Establishment of the MAL-ED birth cohort study site in Vellore, Southern India

The Indian Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development (MAL-ED) site is in Vellore, Tamil Nadu, in south India and is coordinated by the Christian Medical College, Vellore, which has many years of experience in establishing and following cohorts. India is a diverse country, and no single area can be representative with regard to many health and socioeconomic indicators. The site in Vellore is an urban semiorganized settlement or slum. In the study site, the average family size is 5.7, adults who are gainfully employed are mostly unskilled laborers, and 51% of the population uses the field as their toilet facility. Previous studies from Vellore slums have reported stunting in well over a third of children, comparable to national estimates. The infant mortality rate is 38 per 1000 live births, with deaths due mainly to perinatal and infectious causes. Rigorous staff training, monitoring, supervision and refinement of tools have been essential to maintaining the quality of the significantly large quantity of data collected. Establishing a field clinic within the site has minimized inconvenience to participants and researchers and enabled better rapport with the community and better follow-up. These factors contribute to the wealth of information that will be generated from the MAL-ED multisite cohort, which will improve our understanding of enteric infections and its interactions with malnutrition and development of young children.