects

Separate, but related, pilot projects are underway that will utilize the Network as a resource for data and samples. These projects will examine the human genetic and gut microbiome factors that may play a role in the cycle of malnutrition and enteric infection.

To this end, collaborating investigators at the University of Virginia, Washington University, St. Louis and the University of Colorado, Boulder will undertake a genome wide association study of human genes and genomic analyses of intestinal bacterial flora. These studies will utilize samples obtained from malnourished children and matched controls from two Network Sites (Brazil and Bangladesh) with the hopes of expanding to all sites in the future.